fix nullability

# [21.1.0-dev.5](https://github.com/ReVanced/revanced-patcher/compare/v21.1.0-dev.4...v21.1.0-dev.5) (2025-10-16)

.gitattributes

@@ -0,0 +1,9 @@
+#
+# https://help.github.com/articles/dealing-with-line-endings/
+#
+# Linux start script should use lf
+/gradlew        text eol=lf
+
+# These are Windows script files and should use crlf
+*.bat           text eol=crlf
+

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -0,0 +1,109 @@
+name: 🐞 Bug report
+description: Report a bug or an issue.
+title: "bug: "
+labels: ["Bug report"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        <p align="center">
+          <picture>
+            <source
+              width="256px"
+              media="(prefers-color-scheme: dark)"
+              srcset="https://raw.githubusercontent.com/revanced/revanced-patcher/main/assets/revanced-headline/revanced-headline-vertical-dark.svg"
+            >
+            <img 
+              width="256px"
+              src="https://raw.githubusercontent.com/revanced/revanced-patcher/main/assets/revanced-headline/revanced-headline-vertical-light.svg"
+            >
+          </picture>
+          <br>
+          <a href="https://revanced.app/">
+             <picture>
+                 <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://raw.githubusercontent.com/revanced/revanced-patcher/main/assets/revanced-logo/revanced-logo.svg" />
+                 <img height="24px" src="https://raw.githubusercontent.com/revanced/revanced-patcher/main/assets/revanced-logo/revanced-logo.svg" />
+             </picture>
+           </a>&nbsp;&nbsp;&nbsp;
+           <a href="https://github.com/ReVanced">
+               <picture>
+                   <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://i.ibb.co/dMMmCrW/Git-Hub-Mark.png" />
+                   <img height="24px" src="https://i.ibb.co/9wV3HGF/Git-Hub-Mark-Light.png" />
+               </picture>
+           </a>&nbsp;&nbsp;&nbsp;
+           <a href="http://revanced.app/discord">
+               <picture>
+                   <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032563-d4e084b7-244e-4358-af50-26bde6dd4996.png" />
+                   <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032563-d4e084b7-244e-4358-af50-26bde6dd4996.png" />
+               </picture>
+           </a>&nbsp;&nbsp;&nbsp;
+           <a href="https://reddit.com/r/revancedapp">
+               <picture>
+                   <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032351-9d9d5619-8ef7-470a-9eec-2744ece54553.png" />
+                   <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032351-9d9d5619-8ef7-470a-9eec-2744ece54553.png" />
+               </picture>
+           </a>&nbsp;&nbsp;&nbsp;
+           <a href="https://t.me/app_revanced">
+              <picture>
+                 <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032213-faf25ab8-0bc3-4a94-a730-b524c96df124.png" />
+                 <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032213-faf25ab8-0bc3-4a94-a730-b524c96df124.png" />
+              </picture>
+           </a>&nbsp;&nbsp;&nbsp;
+           <a href="https://x.com/revancedapp">
+              <picture>
+                 <source media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/93124920/270180600-7c1b38bf-889b-4d68-bd5e-b9d86f91421a.png">
+                 <img height="24px" src="https://user-images.githubusercontent.com/93124920/270108715-d80743fa-b330-4809-b1e6-79fbdc60d09c.png" />
+              </picture>
+           </a>&nbsp;&nbsp;&nbsp;
+           <a href="https://www.youtube.com/@ReVanced">
+              <picture>
+                 <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032714-c51c7492-0666-44ac-99c2-f003a695ab50.png" />
+                 <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032714-c51c7492-0666-44ac-99c2-f003a695ab50.png" />
+             </picture>
+           </a>
+           <br>
+           <br>
+           Continuing the legacy of Vanced
+        </p>
+
+        # ReVanced Patcher bug report
+
+        Before creating a new bug report, please keep the following in mind:
+
+        - **Do not submit a duplicate bug report**: Search for existing bug reports [here](https://github.com/ReVanced/revanced-patcher/issues?q=label%3A%22Bug+report%22).
+        - **Review the contribution guidelines**: Make sure your bug report adheres to it. You can find the guidelines [here](https://github.com/ReVanced/revanced-patcher/blob/main/CONTRIBUTING.md).
+        - **Do not use the issue page for support**: If you need help or have questions, check out other platforms on [revanced.app](https://revanced.app).
+  - type: textarea
+    attributes:
+      label: Bug description
+      description: |
+        - Describe your bug in detail
+        - Add steps to reproduce the bug if possible (Step 1. ... Step 2. ...)
+        - Add images and videos if possible
+    validations:
+      required: true
+  - type: textarea
+    attributes:
+      label: Error logs
+      description: Exceptions can be captured by running `logcat | grep AndroidRuntime` in a shell.
+      render: shell
+  - type: textarea
+    attributes:
+      label: Solution
+      description: If applicable, add a possible solution to the bug.
+  - type: textarea
+    attributes:
+      label: Additional context
+      description: Add additional context here.
+  - type: checkboxes
+    id: acknowledgements
+    attributes:
+      label: Acknowledgements
+      description: Your bug report will be closed if you don't follow the checklist below.
+      options:
+        - label: I have checked all open and closed bug reports and this is not a duplicate.
+          required: true
+        - label: I have chosen an appropriate title.
+          required: true
+        - label: All requested information has been provided properly.
+          required: true

.github/ISSUE_TEMPLATE/config.yml

@@ -0,0 +1,8 @@
+blank_issues_enabled: false
+contact_links:
+  - name: 📃 Documentation
+    url: https://github.com/revanced/revanced-documentation/
+    about: Don't know how or where to start? Check out our documentation!
+  - name: 🗨 Discussions
+    url: https://github.com/revanced/revanced-suggestions/discussions
+    about: Got something you think should change or be added? Search for or start a new discussion!

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -0,0 +1,107 @@
+name: ⭐ Feature request
+description: Create a detailed request for a new feature.
+title: "feat: "
+labels: ["Feature request"]
+body:
+  - type: markdown
+    attributes:
+      value: |
+        <p align="center">
+          <picture>
+            <source
+              width="256px"
+              media="(prefers-color-scheme: dark)"
+              srcset="https://raw.githubusercontent.com/revanced/revanced-patcher/main/assets/revanced-headline/revanced-headline-vertical-dark.svg"
+            >
+            <img 
+              width="256px"
+              src="https://raw.githubusercontent.com/revanced/revanced-patcher/main/assets/revanced-headline/revanced-headline-vertical-light.svg"
+            >
+          </picture>
+          <br>
+          <a href="https://revanced.app/">
+             <picture>
+                 <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://raw.githubusercontent.com/revanced/revanced-patcher/main/assets/revanced-logo/revanced-logo.svg" />
+                 <img height="24px" src="https://raw.githubusercontent.com/revanced/revanced-patcher/main/assets/revanced-logo/revanced-logo.svg" />
+             </picture>
+           </a>&nbsp;&nbsp;&nbsp;
+           <a href="https://github.com/ReVanced">
+               <picture>
+                   <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://i.ibb.co/dMMmCrW/Git-Hub-Mark.png" />
+                   <img height="24px" src="https://i.ibb.co/9wV3HGF/Git-Hub-Mark-Light.png" />
+               </picture>
+           </a>&nbsp;&nbsp;&nbsp;
+           <a href="http://revanced.app/discord">
+               <picture>
+                   <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032563-d4e084b7-244e-4358-af50-26bde6dd4996.png" />
+                   <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032563-d4e084b7-244e-4358-af50-26bde6dd4996.png" />
+               </picture>
+           </a>&nbsp;&nbsp;&nbsp;
+           <a href="https://reddit.com/r/revancedapp">
+               <picture>
+                   <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032351-9d9d5619-8ef7-470a-9eec-2744ece54553.png" />
+                   <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032351-9d9d5619-8ef7-470a-9eec-2744ece54553.png" />
+               </picture>
+           </a>&nbsp;&nbsp;&nbsp;
+           <a href="https://t.me/app_revanced">
+              <picture>
+                 <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032213-faf25ab8-0bc3-4a94-a730-b524c96df124.png" />
+                 <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032213-faf25ab8-0bc3-4a94-a730-b524c96df124.png" />
+              </picture>
+           </a>&nbsp;&nbsp;&nbsp;
+           <a href="https://x.com/revancedapp">
+              <picture>
+                 <source media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/93124920/270180600-7c1b38bf-889b-4d68-bd5e-b9d86f91421a.png">
+                 <img height="24px" src="https://user-images.githubusercontent.com/93124920/270108715-d80743fa-b330-4809-b1e6-79fbdc60d09c.png" />
+              </picture>
+           </a>&nbsp;&nbsp;&nbsp;
+           <a href="https://www.youtube.com/@ReVanced">
+              <picture>
+                 <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032714-c51c7492-0666-44ac-99c2-f003a695ab50.png" />
+                 <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032714-c51c7492-0666-44ac-99c2-f003a695ab50.png" />
+             </picture>
+           </a>
+           <br>
+           <br>
+           Continuing the legacy of Vanced
+        </p>
+
+        # ReVanced Patcher feature request
+
+        Before creating a new feature request, please keep the following in mind:
+
+        - **Do not submit a duplicate feature request**: Search for existing feature requests [here](https://github.com/ReVanced/revanced-patcher/issues?q=label%3A%22Feature+request%22).
+        - **Review the contribution guidelines**: Make sure your feature request adheres to it. You can find the guidelines [here](https://github.com/ReVanced/revanced-patcher/blob/main/CONTRIBUTING.md).
+        - **Do not use the issue page for support**: If you need help or have questions, check out other platforms on [revanced.app](https://revanced.app).
+
+  - type: textarea
+    attributes:
+      label: Feature description
+      description: |
+        - Describe your feature in detail
+        - Add images, videos, links, examples, references, etc. if possible
+        - Add the target application name in case you request a new patch
+  - type: textarea
+    attributes:
+      label: Motivation
+      description: |
+        A strong motivation is necessary for a feature request to be considered.
+
+        - Why should this feature be implemented? 
+        - What is the explicit use case?
+        - What are the benefits?
+        - What makes this feature important?
+    validations:
+      required: true
+  - type: checkboxes
+    id: acknowledgements
+    attributes:
+      label: Acknowledgements
+      description: Your feature request will be closed if you don't follow the checklist below.
+      options:
+        - label: I have checked all open and closed feature requests and this is not a duplicate.
+          required: true
+        - label: I have chosen an appropriate title.
+          required: true
+        - label: All requested information has been provided properly.
+          required: true

.github/config.yml

@@ -0,0 +1,2 @@
+firstPRMergeComment: >
+  Thank you for contributing to ReVanced. Join us on [Discord](https://revanced.app/discord) to receive a role for your contribution.

.github/dependabot.yml

@@ -0,0 +1,22 @@
+version: 2
+updates:
+  - package-ecosystem: github-actions
+    labels: []
+    directory: /
+    target-branch: dev
+    schedule:
+      interval: monthly
+
+  - package-ecosystem: npm
+    labels: []
+    directory: /
+    target-branch: dev
+    schedule:
+      interval: monthly
+
+  - package-ecosystem: gradle
+    labels: []
+    directory: /
+    target-branch: dev
+    schedule:
+      interval: monthly

.github/workflows/build_pull_request.yml

@@ -0,0 +1,25 @@
+name: Build pull request
+
+on:
+  workflow_dispatch:
+  pull_request:
+    branches:
+      - dev
+
+jobs:
+  release:
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v5
+        with:
+          fetch-depth: 0
+
+      - name: Cache Gradle
+        uses: burrunan/gradle-cache-action@v3
+
+      - name: Build
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: ./gradlew build --no-daemon

.github/workflows/open_pull_request.yml

@@ -0,0 +1,26 @@
+name: Open a PR to main
+
+on:
+  push:
+    branches:
+      - dev
+  workflow_dispatch:
+
+env:
+  MESSAGE: Merge branch `${{ github.head_ref || github.ref_name }}` to `main`
+
+jobs:
+  pull-request:
+    name: Open pull request
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v5
+
+      - name: Open pull request
+        uses: repo-sync/pull-request@v2
+        with:
+          destination_branch: 'main'
+          pr_title: 'chore: ${{ env.MESSAGE }}'
+          pr_body: 'This pull request will ${{ env.MESSAGE }}.'
+          pr_draft: true

.github/workflows/release.yml

@@ -0,0 +1,50 @@
+name: Release
+
+on:
+  workflow_dispatch:
+  push:
+    branches:
+      - main
+      - dev
+
+jobs:
+  release:
+    name: Release
+    permissions:
+      contents: write
+      packages: write
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v5
+
+      - name: Cache Gradle
+        uses: burrunan/gradle-cache-action@v3
+
+      - name: Build
+        env:
+          ORG_GRADLE_PROJECT_githubPackagesUsername: ${{ env.GITHUB_ACTOR }}
+          ORG_GRADLE_PROJECT_githubPackagesPassword: ${{ secrets.GITHUB_TOKEN }}
+        run: ./gradlew build clean
+
+      - name: Setup Node.js
+        uses: actions/setup-node@v5
+        with:
+          node-version: "lts/*"
+          cache: 'npm'
+
+      - name: Install dependencies
+        run: npm install
+
+      - name: Import GPG key
+        uses: crazy-max/ghaction-import-gpg@v6
+        with:
+          gpg_private_key: ${{ secrets.GPG_PRIVATE_KEY }}
+          passphrase: ${{ secrets.GPG_PASSPHRASE }}
+          fingerprint: ${{ vars.GPG_FINGERPRINT }}
+
+      - name: Release
+        uses: cycjimmy/semantic-release-action@v4
+        env:
+          ORG_GRADLE_PROJECT_githubPackagesUsername: ${{ env.GITHUB_ACTOR }}
+          ORG_GRADLE_PROJECT_githubPackagesPassword: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/update_documentation.yml

@@ -0,0 +1,19 @@
+name: Update documentation
+
+on:
+  push:
+    paths:
+      - docs/**
+
+jobs:
+  trigger:
+    runs-on: ubuntu-latest
+    name: Dispatch event to documentation repository
+    if: github.ref == 'refs/heads/main'
+    steps:
+      - uses: peter-evans/repository-dispatch@v3
+        with:
+          token: ${{ secrets.DOCUMENTATION_REPO_ACCESS_TOKEN  }}
+          repository: revanced/revanced-documentation
+          event-type: update-documentation
+          client-payload: '{"repo": "${{ github.event.repository.name }}", "ref": "${{ github.ref }}"}'

.gitignore

@@ -1,117 +1,19 @@
-### Java template
-# Compiled class file
-*.class
-
-# Log file
-*.log
-
-# BlueJ files
-*.ctxt
-
-# Mobile Tools for Java (J2ME)
-.mtj.tmp/
-
-# Package Files #
-*.jar
-*.war
-*.nar
-*.ear
-*.zip
-*.tar.gz
-*.rar
-
-# virtual machine crash logs, see http://www.java.com/en/download/help/error_hotspot.xml
-hs_err_pid*
-
-### JetBrains template
-# Covers JetBrains IDEs: IntelliJ, RubyMine, PhpStorm, AppCode, PyCharm, CLion, Android Studio, WebStorm and Rider
-# Reference: https://intellij-support.jetbrains.com/hc/en-us/articles/206544839
-
-# User-specific stuff
-.idea/**/workspace.xml
-.idea/**/tasks.xml
-.idea/**/usage.statistics.xml
-.idea/**/dictionaries
-.idea/**/shelf
-
-# Generated files
-.idea/**/contentModel.xml
-
-# Sensitive or high-churn files
-.idea/**/dataSources/
-.idea/**/dataSources.ids
-.idea/**/dataSources.local.xml
-.idea/**/sqlDataSources.xml
-.idea/**/dynamic.xml
-.idea/**/uiDesigner.xml
-.idea/**/dbnavigator.xml
-
-# Gradle
-.idea/**/gradle.xml
-.idea/**/libraries
-
-# Gradle and Maven with auto-import
-# When using Gradle or Maven with auto-import, you should exclude module files,
-# since they will be recreated, and may cause churn.  Uncomment if using
-# auto-import.
-.idea/artifacts
-.idea/compiler.xml
-.idea/jarRepositories.xml
-.idea/modules.xml
-.idea/*.iml
-.idea/modules
 *.iml
-*.ipr
-
-# CMake
-cmake-build-*/
-
-# Mongo Explorer plugin
-.idea/**/mongoSettings.xml
-
-# File-based project format
-*.iws
-
-# IntelliJ
-out/
-
-# mpeltonen/sbt-idea plugin
-.idea_modules/
-
-# JIRA plugin
-atlassian-ide-plugin.xml
-
-# Cursive Clojure plugin
-.idea/replstate.xml
-
-# Crashlytics plugin (for Android Studio and IntelliJ)
-com_crashlytics_export_strings.xml
-crashlytics.properties
-crashlytics-build.properties
-fabric.properties
-
-# Editor-based Rest Client
-.idea/httpRequests
-
-# Android studio 3.1+ serialized cache file
-.idea/caches/build_file_checksums.ser
-
-### Gradle template
+.kotlin
 .gradle
 **/build/
+xcuserdata
 !src/**/build/
-
-# Ignore Gradle GUI config
-gradle-app.setting
-
-# Avoid ignoring Gradle wrapper jar file (.jar files are usually ignored)
-!gradle-wrapper.jar
-
-# Cache of project
-.gradletasknamecache
-
-# # Work around https://youtrack.jetbrains.com/issue/IDEA-116898
-# gradle/wrapper/gradle-wrapper.properties
-
-# Avoid ignoring test resources
-!src/test/resources/*
+local.properties
+.idea
+.DS_Store
+captures
+.externalNativeBuild
+.cxx
+*.xcodeproj/*
+!*.xcodeproj/project.pbxproj
+!*.xcodeproj/xcshareddata/
+!*.xcodeproj/project.xcworkspace/
+!*.xcworkspace/contents.xcworkspacedata
+**/xcshareddata/WorkspaceSettings.xcsettings
+node_modules/

.idea/.gitignore

@@ -1,8 +0,0 @@
-# Default ignored files
-/shelf/
-/workspace.xml
-# Editor-based HTTP Client requests
-/httpRequests/
-# Datasource local storage ignored files
-/dataSources/
-/dataSources.local.xml

.idea/codeStyles/Project.xml

@@ -1,10 +0,0 @@
-<component name="ProjectCodeStyleConfiguration">
-  <code_scheme name="Project" version="173">
-    <JetCodeStyleSettings>
-      <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
-    </JetCodeStyleSettings>
-    <codeStyleSettings language="kotlin">
-      <option name="CODE_STYLE_DEFAULTS" value="KOTLIN_OFFICIAL" />
-    </codeStyleSettings>
-  </code_scheme>
-</component>

.idea/codeStyles/codeStyleConfig.xml

@@ -1,5 +0,0 @@
-<component name="ProjectCodeStyleConfiguration">
-  <state>
-    <option name="USE_PER_PROJECT_SETTINGS" value="true" />
-  </state>
-</component>

.idea/discord.xml

@@ -1,7 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="DiscordProjectSettings">
-    <option name="show" value="PROJECT_FILES" />
-    <option name="description" value="" />
-  </component>
-</project>

.idea/misc.xml

@@ -1,10 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="ExternalStorageConfigurationManager" enabled="true" />
-  <component name="FrameworkDetectionExcludesConfiguration">
-    <file type="web" url="file://$PROJECT_DIR$" />
-  </component>
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_17" default="true" project-jdk-name="azul-17" project-jdk-type="JavaSDK">
-    <output url="file://$PROJECT_DIR$/out" />
-  </component>
-</project>

.idea/vcs.xml

@@ -1,6 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<project version="4">
-  <component name="VcsDirectoryMappings">
-    <mapping directory="$PROJECT_DIR$" vcs="Git" />
-  </component>
-</project>

.releaserc

@@ -0,0 +1,44 @@
+{
+  "branches": [
+    "main",
+    {
+      "name": "dev",
+      "prerelease": true
+    }
+  ],
+  "plugins": [
+    [
+      "@semantic-release/commit-analyzer", {
+        "releaseRules": [
+          { "type": "build", "scope": "Needs bump", "release": "patch" }
+        ]
+      }
+    ],
+    "@semantic-release/release-notes-generator",
+    "@semantic-release/changelog",
+    "gradle-semantic-release-plugin",
+    [
+      "@semantic-release/git",
+      {
+        "assets": [
+          "CHANGELOG.md",
+          "gradle.properties"
+        ],
+        "message": "chore: Release v${nextRelease.version} [skip ci]\n\n${nextRelease.notes}"
+      }
+    ],
+    [
+      "@saithodev/semantic-release-backmerge",
+      {
+        backmergeBranches: [{"from": "main", "to": "dev"}],
+        clearWorkspace: true
+      }
+    ],
+    [
+        "@semantic-release/github",
+        {
+            successComment: false
+        }
+    ]
+  ]
+}

CONTRIBUTING.md

@@ -0,0 +1,99 @@
+<p align="center">
+  <picture>
+    <source
+      width="256px"
+      media="(prefers-color-scheme: dark)"
+      srcset="assets/revanced-headline/revanced-headline-vertical-dark.svg"
+    >
+    <img 
+      width="256px"
+      src="assets/revanced-headline/revanced-headline-vertical-light.svg"
+    >
+  </picture>
+  <br>
+  <a href="https://revanced.app/">
+     <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="assets/revanced-logo/revanced-logo.svg" />
+         <img height="24px" src="assets/revanced-logo/revanced-logo.svg" />
+     </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://github.com/ReVanced">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://i.ibb.co/dMMmCrW/Git-Hub-Mark.png" />
+           <img height="24px" src="https://i.ibb.co/9wV3HGF/Git-Hub-Mark-Light.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="http://revanced.app/discord">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032563-d4e084b7-244e-4358-af50-26bde6dd4996.png" />
+           <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032563-d4e084b7-244e-4358-af50-26bde6dd4996.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://reddit.com/r/revancedapp">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032351-9d9d5619-8ef7-470a-9eec-2744ece54553.png" />
+           <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032351-9d9d5619-8ef7-470a-9eec-2744ece54553.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://t.me/app_revanced">
+      <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032213-faf25ab8-0bc3-4a94-a730-b524c96df124.png" />
+         <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032213-faf25ab8-0bc3-4a94-a730-b524c96df124.png" />
+      </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://x.com/revancedapp">
+      <picture>
+         <source media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/93124920/270180600-7c1b38bf-889b-4d68-bd5e-b9d86f91421a.png">
+         <img height="24px" src="https://user-images.githubusercontent.com/93124920/270108715-d80743fa-b330-4809-b1e6-79fbdc60d09c.png" />
+      </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://www.youtube.com/@ReVanced">
+      <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032714-c51c7492-0666-44ac-99c2-f003a695ab50.png" />
+         <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032714-c51c7492-0666-44ac-99c2-f003a695ab50.png" />
+     </picture>
+   </a>
+   <br>
+   <br>
+   Continuing the legacy of Vanced
+</p>
+
+# 👋 Contribution guidelines
+
+This document describes how to contribute to ReVanced Patcher.
+
+## 📖 Resources to help you get started
+
+- The [documentation](https://github.com/ReVanced/revanced-patcher/tree/docs/docs) contains the fundamentals
+  of ReVanced Patcher and how to use ReVanced Patcher to create patches
+- [Our backlog](https://github.com/orgs/ReVanced/projects/12) is where we keep track of what we're working on
+- [Issues](https://github.com/ReVanced/revanced-patcher/issues) are where we keep track of bugs and feature requests
+
+## 🙏 Submitting a feature request
+
+Features can be requested by opening an issue using the
+[Feature request issue template](https://github.com/ReVanced/revanced-patcher/issues/new?assignees=&labels=Feature+request&projects=&template=feature_request.yml&title=feat%3A+).
+
+> **Note**
+> Requests can be accepted or rejected at the discretion of maintainers of ReVanced Patcher.
+> Good motivation has to be provided for a request to be accepted.
+
+## 🐞 Submitting a bug report
+
+If you encounter a bug while using ReVanced Patcher, open an issue using the
+[Bug report issue template](https://github.com/ReVanced/revanced-patcher/issues/new?assignees=&labels=Bug+report&projects=&template=bug_report.yml&title=bug%3A+).
+
+## 📝 How to contribute
+
+1. Before contributing, it is recommended to open an issue to discuss your change
+   with the maintainers of ReVanced Patcher. This will help you determine whether your change is acceptable
+   and whether it is worth your time to implement it
+2. Development happens on the `dev` branch. Fork the repository and create your branch from `dev`
+3. Commit your changes
+4. Submit a pull request to the `dev` branch of the repository and reference issues
+   that your pull request closes in the description of your pull request
+5. Our team will review your pull request and provide feedback. Once your pull request is approved,
+   it will be merged into the `dev` branch and will be included in the next release of ReVanced Patcher
+
+❤️ Thank you for considering contributing to ReVanced Patcher,  
+ReVanced

README.md

@@ -1 +1,125 @@
-# Patcher
+<p align="center">
+  <picture>
+    <source
+      width="256px"
+      media="(prefers-color-scheme: dark)"
+      srcset="assets/revanced-headline/revanced-headline-vertical-dark.svg"
+    >
+    <img 
+      width="256px"
+      src="assets/revanced-headline/revanced-headline-vertical-light.svg"
+    >
+  </picture>
+  <br>
+  <a href="https://revanced.app/">
+     <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="assets/revanced-logo/revanced-logo.svg" />
+         <img height="24px" src="assets/revanced-logo/revanced-logo.svg" />
+     </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://github.com/ReVanced">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://i.ibb.co/dMMmCrW/Git-Hub-Mark.png" />
+           <img height="24px" src="https://i.ibb.co/9wV3HGF/Git-Hub-Mark-Light.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="http://revanced.app/discord">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032563-d4e084b7-244e-4358-af50-26bde6dd4996.png" />
+           <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032563-d4e084b7-244e-4358-af50-26bde6dd4996.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://reddit.com/r/revancedapp">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032351-9d9d5619-8ef7-470a-9eec-2744ece54553.png" />
+           <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032351-9d9d5619-8ef7-470a-9eec-2744ece54553.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://t.me/app_revanced">
+      <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032213-faf25ab8-0bc3-4a94-a730-b524c96df124.png" />
+         <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032213-faf25ab8-0bc3-4a94-a730-b524c96df124.png" />
+      </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://x.com/revancedapp">
+      <picture>
+         <source media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/93124920/270180600-7c1b38bf-889b-4d68-bd5e-b9d86f91421a.png">
+         <img height="24px" src="https://user-images.githubusercontent.com/93124920/270108715-d80743fa-b330-4809-b1e6-79fbdc60d09c.png" />
+      </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://www.youtube.com/@ReVanced">
+      <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032714-c51c7492-0666-44ac-99c2-f003a695ab50.png" />
+         <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032714-c51c7492-0666-44ac-99c2-f003a695ab50.png" />
+     </picture>
+   </a>
+   <br>
+   <br>
+   Continuing the legacy of Vanced
+</p>
+
+# 💉 ReVanced Patcher
+
+![GitHub Workflow Status (with event)](https://img.shields.io/github/actions/workflow/status/ReVanced/revanced-patcher/release.yml)
+![GPLv3 License](https://img.shields.io/badge/License-GPL%20v3-yellow.svg)
+
+ReVanced Patcher used to patch Android applications.
+
+## ❓ About
+
+ReVanced Patcher is a library that is used to patch Android applications.  
+It powers [ReVanced Manager](https://github.com/ReVanced/revanced-manager),
+[ReVanced CLI](https://github.com/ReVanced/revanced-cli)
+and [ReVanced Library](https://github.com/ReVanced/revanced-library) and a rich set of patches have been developed
+using ReVanced Patcher in the [ReVanced Patches](https://github.com/ReVanced/revanced-patches) repository.
+
+## 💪 Features
+
+Some of the features the ReVanced Patcher provides are:
+
+- 🔧 **Patch Dalvik VM bytecode**: Disassemble and assemble Dalvik bytecode
+- 📦 **Patch APK resources**: Decode and build Android APK resources
+- 📂 **Patch arbitrary APK files**: Read and write arbitrary files directly from and to APK files
+- 🧩 **Write modular patches**: Extensive API to write modular patches that can patch Dalvik VM bytecode,
+APK resources and arbitrary APK files
+
+## 🚀 How to get started
+
+To use ReVanced Patcher in your project, follow these steps:
+
+1. [Add the repository](https://docs.github.com/en/packages/working-with-a-github-packages-registry/working-with-the-gradle-registry#using-a-published-package)
+to your project
+2. Add the dependency to your project:
+
+   ```kt
+    dependencies {
+        implementation("app.revanced:revanced-patcher:{$version}")
+    }
+   ```
+
+For a minimal project configuration, 
+see [ReVanced Patches template](https://github.com/ReVanced/revanced-patches-template).
+
+## 📚 Everything else
+
+### 📙 Contributing
+
+Thank you for considering contributing to ReVanced Patcher.
+You can find the contribution guidelines [here](CONTRIBUTING.md).
+
+### 🛠️ Building
+
+To build ReVanced Patcher,
+you can follow the [ReVanced documentation](https://github.com/ReVanced/revanced-documentation).
+
+### 📃 Documentation
+
+The documentation contains the fundamentals of ReVanced Patcher and how to use ReVanced Patcher to create patches.
+You can find it [here](https://github.com/ReVanced/revanced-patcher/tree/main/docs).
+
+## 📜 Licence
+
+ReVanced Patcher is licensed under the GPLv3 license. Please see the [licence file](LICENSE) for more information.
+[tl;dr](https://www.tldrlegal.com/license/gnu-general-public-license-v3-gpl-3) you may copy, distribute and modify ReVanced Patcher as long as you track changes/dates in source files.
+Any modifications to ReVanced Patcher must also be made available under the GPL,
+along with build & install instructions.

assets/revanced-logo/revanced-logo.svg

@@ -0,0 +1 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?><!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd"><svg width="100%" height="100%" viewBox="0 0 800 800" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" xml:space="preserve" xmlns:serif="http://www.serif.com/" style="fill-rule:evenodd;clip-rule:evenodd;stroke-linejoin:round;stroke-miterlimit:2;"><g id="Logo"><g id="Ring"><circle id="Ring-Background" serif:id="Ring Background" cx="400" cy="400" r="400" style="fill:#1b1b1b;"/><path id="Ring1" serif:id="Ring" d="M400,0c220.766,0 400,179.234 400,400c-0,220.766 -179.234,400 -400,400c-220.766,-0 -400,-179.234 -400,-400c0,-220.766 179.234,-400 400,-400Zm-0,36c200.897,-0 364,163.103 364,364c0,200.897 -163.103,364 -364,364c-200.897,0 -364,-163.103 -364,-364c-0,-200.897 163.103,-364 364,-364Z" style="fill:url(#_Linear1);"/></g><g id="Shape"><path id="V-Shape" serif:id="V Shape" d="M538.74,269.872c1.481,-3.382 1.157,-7.283 -0.863,-10.373c-2.021,-3.091 -5.464,-4.954 -9.156,-4.954c-5.148,0 -10.435,0 -14.165,0c-3.1,0 -5.907,1.834 -7.153,4.672c-12.468,28.396 -78.273,178.273 -100.25,228.328c-1.246,2.838 -4.053,4.671 -7.154,4.671c-3.1,0 -5.907,-1.833 -7.153,-4.671c-21.977,-50.055 -87.782,-199.932 -100.25,-228.328c-1.246,-2.838 -4.053,-4.672 -7.153,-4.672c-3.73,0 -9.017,0 -14.164,0c-3.693,0 -7.135,1.863 -9.156,4.954c-2.02,3.09 -2.344,6.991 -0.863,10.373c23.557,53.766 101.872,232.519 117.871,269.034c1.743,3.979 5.674,6.549 10.018,6.549c6.293,-0 15.408,-0 21.701,-0c4.344,-0 8.275,-2.57 10.018,-6.549c15.999,-36.515 94.315,-215.268 117.872,-269.034Z" style="fill:#fff;"/><path id="Diamond" d="M408.119,395.312c-1.675,2.901 -4.77,4.688 -8.119,4.688c-3.349,-0 -6.444,-1.787 -8.119,-4.688c-16.997,-29.44 -56.156,-97.264 -73.153,-126.704c-1.675,-2.901 -1.675,-6.474 0,-9.375c1.675,-2.901 4.77,-4.688 8.119,-4.688c33.995,0 112.311,0 146.306,0c3.349,0 6.444,1.787 8.119,4.688c1.675,2.901 1.675,6.474 -0,9.375c-16.997,29.44 -56.156,97.264 -73.153,126.704Z" style="fill:url(#_Linear2);"/></g></g><defs><linearGradient id="_Linear1" x1="0" y1="0" x2="1" y2="0" gradientUnits="userSpaceOnUse" gradientTransform="matrix(4.89859e-14,800,-800,4.89859e-14,400.001,3.31681e-10)"><stop offset="0" style="stop-color:#f04e98;stop-opacity:1"/><stop offset="0.5" style="stop-color:#5f65d4;stop-opacity:1"/><stop offset="1" style="stop-color:#4e98f0;stop-opacity:1"/></linearGradient><linearGradient id="_Linear2" x1="0" y1="0" x2="1" y2="0" gradientUnits="userSpaceOnUse" gradientTransform="matrix(1.77155e-14,289.317,-282.535,1.73003e-14,400,254.545)"><stop offset="0" style="stop-color:#f04e98;stop-opacity:1"/><stop offset="0.5" style="stop-color:#5f65d4;stop-opacity:1"/><stop offset="1" style="stop-color:#4e98f0;stop-opacity:1"/></linearGradient></defs></svg>

build.gradle.kts

@@ -1,46 +1,5 @@
 plugins {
-    kotlin("jvm") version "1.6.10"
-    `maven-publish`
-}
-
-group = "net.revanced"
-
-repositories {
-    mavenCentral()
-}
-
-dependencies {
-    implementation(kotlin("stdlib"))
-    implementation("org.ow2.asm:asm:9.2")
-    implementation("org.ow2.asm:asm-util:9.2")
-    implementation("org.ow2.asm:asm-tree:9.2")
-    implementation("org.ow2.asm:asm-commons:9.2")
-    implementation("io.github.microutils:kotlin-logging:2.1.21")
-    testImplementation("ch.qos.logback:logback-classic:1.2.11") // use your own logger!
-    testImplementation(kotlin("test"))
-}
-
-tasks.test {
-    useJUnitPlatform()
-    testLogging {
-        events("PASSED", "SKIPPED", "FAILED")
-    }
-}
-
-publishing {
-    repositories {
-        maven {
-            name = "GitHubPackages"
-            url = uri("https://maven.pkg.github.com/ReVancedTeam/revanced-patcher")
-            credentials {
-                username = System.getenv("GITHUB_ACTOR")
-                password = System.getenv("GITHUB_TOKEN")
-            }
-        }
-    }
-    publications {
-        register<MavenPublication>("gpr") {
-            from(components["java"])
-        }
-    }
-}
+    alias(libs.plugins.android.kotlin.multiplatform.library) apply false
+    alias(libs.plugins.kotlinMultiplatform) apply false
+    alias(libs.plugins.vanniktech.mavenPublish) apply false
+}

docs/1_patcher_intro.md

@@ -0,0 +1,111 @@
+<p align="center">
+  <picture>
+    <source
+      width="256px"
+      media="(prefers-color-scheme: dark)"
+      srcset="../assets/revanced-headline/revanced-headline-vertical-dark.svg"
+    >
+    <img 
+      width="256px"
+      src="../assets/revanced-headline/revanced-headline-vertical-light.svg"
+    >
+  </picture>
+  <br>
+  <a href="https://revanced.app/">
+     <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="../assets/revanced-logo/revanced-logo.svg" />
+         <img height="24px" src="../assets/revanced-logo/revanced-logo.svg" />
+     </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://github.com/ReVanced">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://i.ibb.co/dMMmCrW/Git-Hub-Mark.png" />
+           <img height="24px" src="https://i.ibb.co/9wV3HGF/Git-Hub-Mark-Light.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="http://revanced.app/discord">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032563-d4e084b7-244e-4358-af50-26bde6dd4996.png" />
+           <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032563-d4e084b7-244e-4358-af50-26bde6dd4996.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://reddit.com/r/revancedapp">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032351-9d9d5619-8ef7-470a-9eec-2744ece54553.png" />
+           <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032351-9d9d5619-8ef7-470a-9eec-2744ece54553.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://t.me/app_revanced">
+      <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032213-faf25ab8-0bc3-4a94-a730-b524c96df124.png" />
+         <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032213-faf25ab8-0bc3-4a94-a730-b524c96df124.png" />
+      </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://x.com/revancedapp">
+      <picture>
+         <source media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/93124920/270180600-7c1b38bf-889b-4d68-bd5e-b9d86f91421a.png">
+         <img height="24px" src="https://user-images.githubusercontent.com/93124920/270108715-d80743fa-b330-4809-b1e6-79fbdc60d09c.png" />
+      </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://www.youtube.com/@ReVanced">
+      <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032714-c51c7492-0666-44ac-99c2-f003a695ab50.png" />
+         <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032714-c51c7492-0666-44ac-99c2-f003a695ab50.png" />
+     </picture>
+   </a>
+   <br>
+   <br>
+   Continuing the legacy of Vanced
+</p>
+
+# 💉 Introduction to ReVanced Patcher
+
+To create patches for Android apps, it is recommended to know the basic concept of ReVanced Patcher.
+
+## 📙 How it works
+
+ReVanced Patcher is a library that allows modifying Android apps by applying patches.
+It is built on top of [Smali](https://github.com/google/smali) for bytecode manipulation and [Androlib (Apktool)](https://github.com/iBotPeaches/Apktool)
+for resource decoding and encoding.
+
+ReVanced Patcher receives a list of patches and applies them to a given APK file.
+It then returns the modified components of the APK file, such as modified dex files and resources,
+that can be repackaged into a new APK file.
+
+ReVanced Patcher has a simple API that allows you to load patches from RVP (JAR or DEX container) files
+and apply them to an APK file. Later on, you will learn how to create patches.
+
+```kt
+val patches = loadPatchesFromJar(setOf(File("revanced-patches.rvp")))
+
+val patcherResult = Patcher(PatcherConfig(apkFile = File("some.apk"))).use { patcher ->
+    // Here you can access metadata about the APK file through patcher.context.packageMetadata
+    // such as package name, version code, version name, etc.
+
+    // Add patches.
+    patcher += patches
+
+    // Execute the patches.
+    runBlocking {
+        patcher().collect { patchResult ->
+            if (patchResult.exception != null)
+                logger.info { "\"${patchResult.patch}\" failed:\n${patchResult.exception}" }
+            else
+                logger.info { "\"${patchResult.patch}\" succeeded" }
+        }
+    }
+
+    // Compile and save the patched APK file components.
+    patcher.get()
+}
+
+// The result of the patcher contains the modified components of the APK file that can be repackaged into a new APK file.
+val dexFiles = patcherResult.dexFiles
+val resources = patcherResult.resources
+```
+
+## ⏭️ What's next
+
+The next page teaches the fundamentals of ReVanced Patches.
+
+Continue: [🧩 Introduction to ReVanced Patches](2_patches_intro.md)

docs/2_1_setup.md

@@ -0,0 +1,112 @@
+<p align="center">
+  <picture>
+    <source
+      width="256px"
+      media="(prefers-color-scheme: dark)"
+      srcset="../assets/revanced-headline/revanced-headline-vertical-dark.svg"
+    >
+    <img 
+      width="256px"
+      src="../assets/revanced-headline/revanced-headline-vertical-light.svg"
+    >
+  </picture>
+  <br>
+  <a href="https://revanced.app/">
+     <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="../assets/revanced-logo/revanced-logo.svg" />
+         <img height="24px" src="../assets/revanced-logo/revanced-logo.svg" />
+     </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://github.com/ReVanced">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://i.ibb.co/dMMmCrW/Git-Hub-Mark.png" />
+           <img height="24px" src="https://i.ibb.co/9wV3HGF/Git-Hub-Mark-Light.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="http://revanced.app/discord">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032563-d4e084b7-244e-4358-af50-26bde6dd4996.png" />
+           <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032563-d4e084b7-244e-4358-af50-26bde6dd4996.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://reddit.com/r/revancedapp">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032351-9d9d5619-8ef7-470a-9eec-2744ece54553.png" />
+           <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032351-9d9d5619-8ef7-470a-9eec-2744ece54553.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://t.me/app_revanced">
+      <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032213-faf25ab8-0bc3-4a94-a730-b524c96df124.png" />
+         <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032213-faf25ab8-0bc3-4a94-a730-b524c96df124.png" />
+      </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://x.com/revancedapp">
+      <picture>
+         <source media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/93124920/270180600-7c1b38bf-889b-4d68-bd5e-b9d86f91421a.png">
+         <img height="24px" src="https://user-images.githubusercontent.com/93124920/270108715-d80743fa-b330-4809-b1e6-79fbdc60d09c.png" />
+      </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://www.youtube.com/@ReVanced">
+      <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032714-c51c7492-0666-44ac-99c2-f003a695ab50.png" />
+         <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032714-c51c7492-0666-44ac-99c2-f003a695ab50.png" />
+     </picture>
+   </a>
+   <br>
+   <br>
+   Continuing the legacy of Vanced
+</p>
+
+# 👶 Setting up a development environment
+
+To start developing patches with ReVanced Patcher, you must prepare a development environment.
+
+## 📝 Prerequisites
+
+- A Java IDE with Kotlin support, such as [IntelliJ IDEA](https://www.jetbrains.com/idea/)
+- Knowledge of Java, [Kotlin](https://kotlinlang.org), and [Dalvik bytecode](https://source.android.com/docs/core/runtime/dalvik-bytecode)
+- Android reverse engineering skills and tools such as [jadx](https://github.com/skylot/jadx)
+
+## 🏃 Prepare the environment
+
+Throughout the documentation, [ReVanced Patches](https://github.com/revanced/revanced-patches) will be used as an example project.
+
+> [!NOTE]
+> To start a fresh project, 
+> you can use the [ReVanced Patches template](https://github.com/revanced/revanced-patches-template).
+
+1. Clone the repository
+
+   ```bash
+   git clone https://github.com/revanced/revanced-patches && cd revanced-patches
+   ```
+
+2. Build the project
+
+   ```bash
+   ./gradlew build
+   ```
+
+> [!NOTE]
+> If the build fails due to authentication, you may need to authenticate to GitHub Packages.
+> Create a PAT with the scope `read:packages` [here](https://github.com/settings/tokens/new?scopes=read:packages&description=ReVanced) and add your token to ~/.gradle/gradle.properties.
+>
+> Example `gradle.properties` file:
+>
+> ```properties
+> gpr.user = user
+> gpr.key = key
+> ```
+
+3. Open the project in your IDE
+
+> [!TIP]
+> It is a good idea to set up a complete development environment for ReVanced, so that you can also test your patches
+> by following the [ReVanced documentation](https://github.com/ReVanced/revanced-documentation).
+
+## ⏭️ What's next
+
+The next page will go into details about a ReVanced patch.
+
+Continue: [🧩 Anatomy of a patch](2_2_patch_anatomy.md)

docs/2_2_1_fingerprinting.md

@@ -0,0 +1,296 @@
+<p align="center">
+  <picture>
+    <source
+      width="256px"
+      media="(prefers-color-scheme: dark)"
+      srcset="../assets/revanced-headline/revanced-headline-vertical-dark.svg"
+    >
+    <img 
+      width="256px"
+      src="../assets/revanced-headline/revanced-headline-vertical-light.svg"
+    >
+  </picture>
+  <br>
+  <a href="https://revanced.app/">
+     <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="../assets/revanced-logo/revanced-logo.svg" />
+         <img height="24px" src="../assets/revanced-logo/revanced-logo.svg" />
+     </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://github.com/ReVanced">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://i.ibb.co/dMMmCrW/Git-Hub-Mark.png" />
+           <img height="24px" src="https://i.ibb.co/9wV3HGF/Git-Hub-Mark-Light.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="http://revanced.app/discord">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032563-d4e084b7-244e-4358-af50-26bde6dd4996.png" />
+           <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032563-d4e084b7-244e-4358-af50-26bde6dd4996.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://reddit.com/r/revancedapp">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032351-9d9d5619-8ef7-470a-9eec-2744ece54553.png" />
+           <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032351-9d9d5619-8ef7-470a-9eec-2744ece54553.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://t.me/app_revanced">
+      <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032213-faf25ab8-0bc3-4a94-a730-b524c96df124.png" />
+         <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032213-faf25ab8-0bc3-4a94-a730-b524c96df124.png" />
+      </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://x.com/revancedapp">
+      <picture>
+         <source media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/93124920/270180600-7c1b38bf-889b-4d68-bd5e-b9d86f91421a.png">
+         <img height="24px" src="https://user-images.githubusercontent.com/93124920/270108715-d80743fa-b330-4809-b1e6-79fbdc60d09c.png" />
+      </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://www.youtube.com/@ReVanced">
+      <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032714-c51c7492-0666-44ac-99c2-f003a695ab50.png" />
+         <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032714-c51c7492-0666-44ac-99c2-f003a695ab50.png" />
+     </picture>
+   </a>
+   <br>
+   <br>
+   Continuing the legacy of Vanced
+</p>
+
+# 🔎 Fingerprinting
+
+In the context of ReVanced, a fingerprint is a partial description of a method.
+It is used to uniquely match a method by its characteristics.
+Fingerprinting is used to match methods with a limited amount of known information.
+Methods with obfuscated names that change with each update are primary candidates for fingerprinting.
+The goal of fingerprinting is to uniquely identify a method by capturing various attributes, such as the return type,
+access flags, an opcode pattern, strings, and more.
+
+## ⛳️ Example fingerprint
+
+An example fingerprint is shown below:
+
+```kt
+
+package app.revanced.patches.ads.fingerprints
+
+fingerprint {
+    accessFlags(AccessFlags.PUBLIC, AccessFlags.FINAL)
+    returns("Z")
+    parameters("Z")
+    opcodes(Opcode.RETURN)
+    strings("pro")
+    custom { (method, classDef) -> classDef == "Lcom/some/app/ads/AdsLoader;" }
+}
+```
+
+## 🔎 Reconstructing the original code from the example fingerprint from above
+
+The following code is reconstructed from the fingerprint to understand how a fingerprint is created.
+
+The fingerprint contains the following information:
+
+- Method signature:
+
+  ```kt
+  accessFlags(AccessFlags.PUBLIC, AccessFlags.FINAL)
+  returns("Z")
+  parameters("Z")
+  ```
+
+- Method implementation:
+
+  ```kt
+  opcodes(Opcode.RETURN)
+  strings("pro")
+  ```
+
+- Package and class name:
+
+  ```kt
+  custom { (method, classDef) -> classDef == "Lcom/some/app/ads/AdsLoader;" }
+  ```
+
+With this information, the original code can be reconstructed:
+
+```java
+package com.some.app.ads;
+
+<accessFlags>
+
+class AdsLoader {
+    public final boolean <methodName>(boolean <parameter>)
+
+    {
+        // ...
+
+        var userStatus = "pro";
+
+        // ...
+
+        return <returnValue >;
+    }
+}
+```
+
+Using that fingerprint, this method can be matched uniquely from all other methods.
+
+> [!TIP]
+> A fingerprint should contain information about a method likely to remain the same across updates.
+> A method's name is not included in the fingerprint because it will likely change with each update in an obfuscated
+> app.
+> In contrast, the return type, access flags, parameters, patterns of opcodes, and strings are likely to remain the
+> same.
+
+## 🔨 How to use fingerprints
+
+After declaring a fingerprint, it can be used in a patch to find the method it matches to:
+
+```kt
+val fingerprint = fingerprint {
+    // ...
+}
+
+val patch = bytecodePatch {
+    execute {
+        fingerprint.method
+    }
+}
+```
+
+The fingerprint won't be matched again, if it has already been matched once, for performance reasons.
+This makes it useful, to share fingerprints between multiple patches,
+and let the first executing patch match the fingerprint:
+
+```kt
+// Either of these two patches will match the fingerprint first and the other patch can reuse the match:
+val mainActivityPatch1 = bytecodePatch {
+    execute {
+        mainActivityOnCreateFingerprint.method
+    }
+}
+
+val mainActivityPatch2 = bytecodePatch {
+    execute {
+        mainActivityOnCreateFingerprint.method
+    }
+}
+```
+
+> [!WARNING]
+> If the fingerprint can not be matched to any method,
+> accessing certain properties of the fingerprint will raise an exception.
+> Instead, the `orNull` properties can be used to return `null` if no match is found.
+
+> [!TIP]
+> If a fingerprint has an opcode pattern, you can use the `fuzzyPatternScanThreshhold` parameter of the `opcode`
+> function to fuzzy match the pattern.  
+> `null` can be used as a wildcard to match any opcode:
+>
+> ```kt
+> fingerprint(fuzzyPatternScanThreshhold = 2) {
+>   opcodes(
+>     Opcode.ICONST_0,
+>     null,
+>     Opcode.ICONST_1,
+>     Opcode.IRETURN,
+>    )
+>}
+> ```
+
+The following properties can be accessed in a fingerprint:
+
+- `originalClassDef`: The original class definition the fingerprint matches to.
+- `originalClassDefOrNull`: The original class definition the fingerprint matches to.
+- `originalMethod`: The original method the fingerprint matches to.
+- `originalMethodOrNull`: The original method the fingerprint matches to.
+- `classDef`: The class the fingerprint matches to.
+- `classDefOrNull`: The class the fingerprint matches to.
+- `method`: The method the fingerprint matches to. If no match is found, an exception is raised.
+- `methodOrNull`: The method the fingerprint matches to.
+
+The difference between the `original` and non-`original` properties is that the `original` properties return the
+original class or method definition, while the non-`original` properties return a mutable copy of the class or method.
+The mutable copies can be modified. They are lazy properties, so they are only computed
+and only then will effectively replace the `original` method or class definition when accessed.
+
+> [!TIP]
+> If only read-only access to the class or method is needed,
+> the `originalClassDef` and `originalMethod` properties should be used,
+> to avoid making a mutable copy of the class or method.
+
+## 🏹 Manually matching fingerprints
+
+By default, a fingerprint is matched automatically against all classes
+when one of the fingerprint's properties is accessed.
+
+Instead, the fingerprint can be matched manually using various overloads of a fingerprint's `match` function:
+
+- In a **list of classes**, if the fingerprint can match in a known subset of classes
+
+  If you have a known list of classes you know the fingerprint can match in,
+  you can match the fingerprint on the list of classes:
+
+  ```kt
+  execute {
+    val match = showAdsFingerprint(classes)
+  }
+  ```
+
+- In a **single class**, if the fingerprint can match in a single known class
+
+  If you know the fingerprint can match a method in a specific class, you can match the fingerprint in the class:
+
+  ```kt
+  execute {
+    val adsLoaderClass = classes.single { it.name == "Lcom/some/app/ads/Loader;" }
+
+    val match = showAdsFingerprint.match(adsLoaderClass)
+  }
+  ```
+
+  Another common usecase is to use a fingerprint to reduce the search space of a method to a single class.
+
+  ```kt
+  execute {
+    // Match showAdsFingerprint in the class of the ads loader found by adsLoaderClassFingerprint.
+    val match = showAdsFingerprint.match(adsLoaderClassFingerprint.classDef)
+  }
+  ```
+
+- Match a **single method**, to extract certain information about it
+
+  The match of a fingerprint contains useful information about the method,
+  such as the start and end index of an opcode pattern or the indices of the instructions with certain string
+  references.
+  A fingerprint can be leveraged to extract such information from a method instead of manually figuring it out:
+
+  ```kt
+  execute {
+    val currentPlanFingerprint = fingerprint {
+      strings("free", "trial")
+    }
+
+    currentPlanFingerprint.match(adsFingerprint.method).let { match ->
+      match.stringMatches.forEach { match ->
+        println("The index of the string '${match.string}' is ${match.index}")
+      }
+    }
+  }
+  ```
+
+> [!WARNING]
+> If the fingerprint can not be matched to any method, calling `match` will raise an
+> exception.
+> Instead, the `orNull` overloads can be used to return `null` if no match is found.
+
+> [!TIP]
+> To see real-world examples of fingerprints,
+> check out the repository for [ReVanced Patches](https://github.com/revanced/revanced-patches).
+
+## ⏭️ What's next
+
+The next page discusses the structure and conventions of patches.
+
+Continue: [📜 Project structure and conventions](3_structure_and_conventions.md)

docs/2_2_patch_anatomy.md

@@ -0,0 +1,262 @@
+<p align="center">
+  <picture>
+    <source
+      width="256px"
+      media="(prefers-color-scheme: dark)"
+      srcset="../assets/revanced-headline/revanced-headline-vertical-dark.svg"
+    >
+    <img 
+      width="256px"
+      src="../assets/revanced-headline/revanced-headline-vertical-light.svg"
+    >
+  </picture>
+  <br>
+  <a href="https://revanced.app/">
+     <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="../assets/revanced-logo/revanced-logo.svg" />
+         <img height="24px" src="../assets/revanced-logo/revanced-logo.svg" />
+     </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://github.com/ReVanced">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://i.ibb.co/dMMmCrW/Git-Hub-Mark.png" />
+           <img height="24px" src="https://i.ibb.co/9wV3HGF/Git-Hub-Mark-Light.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="http://revanced.app/discord">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032563-d4e084b7-244e-4358-af50-26bde6dd4996.png" />
+           <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032563-d4e084b7-244e-4358-af50-26bde6dd4996.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://reddit.com/r/revancedapp">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032351-9d9d5619-8ef7-470a-9eec-2744ece54553.png" />
+           <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032351-9d9d5619-8ef7-470a-9eec-2744ece54553.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://t.me/app_revanced">
+      <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032213-faf25ab8-0bc3-4a94-a730-b524c96df124.png" />
+         <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032213-faf25ab8-0bc3-4a94-a730-b524c96df124.png" />
+      </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://x.com/revancedapp">
+      <picture>
+         <source media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/93124920/270180600-7c1b38bf-889b-4d68-bd5e-b9d86f91421a.png">
+         <img height="24px" src="https://user-images.githubusercontent.com/93124920/270108715-d80743fa-b330-4809-b1e6-79fbdc60d09c.png" />
+      </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://www.youtube.com/@ReVanced">
+      <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032714-c51c7492-0666-44ac-99c2-f003a695ab50.png" />
+         <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032714-c51c7492-0666-44ac-99c2-f003a695ab50.png" />
+     </picture>
+   </a>
+   <br>
+   <br>
+   Continuing the legacy of Vanced
+</p>
+
+# 🧩 Anatomy of a ReVanced patch
+
+Learn the API to create patches using ReVanced Patcher.
+
+## ⛳️ Example patch
+
+The following example patch disables ads in an app.  
+In the following sections, each part of the patch will be explained in detail.
+
+```kt
+package app.revanced.patches.ads
+
+val disableAdsPatch = bytecodePatch(
+    name = "Disable ads",
+    description = "Disable ads in the app.",
+) {
+    compatibleWith("com.some.app"("1.0.0"))
+
+    // Patches can depend on other patches, executing them first.
+    dependsOn(disableAdsResourcePatch)
+
+    // Merge precompiled DEX files into the patched app, before the patch is executed.
+    extendWith("disable-ads.rve")
+
+    // Business logic of the patch to disable ads in the app.
+    execute {
+        // Fingerprint to find the method to patch.
+        val showAdsFingerprint = fingerprint {
+            // More about fingerprints on the next page of the documentation.
+        }
+
+        // In the method that shows ads,
+        // call DisableAdsPatch.shouldDisableAds() from the extension (precompiled DEX file)
+        // to enable or disable ads.
+        showAdsFingerprint.method.addInstructions(
+            0,
+            """
+                invoke-static {}, LDisableAdsPatch;->shouldDisableAds()Z
+                move-result v0
+                return v0
+            """
+        )
+    }
+}
+```
+
+> [!TIP]
+> To see real-world examples of patches,
+> check out the repository for [ReVanced Patches](https://github.com/revanced/revanced-patches).
+
+## 🧩 Patch API
+
+### ⚙️ Patch options
+
+Patches can have options to get and set before a patch is executed.
+Options are useful for making patches configurable.
+After loading the patches using `PatchLoader`, options can be set for a patch.
+Multiple types are already built into ReVanced Patcher and are supported by any application that uses ReVanced Patcher.
+
+To define an option, use the available `option` functions:
+
+```kt
+val patch = bytecodePatch(name = "Patch") {
+    // Add an inbuilt option and delegate it to a property.
+    val value by stringOption(name = "Inbuilt option")
+
+    // Add an option with a custom type and delegate it to a property.
+    val string by option<String>(name = "String option")
+
+    execute {
+        println(value)
+        println(string)
+    }
+}
+```
+
+Options of a patch can be set after loading the patches with `PatchLoader` by obtaining the instance for the patch:
+
+```kt
+loadPatchesJar(patches).apply {
+    // Type is checked at runtime.
+    first { it.name == "Patch" }.options["Option"] = "Value"
+}
+```
+
+The type of an option can be obtained from the `type` property of the option:
+
+```kt
+option.type // The KType of the option. Captures the full type information of the option.
+```
+
+Options can be declared outside a patch and added to a patch manually:
+
+```kt
+val option = stringOption(name = "Option")
+
+bytecodePatch(name = "Patch") {
+    val value by option()
+}
+```
+
+This is useful when the same option is referenced in multiple patches.
+
+### 🧩 Extensions
+
+An extension is a precompiled DEX file merged into the patched app before a patch is executed.
+While patches are compile-time constructs, extensions are runtime constructs
+that extend the patched app with additional classes.
+
+Assume you want to add a complex feature to an app that would need multiple classes and methods:
+
+```java
+public class ComplexPatch {
+    public static void doSomething() {
+        // ...
+    }
+}
+```
+
+After compiling the above code as a DEX file, you can add the DEX file as a resource in the patches file
+and use it in a patch:
+
+```kt
+val patch = bytecodePatch(name = "Complex patch") {
+    extendWith("complex-patch.rve")
+
+    execute {
+        fingerprint.method.addInstructions(0, "invoke-static { }, LComplexPatch;->doSomething()V")
+    }
+}
+```
+
+ReVanced Patcher merges the classes from the extension into `context.classes` before executing the patch.
+When the patch is executed, it can reference the classes and methods from the extension.
+
+> [!NOTE]
+>
+> The [ReVanced Patches template](https://github.com/ReVanced/revanced-patches-template) repository
+> is a template project to create patches and extensions.
+
+> [!TIP]
+> To see real-world examples of extensions,
+> check out the repository for [ReVanced Patches](https://github.com/revanced/revanced-patches).
+
+### ♻️ Finalization
+
+Patches can have a finalization block called after all patches have been executed, in reverse order of patch execution.
+The finalization block is called after all patches that depend on the patch have been executed.
+This is useful for doing post-processing tasks.
+A simple real-world example would be a patch that opens a resource file of the app for writing.
+Other patches that depend on this patch can write to the file, and the finalization block can close the file.
+
+```kt
+val patch = bytecodePatch(name = "Patch") {
+    dependsOn(
+        bytecodePatch(name = "Dependency") {
+            execute {
+                print("1")
+            }
+
+            finalize {
+                print("4")
+            }
+        }
+    )
+
+    execute {
+        print("2")
+    }
+
+    finalize {
+        print("3")
+    }
+}
+```
+
+Because `Patch` depends on `Dependency`, first `Dependency` is executed, then `Patch`.
+Finalization blocks are called in reverse order of patch execution, which means,
+first, the finalization block of `Patch`, then the finalization block of `Dependency` is called.
+The output after executing the patch above would be `1234`.
+The same order is followed for multiple patches depending on the patch.
+
+## 💡 Additional tips
+
+- When using `PatchLoader` to load patches, only patches with a name are loaded.
+  Refer to the inline documentation of `PatchLoader` for detailed information.
+- Patches can depend on others. Dependencies are executed first.
+  The dependent patch will not be executed if a dependency raises an exception while executing.
+- A patch can declare compatibility with specific packages and versions,
+  but patches can still be executed on any package or version.
+  It is recommended that compatibility is specified to present known compatible packages and versions.
+    - If `compatibleWith` is not used, the patch is treated as compatible with any package
+- If a package is specified with no versions, the patch is compatible with any version of the package
+- If an empty array of versions is specified, the patch is not compatible with any version of the package.
+  This is useful for declaring incompatibility with a specific package.
+- A patch can raise a `PatchException` at any time of execution to indicate that the patch failed to execute.
+
+## ⏭️ What's next
+
+The next page explains the concept of fingerprinting in ReVanced Patcher.
+
+Continue: [🔎 Fingerprinting](2_2_1_fingerprinting.md)

docs/2_patches_intro.md

@@ -0,0 +1,126 @@
+<p align="center">
+  <picture>
+    <source
+      width="256px"
+      media="(prefers-color-scheme: dark)"
+      srcset="../assets/revanced-headline/revanced-headline-vertical-dark.svg"
+    >
+    <img 
+      width="256px"
+      src="../assets/revanced-headline/revanced-headline-vertical-light.svg"
+    >
+  </picture>
+  <br>
+  <a href="https://revanced.app/">
+     <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="../assets/revanced-logo/revanced-logo.svg" />
+         <img height="24px" src="../assets/revanced-logo/revanced-logo.svg" />
+     </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://github.com/ReVanced">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://i.ibb.co/dMMmCrW/Git-Hub-Mark.png" />
+           <img height="24px" src="https://i.ibb.co/9wV3HGF/Git-Hub-Mark-Light.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="http://revanced.app/discord">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032563-d4e084b7-244e-4358-af50-26bde6dd4996.png" />
+           <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032563-d4e084b7-244e-4358-af50-26bde6dd4996.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://reddit.com/r/revancedapp">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032351-9d9d5619-8ef7-470a-9eec-2744ece54553.png" />
+           <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032351-9d9d5619-8ef7-470a-9eec-2744ece54553.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://t.me/app_revanced">
+      <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032213-faf25ab8-0bc3-4a94-a730-b524c96df124.png" />
+         <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032213-faf25ab8-0bc3-4a94-a730-b524c96df124.png" />
+      </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://x.com/revancedapp">
+      <picture>
+         <source media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/93124920/270180600-7c1b38bf-889b-4d68-bd5e-b9d86f91421a.png">
+         <img height="24px" src="https://user-images.githubusercontent.com/93124920/270108715-d80743fa-b330-4809-b1e6-79fbdc60d09c.png" />
+      </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://www.youtube.com/@ReVanced">
+      <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032714-c51c7492-0666-44ac-99c2-f003a695ab50.png" />
+         <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032714-c51c7492-0666-44ac-99c2-f003a695ab50.png" />
+     </picture>
+   </a>
+   <br>
+   <br>
+   Continuing the legacy of Vanced
+</p>
+
+# 🧩 Introduction to ReVanced Patches
+
+Learn the basic concepts of ReVanced Patcher and how to create patches.
+
+## 📙 Fundamentals
+
+A patch is a piece of code that modifies an Android application.  
+There are multiple types of patches. Each type can modify a different part of the APK, such as the Dalvik VM bytecode, 
+the APK resources, or arbitrary files in the APK:
+
+- A `BytecodePatch` modifies the Dalvik VM bytecode
+- A `ResourcePatch` modifies (decoded) resources
+- A `RawResourcePatch` modifies arbitrary files
+
+Each patch can declare a set of dependencies on other patches. ReVanced Patcher will first execute dependencies
+before executing the patch itself. This way, multiple patches can work together for abstract purposes in a modular way.
+
+The `execute` function is the entry point for a patch. It is called by ReVanced Patcher when the patch is executed.
+The `execute` function receives an instance of a context object that provides access to the APK.
+The patch can use this context to modify the APK.
+
+Each type of context provides different APIs to modify the APK. For example, the `BytecodePatchContext` provides APIs
+to modify the Dalvik VM bytecode, while the `ResourcePatchContext` provides APIs to modify resources.
+
+The difference between `ResourcePatch` and `RawResourcePatch` is that ReVanced Patcher will decode the resources
+if it is supplied a `ResourcePatch` for execution or if any patch depends on a `ResourcePatch`
+and will not decode the resources before executing `RawResourcePatch`.
+Both, `ResourcePatch` and `RawResourcePatch` can modify arbitrary files in the APK,
+whereas only `ResourcePatch` can modify decoded resources. The choice of which type to use depends on the use case.
+Decoding and building resources is a time- and resource-consuming,
+so if the patch does not need to modify decoded resources, it is better to use `RawResourcePatch` or `BytecodePatch`.
+
+Example of patches:
+
+```kt
+@Surpress("unused")
+val bytecodePatch = bytecodePatch {
+    execute { 
+        // More about this on the next page of the documentation.
+    }
+}
+
+@Surpress("unused")
+val rawResourcePatch = rawResourcePatch {
+    execute {
+        // More about this on the next page of the documentation.
+    }
+}
+
+@Surpress("unused")
+val resourcePatch = resourcePatch {
+    execute {
+        // More about this on the next page of the documentation.
+    }
+}
+```
+
+> [!TIP]
+> To see real-world examples of patches,
+> check out the repository for [ReVanced Patches](https://github.com/revanced/revanced-patches).
+
+## ⏭️ Whats next
+
+The next page will guide you through creating a development environment for creating patches.
+
+Continue: [👶 Setting up a development environment](2_1_setup.md)

docs/3_structure_and_conventions.md

@@ -0,0 +1,105 @@
+<p align="center">
+  <picture>
+    <source
+      width="256px"
+      media="(prefers-color-scheme: dark)"
+      srcset="../assets/revanced-headline/revanced-headline-vertical-dark.svg"
+    >
+    <img 
+      width="256px"
+      src="../assets/revanced-headline/revanced-headline-vertical-light.svg"
+    >
+  </picture>
+  <br>
+  <a href="https://revanced.app/">
+     <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="../assets/revanced-logo/revanced-logo.svg" />
+         <img height="24px" src="../assets/revanced-logo/revanced-logo.svg" />
+     </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://github.com/ReVanced">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://i.ibb.co/dMMmCrW/Git-Hub-Mark.png" />
+           <img height="24px" src="https://i.ibb.co/9wV3HGF/Git-Hub-Mark-Light.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="http://revanced.app/discord">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032563-d4e084b7-244e-4358-af50-26bde6dd4996.png" />
+           <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032563-d4e084b7-244e-4358-af50-26bde6dd4996.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://reddit.com/r/revancedapp">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032351-9d9d5619-8ef7-470a-9eec-2744ece54553.png" />
+           <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032351-9d9d5619-8ef7-470a-9eec-2744ece54553.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://t.me/app_revanced">
+      <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032213-faf25ab8-0bc3-4a94-a730-b524c96df124.png" />
+         <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032213-faf25ab8-0bc3-4a94-a730-b524c96df124.png" />
+      </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://x.com/revancedapp">
+      <picture>
+         <source media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/93124920/270180600-7c1b38bf-889b-4d68-bd5e-b9d86f91421a.png">
+         <img height="24px" src="https://user-images.githubusercontent.com/93124920/270108715-d80743fa-b330-4809-b1e6-79fbdc60d09c.png" />
+      </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://www.youtube.com/@ReVanced">
+      <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032714-c51c7492-0666-44ac-99c2-f003a695ab50.png" />
+         <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032714-c51c7492-0666-44ac-99c2-f003a695ab50.png" />
+     </picture>
+   </a>
+   <br>
+   <br>
+   Continuing the legacy of Vanced
+</p>
+
+# 📜 Project structure and conventions
+
+Over time, a specific project structure and conventions have been established.
+
+## 📁 File structure
+
+Patches are organized in a specific way. The file structure looks as follows:
+
+```text
+📦your.patches.app.category
+ ├ 🔍Fingerprints.kt
+ └ 🧩SomePatch.kt
+```
+
+> [!NOTE]
+> Moving fingerprints to a separate file isn't strictly necessary, but it helps the organization when a patch uses multiple fingerprints.
+
+## 📙 Conventions
+
+- 🔥 Name a patch after what it does. For example, if a patch removes ads, name it `Remove ads`.
+  If a patch changes the color of a button, name it `Change button color`
+- 🔥 Write the patch description in the third person, present tense, and end it with a period.
+  If a patch removes ads, the description can be omitted because of redundancy,
+  but if a patch changes the color of a button, the description can be _Changes the color of the resume button to red._
+- 🔥 Write patches with modularity and reusability in mind. Patches can depend on each other,
+  so it is important to write patches in a way that can be used in different contexts.
+- 🔥🔥 Keep patches as minimal as possible. This reduces the risk of failing patches.
+  Instead of involving many abstract changes in one patch or writing entire methods or classes in a patch,
+  you can write code in extensions. An extension is a precompiled DEX file that is merged into the patched app 
+  before this patch is executed.
+  Patches can then reference methods and classes from extensions.
+  A real-world example of extensions can be found in the [ReVanced Patches](https://github.com/ReVanced/revanced-patches) repository
+- 🔥🔥🔥 Do not overload a fingerprint with information about a method that's likely to change.
+  In the example of an obfuscated method, it's better to fingerprint the method by its return type
+  and parameters rather than its name because the name is likely to change. An intelligent selection
+  of an opcode pattern or strings in a method can result in a strong fingerprint dynamic to app updates.
+- 🔥🔥🔥 Document your patches. Patches are abstract, so it is important to document parts of the code
+  that are not self-explanatory. For example, explain why and how a certain method is patched or large blocks
+  of instructions that are modified or added to a method
+
+## ⏭️ What's next
+
+The next page discusses useful APIs for patch development.
+
+Continue: [💪 Advanced APIs](4_apis.md)

docs/4_apis.md

@@ -0,0 +1,117 @@
+# 💪 Advanced APIs
+
+A handful of APIs are available to make patch development easier and more efficient.
+
+## 📙 Overview
+
+1. 👹 Create mutable replacements of classes with `proxy(ClassDef)`
+2. 🔍 Find and create mutable replaces with `classBy(Predicate)`
+3. 🏃‍ Navigate method calls recursively by index with `navigate(Method)`
+4. 💾 Read and write resource files with `get(String, Boolean)` and `delete(String)`
+5. 📃 Read and write DOM files using `document(String)` and  `document(InputStream)`
+
+### 🧰 APIs
+
+#### 👹 `proxy(ClassDef)`
+
+By default, the classes are immutable, meaning they cannot be modified.
+To make a class mutable, use the `proxy(ClassDef)` function.
+This function creates a lazy mutable copy of the class definition.
+Accessing the property will replace the original class definition with the mutable copy,
+thus allowing you to make changes to the class. Subsequent accesses will return the same mutable copy.
+
+```kt
+execute {
+    val mutableClass = proxy(classDef)
+    mutableClass.methods.add(Method())
+}
+```
+
+#### 🔍 `classBy(Predicate)`
+
+The `classBy(Predicate)` function is an alternative to finding and creating mutable classes by a predicate.
+It automatically proxies the class definition, making it mutable.
+
+```kt
+execute {
+    // Alternative to proxy(classes.find { it.name == "Lcom/example/MyClass;" })?.classDef
+    val classDef = classBy { it.name == "Lcom/example/MyClass;" }?.classDef
+}
+```
+
+#### 🏃‍ `navigate(Method).at(index)`
+
+The `navigate(Method)` function allows you to navigate method calls recursively by index.
+
+```kt
+execute {
+    // Sequentially navigate to the instructions at index 1 within 'someMethod'.
+    val method = navigate(someMethod).to(1).original() // original() returns the original immutable method.
+    
+    // Further navigate to the second occurrence where the instruction's opcode is 'INVOKEVIRTUAL'.
+    // stop() returns the mutable copy of the method.
+    val method = navigate(someMethod).to(2) { instruction -> instruction.opcode == Opcode.INVOKEVIRTUAL }.stop()
+    
+    // Alternatively, to stop(), you can delegate the method to a variable.
+    val method by navigate(someMethod).to(1)
+    
+    // You can chain multiple calls to at() to navigate deeper into the method.
+    val method by navigate(someMethod).to(1).to(2, 3, 4).to(5)
+}
+```
+
+#### 💾 `get(String, Boolean)` and `delete(String)`
+
+The `get(String, Boolean)` function returns a `File` object that can be used to read and write resource files.
+
+```kt
+execute {
+    val file = get("res/values/strings.xml")
+    val content = file.readText()
+    file.writeText(content)
+}
+```
+
+The `delete` function can mark files for deletion when the APK is rebuilt.
+
+```kt
+execute {
+    delete("res/values/strings.xml")
+}
+```
+
+#### 📃 `document(String)`  and  `document(InputStream)`
+
+The `document` function is used to read and write DOM files.
+
+```kt
+execute {
+    document("res/values/strings.xml").use { document ->
+        val element = doc.createElement("string").apply {
+            textContent = "Hello, World!"
+        }
+        document.documentElement.appendChild(element)
+    }
+}
+```
+
+You can also read documents from an `InputStream`:
+
+```kt
+execute {
+    val inputStream = classLoader.getResourceAsStream("some.xml")
+    document(inputStream).use { document ->
+        // ...
+    }
+}
+```
+
+## 🎉 Afterword
+
+ReVanced Patcher is a powerful library to patch Android applications, offering a rich set of APIs to develop patches
+that outlive app updates. Patches make up ReVanced; without you, the community of patch developers,
+ReVanced would not be what it is today. We hope that this documentation has been helpful to you
+and are excited to see what you will create with ReVanced Patcher. If you have any questions or need help,
+talk to us on one of our platforms linked on [revanced.app](https://revanced.app) or open an issue in case of a bug or
+feature request,  
+ReVanced

docs/README.md

@@ -0,0 +1,73 @@
+<p align="center">
+  <picture>
+    <source
+      width="256px"
+      media="(prefers-color-scheme: dark)"
+      srcset="../assets/revanced-headline/revanced-headline-vertical-dark.svg"
+    >
+    <img 
+      width="256px"
+      src="../assets/revanced-headline/revanced-headline-vertical-light.svg"
+    >
+  </picture>
+  <br>
+  <a href="https://revanced.app/">
+     <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="../assets/revanced-logo/revanced-logo.svg" />
+         <img height="24px" src="../assets/revanced-logo/revanced-logo.svg" />
+     </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://github.com/ReVanced">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://i.ibb.co/dMMmCrW/Git-Hub-Mark.png" />
+           <img height="24px" src="https://i.ibb.co/9wV3HGF/Git-Hub-Mark-Light.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="http://revanced.app/discord">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032563-d4e084b7-244e-4358-af50-26bde6dd4996.png" />
+           <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032563-d4e084b7-244e-4358-af50-26bde6dd4996.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://reddit.com/r/revancedapp">
+       <picture>
+           <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032351-9d9d5619-8ef7-470a-9eec-2744ece54553.png" />
+           <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032351-9d9d5619-8ef7-470a-9eec-2744ece54553.png" />
+       </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://t.me/app_revanced">
+      <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032213-faf25ab8-0bc3-4a94-a730-b524c96df124.png" />
+         <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032213-faf25ab8-0bc3-4a94-a730-b524c96df124.png" />
+      </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://x.com/revancedapp">
+      <picture>
+         <source media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/93124920/270180600-7c1b38bf-889b-4d68-bd5e-b9d86f91421a.png">
+         <img height="24px" src="https://user-images.githubusercontent.com/93124920/270108715-d80743fa-b330-4809-b1e6-79fbdc60d09c.png" />
+      </picture>
+   </a>&nbsp;&nbsp;&nbsp;
+   <a href="https://www.youtube.com/@ReVanced">
+      <picture>
+         <source height="24px" media="(prefers-color-scheme: dark)" srcset="https://user-images.githubusercontent.com/13122796/178032714-c51c7492-0666-44ac-99c2-f003a695ab50.png" />
+         <img height="24px" src="https://user-images.githubusercontent.com/13122796/178032714-c51c7492-0666-44ac-99c2-f003a695ab50.png" />
+     </picture>
+   </a>
+   <br>
+   <br>
+   Continuing the legacy of Vanced
+</p>
+
+# 💉 Documentation of ReVanced Patcher
+
+This documentation contains the fundamentals of ReVanced Patcher and how to use ReVanced Patcher to create patches
+
+## 📖 Table of content
+
+1. [💉 Introduction to ReVanced Patcher](1_patcher_intro.md)
+2. [🧩 Introduction to ReVanced Patches](2_patches_intro.md)
+   1. [👶 Setting up a development environment](2_1_setup.md)
+   2. [🧩 Anatomy of a ReVanced patch](2_2_patch_anatomy.md)
+      1. [🔎 Fingerprinting](2_2_1_fingerprinting.md)
+   3. [📜 Project structure and conventions](3_structure_and_conventions.md)
+   4. [💪 Advanced APIs](4_apis.md)

gradle.properties

@@ -1,2 +1,11 @@
+version = 22.0.0-local
+#Kotlin
 kotlin.code.style=official
-version=1.0.0
+kotlin.daemon.jvmargs=-Xmx3072M
+#Gradle
+org.gradle.jvmargs=-Xmx2048M -Dfile.encoding=UTF-8 -Dkotlin.daemon.jvm.options\="-Xmx2048M"
+org.gradle.caching=true
+org.gradle.configuration-cache=true
+#Android
+android.nonTransitiveRClass=true
+android.useAndroidX=true

gradle/libs.versions.toml

@@ -0,0 +1,28 @@
+
+[versions]
+agp = "8.12.3"
+android-compileSdk = "36"
+android-minSdk = "26"
+kotlin = "2.3.0"
+apktool-lib = "2.10.1.1"
+mockk = "1.14.7"
+multidexlib2 = "3.0.3.r3"
+# Tracking https://github.com/google/smali/issues/64.
+#noinspection GradleDependency
+smali = "3.0.9"
+xpp3 = "1.1.4c"
+vanniktechMavenPublish = "0.35.0"
+
+[libraries]
+apktool-lib = { module = "app.revanced:apktool-lib", version.ref = "apktool-lib" }
+kotlin-reflect = { module = "org.jetbrains.kotlin:kotlin-reflect", version.ref = "kotlin" }
+kotlin-test = { module = "org.jetbrains.kotlin:kotlin-test", version.ref = "kotlin" }
+mockk = { module = "io.mockk:mockk", version.ref = "mockk" }
+multidexlib2 = { module = "app.revanced:multidexlib2", version.ref = "multidexlib2" }
+smali = { module = "com.android.tools.smali:smali", version.ref = "smali" }
+xpp3 = { module = "xpp3:xpp3", version.ref = "xpp3" }
+
+[plugins]
+android-kotlin-multiplatform-library = { id = "com.android.kotlin.multiplatform.library", version.ref = "agp" }
+kotlinMultiplatform = { id = "org.jetbrains.kotlin.multiplatform", version.ref = "kotlin" }
+vanniktech-mavenPublish = { id = "com.vanniktech.maven.publish", version.ref = "vanniktechMavenPublish" }

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,7 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.2-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-9.2.1-bin.zip
+networkTimeout=10000
+validateDistributionUrl=true
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists

gradlew

@@ -1,7 +1,7 @@
-#!/usr/bin/env sh
+#!/bin/sh
 
 #
-# Copyright 2015 the original author or authors.
+# Copyright © 2015 the original authors.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -15,81 +15,114 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 #
+# SPDX-License-Identifier: Apache-2.0
+#
 
 ##############################################################################
-##
-##  Gradle start up script for UN*X
-##
+#
+#   Gradle start up script for POSIX generated by Gradle.
+#
+#   Important for running:
+#
+#   (1) You need a POSIX-compliant shell to run this script. If your /bin/sh is
+#       noncompliant, but you have some other compliant shell such as ksh or
+#       bash, then to run this script, type that shell name before the whole
+#       command line, like:
+#
+#           ksh Gradle
+#
+#       Busybox and similar reduced shells will NOT work, because this script
+#       requires all of these POSIX shell features:
+#         * functions;
+#         * expansions «$var», «${var}», «${var:-default}», «${var+SET}»,
+#           «${var#prefix}», «${var%suffix}», and «$( cmd )»;
+#         * compound commands having a testable exit status, especially «case»;
+#         * various built-in commands including «command», «set», and «ulimit».
+#
+#   Important for patching:
+#
+#   (2) This script targets any POSIX shell, so it avoids extensions provided
+#       by Bash, Ksh, etc; in particular arrays are avoided.
+#
+#       The "traditional" practice of packing multiple parameters into a
+#       space-separated string is a well documented source of bugs and security
+#       problems, so this is (mostly) avoided, by progressively accumulating
+#       options in "$@", and eventually passing that to Java.
+#
+#       Where the inherited environment variables (DEFAULT_JVM_OPTS, JAVA_OPTS,
+#       and GRADLE_OPTS) rely on word-splitting, this is performed explicitly;
+#       see the in-line comments for details.
+#
+#       There are tweaks for specific operating systems such as AIX, CygWin,
+#       Darwin, MinGW, and NonStop.
+#
+#   (3) This script is generated from the Groovy template
+#       https://github.com/gradle/gradle/blob/HEAD/platforms/jvm/plugins-application/src/main/resources/org/gradle/api/internal/plugins/unixStartScript.txt
+#       within the Gradle project.
+#
+#       You can find Gradle at https://github.com/gradle/gradle/.
+#
 ##############################################################################
 
 # Attempt to set APP_HOME
+
 # Resolve links: $0 may be a link
-PRG="$0"
-# Need this for relative symlinks.
-while [ -h "$PRG" ] ; do
-    ls=`ls -ld "$PRG"`
-    link=`expr "$ls" : '.*-> \(.*\)$'`
-    if expr "$link" : '/.*' > /dev/null; then
-        PRG="$link"
-    else
-        PRG=`dirname "$PRG"`"/$link"
-    fi
+app_path=$0
+
+# Need this for daisy-chained symlinks.
+while
+    APP_HOME=${app_path%"${app_path##*/}"}  # leaves a trailing /; empty if no leading path
+    [ -h "$app_path" ]
+do
+    ls=$( ls -ld "$app_path" )
+    link=${ls#*' -> '}
+    case $link in             #(
+      /*)   app_path=$link ;; #(
+      *)    app_path=$APP_HOME$link ;;
+    esac
 done
-SAVED="`pwd`"
-cd "`dirname \"$PRG\"`/" >/dev/null
-APP_HOME="`pwd -P`"
-cd "$SAVED" >/dev/null
 
-APP_NAME="Gradle"
-APP_BASE_NAME=`basename "$0"`
-
-# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
-DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+# This is normally unused
+# shellcheck disable=SC2034
+APP_BASE_NAME=${0##*/}
+# Discard cd standard output in case $CDPATH is set (https://github.com/gradle/gradle/issues/25036)
+APP_HOME=$( cd -P "${APP_HOME:-./}" > /dev/null && printf '%s\n' "$PWD" ) || exit
 
 # Use the maximum available, or set MAX_FD != -1 to use that value.
-MAX_FD="maximum"
+MAX_FD=maximum
 
 warn () {
     echo "$*"
-}
+} >&2
 
 die () {
     echo
     echo "$*"
     echo
     exit 1
-}
+} >&2
 
 # OS specific support (must be 'true' or 'false').
 cygwin=false
 msys=false
 darwin=false
 nonstop=false
-case "`uname`" in
-  CYGWIN* )
-    cygwin=true
-    ;;
-  Darwin* )
-    darwin=true
-    ;;
-  MSYS* | MINGW* )
-    msys=true
-    ;;
-  NONSTOP* )
-    nonstop=true
-    ;;
+case "$( uname )" in                #(
+  CYGWIN* )         cygwin=true  ;; #(
+  Darwin* )         darwin=true  ;; #(
+  MSYS* | MINGW* )  msys=true    ;; #(
+  NONSTOP* )        nonstop=true ;;
 esac
 
-CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar
 
 
 # Determine the Java command to use to start the JVM.
 if [ -n "$JAVA_HOME" ] ; then
     if [ -x "$JAVA_HOME/jre/sh/java" ] ; then
         # IBM's JDK on AIX uses strange locations for the executables
-        JAVACMD="$JAVA_HOME/jre/sh/java"
+        JAVACMD=$JAVA_HOME/jre/sh/java
     else
-        JAVACMD="$JAVA_HOME/bin/java"
+        JAVACMD=$JAVA_HOME/bin/java
     fi
     if [ ! -x "$JAVACMD" ] ; then
         die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME
@@ -98,88 +131,118 @@ Please set the JAVA_HOME variable in your environment to match the
 location of your Java installation."
     fi
 else
-    JAVACMD="java"
-    which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
+    JAVACMD=java
+    if ! command -v java >/dev/null 2>&1
+    then
+        die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
 
 Please set the JAVA_HOME variable in your environment to match the
 location of your Java installation."
+    fi
 fi
 
 # Increase the maximum file descriptors if we can.
-if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then
-    MAX_FD_LIMIT=`ulimit -H -n`
-    if [ $? -eq 0 ] ; then
-        if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then
-            MAX_FD="$MAX_FD_LIMIT"
-        fi
-        ulimit -n $MAX_FD
-        if [ $? -ne 0 ] ; then
-            warn "Could not set maximum file descriptor limit: $MAX_FD"
-        fi
-    else
-        warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT"
-    fi
-fi
-
-# For Darwin, add options to specify how the application appears in the dock
-if $darwin; then
-    GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\""
-fi
-
-# For Cygwin or MSYS, switch paths to Windows format before running java
-if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then
-    APP_HOME=`cygpath --path --mixed "$APP_HOME"`
-    CLASSPATH=`cygpath --path --mixed "$CLASSPATH"`
-
-    JAVACMD=`cygpath --unix "$JAVACMD"`
-
-    # We build the pattern for arguments to be converted via cygpath
-    ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null`
-    SEP=""
-    for dir in $ROOTDIRSRAW ; do
-        ROOTDIRS="$ROOTDIRS$SEP$dir"
-        SEP="|"
-    done
-    OURCYGPATTERN="(^($ROOTDIRS))"
-    # Add a user-defined pattern to the cygpath arguments
-    if [ "$GRADLE_CYGPATTERN" != "" ] ; then
-        OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)"
-    fi
-    # Now convert the arguments - kludge to limit ourselves to /bin/sh
-    i=0
-    for arg in "$@" ; do
-        CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -`
-        CHECK2=`echo "$arg"|egrep -c "^-"`                                 ### Determine if an option
-
-        if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then                    ### Added a condition
-            eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"`
-        else
-            eval `echo args$i`="\"$arg\""
-        fi
-        i=`expr $i + 1`
-    done
-    case $i in
-        0) set -- ;;
-        1) set -- "$args0" ;;
-        2) set -- "$args0" "$args1" ;;
-        3) set -- "$args0" "$args1" "$args2" ;;
-        4) set -- "$args0" "$args1" "$args2" "$args3" ;;
-        5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;;
-        6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;;
-        7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;;
-        8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;;
-        9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;;
+if ! "$cygwin" && ! "$darwin" && ! "$nonstop" ; then
+    case $MAX_FD in #(
+      max*)
+        # In POSIX sh, ulimit -H is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        MAX_FD=$( ulimit -H -n ) ||
+            warn "Could not query maximum file descriptor limit"
+    esac
+    case $MAX_FD in  #(
+      '' | soft) :;; #(
+      *)
+        # In POSIX sh, ulimit -n is undefined. That's why the result is checked to see if it worked.
+        # shellcheck disable=SC2039,SC3045
+        ulimit -n "$MAX_FD" ||
+            warn "Could not set maximum file descriptor limit to $MAX_FD"
     esac
 fi
 
-# Escape application args
-save () {
-    for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done
-    echo " "
-}
-APP_ARGS=`save "$@"`
+# Collect all arguments for the java command, stacking in reverse order:
+#   * args from the command line
+#   * the main class name
+#   * -classpath
+#   * -D...appname settings
+#   * --module-path (only if needed)
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and GRADLE_OPTS environment variables.
 
-# Collect all arguments for the java command, following the shell quoting and substitution rules
-eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS"
+# For Cygwin or MSYS, switch paths to Windows format before running java
+if "$cygwin" || "$msys" ; then
+    APP_HOME=$( cygpath --path --mixed "$APP_HOME" )
+
+    JAVACMD=$( cygpath --unix "$JAVACMD" )
+
+    # Now convert the arguments - kludge to limit ourselves to /bin/sh
+    for arg do
+        if
+            case $arg in                                #(
+              -*)   false ;;                            # don't mess with options #(
+              /?*)  t=${arg#/} t=/${t%%/*}              # looks like a POSIX filepath
+                    [ -e "$t" ] ;;                      #(
+              *)    false ;;
+            esac
+        then
+            arg=$( cygpath --path --ignore --mixed "$arg" )
+        fi
+        # Roll the args list around exactly as many times as the number of
+        # args, so each arg winds up back in the position where it started, but
+        # possibly modified.
+        #
+        # NB: a `for` loop captures its iteration list before it begins, so
+        # changing the positional parameters here affects neither the number of
+        # iterations, nor the values presented in `arg`.
+        shift                   # remove old arg
+        set -- "$@" "$arg"      # push replacement arg
+    done
+fi
+
+
+# Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script.
+DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"'
+
+# Collect all arguments for the java command:
+#   * DEFAULT_JVM_OPTS, JAVA_OPTS, and optsEnvironmentVar are not allowed to contain shell fragments,
+#     and any embedded shellness will be escaped.
+#   * For example: A user cannot expect ${Hostname} to be expanded, as it is an environment variable and will be
+#     treated as '${Hostname}' itself on the command line.
+
+set -- \
+        "-Dorg.gradle.appname=$APP_BASE_NAME" \
+        -jar "$APP_HOME/gradle/wrapper/gradle-wrapper.jar" \
+        "$@"
+
+# Stop when "xargs" is not available.
+if ! command -v xargs >/dev/null 2>&1
+then
+    die "xargs is not available"
+fi
+
+# Use "xargs" to parse quoted args.
+#
+# With -n1 it outputs one arg per line, with the quotes and backslashes removed.
+#
+# In Bash we could simply go:
+#
+#   readarray ARGS < <( xargs -n1 <<<"$var" ) &&
+#   set -- "${ARGS[@]}" "$@"
+#
+# but POSIX shell has neither arrays nor command substitution, so instead we
+# post-process each arg (as a line of input to sed) to backslash-escape any
+# character that might be a shell metacharacter, then use eval to reverse
+# that process (while maintaining the separation between arguments), and wrap
+# the whole thing up as a single "set" statement.
+#
+# This will of course break if any of these variables contains a newline or
+# an unmatched quote.
+#
+
+eval "set -- $(
+        printf '%s\n' "$DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS" |
+        xargs -n1 |
+        sed ' s~[^-[:alnum:]+,./:=@_]~\\&~g; ' |
+        tr '\n' ' '
+    )" '"$@"'
 
 exec "$JAVACMD" "$@"

gradlew.bat

@@ -13,8 +13,10 @@
 @rem See the License for the specific language governing permissions and
 @rem limitations under the License.
 @rem
+@rem SPDX-License-Identifier: Apache-2.0
+@rem
 
-@if "%DEBUG%" == "" @echo off
+@if "%DEBUG%"=="" @echo off
 @rem ##########################################################################
 @rem
 @rem  Gradle startup script for Windows
@@ -25,7 +27,8 @@
 if "%OS%"=="Windows_NT" setlocal
 
 set DIRNAME=%~dp0
-if "%DIRNAME%" == "" set DIRNAME=.
+if "%DIRNAME%"=="" set DIRNAME=.
+@rem This is normally unused
 set APP_BASE_NAME=%~n0
 set APP_HOME=%DIRNAME%
 
@@ -40,13 +43,13 @@ if defined JAVA_HOME goto findJavaFromJavaHome
 
 set JAVA_EXE=java.exe
 %JAVA_EXE% -version >NUL 2>&1
-if "%ERRORLEVEL%" == "0" goto execute
+if %ERRORLEVEL% equ 0 goto execute
 
-echo.
-echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH.
-echo.
-echo Please set the JAVA_HOME variable in your environment to match the
-echo location of your Java installation.
+echo. 1>&2
+echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
 
 goto fail
 
@@ -56,32 +59,33 @@ set JAVA_EXE=%JAVA_HOME%/bin/java.exe
 
 if exist "%JAVA_EXE%" goto execute
 
-echo.
-echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME%
-echo.
-echo Please set the JAVA_HOME variable in your environment to match the
-echo location of your Java installation.
+echo. 1>&2
+echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 1>&2
+echo. 1>&2
+echo Please set the JAVA_HOME variable in your environment to match the 1>&2
+echo location of your Java installation. 1>&2
 
 goto fail
 
 :execute
 @rem Setup the command line
 
-set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar
 
 
 @rem Execute Gradle
-"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %*
+"%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -jar "%APP_HOME%\gradle\wrapper\gradle-wrapper.jar" %*
 
 :end
 @rem End local scope for the variables with windows NT shell
-if "%ERRORLEVEL%"=="0" goto mainEnd
+if %ERRORLEVEL% equ 0 goto mainEnd
 
 :fail
 rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of
 rem the _cmd.exe /c_ return code!
-if  not "" == "%GRADLE_EXIT_CONSOLE%" exit 1
-exit /b 1
+set EXIT_CODE=%ERRORLEVEL%
+if %EXIT_CODE% equ 0 set EXIT_CODE=1
+if not ""=="%GRADLE_EXIT_CONSOLE%" exit %EXIT_CODE%
+exit /b %EXIT_CODE%
 
 :mainEnd
 if "%OS%"=="Windows_NT" endlocal

package.json

@@ -0,0 +1,9 @@
+{
+  "devDependencies": {
+    "@saithodev/semantic-release-backmerge": "^4.0.1",
+    "@semantic-release/changelog": "^6.0.3",
+    "@semantic-release/git": "^10.0.1",
+    "gradle-semantic-release-plugin": "^1.10.1",
+    "semantic-release": "^24.2.9"
+  }
+}

patcher/build.gradle.kts

@@ -0,0 +1,110 @@
+import com.android.build.api.dsl.androidLibrary
+import org.jetbrains.kotlin.gradle.dsl.JvmTarget
+import org.jetbrains.kotlin.gradle.dsl.abi.ExperimentalAbiValidation
+
+plugins {
+    alias(libs.plugins.kotlinMultiplatform)
+    alias(libs.plugins.android.kotlin.multiplatform.library)
+    alias(libs.plugins.vanniktech.mavenPublish)
+}
+
+group = "app.revanced"
+
+kotlin {
+    @OptIn(ExperimentalAbiValidation::class)
+    abiValidation {
+        enabled = true
+    }
+
+    jvm()
+
+    androidLibrary {
+        namespace = "app.revanced.patcher"
+        compileSdk = libs.versions.android.compileSdk.get().toInt()
+        minSdk = libs.versions.android.minSdk.get().toInt()
+
+        withHostTestBuilder {}.configure {}
+        withDeviceTestBuilder {
+            sourceSetTreeName = "test"
+        }
+
+        compilations.configureEach {
+            compilerOptions.configure {
+                jvmTarget.set(
+                    JvmTarget.JVM_11
+                )
+            }
+        }
+    }
+
+    sourceSets {
+        commonMain.dependencies {
+            implementation(libs.apktool.lib)
+            implementation(libs.kotlin.reflect)
+            implementation(libs.multidexlib2)
+            implementation(libs.smali)
+            implementation(libs.xpp3)
+        }
+
+        jvmTest.dependencies {
+            implementation(libs.mockk)
+            implementation(libs.kotlin.test)
+        }
+    }
+
+    compilerOptions {
+        freeCompilerArgs.addAll(
+            "-Xexplicit-backing-fields",
+            "-Xcontext-parameters"
+        )
+    }
+}
+
+tasks {
+    named<Test>("jvmTest") {
+        useJUnitPlatform()
+    }
+}
+
+mavenPublishing {
+    publishing {
+        repositories {
+            maven {
+                name = "githubPackages"
+                url = uri("https://maven.pkg.github.com/revanced/revanced-patcher")
+                credentials(PasswordCredentials::class)
+            }
+        }
+    }
+
+    signAllPublications()
+    extensions.getByType<SigningExtension>().useGpgCmd()
+
+    coordinates(group.toString(), project.name, version.toString())
+
+    pom {
+        name = "ReVanced Patcher"
+        description = "Patcher used by ReVanced."
+        inceptionYear = "2022"
+        url = "https://revanced.app"
+        licenses {
+            license {
+                name = "GNU General Public License v3.0"
+                url = "https://www.gnu.org/licenses/gpl-3.0.en.html"
+            }
+        }
+        developers {
+            developer {
+                id = "ReVanced"
+                name = "ReVanced"
+                email = "contact@revanced.app"
+            }
+        }
+        scm {
+            connection = "scm:git:git://github.com/revanced/revanced-patcher.git"
+            developerConnection = "scm:git:git@github.com:revanced/revanced-patcher.git"
+            url = "https://github.com/revanced/revanced-patcher"
+        }
+    }
+}
+

patcher/src/androidMain/kotlin/app/revanced/patcher/patch/Patch.android.kt

@@ -0,0 +1,39 @@
+package app.revanced.patcher.patch
+
+import dalvik.system.DexClassLoader
+import lanchon.multidexlib2.BasicDexFileNamer
+import lanchon.multidexlib2.MultiDexIO
+import java.io.File
+
+actual val Class<*>.isPatch get() = Patch::class.java.isAssignableFrom(this)
+
+/**
+ * Loads patches from DEX files declared as public static fields
+ * or returned by public static and non-parametrized methods.
+ * Patches with no name are not loaded. If a patches file fails to load,
+ * the [onFailedToLoad] callback is invoked with the file and the throwable
+ * and the loading continues for the other files.
+ *
+ * @param patchesFiles The DEX files to load the patches from.
+ * @param onFailedToLoad A callback invoked when a patches file fails to load.
+ *
+ * @return The loaded patches.
+ */
+actual fun loadPatches(
+    vararg patchesFiles: File,
+    onFailedToLoad: (patchesFile: File, throwable: Throwable) -> Unit,
+) = loadPatches(
+    patchesFiles = patchesFiles,
+    { patchBundle ->
+        MultiDexIO.readDexFile(true, patchBundle, BasicDexFileNamer(), null, null).classes
+            .map { classDef ->
+                classDef.type.substring(1, classDef.length - 1)
+            }
+    },
+    DexClassLoader(
+        patchesFiles.joinToString(File.pathSeparator) { it.absolutePath },
+        null,
+        null, null
+    ),
+    onFailedToLoad
+)

patcher/src/androidMain/kotlin/collections/MutableMap.android.kt

@@ -0,0 +1,7 @@
+package collections
+
+actual fun <K, V> MutableMap<K, V>.kmpMerge(
+    key: K,
+    value: V,
+    remappingFunction: (oldValue: V, newValue: V) -> V
+) = merge(key, value, remappingFunction)

patcher/src/androidMain/kotlin/java/io/File.android.kt

@@ -0,0 +1,8 @@
+package java.io
+
+import java.nio.charset.Charset
+
+internal actual fun File.kmpResolve(child: String) = resolve(child)
+internal actual fun File.kmpDeleteRecursively() = deleteRecursively()
+internal actual fun File.kmpInputStream() = inputStream()
+internal actual fun File.kmpBufferedWriter(charset: Charset) = bufferedWriter(charset)

patcher/src/commonMain/kotlin/app/revanced/patcher/Fingerprint.kt

@@ -0,0 +1,363 @@
+@file:Suppress("unused", "MemberVisibilityCanBePrivate")
+
+package app.revanced.patcher
+
+import app.revanced.patcher.extensions.instructionsOrNull
+import app.revanced.patcher.patch.BytecodePatchContext
+import app.revanced.patcher.patch.PatchException
+import com.android.tools.smali.dexlib2.AccessFlags
+import com.android.tools.smali.dexlib2.Opcode
+import com.android.tools.smali.dexlib2.iface.ClassDef
+import com.android.tools.smali.dexlib2.iface.Method
+import com.android.tools.smali.dexlib2.iface.instruction.ReferenceInstruction
+import com.android.tools.smali.dexlib2.iface.reference.StringReference
+import com.android.tools.smali.dexlib2.util.MethodUtil
+
+@Deprecated("Use the matcher API instead.")
+class Fingerprint internal constructor(
+    internal val accessFlags: Int?,
+    internal val returnType: String?,
+    internal val parameters: List<String>?,
+    internal val opcodes: List<Opcode?>?,
+    internal val strings: List<String>?,
+    internal val custom: ((method: Method, classDef: ClassDef) -> Boolean)?,
+    private val fuzzyPatternScanThreshold: Int,
+) {
+    @Suppress("ktlint:standard:backing-property-naming")
+    // Backing field needed for lazy initialization.
+    private var _matchOrNull: FingerprintMatch? = null
+
+    context(_: BytecodePatchContext)
+    private val matchOrNull: FingerprintMatch?
+        get() = matchOrNull()
+
+    context(context: BytecodePatchContext)
+    internal fun matchOrNull(): FingerprintMatch? {
+        if (_matchOrNull != null) return _matchOrNull
+
+        var match = strings?.mapNotNull {
+            context.classDefs.methodsByString[it]
+        }?.minByOrNull { it.size }?.let { methodClasses ->
+            methodClasses.forEach { method ->
+                val match = matchOrNull(method, context.classDefs[method.definingClass]!!)
+                if (match != null) return@let match
+            }
+
+            null
+        }
+        if (match != null) return match
+        context.classDefs.forEach { classDef ->
+            match = matchOrNull(classDef)
+            if (match != null) return match
+        }
+
+        return null
+    }
+
+    context(_: BytecodePatchContext)
+    fun matchOrNull(
+        classDef: ClassDef,
+    ): FingerprintMatch? {
+        if (_matchOrNull != null) return _matchOrNull
+
+        for (method in classDef.methods) {
+            val match = matchOrNull(method, classDef)
+            if (match != null) return match
+        }
+
+        return null
+    }
+
+    context(context: BytecodePatchContext)
+    fun matchOrNull(
+        method: Method,
+    ) = matchOrNull(method, context.classDefs[method.definingClass]!!)
+
+    context(context: BytecodePatchContext)
+    fun matchOrNull(
+        method: Method,
+        classDef: ClassDef,
+    ): FingerprintMatch? {
+        if (_matchOrNull != null) return _matchOrNull
+
+        if (returnType != null && !method.returnType.startsWith(returnType)) {
+            return null
+        }
+
+        if (accessFlags != null && accessFlags != method.accessFlags) {
+            return null
+        }
+
+        fun parametersEqual(
+            parameters1: Iterable<CharSequence>,
+            parameters2: Iterable<CharSequence>,
+        ): Boolean {
+            if (parameters1.count() != parameters2.count()) return false
+            val iterator1 = parameters1.iterator()
+            parameters2.forEach {
+                if (!it.startsWith(iterator1.next())) return false
+            }
+            return true
+        }
+
+        // TODO: parseParameters()
+        if (parameters != null && !parametersEqual(parameters, method.parameterTypes)) {
+            return null
+        }
+
+        if (custom != null && !custom.invoke(method, classDef)) {
+            return null
+        }
+
+        val stringMatches: List<FingerprintMatch.StringMatch>? =
+            if (strings != null) {
+                buildList {
+                    val instructions = method.instructionsOrNull ?: return null
+
+                    val stringsList = strings.toMutableList()
+
+                    instructions.forEachIndexed { instructionIndex, instruction ->
+                        if (
+                            instruction.opcode != Opcode.CONST_STRING &&
+                            instruction.opcode != Opcode.CONST_STRING_JUMBO
+                        ) {
+                            return@forEachIndexed
+                        }
+
+                        val string = ((instruction as ReferenceInstruction).reference as StringReference).string
+                        val index = stringsList.indexOfFirst(string::contains)
+                        if (index == -1) return@forEachIndexed
+
+                        add(FingerprintMatch.StringMatch(string, instructionIndex))
+                        stringsList.removeAt(index)
+                    }
+
+                    if (stringsList.isNotEmpty()) return null
+                }
+            } else {
+                null
+            }
+
+        val patternMatch = if (opcodes != null) {
+            val instructions = method.instructionsOrNull ?: return null
+
+            fun patternScan(): FingerprintMatch.PatternMatch? {
+                val fingerprintFuzzyPatternScanThreshold = fuzzyPatternScanThreshold
+
+                val instructionLength = instructions.count()
+                val patternLength = opcodes.size
+
+                for (index in 0 until instructionLength) {
+                    var patternIndex = 0
+                    var threshold = fingerprintFuzzyPatternScanThreshold
+
+                    while (index + patternIndex < instructionLength) {
+                        val originalOpcode = instructions.elementAt(index + patternIndex).opcode
+                        val patternOpcode = opcodes.elementAt(patternIndex)
+
+                        if (patternOpcode != null && patternOpcode.ordinal != originalOpcode.ordinal) {
+                            // Reaching maximum threshold (0) means,
+                            // the pattern does not match to the current instructions.
+                            if (threshold-- == 0) break
+                        }
+
+                        if (patternIndex < patternLength - 1) {
+                            // If the entire pattern has not been scanned yet, continue the scan.
+                            patternIndex++
+                            continue
+                        }
+
+                        // The entire pattern has been scanned.
+                        return FingerprintMatch.PatternMatch(
+                            index,
+                            index + patternIndex,
+                        )
+                    }
+                }
+
+                return null
+            }
+
+            patternScan() ?: return null
+        } else {
+            null
+        }
+
+        _matchOrNull = FingerprintMatch(
+            context,
+            classDef,
+            method,
+            patternMatch,
+            stringMatches,
+        )
+
+        return _matchOrNull
+    }
+
+    private val exception get() = PatchException("Failed to match the fingerprint: $this")
+
+    context(_: BytecodePatchContext)
+    private val match
+        get() = matchOrNull ?: throw exception
+
+    context(_: BytecodePatchContext)
+    fun match(
+        classDef: ClassDef,
+    ) = matchOrNull(classDef) ?: throw exception
+
+    context(_: BytecodePatchContext)
+    fun match(
+        method: Method,
+    ) = matchOrNull(method) ?: throw exception
+
+    context(_: BytecodePatchContext)
+    fun match(
+        method: Method,
+        classDef: ClassDef,
+    ) = matchOrNull(method, classDef) ?: throw exception
+
+    context(_: BytecodePatchContext)
+    val originalClassDefOrNull
+        get() = matchOrNull?.originalClassDef
+
+    context(_: BytecodePatchContext)
+    val originalMethodOrNull
+        get() = matchOrNull?.originalMethod
+
+    context(_: BytecodePatchContext)
+    val classDefOrNull
+        get() = matchOrNull?.classDef
+
+    context(_: BytecodePatchContext)
+    val methodOrNull
+        get() = matchOrNull?.method
+
+    context(_: BytecodePatchContext)
+    val patternMatchOrNull
+        get() = matchOrNull?.patternMatch
+
+    context(_: BytecodePatchContext)
+    val stringMatchesOrNull
+        get() = matchOrNull?.stringMatches
+
+    context(_: BytecodePatchContext)
+    val originalClassDef
+        get() = match.originalClassDef
+
+    context(_: BytecodePatchContext)
+    val originalMethod
+        get() = match.originalMethod
+
+    context(_: BytecodePatchContext)
+    val classDef
+        get() = match.classDef
+
+    context(_: BytecodePatchContext)
+    val method
+        get() = match.method
+
+    context(_: BytecodePatchContext)
+    val patternMatch
+        get() = match.patternMatch
+
+    context(_: BytecodePatchContext)
+    val stringMatches
+        get() = match.stringMatches
+}
+
+@Deprecated("Use the matcher API instead.")
+class FingerprintMatch internal constructor(
+    val context: BytecodePatchContext,
+    val originalClassDef: ClassDef,
+    val originalMethod: Method,
+    val patternMatch: PatternMatch?,
+    val stringMatches: List<StringMatch>?,
+) {
+
+    val classDef by lazy {
+        val classDef = context.classDefs[originalClassDef.type]!!
+
+        context.classDefs.getOrReplaceMutable(classDef)
+    }
+
+    val method by lazy { classDef.methods.first { MethodUtil.methodSignaturesMatch(it, originalMethod) } }
+
+    class PatternMatch internal constructor(
+        val startIndex: Int,
+        val endIndex: Int,
+    )
+
+    class StringMatch internal constructor(val string: String, val index: Int)
+}
+
+@Deprecated("Use the matcher API instead.")
+class FingerprintBuilder internal constructor(
+    private val fuzzyPatternScanThreshold: Int = 0,
+) {
+    private var accessFlags: Int? = null
+    private var returnType: String? = null
+    private var parameters: List<String>? = null
+    private var opcodes: List<Opcode?>? = null
+    private var strings: List<String>? = null
+    private var customBlock: ((method: Method, classDef: ClassDef) -> Boolean)? = null
+
+    fun accessFlags(accessFlags: Int) {
+        this.accessFlags = accessFlags
+    }
+
+    fun accessFlags(vararg accessFlags: AccessFlags) {
+        this.accessFlags = accessFlags.fold(0) { acc, it -> acc or it.value }
+    }
+
+    fun returns(returnType: String) {
+        this.returnType = returnType
+    }
+
+    fun parameters(vararg parameters: String) {
+        this.parameters = parameters.toList()
+    }
+
+    fun opcodes(vararg opcodes: Opcode?) {
+        this.opcodes = opcodes.toList()
+    }
+
+    fun opcodes(instructions: String) {
+        this.opcodes = instructions.trimIndent().split("\n").filter {
+            it.isNotBlank()
+        }.map {
+            // Remove any operands.
+            val name = it.split(" ", limit = 1).first().trim()
+            if (name == "null") return@map null
+
+            opcodesByName[name] ?: throw Exception("Unknown opcode: $name")
+        }
+    }
+
+    fun strings(vararg strings: String) {
+        this.strings = strings.toList()
+    }
+
+    fun custom(customBlock: (method: Method, classDef: ClassDef) -> Boolean) {
+        this.customBlock = customBlock
+    }
+
+    internal fun build() = Fingerprint(
+        accessFlags,
+        returnType,
+        parameters,
+        opcodes,
+        strings,
+        customBlock,
+        fuzzyPatternScanThreshold,
+    )
+
+    private companion object {
+        val opcodesByName = Opcode.entries.associateBy { it.name }
+    }
+}
+
+@Deprecated("Use the matcher API instead.")
+fun fingerprint(
+    fuzzyPatternScanThreshold: Int = 0,
+    block: FingerprintBuilder.() -> Unit,
+) = FingerprintBuilder(fuzzyPatternScanThreshold).apply(block).build()

patcher/src/commonMain/kotlin/app/revanced/patcher/Patching.kt

@@ -0,0 +1,152 @@
+package app.revanced.patcher
+
+import app.revanced.patcher.patch.*
+import java.io.File
+import java.io.InputStream
+import java.io.deleteRecursively
+import java.io.resolve
+import java.util.logging.Logger
+
+fun patcher(
+    apkFile: File,
+    temporaryFilesPath: File = File("revanced-patcher-temporary-files"),
+    aaptBinaryPath: File? = null,
+    frameworkFileDirectory: String? = null,
+    getPatches: (packageName: String, versionName: String) -> Set<Patch>,
+): (emit: (PatchResult) -> Unit) -> PatchesResult {
+    val logger = Logger.getLogger("Patcher")
+
+    if (temporaryFilesPath.exists()) {
+        logger.info("Deleting existing temporary files directory")
+
+        if (!temporaryFilesPath.deleteRecursively())
+            logger.severe("Failed to delete existing temporary files directory")
+    }
+
+    val apkFilesPath = temporaryFilesPath.resolve("apk").also { it.mkdirs() }
+    val patchedFilesPath = temporaryFilesPath.resolve("patched").also { it.mkdirs() }
+
+    val resourcePatchContext = ResourcePatchContext(
+        apkFile,
+        apkFilesPath,
+        patchedFilesPath,
+        aaptBinaryPath,
+        frameworkFileDirectory
+    )
+
+    val (packageName, versionName) = resourcePatchContext.decodeManifest()
+    val patches = getPatches(packageName, versionName)
+
+    return { emit: (PatchResult) -> Unit ->
+        if (patches.any { patch -> patch.patchesResources }) resourcePatchContext.decodeResources()
+
+        // After initializing the resource context, to keep memory usage time low.
+        val bytecodePatchContext = BytecodePatchContext(
+            apkFile,
+            patchedFilesPath
+        )
+
+        logger.info("Warming up the cache")
+
+        bytecodePatchContext.classDefs.initializeCache()
+
+        logger.info("Applying patches")
+
+        patches.apply(bytecodePatchContext, resourcePatchContext, emit)
+    }
+}
+
+// Public for testing.
+fun Set<Patch>.apply(
+    bytecodePatchContext: BytecodePatchContext,
+    resourcePatchContext: ResourcePatchContext,
+    emit: (PatchResult) -> Unit
+): PatchesResult {
+    val appliedPatches = LinkedHashMap<Patch, PatchResult>()
+
+    sortedBy { it.name }.forEach { patch ->
+        fun Patch.apply(): PatchResult {
+            val result = appliedPatches[this]
+
+            return if (result == null) {
+                val failedDependency = dependencies.asSequence().map { it.apply() }.firstOrNull { it.exception != null }
+                if (failedDependency != null) return patchResult(
+                    "The dependant patch \"$failedDependency\" of the patch \"$this\" raised an exception:\n" +
+                            failedDependency.exception!!.stackTraceToString(),
+                )
+
+                val exception = runCatching { apply(bytecodePatchContext, resourcePatchContext) }
+                    .exceptionOrNull() as? Exception
+
+                patchResult(exception).also { result -> appliedPatches[this] = result }
+            } else if (result.exception == null) result
+            else patchResult("The patch '$this' has failed previously")
+        }
+
+        val patchResult = patch.apply()
+
+        // If an exception occurred or the patch has no finalize block, emit the result.
+        if (patchResult.exception != null || patch.afterDependents == null) {
+            emit(patchResult)
+        }
+    }
+
+    val succeededPatchesWithFinalizeBlock = appliedPatches.values.filter {
+        it.exception == null && it.patch.afterDependents != null
+    }
+
+    succeededPatchesWithFinalizeBlock.asReversed().forEach { result ->
+        val patch = result.patch
+        runCatching { patch.afterDependents!!.invoke(bytecodePatchContext, resourcePatchContext) }.fold(
+            { emit(result) },
+            {
+                emit(
+                    PatchResult(
+                        patch,
+                        PatchException(
+                            "The patch \"$patch\" raised an exception:\n" + it.stackTraceToString(),
+                            it,
+                        ),
+                    )
+                )
+            }
+        )
+    }
+
+    return PatchesResult(bytecodePatchContext.get(), resourcePatchContext.get())
+}
+
+/**
+ * The result of applying patches.
+ *
+ * @param dexFiles The patched dex files.
+ * @param resources The patched resources.
+ */
+class PatchesResult internal constructor(
+    val dexFiles: Set<PatchedDexFile>,
+    val resources: PatchedResources?,
+) {
+
+    /**
+     * A dex file.
+     *
+     * @param name The original name of the dex file.
+     * @param stream The dex file as [InputStream].
+     */
+    class PatchedDexFile internal constructor(val name: String, val stream: InputStream)
+
+    /**
+     * The resources of a patched apk.
+     *
+     * @param resourcesApk The compiled resources.apk file.
+     * @param otherResources The directory containing other resources files.
+     * @param doNotCompress List of files that should not be compressed.
+     * @param deleteResources List of resources that should be deleted.
+     */
+    class PatchedResources internal constructor(
+        val resourcesApk: File?,
+        val otherResources: File?,
+        val doNotCompress: Set<String>,
+        val deleteResources: Set<String>,
+    )
+}

patcher/src/commonMain/kotlin/app/revanced/patcher/extensions/Instruction.kt

@@ -0,0 +1,115 @@
+package app.revanced.patcher.extensions
+
+import com.android.tools.smali.dexlib2.AccessFlags
+import com.android.tools.smali.dexlib2.Opcodes
+import com.android.tools.smali.dexlib2.builder.BuilderInstruction
+import com.android.tools.smali.dexlib2.iface.instruction.Instruction
+import com.android.tools.smali.dexlib2.iface.instruction.NarrowLiteralInstruction
+import com.android.tools.smali.dexlib2.iface.instruction.ReferenceInstruction
+import com.android.tools.smali.dexlib2.iface.reference.*
+import com.android.tools.smali.dexlib2.writer.builder.DexBuilder
+import com.android.tools.smali.smali.smaliFlexLexer
+import com.android.tools.smali.smali.smaliParser
+import com.android.tools.smali.smali.smaliTreeWalker
+import org.antlr.runtime.CommonTokenStream
+import org.antlr.runtime.TokenSource
+import org.antlr.runtime.tree.CommonTreeNodeStream
+import java.io.StringReader
+
+
+private inline fun <reified T : Reference> Instruction.reference(): T? =
+    (this as? ReferenceInstruction)?.reference as? T
+
+val Instruction.reference: Reference?
+    get() = reference()
+
+val Instruction.methodReference
+    get() = reference<MethodReference>()
+
+val Instruction.fieldReference
+    get() = reference<FieldReference>()
+
+val Instruction.typeReference
+    get() = reference<TypeReference>()
+
+val Instruction.stringReference
+    get() = reference<StringReference>()
+
+/** TODO: This is technically missing for consistency:
+
+private inline fun <reified T : Reference> Instruction.reference2(): T? =
+(this as? DualReferenceInstruction)?.reference2 as? T
+
+val Instruction.reference2: Reference?
+get() = reference2()
+
+val Instruction.methodReference2
+get() = reference2<MethodReference>()
+
+val Instruction.fieldReference2
+get() = reference2<FieldReference>()
+
+val Instruction.typeReference2
+get() = reference2<TypeReference>()
+
+val Instruction.stringReference2
+get() = reference2<StringReference>()
+ **/
+
+val Instruction.type
+    get() = typeReference?.type
+
+val Instruction.string
+    get() = stringReference?.string
+val Instruction.wideLiteral
+    get() = (this as? NarrowLiteralInstruction)?.wideLiteral
+
+
+private const val CLASS_HEADER = ".class LInlineCompiler;\n.super Ljava/lang/Object;\n"
+private const val STATIC_HEADER = "$CLASS_HEADER.method public static dummyMethod("
+private const val HEADER = "$CLASS_HEADER.method public dummyMethod("
+private val sb by lazy { StringBuilder(512) }
+
+/**
+ * Compile lines of Smali code to a list of instructions.
+ *
+ * Note: Adding compiled instructions to an existing method with
+ * offset instructions WITHOUT specifying a parent method will not work.
+ * @param templateMethod The method to compile the instructions against.
+ * @returns A list of instructions.
+ */
+fun String.toInstructions(templateMethod: com.android.tools.smali.dexlib2.mutable.MutableMethod? = null): List<BuilderInstruction> {
+    val parameters = templateMethod?.parameterTypes?.joinToString("") { it } ?: ""
+    val registers = templateMethod?.implementation?.registerCount ?: 1 // TODO: Should this be 0?
+    val isStatic = templateMethod?.let { AccessFlags.STATIC.isSet(it.accessFlags) } ?: true
+
+    sb.setLength(0) // reset
+
+    if (isStatic) sb.append(STATIC_HEADER) else sb.append(HEADER)
+    sb.append(parameters).append(")V\n")
+    sb.append("    .registers ").append(registers).append("\n")
+    sb.append(trimIndent()).append("\n")
+    sb.append(".end method")
+
+    val reader = StringReader(sb.toString())
+    val lexer = smaliFlexLexer(reader, 15)
+    val tokens = CommonTokenStream(lexer as TokenSource)
+    val parser = smaliParser(tokens)
+    val fileTree = parser.smali_file()
+
+    if (lexer.numberOfSyntaxErrors > 0 || parser.numberOfSyntaxErrors > 0) {
+        throw IllegalStateException(
+            "Lexer errors: ${lexer.numberOfSyntaxErrors}, Parser errors: ${parser.numberOfSyntaxErrors}"
+        )
+    }
+
+    val treeStream = CommonTreeNodeStream(fileTree.tree).apply {
+        tokenStream = tokens
+    }
+
+    val walker = smaliTreeWalker(treeStream)
+    walker.setDexBuilder(DexBuilder(Opcodes.getDefault()))
+
+    val classDef = walker.smali_file()
+    return classDef.methods.first().instructions.map { it as BuilderInstruction }
+}

patcher/src/commonMain/kotlin/app/revanced/patcher/extensions/Method.kt

@@ -0,0 +1,446 @@
+package app.revanced.patcher.extensions
+
+import com.android.tools.smali.dexlib2.AccessFlags
+import com.android.tools.smali.dexlib2.builder.BuilderInstruction
+import com.android.tools.smali.dexlib2.builder.BuilderOffsetInstruction
+import com.android.tools.smali.dexlib2.builder.Label
+import com.android.tools.smali.dexlib2.builder.MutableMethodImplementation
+import com.android.tools.smali.dexlib2.builder.instruction.*
+import com.android.tools.smali.dexlib2.iface.Method
+import com.android.tools.smali.dexlib2.iface.MethodImplementation
+import com.android.tools.smali.dexlib2.iface.instruction.Instruction
+import com.android.tools.smali.dexlib2.mutable.MutableMethod
+
+fun Method.accessFlags(vararg flags: AccessFlags) =
+    accessFlags.and(flags.map { it.ordinal }.reduce { acc, i -> acc or i }) != 0
+
+/**
+ * Add instructions to a method at the given index.
+ *
+ * @param index The index to add the instructions at.
+ * @param instructions The instructions to add.
+ */
+fun MutableMethodImplementation.addInstructions(
+    index: Int,
+    instructions: List<BuilderInstruction>,
+) = instructions.asReversed().forEach { addInstruction(index, it) }
+
+/**
+ * Add instructions to a method.
+ * The instructions will be added at the end of the method.
+ *
+ * @param instructions The instructions to add.
+ */
+fun MutableMethodImplementation.addInstructions(instructions: List<BuilderInstruction>) =
+    instructions.forEach { addInstruction(it) }
+
+/**
+ * Remove instructions from a method at the given index.
+ *
+ * @param index The index to remove the instructions at.
+ * @param count The amount of instructions to remove.
+ */
+fun MutableMethodImplementation.removeInstructions(
+    index: Int,
+    count: Int,
+) = repeat(count) {
+    removeInstruction(index)
+}
+
+/**
+ * Remove the first instructions from a method.
+ *
+ * @param count The amount of instructions to remove.
+ */
+fun MutableMethodImplementation.removeInstructions(count: Int) = removeInstructions(0, count)
+
+/**
+ * Replace instructions at the given index with the given instructions.
+ * The amount of instructions to replace is the amount of instructions in the given list.
+ *
+ * @param index The index to replace the instructions at.
+ * @param instructions The instructions to replace the instructions with.
+ */
+fun MutableMethodImplementation.replaceInstructions(
+    index: Int,
+    instructions: List<BuilderInstruction>,
+) = instructions.forEachIndexed { i, instruction -> replaceInstruction(index + i, instruction) }
+
+/**
+ * Add an instruction to a method at the given index.
+ *
+ * @param index The index to add the instruction at.
+ * @param instruction The instruction to add.
+ */
+fun MutableMethod.addInstruction(
+    index: Int,
+    instruction: BuilderInstruction,
+) = implementation!!.addInstruction(index, instruction)
+
+/**
+ * Add an instruction to a method.
+ *
+ * @param instruction The instructions to add.
+ */
+fun MutableMethod.addInstruction(instruction: BuilderInstruction) = implementation!!.addInstruction(instruction)
+
+/**
+ * Add an instruction to a method at the given index.
+ *
+ * @param index The index to add the instruction at.
+ * @param smaliInstructions The instruction to add.
+ */
+fun MutableMethod.addInstruction(
+    index: Int,
+    smaliInstructions: String,
+) = implementation!!.addInstruction(index, smaliInstructions.toInstructions(this).first())
+
+/**
+ * Add an instruction to a method.
+ *
+ * @param smaliInstructions The instruction to add.
+ */
+fun MutableMethod.addInstruction(smaliInstructions: String) =
+    implementation!!.addInstruction(smaliInstructions.toInstructions(this).first())
+
+/**
+ * Add instructions to a method at the given index.
+ *
+ * @param index The index to add the instructions at.
+ * @param instructions The instructions to add.
+ */
+fun MutableMethod.addInstructions(
+    index: Int,
+    instructions: List<BuilderInstruction>,
+) = implementation!!.addInstructions(index, instructions)
+
+/**
+ * Add instructions to a method.
+ *
+ * @param instructions The instructions to add.
+ */
+fun MutableMethod.addInstructions(instructions: List<BuilderInstruction>) =
+    implementation!!.addInstructions(instructions)
+
+/**
+ * Add instructions to a method.
+ *
+ * @param smaliInstructions The instructions to add.
+ */
+fun MutableMethod.addInstructions(
+    index: Int,
+    smaliInstructions: String,
+) = implementation!!.addInstructions(index, smaliInstructions.toInstructions(this))
+
+/**
+ * Add instructions to a method.
+ *
+ * @param smaliInstructions The instructions to add.
+ */
+fun MutableMethod.addInstructions(smaliInstructions: String) =
+    implementation!!.addInstructions(smaliInstructions.toInstructions(this))
+
+/**
+ * Add instructions to a method at the given index.
+ *
+ * @param index The index to add the instructions at.
+ * @param smaliInstructions The instructions to add.
+ * @param externalLabels A list of [ExternalLabel] for instructions outside of [smaliInstructions].
+ */
+// Special function for adding instructions with external labels.
+fun MutableMethod.addInstructionsWithLabels(
+    index: Int,
+    smaliInstructions: String,
+    vararg externalLabels: ExternalLabel,
+) {
+    // Create reference dummy instructions for the instructions.
+    val nopSmali =
+        StringBuilder(smaliInstructions).also { builder ->
+            externalLabels.forEach { (name, _) ->
+                builder.append("\n:$name\nnop")
+            }
+        }.toString()
+
+    // Compile the instructions with the dummy labels
+    val compiledInstructions = nopSmali.toInstructions(this)
+
+    // Add the compiled list of instructions to the method.
+    addInstructions(
+        index,
+        compiledInstructions.subList(0, compiledInstructions.size - externalLabels.size),
+    )
+
+    implementation!!.apply {
+        this@apply.instructions.subList(index, index + compiledInstructions.size - externalLabels.size)
+            .forEachIndexed { compiledInstructionIndex, compiledInstruction ->
+                // If the compiled instruction is not an offset instruction, skip it.
+                if (compiledInstruction !is BuilderOffsetInstruction) return@forEachIndexed
+
+                /**
+                 * Create a new label for the instruction
+                 * and replace it with the label of the [compiledInstruction] at [compiledInstructionIndex].
+                 */
+                fun Instruction.makeNewLabel() {
+                    fun replaceOffset(
+                        i: BuilderOffsetInstruction,
+                        label: Label,
+                    ): BuilderOffsetInstruction {
+                        return when (i) {
+                            is BuilderInstruction10t -> BuilderInstruction10t(i.opcode, label)
+                            is BuilderInstruction20t -> BuilderInstruction20t(i.opcode, label)
+                            is BuilderInstruction21t -> BuilderInstruction21t(i.opcode, i.registerA, label)
+                            is BuilderInstruction22t ->
+                                BuilderInstruction22t(
+                                    i.opcode,
+                                    i.registerA,
+                                    i.registerB,
+                                    label,
+                                )
+
+                            is BuilderInstruction30t -> BuilderInstruction30t(i.opcode, label)
+                            is BuilderInstruction31t -> BuilderInstruction31t(i.opcode, i.registerA, label)
+                            else -> throw IllegalStateException(
+                                "A non-offset instruction was given, this should never happen!",
+                            )
+                        }
+                    }
+
+                    // Create the final label.
+                    val label = newLabelForIndex(this@apply.instructions.indexOf(this))
+
+                    // Create the final instruction with the new label.
+                    val newInstruction =
+                        replaceOffset(
+                            compiledInstruction,
+                            label,
+                        )
+
+                    // Replace the instruction pointing to the dummy label
+                    // with the new instruction pointing to the real instruction.
+                    replaceInstruction(index + compiledInstructionIndex, newInstruction)
+                }
+
+                // If the compiled instruction targets its own instruction,
+                // which means it points to some of its own, simply an offset has to be applied.
+                val labelIndex = compiledInstruction.target.location.index
+                if (labelIndex < compiledInstructions.size - externalLabels.size) {
+                    // Get the targets index (insertion index + the index of the dummy instruction).
+                    this.instructions[index + labelIndex].makeNewLabel()
+                    return@forEachIndexed
+                }
+
+                // Since the compiled instruction points to a dummy instruction,
+                // we can find the real instruction which it was created for by calculation.
+
+                // Get the index of the instruction in the externalLabels list
+                // which the dummy instruction was created for.
+                // This works because we created the dummy instructions in the same order as the externalLabels list.
+                val (_, instruction) = externalLabels[(compiledInstructions.size - 1) - labelIndex]
+                instruction.makeNewLabel()
+            }
+    }
+}
+
+/**
+ * Remove an instruction at the given index.
+ *
+ * @param index The index to remove the instruction at.
+ */
+fun MutableMethod.removeInstruction(index: Int) = implementation!!.removeInstruction(index)
+
+/**
+ * Remove instructions at the given index.
+ *
+ * @param index The index to remove the instructions at.
+ * @param count The amount of instructions to remove.
+ */
+fun MutableMethod.removeInstructions(
+    index: Int,
+    count: Int,
+) = implementation!!.removeInstructions(index, count)
+
+/**
+ * Remove instructions at the given index.
+ *
+ * @param count The amount of instructions to remove.
+ */
+fun MutableMethod.removeInstructions(count: Int) = implementation!!.removeInstructions(count)
+
+/**
+ * Replace an instruction at the given index.
+ *
+ * @param index The index to replace the instruction at.
+ * @param instruction The instruction to replace the instruction with.
+ */
+fun MutableMethod.replaceInstruction(
+    index: Int,
+    instruction: BuilderInstruction,
+) = implementation!!.replaceInstruction(index, instruction)
+
+/**
+ * Replace an instruction at the given index.
+ *
+ * @param index The index to replace the instruction at.
+ * @param smaliInstruction The smali instruction to replace the instruction with.
+ */
+fun MutableMethod.replaceInstruction(
+    index: Int,
+    smaliInstruction: String,
+) = implementation!!.replaceInstruction(index, smaliInstruction.toInstructions(this).first())
+
+/**
+ * Replace instructions at the given index.
+ *
+ * @param index The index to replace the instructions at.
+ * @param instructions The instructions to replace the instructions with.
+ */
+fun MutableMethod.replaceInstructions(
+    index: Int,
+    instructions: List<BuilderInstruction>,
+) = implementation!!.replaceInstructions(index, instructions)
+
+/**
+ * Replace instructions at the given index.
+ *
+ * @param index The index to replace the instructions at.
+ * @param smaliInstructions The smali instructions to replace the instructions with.
+ */
+fun MutableMethod.replaceInstructions(
+    index: Int,
+    smaliInstructions: String,
+) = implementation!!.replaceInstructions(index, smaliInstructions.toInstructions(this))
+
+/**
+ * Get an instruction at the given index.
+ *
+ * @param index The index to get the instruction at.
+ * @return The instruction.
+ */
+fun MethodImplementation.getInstruction(index: Int) = instructions.elementAt(index)
+
+/**
+ * Get an instruction at the given index.
+ *
+ * @param index The index to get the instruction at.
+ * @param T The type of instruction to return.
+ * @return The instruction.
+ */
+@Suppress("UNCHECKED_CAST")
+fun <T> MethodImplementation.getInstruction(index: Int): T = getInstruction(index) as T
+
+/**
+ * Get an instruction at the given index.
+ *
+ * @param index The index to get the instruction at.
+ * @return The instruction.
+ */
+fun MutableMethodImplementation.getInstruction(index: Int): BuilderInstruction = instructions[index]
+
+/**
+ * Get an instruction at the given index.
+ *
+ * @param index The index to get the instruction at.
+ * @param T The type of instruction to return.
+ * @return The instruction.
+ */
+@Suppress("UNCHECKED_CAST")
+fun <T> MutableMethodImplementation.getInstruction(index: Int): T = getInstruction(index) as T
+
+/**
+ * Get an instruction at the given index.
+ * @param index The index to get the instruction at.
+ * @return The instruction or null if the method has no implementation.
+ */
+fun Method.getInstructionOrNull(index: Int): Instruction? = implementation?.getInstruction(index)
+
+/**
+ * Get an instruction at the given index.
+ * @param index The index to get the instruction at.
+ * @return The instruction.
+ */
+fun Method.getInstruction(index: Int): Instruction = getInstructionOrNull(index)!!
+
+/**
+ * Get an instruction at the given index.
+ * @param index The index to get the instruction at.
+ * @param T The type of instruction to return.
+ * @return The instruction or null if the method has no implementation.
+ */
+fun <T> Method.getInstructionOrNull(index: Int): T? = implementation?.getInstruction<T>(index)
+
+/**
+ * Get an instruction at the given index.
+ * @param index The index to get the instruction at.
+ * @param T The type of instruction to return.
+ * @return The instruction.
+ */
+fun <T> Method.getInstruction(index: Int): T = getInstructionOrNull<T>(index)!!
+
+/**
+ * Get an instruction at the given index.
+ * @param index The index to get the instruction at.
+ * @return The instruction or null if the method has no implementation.
+ */
+fun MutableMethod.getInstructionOrNull(index: Int): BuilderInstruction? = implementation?.getInstruction(index)
+
+/**
+ * Get an instruction at the given index.
+ * @param index The index to get the instruction at.
+ * @return The instruction.
+ */
+fun MutableMethod.getInstruction(index: Int): BuilderInstruction = getInstructionOrNull(index)!!
+
+/**
+ * Get an instruction at the given index.
+ * @param index The index to get the instruction at.
+ * @param T The type of instruction to return.
+ * @return The instruction or null if the method has no implementation.
+ */
+fun <T> MutableMethod.getInstructionOrNull(index: Int): T? = implementation?.getInstruction<T>(index)
+
+/**
+ * Get an instruction at the given index.
+ * @param index The index to get the instruction at.
+ * @param T The type of instruction to return.
+ * @return The instruction.
+ */
+fun <T> MutableMethod.getInstruction(index: Int): T = getInstructionOrNull<T>(index)!!
+
+/**
+ * The instructions of a method.
+ * @return The instructions or null if the method has no implementation.
+ */
+val Method.instructionsOrNull: Iterable<Instruction>? get() = implementation?.instructions
+
+/**
+ * The instructions of a method.
+ * @return The instructions.
+ */
+val Method.instructions: Iterable<Instruction> get() = instructionsOrNull!!
+
+/**
+ * The instructions of a method.
+ * @return The instructions or null if the method has no implementation.
+ */
+val MutableMethod.instructionsOrNull: MutableList<BuilderInstruction>? get() = implementation?.instructions
+
+/**
+ * The instructions of a method.
+ * @return The instructions.
+ */
+val MutableMethod.instructions: MutableList<BuilderInstruction> get() = instructionsOrNull!!
+
+/**
+ * Create a label for the instruction at given index.
+ *
+ * @param index The index to create the label for the instruction at.
+ * @return The label.
+ */
+fun MutableMethod.newLabel(index: Int) = implementation!!.newLabelForIndex(index)
+
+/**
+ * A class that represents a label for an instruction.
+ * @param name The label name.
+ * @param instruction The instruction that this label is for.
+ */
+data class ExternalLabel(internal val name: String, internal val instruction: Instruction)

patcher/src/commonMain/kotlin/app/revanced/patcher/patch/BytecodePatchContext.kt

@@ -0,0 +1,264 @@
+package app.revanced.patcher.patch
+
+import app.revanced.patcher.PatchesResult
+import app.revanced.patcher.extensions.instructionsOrNull
+import app.revanced.patcher.extensions.string
+import app.revanced.patcher.util.ClassMerger.merge
+import app.revanced.patcher.util.MethodNavigator
+import com.android.tools.smali.dexlib2.iface.ClassDef
+import com.android.tools.smali.dexlib2.iface.DexFile
+import com.android.tools.smali.dexlib2.iface.Method
+import com.android.tools.smali.dexlib2.iface.reference.MethodReference
+import com.android.tools.smali.dexlib2.mutable.MutableClassDef
+import com.android.tools.smali.dexlib2.mutable.MutableClassDef.Companion.toMutable
+import lanchon.multidexlib2.BasicDexFileNamer
+import lanchon.multidexlib2.DexIO
+import lanchon.multidexlib2.MultiDexIO
+import lanchon.multidexlib2.RawDexIO
+import java.io.*
+import java.util.logging.Logger
+import kotlin.reflect.jvm.jvmName
+
+/**
+ * A context for patches containing the current state of the bytecode.
+ *
+ * @param apkFile The apk [File] to patch.
+ * @param patchedFilesPath The path to the temporary apk files directory.
+ */
+@Suppress("MemberVisibilityCanBePrivate")
+class BytecodePatchContext internal constructor(
+    internal val apkFile: File,
+    internal val patchedFilesPath: File,
+) : PatchContext<Set<PatchesResult.PatchedDexFile>> {
+    private val logger = Logger.getLogger(this::class.jvmName)
+
+    inner class ClassDefs private constructor(
+        dexFile: DexFile,
+        private val classDefs: MutableSet<ClassDef> = dexFile.classes.toMutableSet()
+    ) :
+        MutableSet<ClassDef> by classDefs {
+        private val byType = mutableMapOf<String, ClassDef>()
+
+        operator fun get(name: String): ClassDef? = byType[name]
+
+        // Better performance according to
+        // https://github.com/LisoUseInAIKyrios/revanced-patcher/commit/9b6d95d4f414a35ed68da37b0ecd8549df1ef63a
+        private val _methodsByStrings =
+            LinkedHashMap<String, MutableSet<Method>>(2 * size, 0.5f)
+
+        val methodsByString: Map<String, Set<Method>> = _methodsByStrings
+
+        // Can have a use-case in the future:
+        // private val _methodsWithString = methodsByString.values.flatten().toMutableSet()
+        // val methodsWithString: Set<Method> = _methodsWithString
+
+        constructor() : this(
+            MultiDexIO.readDexFile(
+                true,
+                apkFile,
+                BasicDexFileNamer(),
+                null,
+                null
+            )
+        )
+
+        internal val opcodes = dexFile.opcodes
+
+        override fun add(element: ClassDef): Boolean {
+            val added = classDefs.add(element)
+            if (added) addCache(element)
+
+            return added
+        }
+
+        override fun addAll(elements: Collection<ClassDef>): Boolean {
+            var anyAdded = false
+            elements.forEach { element ->
+                val added = classDefs.add(element)
+                if (added) {
+                    addCache(element)
+                    anyAdded = true
+                }
+            }
+
+            return anyAdded
+        }
+
+        // TODO: There is one default method "removeIf" in MutableSet, which we cannot override in the common module.
+        //  The method must be overloaded with a NotImplementedException to avoid cache desynchronization.
+
+        override fun clear() {
+            classDefs.clear()
+            byType.clear()
+            _methodsByStrings.clear()
+        }
+
+        override fun remove(element: ClassDef): Boolean {
+            val removed = classDefs.remove(element)
+            if (removed) removeCache(element)
+
+            return removed
+        }
+
+        override fun removeAll(elements: Collection<ClassDef>): Boolean {
+            var anyRemoved = false
+            elements.forEach { element ->
+                val removed = classDefs.remove(element)
+                if (removed) {
+                    removeCache(element)
+                    anyRemoved = true
+                }
+            }
+
+            return anyRemoved
+        }
+
+        override fun retainAll(elements: Collection<ClassDef>) =
+            removeAll(classDefs.asSequence().filter { it !in elements })
+
+        private fun addCache(classDef: ClassDef) {
+            byType[classDef.type] = classDef
+
+            classDef.forEachString { method, string ->
+                _methodsByStrings.getOrPut(string) {
+                    // Maybe adjusting load factor/ initial size can improve performance.
+                    mutableSetOf()
+                } += method
+            }
+        }
+
+        private fun removeCache(classDef: ClassDef) {
+            byType -= classDef.type
+
+            classDef.forEachString { method, string ->
+                if (_methodsByStrings[string]?.also { it -= method }?.isEmpty() == true)
+                    _methodsByStrings -= string
+            }
+        }
+
+
+        private fun ClassDef.forEachString(action: (Method, String) -> Unit) {
+            methods.asSequence().forEach { method ->
+                method.instructionsOrNull?.asSequence()
+                    ?.mapNotNull { it.string }
+                    ?.forEach { string -> action(method, string) }
+            }
+        }
+
+        /**
+         * Get a mutable version of the given [classDef], replacing it in the set if necessary.
+         *
+         * @param classDef The [ClassDef] to get or replace.
+         * @return The mutable version of the [classDef].
+         * @see MutableClassDef
+         * @see toMutable
+         */
+        fun getOrReplaceMutable(classDef: ClassDef): MutableClassDef {
+            if (classDef !is MutableClassDef) {
+                val mutableClassDef = classDef.toMutable()
+                this -= classDef
+                this += mutableClassDef
+
+                return mutableClassDef
+            }
+
+            return classDef
+        }
+
+        internal fun initializeCache() = classDefs.forEach(::addCache)
+
+        internal fun clearCache() {
+            byType.clear()
+            _methodsByStrings.clear()
+        }
+    }
+
+    /**
+     * The list of classes.
+     */
+    val classDefs = ClassDefs()
+
+    /**
+     * Extend this [BytecodePatchContext] with [extensionInputStream].
+     *
+     * @param extensionInputStream The input stream for an extension dex file.
+     */
+    internal fun extendWith(extensionInputStream: InputStream) {
+        RawDexIO.readRawDexFile(
+            extensionInputStream, 0, null
+        ).classes.forEach { classDef ->
+            val existingClass = classDefs[classDef.type] ?: run {
+                logger.fine { "Adding class \"$classDef\"" }
+
+                classDefs += classDef
+
+                return@forEach
+            }
+
+            logger.fine { "Class \"$classDef\" exists already. Adding missing methods and fields." }
+
+            existingClass.merge(classDef, this@BytecodePatchContext).let { mergedClass ->
+                // If the class was merged, replace the original class with the merged class.
+                if (mergedClass === existingClass) {
+                    return@let
+                }
+
+                classDefs -= existingClass
+                classDefs += mergedClass
+            }
+        }
+
+        extensionInputStream.close()
+    }
+
+    /**
+     * Navigate a method.
+     *
+     * @param method The method to navigate.
+     *
+     * @return A [MethodNavigator] for the method.
+     */
+    fun navigate(method: MethodReference) = MethodNavigator(method)
+
+    /**
+     * Compile bytecode from the [BytecodePatchContext].
+     *
+     * @return The compiled bytecode.
+     */
+    override fun get(): Set<PatchesResult.PatchedDexFile> {
+        logger.info("Compiling patched dex files")
+
+        classDefs.clearCache()
+        System.gc()
+
+        val patchedDexFileResults =
+            patchedFilesPath.resolve("dex").also {
+                it.deleteRecursively() // Make sure the directory is empty.
+                it.mkdirs()
+            }.apply {
+                MultiDexIO.writeDexFile(
+                    true,
+                    -1,
+                    this,
+                    BasicDexFileNamer(),
+                    object : DexFile {
+                        override fun getClasses() = classDefs.let {
+                            // More performant according to
+                            // https://github.com/LisoUseInAIKyrios/revanced-patcher/
+                            // commit/8c26ad08457fb1565ea5794b7930da42a1c81cf1
+                            // #diff-be698366d9868784ecf7da3fd4ac9d2b335b0bb637f9f618fbe067dbd6830b8fR197
+                            // TODO: Benchmark, if actually faster.
+                            HashSet<ClassDef>(it.size * 3 / 2).apply { addAll(it) }
+                        }
+
+                        override fun getOpcodes() = classDefs.opcodes
+                    },
+                    DexIO.DEFAULT_MAX_DEX_POOL_SIZE,
+                ) { _, entryName, _ -> logger.info { "Compiled $entryName" } }
+            }.listFiles { it.isFile }!!.map {
+                PatchesResult.PatchedDexFile(it.name, it.inputStream())
+            }.toSet()
+
+        return patchedDexFileResults
+    }
+}

patcher/src/commonMain/kotlin/app/revanced/patcher/patch/Option.kt

@@ -0,0 +1,816 @@
+@file:Suppress("unused")
+
+package app.revanced.patcher.patch
+
+import kotlin.reflect.KProperty
+import kotlin.reflect.KType
+import kotlin.reflect.jvm.jvmName
+import kotlin.reflect.typeOf
+
+/**
+ * An option.
+ *
+ * @param T The value type of the option.
+ * @param name The name.
+ * @param default The default value.
+ * @param values Eligible option values mapped to a human-readable name.
+ * @param description A description.
+ * @param required Whether the option is required.
+ * @param type The type of the option value (to handle type erasure).
+ * @param validator The function to validate the option value.
+ *
+ * @constructor Create a new [Option].
+ */
+@Suppress("MemberVisibilityCanBePrivate", "unused")
+class Option<T>
+@PublishedApi
+internal constructor(
+    val name: String,
+    val default: T? = null,
+    val values: Map<String, T?>? = null,
+    val description: String? = null,
+    val required: Boolean = false,
+    val type: KType,
+    val validator: Option<T>.(T?) -> Boolean = { true },
+) {
+    /**
+     * The value of the [Option].
+     */
+    var value: T?
+        /**
+         * Set the value of the [Option].
+         *
+         * @param value The value to set.
+         *
+         * @throws OptionException.ValueRequiredException If the value is required but null.
+         * @throws OptionException.ValueValidationException If the value is invalid.
+         */
+        set(value) {
+            assertRequiredButNotNull(value)
+            assertValid(value)
+
+            uncheckedValue = value
+        }
+        /**
+         * Get the value of the [Option].
+         *
+         * @return The value.
+         *
+         * @throws OptionException.ValueRequiredException If the value is required but null.
+         * @throws OptionException.ValueValidationException If the value is invalid.
+         */
+        get() {
+            assertRequiredButNotNull(uncheckedValue)
+            assertValid(uncheckedValue)
+
+            return uncheckedValue
+        }
+
+    // The unchecked value is used to allow setting the value without validation.
+    private var uncheckedValue = default
+
+    /**
+     * Reset the [Option] to its default value.
+     * Override this method if you need to mutate the value instead of replacing it.
+     */
+    fun reset() {
+        uncheckedValue = default
+    }
+
+    private fun assertRequiredButNotNull(value: T?) {
+        if (required && value == null) throw OptionException.ValueRequiredException(this)
+    }
+
+    private fun assertValid(value: T?) {
+        if (!validator(value)) throw OptionException.ValueValidationException(value, this)
+    }
+
+    override fun toString() = value.toString()
+
+    operator fun getValue(
+        thisRef: Any?,
+        property: KProperty<*>,
+    ) = value
+
+    operator fun setValue(
+        thisRef: Any?,
+        property: KProperty<*>,
+        value: T?,
+    ) {
+        this.value = value
+    }
+}
+
+/**
+ * A collection of [Option]s where options can be set and retrieved by their key.
+ *
+ * @param options The options.
+ *
+ * @constructor Create a new [Options].
+ */
+class Options internal constructor(
+    private val options: Map<String, Option<*>>,
+) : Map<String, Option<*>> by options {
+    internal constructor(options: Set<Option<*>>) : this(options.associateBy { it.name })
+
+    /**
+     * Set an option's value.
+     *
+     * @param name The name.
+     * @param value The value.
+     *
+     * @throws OptionException.OptionNotFoundException If the option does not exist.
+     */
+    operator fun <T : Any> set(name: String, value: T?) {
+        val option = this[name]
+
+        try {
+            @Suppress("UNCHECKED_CAST")
+            (option as Option<T>).value = value
+        } catch (e: ClassCastException) {
+            throw OptionException.InvalidValueTypeException(
+                value?.let { it::class.jvmName } ?: "null",
+                option.value?.let { it::class.jvmName } ?: "null",
+            )
+        }
+    }
+
+    /**
+     * Get an option.
+     *
+     * @param key The name.
+     *
+     * @return The option.
+     */
+    override fun get(key: String) = options[key] ?: throw OptionException.OptionNotFoundException(key)
+}
+
+/**
+ * Create a new [Option] with a string value.
+ *
+ * @param name The name.
+ * @param default The default value.
+ * @param values Eligible option values mapped to a human-readable name.
+ * @param description A description.
+ * @param required Whether the option is required.
+ * @param validator The function to validate the option value.
+ *
+ * @return The created [Option].
+ *
+ * @see Option
+ */
+fun stringOption(
+    name: String,
+    default: String? = null,
+    values: Map<String, String?>? = null,
+    description: String? = null,
+    required: Boolean = false,
+    validator: Option<String>.(String?) -> Boolean = { true },
+) = option(
+    name,
+    default,
+    values,
+    description,
+    required,
+    validator,
+)
+
+/**
+ * Create a new [Option] with a string value and add it to the current [PatchBuilder].
+ *
+ * @param name The name.
+ * @param default The default value.
+ * @param values Eligible option values mapped to a human-readable name.
+ * @param description A description.
+ * @param required Whether the option is required.
+ * @param validator The function to validate the option value.
+ *
+ * @return The created [Option].
+ *
+ * @see Option
+ */
+fun PatchBuilder<*>.stringOption(
+    name: String,
+    default: String? = null,
+    values: Map<String, String?>? = null,
+    description: String? = null,
+    required: Boolean = false,
+    validator: Option<String>.(String?) -> Boolean = { true },
+) = option(
+    name,
+    default,
+    values,
+    description,
+    required,
+    validator,
+)
+
+/**
+ * Create a new [Option] with an integer value.
+ *
+ * @param name The name.
+ * @param default The default value.
+ * @param values Eligible option values mapped to a human-readable name.
+ * @param description A description.
+ * @param required Whether the option is required.
+ * @param validator The function to validate the option value.
+ *
+ * @return The created [Option].
+ *
+ * @see Option
+ */
+fun intOption(
+    name: String,
+    default: Int? = null,
+    values: Map<String, Int?>? = null,
+    description: String? = null,
+    required: Boolean = false,
+    validator: Option<Int>.(Int?) -> Boolean = { true },
+) = option(
+    name,
+    default,
+    values,
+    description,
+    required,
+    validator,
+)
+
+/**
+ * Create a new [Option] with an integer value and add it to the current [PatchBuilder].
+ *
+ * @param name The name.
+ * @param default The default value.
+ * @param values Eligible option values mapped to a human-readable name.
+ * @param description A description.
+ * @param required Whether the option is required.
+ * @param validator The function to validate the option value.
+ *
+ * @return The created [Option].
+ *
+ * @see Option
+ */
+fun PatchBuilder<*>.intOption(
+    name: String,
+    default: Int? = null,
+    values: Map<String, Int?>? = null,
+    description: String? = null,
+    required: Boolean = false,
+    validator: Option<Int>.(Int?) -> Boolean = { true },
+) = option(
+    name,
+    default,
+    values,
+    description,
+    required,
+    validator,
+)
+
+/**
+ * Create a new [Option] with a boolean value.
+ *
+ * @param name The name.
+ * @param default The default value.
+ * @param values Eligible option values mapped to a human-readable name.
+ * @param description A description.
+ * @param required Whether the option is required.
+ * @param validator The function to validate the option value.
+ *
+ * @return The created [Option].
+ *
+ * @see Option
+ */
+fun booleanOption(
+    name: String,
+    default: Boolean? = null,
+    values: Map<String, Boolean?>? = null,
+    description: String? = null,
+    required: Boolean = false,
+    validator: Option<Boolean>.(Boolean?) -> Boolean = { true },
+) = option(
+    name,
+    default,
+    values,
+    description,
+    required,
+    validator,
+)
+
+/**
+ * Create a new [Option] with a boolean value and add it to the current [PatchBuilder].
+ *
+ * @param name The name.
+ * @param default The default value.
+ * @param values Eligible option values mapped to a human-readable name.
+ * @param description A description.
+ * @param required Whether the option is required.
+ * @param validator The function to validate the option value.
+ *
+ * @return The created [Option].
+ *
+ * @see Option
+ */
+fun PatchBuilder<*>.booleanOption(
+    name: String,
+    default: Boolean? = null,
+    values: Map<String, Boolean?>? = null,
+    description: String? = null,
+    required: Boolean = false,
+    validator: Option<Boolean>.(Boolean?) -> Boolean = { true },
+) = option(
+    name,
+    default,
+    values,
+    description,
+    required,
+    validator,
+)
+
+/**
+ * Create a new [Option] with a float value.
+ *
+ * @param name The name.
+ * @param default The default value.
+ * @param values Eligible option values mapped to a human-readable name.
+ * @param description A description.
+ * @param required Whether the option is required.
+ * @param validator The function to validate the option value.
+ *
+ * @return The created [Option].
+ *
+ * @see Option
+ */
+fun floatOption(
+    name: String,
+    default: Float? = null,
+    values: Map<String, Float?>? = null,
+    description: String? = null,
+    required: Boolean = false,
+    validator: Option<Float>.(Float?) -> Boolean = { true },
+) = option(
+    name,
+    default,
+    values,
+    description,
+    required,
+    validator,
+)
+
+/**
+ * Create a new [Option] with a float value and add it to the current [PatchBuilder].
+ *
+ * @param name The name.
+ * @param default The default value.
+ * @param values Eligible option values mapped to a human-readable name.
+ * @param description A description.
+ * @param required Whether the option is required.
+ * @param validator The function to validate the option value.
+ *
+ * @return The created [Option].
+ *
+ * @see Option
+ */
+fun PatchBuilder<*>.floatOption(
+    name: String,
+    default: Float? = null,
+    values: Map<String, Float?>? = null,
+    description: String? = null,
+    required: Boolean = false,
+    validator: Option<Float>.(Float?) -> Boolean = { true },
+) = option(
+    name,
+    default,
+    values,
+    description,
+    required,
+    validator,
+)
+
+/**
+ * Create a new [Option] with a long value.
+ *
+ * @param name The name.
+ * @param default The default value.
+ * @param values Eligible option values mapped to a human-readable name.
+ * @param description A description.
+ * @param required Whether the option is required.
+ * @param validator The function to validate the option value.
+ *
+ * @return The created [Option].
+ *
+ * @see Option
+ */
+fun longOption(
+    name: String,
+    default: Long? = null,
+    values: Map<String, Long?>? = null,
+    description: String? = null,
+    required: Boolean = false,
+    validator: Option<Long>.(Long?) -> Boolean = { true },
+) = option(
+    name,
+    default,
+    values,
+    description,
+    required,
+    validator,
+)
+
+/**
+ * Create a new [Option] with a long value and add it to the current [PatchBuilder].
+ *
+ * @param name The name.
+ * @param default The default value.
+ * @param values Eligible option values mapped to a human-readable name.
+ * @param description A description.
+ * @param required Whether the option is required.
+ * @param validator The function to validate the option value.
+ *
+ * @return The created [Option].
+ *
+ * @see Option
+ */
+fun PatchBuilder<*>.longOption(
+    name: String,
+    default: Long? = null,
+    values: Map<String, Long?>? = null,
+    description: String? = null,
+    required: Boolean = false,
+    validator: Option<Long>.(Long?) -> Boolean = { true },
+) = option(
+    name,
+    default,
+    values,
+    description,
+    required,
+    validator,
+)
+
+/**
+ * Create a new [Option] with a string list value.
+ *
+ * @param name The name.
+ * @param default The default value.
+ * @param values Eligible option values mapped to a human-readable name.
+ * @param description A description.
+ * @param required Whether the option is required.
+ * @param validator The function to validate the option value.
+ *
+ * @return The created [Option].
+ *
+ * @see Option
+ */
+fun stringsOption(
+    name: String,
+    default: List<String>? = null,
+    values: Map<String, List<String>?>? = null,
+    description: String? = null,
+    required: Boolean = false,
+    validator: Option<List<String>>.(List<String>?) -> Boolean = { true },
+) = option(
+    name,
+    default,
+    values,
+    description,
+    required,
+    validator,
+)
+
+/**
+ * Create a new [Option] with a string list value and add it to the current [PatchBuilder].
+ *
+ * @param name The name.
+ * @param default The default value.
+ * @param values Eligible option values mapped to a human-readable name.
+ * @param description A description.
+ * @param required Whether the option is required.
+ * @param validator The function to validate the option value.
+ *
+ * @return The created [Option].
+ *
+ * @see Option
+ */
+fun PatchBuilder<*>.stringsOption(
+    name: String,
+    default: List<String>? = null,
+    values: Map<String, List<String>?>? = null,
+    description: String? = null,
+    required: Boolean = false,
+    validator: Option<List<String>>.(List<String>?) -> Boolean = { true },
+) = option(
+    name,
+    default,
+    values,
+    description,
+    required,
+    validator,
+)
+
+/**
+ * Create a new [Option] with an integer list value.
+ *
+ * @param name The name.
+ * @param default The default value.
+ * @param values Eligible option values mapped to a human-readable name.
+ * @param description A description.
+ * @param required Whether the option is required.
+ * @param validator The function to validate the option value.
+ *
+ * @return The created [Option].
+ *
+ * @see Option
+ */
+fun intsOption(
+    name: String,
+    default: List<Int>? = null,
+    values: Map<String, List<Int>?>? = null,
+    description: String? = null,
+    required: Boolean = false,
+    validator: Option<List<Int>>.(List<Int>?) -> Boolean = { true },
+) = option(
+    name,
+    default,
+    values,
+    description,
+    required,
+    validator,
+)
+
+/**
+ * Create a new [Option] with an integer list value and add it to the current [PatchBuilder].
+ *
+ * @param name The name.
+ * @param default The default value.
+ * @param values Eligible option values mapped to a human-readable name.
+ * @param description A description.
+ * @param required Whether the option is required.
+ * @param validator The function to validate the option value.
+ *
+ * @return The created [Option].
+ *
+ * @see Option
+ */
+fun PatchBuilder<*>.intsOption(
+    name: String,
+    default: List<Int>? = null,
+    values: Map<String, List<Int>?>? = null,
+    description: String? = null,
+    required: Boolean = false,
+    validator: Option<List<Int>>.(List<Int>?) -> Boolean = { true },
+) = option(
+    name,
+    default,
+    values,
+    description,
+    required,
+    validator,
+)
+
+/**
+ * Create a new [Option] with a boolean list value.
+ *
+ * @param name The name.
+ * @param default The default value.
+ * @param values Eligible option values mapped to a human-readable name.
+ * @param description A description.
+ * @param required Whether the option is required.
+ * @param validator The function to validate the option value.
+ *
+ * @return The created [Option].
+ *
+ * @see Option
+ */
+fun booleansOption(
+    name: String,
+    default: List<Boolean>? = null,
+    values: Map<String, List<Boolean>?>? = null,
+    description: String? = null,
+    required: Boolean = false,
+    validator: Option<List<Boolean>>.(List<Boolean>?) -> Boolean = { true },
+) = option(
+    name,
+    default,
+    values,
+    description,
+    required,
+    validator,
+)
+
+/**
+ * Create a new [Option] with a boolean list value and add it to the current [PatchBuilder].
+ *
+ * @param name The name.
+ * @param default The default value.
+ * @param values Eligible option values mapped to a human-readable name.
+ * @param description A description.
+ * @param required Whether the option is required.
+ * @param validator The function to validate the option value.
+ *
+ * @return The created [Option].
+ *
+ * @see Option
+ */
+fun PatchBuilder<*>.booleansOption(
+    name: String,
+    default: List<Boolean>? = null,
+    values: Map<String, List<Boolean>?>? = null,
+    description: String? = null,
+    required: Boolean = false,
+    validator: Option<List<Boolean>>.(List<Boolean>?) -> Boolean = { true },
+) = option(
+    name,
+    default,
+    values,
+    description,
+    required,
+    validator,
+)
+
+/**
+ * Create a new [Option] with a float list value and add it to the current [PatchBuilder].
+ *
+ * @param name The name.
+ * @param default The default value.
+ * @param values Eligible option values mapped to a human-readable name.
+ * @param description A description.
+ * @param required Whether the option is required.
+ * @param validator The function to validate the option value.
+ *
+ * @return The created [Option].
+ *
+ * @see Option
+ */
+fun PatchBuilder<*>.floatsOption(
+    name: String,
+    default: List<Float>? = null,
+    values: Map<String, List<Float>?>? = null,
+    description: String? = null,
+    required: Boolean = false,
+    validator: Option<List<Float>>.(List<Float>?) -> Boolean = { true },
+) = option(
+    name,
+    default,
+    values,
+    description,
+    required,
+    validator,
+)
+
+/**
+ * Create a new [Option] with a long list value.
+ *
+ * @param name The name.
+ * @param default The default value.
+ * @param values Eligible option values mapped to a human-readable name.
+ * @param description A description.
+ * @param required Whether the option is required.
+ * @param validator The function to validate the option value.
+ *
+ * @return The created [Option].
+ *
+ * @see Option
+ */
+fun longsOption(
+    name: String,
+    default: List<Long>? = null,
+    values: Map<String, List<Long>?>? = null,
+    description: String? = null,
+    required: Boolean = false,
+    validator: Option<List<Long>>.(List<Long>?) -> Boolean = { true },
+) = option(
+    name,
+    default,
+    values,
+    description,
+    required,
+    validator,
+)
+
+/**
+ * Create a new [Option] with a long list value and add it to the current [PatchBuilder].
+ *
+ * @param name The name.
+ * @param default The default value.
+ * @param values Eligible option values mapped to a human-readable name.
+ * @param description A description.
+ * @param required Whether the option is required.
+ * @param validator The function to validate the option value.
+ *
+ * @return The created [Option].
+ *
+ * @see Option
+ */
+fun PatchBuilder<*>.longsOption(
+    name: String,
+    default: List<Long>? = null,
+    values: Map<String, List<Long>?>? = null,
+    description: String? = null,
+    required: Boolean = false,
+    validator: Option<List<Long>>.(List<Long>?) -> Boolean = { true },
+) = option(
+    name,
+    default,
+    values,
+    description,
+    required,
+    validator,
+)
+
+/**
+ * Create a new [Option].
+ *
+ * @param name The name.
+ * @param default The default value.
+ * @param values Eligible option values mapped to a human-readable name.
+ * @param description A description.
+ * @param required Whether the option is required.
+ * @param validator The function to validate the option value.
+ *
+ * @return The created [Option].
+ *
+ * @see Option
+ */
+inline fun <reified T> option(
+    name: String,
+    default: T? = null,
+    values: Map<String, T?>? = null,
+    description: String? = null,
+    required: Boolean = false,
+    noinline validator: Option<T>.(T?) -> Boolean = { true },
+) = Option(
+    name,
+    default,
+    values,
+    description,
+    required,
+    typeOf<T>(),
+    validator,
+)
+
+/**
+ * Create a new [Option] and add it to the current [PatchBuilder].
+ *
+ * @param name The name.
+ * @param default The default value.
+ * @param values Eligible option values mapped to a human-readable name.
+ * @param description A description.
+ * @param required Whether the option is required.
+ * @param validator The function to validate the option value.
+ *
+ * @return The created [Option].
+ *
+ * @see Option
+ */
+inline fun <reified T> PatchBuilder<*>.option(
+    name: String,
+    default: T? = null,
+    values: Map<String, T?>? = null,
+    description: String? = null,
+    required: Boolean = false,
+    noinline validator: Option<T>.(T?) -> Boolean = { true },
+) = app.revanced.patcher.patch.option(
+    name,
+    default,
+    values,
+    description,
+    required,
+    validator,
+).also { it() }
+
+/**
+ * An exception thrown when using [Option]s.
+ *
+ * @param errorMessage The exception message.
+ */
+sealed class OptionException(errorMessage: String) : Exception(errorMessage, null) {
+    /**
+     * An exception thrown when a [Option] is set to an invalid value.
+     *
+     * @param invalidType The type of the value that was passed.
+     * @param expectedType The type of the value that was expected.
+     */
+    class InvalidValueTypeException(invalidType: String, expectedType: String) :
+        OptionException("Type $expectedType was expected but received type $invalidType")
+
+    /**
+     * An exception thrown when a value did not satisfy the value conditions specified by the [Option].
+     *
+     * @param value The value that failed validation.
+     */
+    class ValueValidationException(value: Any?, option: Option<*>) :
+        OptionException("The option value \"$value\" failed validation for ${option.name}")
+
+    /**
+     * An exception thrown when a value is required but null was passed.
+     *
+     * @param option The [Option] that requires a value.
+     */
+    class ValueRequiredException(option: Option<*>) :
+        OptionException("The option ${option.name} requires a value, but the value was null")
+
+    /**
+     * An exception thrown when a [Option] is not found.
+     *
+     * @param name The name of the [Option].
+     */
+    class OptionNotFoundException(name: String) : OptionException("No option with name $name")
+}

patcher/src/commonMain/kotlin/app/revanced/patcher/patch/Patch.kt

@@ -0,0 +1,273 @@
+@file:Suppress("MemberVisibilityCanBePrivate", "unused")
+
+package app.revanced.patcher.patch
+
+import java.io.File
+import java.io.InputStream
+import java.lang.reflect.Member
+import java.lang.reflect.Method
+import java.lang.reflect.Modifier
+import java.util.function.Supplier
+import kotlin.properties.ReadOnlyProperty
+
+typealias PackageName = String
+typealias VersionName = String
+typealias Package = Pair<PackageName, Set<VersionName>?>
+
+enum class PatchType(internal val prefix: String) {
+    BYTECODE("Bytecode"),
+    RAW_RESOURCE("RawResource"),
+    RESOURCE("Resource")
+}
+
+internal val Patch.patchesResources: Boolean get() = type == PatchType.RESOURCE || dependencies.any { it.patchesResources }
+
+open class Patch internal constructor(
+    val name: String?,
+    val description: String?,
+    val use: Boolean,
+    val dependencies: Set<Patch>,
+    val compatiblePackages: Set<Package>?,
+    options: Set<Option<*>>,
+    internal val apply: context(BytecodePatchContext, ResourcePatchContext) () -> Unit,
+    // Must be nullable, so that Patcher.invoke can check,
+    // if a patch has an "afterDependents" in order to not emit it twice.
+    internal var afterDependents: (context(BytecodePatchContext, ResourcePatchContext) () -> Unit)?,
+    internal val type: PatchType,
+) {
+    val options = Options(options)
+
+    override fun toString() = name ?: "${type.prefix}Patch@${System.identityHashCode(this)}"
+}
+
+sealed class PatchBuilder<C : PatchContext<*>>(
+    private val type: PatchType,
+    private val getPatchContext: context(BytecodePatchContext, ResourcePatchContext) () -> C
+) {
+    private var compatiblePackages: MutableSet<Package>? = null
+    private val dependencies = mutableSetOf<Patch>()
+    private val options = mutableSetOf<Option<*>>()
+
+    internal var apply: context(BytecodePatchContext, ResourcePatchContext) () -> Unit = { }
+    internal var afterDependents: (context(BytecodePatchContext, ResourcePatchContext)  () -> Unit)? = null
+
+    context(_: BytecodePatchContext, _: ResourcePatchContext)
+    private val patchContext get() = getPatchContext()
+
+    fun apply(block: C.() -> Unit) {
+        apply = { block(patchContext) }
+    }
+
+    fun afterDependents(block: C.() -> Unit) {
+        afterDependents = { block(patchContext) }
+    }
+
+    operator fun <T> Option<T>.invoke() = apply {
+        options += this
+    }
+
+    operator fun String.invoke(vararg versions: VersionName) = invoke(versions.toSet())
+
+    private operator fun String.invoke(versions: Set<VersionName>? = null): Package = this to versions
+
+    fun compatibleWith(vararg packages: Package) {
+        if (compatiblePackages == null) {
+            compatiblePackages = mutableSetOf()
+        }
+
+        compatiblePackages!! += packages
+    }
+
+    fun compatibleWith(vararg packages: String) = compatibleWith(*packages.map { it() }.toTypedArray())
+
+    fun dependsOn(vararg patches: Patch) {
+        dependencies += patches
+    }
+
+
+    fun build(name: String?, description: String?, use: Boolean) = Patch(
+        name,
+        description,
+        use,
+        dependencies,
+        compatiblePackages,
+        options,
+        apply,
+        afterDependents,
+        type,
+    )
+}
+
+class BytecodePatchBuilder private constructor(
+    private var extensionInputStream: InputStream? = null
+) : PatchBuilder<BytecodePatchContext>(
+    PatchType.BYTECODE,
+    {
+        // Extend the context with the extension, before returning it to the patch before applying it.
+        contextOf<BytecodePatchContext>().apply {
+            if (extensionInputStream != null) extendWith(extensionInputStream)
+        }
+    }
+) {
+    internal constructor() : this(null)
+
+    fun extendWith(extension: String) {
+        // Should be the classloader which loaded the patch class.
+        val classLoader = Class.forName(Thread.currentThread().stackTrace[2].className).classLoader!!
+
+        extensionInputStream = classLoader.getResourceAsStream(extension)
+            ?: throw PatchException("Extension \"$extension\" not found")
+    }
+}
+
+open class ResourcePatchBuilder internal constructor(type: PatchType) : PatchBuilder<ResourcePatchContext>(
+    type,
+    { contextOf<ResourcePatchContext>() }
+) {
+    internal constructor() : this(PatchType.RESOURCE)
+}
+
+class RawResourcePatchBuilder internal constructor() : ResourcePatchBuilder()
+
+fun bytecodePatch(
+    name: String? = null,
+    description: String? = null,
+    use: Boolean = true,
+    block: BytecodePatchBuilder.() -> Unit
+) = BytecodePatchBuilder().apply(block).build(name, description, use)
+
+fun resourcePatch(
+    name: String? = null,
+    description: String? = null,
+    use: Boolean = true,
+    block: ResourcePatchBuilder.() -> Unit
+) = ResourcePatchBuilder().apply(block).build(name, description, use)
+
+fun rawResourcePatch(
+    name: String? = null,
+    description: String? = null,
+    use: Boolean = true,
+    block: RawResourcePatchBuilder.() -> Unit
+) = RawResourcePatchBuilder().apply(block).build(name, description, use)
+
+private fun <B : PatchBuilder<*>> creatingPatch(
+    description: String? = null,
+    use: Boolean = true,
+    block: B.() -> Unit,
+    patchSupplier: (String?, String?, Boolean, B.() -> Unit) -> Patch
+) = ReadOnlyProperty<Any?, Patch> { _, property -> patchSupplier(property.name, description, use, block) }
+
+fun creatingBytecodePatch(
+    description: String? = null,
+    use: Boolean = true,
+    block: BytecodePatchBuilder.() -> Unit,
+) = creatingPatch(description, use, block) { name, description, use, block ->
+    bytecodePatch(name, description, use, block)
+}
+
+fun creatingResourcePatch(
+    description: String? = null,
+    use: Boolean = true,
+    block: ResourcePatchBuilder.() -> Unit,
+) = creatingPatch(description, use, block) { name, description, use, block ->
+    resourcePatch(name, description, use, block)
+}
+
+fun creatingRawResourcePatch(
+    description: String? = null,
+    use: Boolean = true,
+    block: RawResourcePatchBuilder.() -> Unit,
+) = creatingPatch(description, use, block) { name, description, use, block ->
+    rawResourcePatch(name, description, use, block)
+}
+
+
+/**
+ * A common interface for contexts such as [ResourcePatchContext] and [BytecodePatchContext].
+ */
+
+sealed interface PatchContext<T> : Supplier<T>
+
+/**
+ * An exception thrown when patching.
+ *
+ * @param errorMessage The exception message.
+ * @param cause The corresponding [Throwable].
+ */
+class PatchException(errorMessage: String?, cause: Throwable?) : Exception(errorMessage, cause) {
+    constructor(errorMessage: String) : this(errorMessage, null)
+    constructor(cause: Throwable) : this(cause.message, cause)
+}
+
+/**
+ * A result of applying a [Patch].
+ *
+ * @param patch The [Patch] that ran.
+ * @param exception The [PatchException] thrown, if any.
+ */
+class PatchResult internal constructor(val patch: Patch, val exception: PatchException? = null)
+
+/**
+ * Creates a [PatchResult] for this [Patch].
+ *
+ * @param exception The [PatchException] thrown, if any.
+ * @return The created [PatchResult].
+ */
+internal fun Patch.patchResult(exception: Exception? = null) = PatchResult(this, exception?.toPatchException())
+
+/**
+ * Creates a [PatchResult] for this [Patch] with the given error message.
+ *
+ * @param errorMessage The error message.
+ * @return The created [PatchResult].
+ */
+internal fun Patch.patchResult(errorMessage: String) = PatchResult(this, PatchException(errorMessage))
+private fun Exception.toPatchException() = this as? PatchException ?: PatchException(this)
+
+/**
+ * A collection of patches loaded from patches files.
+ *
+ * @property patchesByFile The patches mapped by their patches file.
+ */
+class Patches internal constructor(val patchesByFile: Map<File, Set<Patch>>) : Set<Patch>
+by patchesByFile.values.flatten().toSet()
+
+// Must be internal and a separate function for testing.
+@Suppress("MISSING_DEPENDENCY_IN_INFERRED_TYPE_ANNOTATION_WARNING")
+internal fun getPatches(classNames: List<String>, classLoader: ClassLoader): Set<Patch> {
+    fun Member.isUsable() =
+        Modifier.isPublic(modifiers) && Modifier.isStatic(modifiers) && (this !is Method || parameterCount == 0)
+
+    fun Class<*>.getPatchFields() = fields
+        .filter { it.type.isPatch && it.isUsable() }
+        .map { it.get(null) as Patch }
+
+    fun Class<*>.getPatchMethods() = methods
+        .filter { it.returnType.isPatch && it.parameterCount == 0 && it.isUsable() }
+        .map { it.invoke(null) as Patch }
+
+    return classNames
+        .map { classLoader.loadClass(it) }
+        .flatMap { it.getPatchMethods() + it.getPatchFields() }
+        .filter { it.name != null }
+        .toSet()
+}
+
+internal fun loadPatches(
+    vararg patchesFiles: File,
+    getBinaryClassNames: (patchesFile: File) -> List<String>,
+    classLoader: ClassLoader,
+    onFailedToLoad: (File, Throwable) -> Unit
+) = Patches(patchesFiles.map { file ->
+    file to getBinaryClassNames(file)
+}.mapNotNull { (file, classNames) ->
+    runCatching { file to getPatches(classNames, classLoader) }
+        .onFailure { onFailedToLoad(file, it) }.getOrNull()
+}.toMap())
+
+expect fun loadPatches(
+    vararg patchesFiles: File,
+    onFailedToLoad: (patchesFile: File, throwable: Throwable) -> Unit = { _, _ -> },
+): Patches
+
+internal expect val Class<*>.isPatch: Boolean

patcher/src/commonMain/kotlin/app/revanced/patcher/patch/ResourcePatchContext.kt

@@ -0,0 +1,229 @@
+package app.revanced.patcher.patch
+
+import app.revanced.patcher.PatchesResult
+import app.revanced.patcher.util.Document
+import brut.androlib.AaptInvoker
+import brut.androlib.ApkDecoder
+import brut.androlib.Config
+import brut.androlib.apk.ApkInfo
+import brut.androlib.apk.UsesFramework
+import brut.androlib.res.Framework
+import brut.androlib.res.ResourcesDecoder
+import brut.androlib.res.decoder.AndroidManifestPullStreamDecoder
+import brut.androlib.res.decoder.AndroidManifestResourceParser
+import brut.androlib.res.xml.ResXmlUtils
+import brut.directory.ExtFile
+import java.io.File
+import java.io.InputStream
+import java.io.OutputStream
+import java.io.resolve
+import java.nio.file.Files
+import java.util.logging.Logger
+import kotlin.reflect.jvm.jvmName
+
+/**
+ * A context for patches containing the current state of resources.
+ *
+ * @param apkFile The apk file to patch.
+ * @param apkFilesPath The path to the temporary apk files directory.
+ * @param patchedFilesPath The path to the temporary patched files directory.
+ * @param aaptBinaryPath The path to a custom aapt binary.
+ * @param frameworkFileDirectory The path to the directory to cache the framework file in.
+ */
+class ResourcePatchContext internal constructor(
+    private val apkFile: File,
+    private val apkFilesPath: File,
+    private val patchedFilesPath: File,
+    aaptBinaryPath: File? = null,
+    frameworkFileDirectory: String? = null,
+) : PatchContext<PatchesResult.PatchedResources?> {
+    private val apkInfo = ApkInfo(ExtFile(apkFile))
+
+    private val logger = Logger.getLogger(ResourcePatchContext::class.jvmName)
+
+    private val resourceConfig = Config.getDefaultConfig().apply {
+        aaptBinary = aaptBinaryPath
+        frameworkDirectory = frameworkFileDirectory
+    }
+
+    internal var decodingMode = ResourceDecodingMode.MANIFEST
+
+    /**
+     * Read a document from an [InputStream].
+     */
+    fun document(inputStream: InputStream) = Document(inputStream)
+
+    /**
+     * Read and write documents in the [apkFile].
+     */
+    fun document(path: String) = Document(get(path))
+
+    /**
+     * Set of resources from [apkFile] to delete.
+     */
+    private val deleteResources = mutableSetOf<String>()
+
+    internal fun decodeManifest(): Pair<PackageName, VersionName> {
+        logger.info("Decoding manifest")
+
+        val resourcesDecoder = ResourcesDecoder(resourceConfig, apkInfo)
+
+        // Decode manually instead of using resourceDecoder.decodeManifest
+        // because it does not support decoding to an OutputStream.
+        AndroidManifestPullStreamDecoder(
+            AndroidManifestResourceParser(resourcesDecoder.resTable),
+            resourcesDecoder.newXmlSerializer(),
+        ).decode(
+            apkInfo.apkFile.directory.getFileInput("AndroidManifest.xml"),
+            // Older Android versions do not support OutputStream.nullOutputStream()
+            object : OutputStream() {
+                override fun write(b: Int) { // Do nothing.
+                }
+            },
+        )
+
+        // Get the package name and version from the manifest using the XmlPullStreamDecoder.
+        // The call to AndroidManifestPullStreamDecoder.decode() above sets apkInfo.
+        val packageName = resourcesDecoder.resTable.packageRenamed
+        val packageVersion =
+            apkInfo.versionInfo.versionName ?: apkInfo.versionInfo.versionCode
+
+        /*
+         When the main resource package is not loaded, the ResTable is flagged as sparse.
+         Because ResourcesDecoder.decodeResources loads the main package and is not called here,
+         set sparseResources to false again to prevent the ResTable from being flagged as sparse falsely,
+         in case ResourcesDecoder.decodeResources is not later used in the patching process
+          to set sparseResources correctly.
+
+         See ARSCDecoder.readTableType for more info.
+         */
+        apkInfo.sparseResources = false
+
+        return packageName to packageVersion
+    }
+
+    internal fun decodeResources() {
+        logger.info("Decoding resources")
+
+        val resourcesDecoder = ResourcesDecoder(resourceConfig, apkInfo).also {
+            it.decodeResources(apkFilesPath)
+            it.decodeManifest(apkFilesPath)
+        }
+
+        // Record uncompressed files to preserve their state when recompiling.
+        ApkDecoder(apkInfo, resourceConfig).recordUncompressedFiles(resourcesDecoder.resFileMapping)
+
+        // Get the ids of the used framework packages to include them for reference when recompiling.
+        apkInfo.usesFramework = UsesFramework().apply {
+            ids = resourcesDecoder.resTable.listFramePackages().map { it.id }
+        }
+    }
+
+    /**
+     * Compile resources in [apkFilesPath].
+     *
+     * @return The [PatchesResult.PatchedResources].
+     */
+    override fun get(): PatchesResult.PatchedResources {
+        logger.info("Compiling patched resources")
+
+        val resourcesPath = patchedFilesPath.resolve("resources").also { it.mkdirs() }
+
+        val resourcesApkFile = if (decodingMode == ResourceDecodingMode.ALL) {
+            val resourcesApkFile = resourcesPath.resolve("resources.apk").also { it.createNewFile() }
+
+            val manifestFile = apkFilesPath.resolve("AndroidManifest.xml").also {
+                ResXmlUtils.fixingPublicAttrsInProviderAttributes(it)
+            }
+            val resPath = apkFilesPath.resolve("res")
+            val frameworkApkFiles = with(Framework(resourceConfig)) {
+                apkInfo.usesFramework.ids.map { id -> getFrameworkApk(id, null) }
+            }.toTypedArray()
+
+            AaptInvoker(
+                resourceConfig,
+                apkInfo
+            ).invoke(resourcesApkFile, manifestFile, resPath, null, null, frameworkApkFiles)
+
+            resourcesApkFile
+        } else null
+
+
+        val otherFiles = apkFilesPath.listFiles()!!.filter {
+            // Excluded because present in resources.other.
+            // TODO: We are reusing apkFiles as a temporarily directory for extracting resources.
+            //  This is not ideal as it could conflict with files such as the ones that are filtered here.
+            //  The problem is that ResourcePatchContext#get returns a File relative to apkFiles,
+            //  and we need to extract files to that directory.
+            //  A solution would be to use apkFiles as the working directory for the patching process.
+            //  Once all patches have been executed, we can move the decoded resources to a new directory.
+            //  The filters wouldn't be needed anymore.
+            //  For now, we assume that the files we filter here are not needed for the patching process.
+            it.name != "AndroidManifest.xml" &&
+                    it.name != "res" &&
+                    // Generated by Androlib.
+                    it.name != "build"
+        }
+        val otherResourceFiles = if (otherFiles.isNotEmpty()) {
+            // Move the other resources files.
+            resourcesPath.resolve("other").also { it.mkdirs() }.apply {
+                otherFiles.forEach { file ->
+                    Files.move(file.toPath(), resolve(file.name).toPath())
+                }
+            }
+        } else null
+
+        return PatchesResult.PatchedResources(
+            resourcesApkFile,
+            otherResourceFiles,
+            apkInfo.doNotCompress?.toSet() ?: emptySet(),
+            deleteResources,
+        )
+    }
+
+    /**
+     * Get a file from [apkFilesPath].
+     *
+     * @param path The path of the file.
+     * @param copy Whether to copy the file from [apkFile] if it does not exist yet in [apkFilesPath].
+     */
+    operator fun get(
+        path: String,
+        copy: Boolean = true,
+    ) = apkFilesPath.resolve(path).apply {
+        if (copy && !exists()) {
+            with(ExtFile(apkFile).directory) {
+                if (containsFile(path) || containsDir(path)) {
+                    copyToDir(apkFilesPath, path)
+                }
+            }
+        }
+    }
+
+    /**
+     * Mark a file for deletion when the APK is rebuilt.
+     *
+     * @param name The name of the file to delete.
+     */
+    fun delete(name: String) = deleteResources.add(name)
+
+    /**
+     * How to handle resources decoding and compiling.
+     */
+    internal enum class ResourceDecodingMode {
+        /**
+         * Decode and compile all resources.
+         */
+        ALL,
+
+        /**
+         * Do not decode or compile any resources.
+         */
+        NONE,
+
+        /**
+         * Do not decode or compile any resources.
+         */
+        MANIFEST,
+    }
+}

patcher/src/commonMain/kotlin/app/revanced/patcher/util/ClassMerger.kt

@@ -0,0 +1,239 @@
+package app.revanced.patcher.util
+
+import com.android.tools.smali.dexlib2.mutable.MutableClassDef
+import com.android.tools.smali.dexlib2.mutable.MutableClassDef.Companion.toMutable
+import com.android.tools.smali.dexlib2.mutable.MutableField
+import com.android.tools.smali.dexlib2.mutable.MutableField.Companion.toMutable
+import com.android.tools.smali.dexlib2.mutable.MutableMethod
+import com.android.tools.smali.dexlib2.mutable.MutableMethod.Companion.toMutable
+import app.revanced.patcher.patch.BytecodePatchContext
+import app.revanced.patcher.util.ClassMerger.Utils.asMutableClass
+import app.revanced.patcher.util.ClassMerger.Utils.filterAny
+import app.revanced.patcher.util.ClassMerger.Utils.filterNotAny
+import app.revanced.patcher.util.ClassMerger.Utils.isPublic
+import app.revanced.patcher.util.ClassMerger.Utils.toPublic
+import app.revanced.patcher.util.ClassMerger.Utils.traverseClassHierarchy
+import com.android.tools.smali.dexlib2.AccessFlags
+import com.android.tools.smali.dexlib2.iface.ClassDef
+import com.android.tools.smali.dexlib2.util.MethodUtil
+import java.util.logging.Logger
+import kotlin.reflect.KFunction2
+import kotlin.reflect.jvm.jvmName
+
+/**
+ * Experimental class to merge a [ClassDef] with another.
+ * Note: This will not consider method implementations or if the class is missing a superclass or interfaces.
+ */
+internal object ClassMerger {
+    private val logger = Logger.getLogger(ClassMerger::class.jvmName)
+
+    /**
+     * Merge a class with [otherClass].
+     *
+     * @param otherClass The class to merge with
+     * @param context The context to traverse the class hierarchy in.
+     * @return The merged class or the original class if no merge was needed.
+     */
+    fun ClassDef.merge(
+        otherClass: ClassDef,
+        context: BytecodePatchContext,
+    ) = this
+        // .fixFieldAccess(otherClass)
+        // .fixMethodAccess(otherClass)
+        .addMissingFields(otherClass)
+        .addMissingMethods(otherClass)
+        .publicize(otherClass, context)
+
+    /**
+     * Add methods which are missing but existing in [fromClass].
+     *
+     * @param fromClass The class to add missing methods from.
+     */
+    private fun ClassDef.addMissingMethods(fromClass: ClassDef): ClassDef {
+        val missingMethods =
+            fromClass.methods.let { fromMethods ->
+                methods.filterNot { method ->
+                    fromMethods.any { fromMethod ->
+                        MethodUtil.methodSignaturesMatch(fromMethod, method)
+                    }
+                }
+            }
+
+        if (missingMethods.isEmpty()) return this
+
+        logger.fine { "Found ${missingMethods.size} missing methods" }
+
+        return asMutableClass().apply {
+            methods.addAll(missingMethods.map { it.toMutable() })
+        }
+    }
+
+    /**
+     * Add fields which are missing but existing in [fromClass].
+     *
+     * @param fromClass The class to add missing fields from.
+     */
+    private fun ClassDef.addMissingFields(fromClass: ClassDef): ClassDef {
+        val missingFields =
+            fields.filterNotAny(fromClass.fields) { field, fromField ->
+                fromField.name == field.name
+            }
+
+        if (missingFields.isEmpty()) return this
+
+        logger.fine { "Found ${missingFields.size} missing fields" }
+
+        return asMutableClass().apply {
+            fields.addAll(missingFields.map { it.toMutable() })
+        }
+    }
+
+    /**
+     * Make a class and its super class public recursively.
+     * @param reference The class to check the [AccessFlags] of.
+     * @param context The context to traverse the class hierarchy in.
+     */
+    private fun ClassDef.publicize(
+        reference: ClassDef,
+        context: BytecodePatchContext,
+    ) = if (reference.accessFlags.isPublic() && !accessFlags.isPublic()) {
+        this.asMutableClass().apply {
+            context.traverseClassHierarchy(this) {
+                if (accessFlags.isPublic()) return@traverseClassHierarchy
+
+                logger.fine { "Publicizing ${this.type}" }
+
+                accessFlags = accessFlags.toPublic()
+            }
+        }
+    } else {
+        this
+    }
+
+    /**
+     * Publicize fields if they are public in [reference].
+     *
+     * @param reference The class to check the [AccessFlags] of the fields in.
+     */
+    private fun ClassDef.fixFieldAccess(reference: ClassDef): ClassDef {
+        val brokenFields =
+            fields.filterAny(reference.fields) { field, referenceField ->
+                if (field.name != referenceField.name) return@filterAny false
+
+                referenceField.accessFlags.isPublic() && !field.accessFlags.isPublic()
+            }
+
+        if (brokenFields.isEmpty()) return this
+
+        logger.fine { "Found ${brokenFields.size} broken fields" }
+
+        /**
+         * Make a field public.
+         */
+        fun MutableField.publicize() {
+            accessFlags = accessFlags.toPublic()
+        }
+
+        return asMutableClass().apply {
+            fields.filter { brokenFields.contains(it) }.forEach(MutableField::publicize)
+        }
+    }
+
+    /**
+     * Publicize methods if they are public in [reference].
+     *
+     * @param reference The class to check the [AccessFlags] of the methods in.
+     */
+    private fun ClassDef.fixMethodAccess(reference: ClassDef): ClassDef {
+        val brokenMethods =
+            methods.filterAny(reference.methods) { method, referenceMethod ->
+                if (!MethodUtil.methodSignaturesMatch(method, referenceMethod)) return@filterAny false
+
+                referenceMethod.accessFlags.isPublic() && !method.accessFlags.isPublic()
+            }
+
+        if (brokenMethods.isEmpty()) return this
+
+        logger.fine { "Found ${brokenMethods.size} methods" }
+
+        /**
+         * Make a method public.
+         */
+        fun MutableMethod.publicize() {
+            accessFlags = accessFlags.toPublic()
+        }
+
+        return asMutableClass().apply {
+            methods.filter { brokenMethods.contains(it) }.forEach(MutableMethod::publicize)
+        }
+    }
+
+    private object Utils {
+        /**
+         * traverse the class hierarchy starting from the given root class
+         *
+         * @param targetClass the class to start traversing the class hierarchy from
+         * @param callback function that is called for every class in the hierarchy
+         */
+        fun BytecodePatchContext.traverseClassHierarchy(
+            targetClass: MutableClassDef,
+            callback: MutableClassDef.() -> Unit,
+        ) {
+            callback(targetClass)
+
+            classDefs[targetClass.superclass ?: return]?.let { classDef ->
+                traverseClassHierarchy(classDefs.getOrReplaceMutable(classDef), callback)
+            }
+        }
+
+        fun ClassDef.asMutableClass() = this as? MutableClassDef ?: this.toMutable()
+
+        /**
+         * Check if the [AccessFlags.PUBLIC] flag is set.
+         *
+         * @return True, if the flag is set.
+         */
+        fun Int.isPublic() = AccessFlags.PUBLIC.isSet(this)
+
+        /**
+         * Make [AccessFlags] public.
+         *
+         * @return The new [AccessFlags].
+         */
+        fun Int.toPublic() = or(AccessFlags.PUBLIC.value).and(AccessFlags.PRIVATE.value.inv())
+
+        /**
+         * Filter [this] on [needles] matching the given [predicate].
+         *
+         * @param needles The needles to filter [this] with.
+         * @param predicate The filter.
+         * @return The [this] filtered on [needles] matching the given [predicate].
+         */
+        fun <HayType, NeedleType> Iterable<HayType>.filterAny(
+            needles: Iterable<NeedleType>,
+            predicate: (HayType, NeedleType) -> Boolean,
+        ) = Iterable<HayType>::filter.any(this, needles, predicate)
+
+        /**
+         * Filter [this] on [needles] not matching the given [predicate].
+         *
+         * @param needles The needles to filter [this] with.
+         * @param predicate The filter.
+         * @return The [this] filtered on [needles] not matching the given [predicate].
+         */
+        fun <HayType, NeedleType> Iterable<HayType>.filterNotAny(
+            needles: Iterable<NeedleType>,
+            predicate: (HayType, NeedleType) -> Boolean,
+        ) = Iterable<HayType>::filterNot.any(this, needles, predicate)
+
+        fun <HayType, NeedleType> KFunction2<Iterable<HayType>, (HayType) -> Boolean, List<HayType>>.any(
+            haystack: Iterable<HayType>,
+            needles: Iterable<NeedleType>,
+            predicate: (HayType, NeedleType) -> Boolean,
+        ) = this(haystack) { hay ->
+            needles.any { needle ->
+                predicate(hay, needle)
+            }
+        }
+    }
+}

patcher/src/commonMain/kotlin/app/revanced/patcher/util/Document.kt

@@ -0,0 +1,61 @@
+package app.revanced.patcher.util
+
+import collections.merge
+import com.google.common.base.Charsets
+import org.w3c.dom.Document
+import java.io.Closeable
+import java.io.File
+import java.io.InputStream
+import java.io.bufferedWriter
+import java.io.inputStream
+import javax.xml.parsers.DocumentBuilderFactory
+import javax.xml.transform.OutputKeys
+import javax.xml.transform.TransformerFactory
+import javax.xml.transform.dom.DOMSource
+import javax.xml.transform.stream.StreamResult
+import kotlin.use
+
+class Document internal constructor(
+    inputStream: InputStream,
+) : Document by DocumentBuilderFactory.newInstance().newDocumentBuilder().parse(inputStream), Closeable {
+    private var file: File? = null
+
+    init {
+        normalize()
+    }
+
+    internal constructor(file: File) : this(file.inputStream()) {
+        this.file = file
+        readerCount.merge(file, 1, Int::plus)
+    }
+
+    override fun close() {
+        file?.let {
+            if (readerCount[it]!! > 1) {
+                throw IllegalStateException(
+                    "Two or more instances are currently reading $it." +
+                            "To be able to close this instance, no other instances may be reading $it at the same time.",
+                )
+            } else {
+                readerCount.remove(it)
+            }
+
+            val transformer = TransformerFactory.newInstance().newTransformer()
+            // Set to UTF-16 to prevent surrogate pairs from being escaped to invalid numeric character references, but save as UTF-8.
+            if (isAndroid) {
+                transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-16")
+                transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes")
+                val writer = it.bufferedWriter(charset = Charsets.UTF_8)
+                transformer.transform(DOMSource(this), StreamResult(writer))
+                writer.close()
+            } else {
+                transformer.transform(DOMSource(this), StreamResult(it))
+            }
+        }
+    }
+
+    private companion object {
+        private val readerCount = mutableMapOf<File, Int>()
+        private val isAndroid = System.getProperty("java.runtime.name") == "Android Runtime"
+    }
+}

patcher/src/commonMain/kotlin/app/revanced/patcher/util/MethodNavigator.kt

@@ -0,0 +1,119 @@
+@file:Suppress("unused")
+
+package app.revanced.patcher.util
+
+import com.android.tools.smali.dexlib2.mutable.MutableMethod
+import app.revanced.patcher.extensions.instructionsOrNull
+import app.revanced.patcher.patch.BytecodePatchContext
+import com.android.tools.smali.dexlib2.iface.ClassDef
+import com.android.tools.smali.dexlib2.iface.Method
+import com.android.tools.smali.dexlib2.iface.instruction.Instruction
+import com.android.tools.smali.dexlib2.iface.instruction.ReferenceInstruction
+import com.android.tools.smali.dexlib2.iface.reference.MethodReference
+import com.android.tools.smali.dexlib2.util.MethodUtil
+import kotlin.reflect.KProperty
+
+/**
+ * A navigator for methods.
+ *
+ * @param startMethod The [Method] to start navigating from.
+ *
+ * @constructor Creates a new [MethodNavigator].
+ *
+ * @throws NavigateException If the method does not have an implementation.
+ * @throws NavigateException If the instruction at the specified index is not a method reference.
+ */
+class MethodNavigator internal constructor(
+    private var startMethod: MethodReference,
+) {
+    private var lastNavigatedMethodReference = startMethod
+
+    context(_: BytecodePatchContext)
+    private val lastNavigatedMethodInstructions
+        get() = with(original()) {
+            instructionsOrNull ?: throw NavigateException("Method $this does not have an implementation.")
+        }
+
+    /**
+     * Navigate to the method at the specified index.
+     *
+     * @param index The index of the method to navigate to.
+     *
+     * @return This [MethodNavigator].
+     */
+    context(_: BytecodePatchContext)
+    fun to(vararg index: Int): MethodNavigator {
+        index.forEach {
+            lastNavigatedMethodReference = lastNavigatedMethodInstructions.getMethodReferenceAt(it)
+        }
+
+        return this
+    }
+
+    /**
+     * Navigate to the method at the specified index that matches the specified predicate.
+     *
+     * @param index The index of the method to navigate to.
+     * @param predicate The predicate to match.
+     */
+    context(_: BytecodePatchContext)
+    fun to(index: Int = 0, predicate: (Instruction) -> Boolean): MethodNavigator {
+        lastNavigatedMethodReference = lastNavigatedMethodInstructions.asSequence()
+            .filter(predicate).asIterable().getMethodReferenceAt(index)
+
+        return this
+    }
+
+    /**
+     * Get the method reference at the specified index.
+     *
+     * @param index The index of the method reference to get.
+     */
+    private fun Iterable<Instruction>.getMethodReferenceAt(index: Int): MethodReference {
+        val instruction = elementAt(index) as? ReferenceInstruction
+            ?: throw NavigateException("Instruction at index $index is not a method reference.")
+
+        return instruction.reference as MethodReference
+    }
+
+    /**
+     * Get the last navigated method mutably.
+     *
+     * @return The last navigated method mutably.
+     */
+    context(context: BytecodePatchContext)
+    fun stop() = context.classDefs[lastNavigatedMethodReference.definingClass]!!
+        .firstMethodBySignature as MutableMethod
+
+
+    /**
+     * Get the last navigated method mutably.
+     *
+     * @return The last navigated method mutably.
+     */
+    operator fun getValue(context: BytecodePatchContext?, property: KProperty<*>) =
+        context(requireNotNull(context)) { stop() }
+
+    /**
+     * Get the last navigated method immutably.
+     *
+     * @return The last navigated method immutably.
+     */
+    context(context: BytecodePatchContext)
+    fun original(): Method = context.classDefs[lastNavigatedMethodReference.definingClass]!!.firstMethodBySignature
+
+    /**
+     * Find the first [lastNavigatedMethodReference] in the class.
+     */
+    private val ClassDef.firstMethodBySignature
+        get() = methods.first {
+            MethodUtil.methodSignaturesMatch(it, lastNavigatedMethodReference)
+        }
+
+    /**
+     * An exception thrown when navigating fails.
+     *
+     * @param message The message of the exception.
+     */
+    internal class NavigateException internal constructor(message: String) : Exception(message)
+}

patcher/src/commonMain/kotlin/collections/MutableMap.kt

@@ -0,0 +1,13 @@
+package collections
+
+internal expect fun <K, V> MutableMap<K, V>.kmpMerge(
+    key: K,
+    value: V,
+    remappingFunction: (oldValue: V, newValue: V) -> V,
+)
+
+internal fun <K, V> MutableMap<K, V>.merge(
+    key: K,
+    value: V,
+    remappingFunction: (oldValue: V, newValue: V) -> V,
+) = kmpMerge(key, value, remappingFunction)

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/iface/value/MutableAnnotationEncodedValue.kt

@@ -0,0 +1,26 @@
+package com.android.tools.smali.dexlib2.iface.value
+
+import com.android.tools.smali.dexlib2.base.value.BaseAnnotationEncodedValue
+import com.android.tools.smali.dexlib2.mutable.MutableAnnotationElement.Companion.toMutable
+
+class MutableAnnotationEncodedValue(annotationEncodedValue: AnnotationEncodedValue) :
+    BaseAnnotationEncodedValue(),
+    MutableEncodedValue {
+    private var type = annotationEncodedValue.type
+
+    private val _elements by lazy {
+        annotationEncodedValue.elements.map { annotationElement -> annotationElement.toMutable() }.toMutableSet()
+    }
+
+    fun setType(type: String) {
+        this.type = type
+    }
+
+    override fun getType() = this.type
+
+    override fun getElements() = _elements
+
+    companion object {
+        fun AnnotationEncodedValue.toMutable() = MutableAnnotationEncodedValue(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/iface/value/MutableArrayEncodedValue.kt

@@ -0,0 +1,16 @@
+package com.android.tools.smali.dexlib2.iface.value
+
+import com.android.tools.smali.dexlib2.base.value.BaseArrayEncodedValue
+import com.android.tools.smali.dexlib2.iface.value.MutableEncodedValue.Companion.toMutable
+
+class MutableArrayEncodedValue(arrayEncodedValue: ArrayEncodedValue) : BaseArrayEncodedValue(), MutableEncodedValue {
+    private val _value by lazy {
+        arrayEncodedValue.value.map { encodedValue -> encodedValue.toMutable() }.toMutableList()
+    }
+
+    override fun getValue() = _value
+
+    companion object {
+        fun ArrayEncodedValue.toMutable(): MutableArrayEncodedValue = MutableArrayEncodedValue(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/iface/value/MutableBooleanEncodedValue.kt

@@ -0,0 +1,19 @@
+package com.android.tools.smali.dexlib2.iface.value
+
+import com.android.tools.smali.dexlib2.base.value.BaseBooleanEncodedValue
+
+class MutableBooleanEncodedValue(booleanEncodedValue: BooleanEncodedValue) :
+    BaseBooleanEncodedValue(),
+    MutableEncodedValue {
+    private var value = booleanEncodedValue.value
+
+    fun setValue(value: Boolean) {
+        this.value = value
+    }
+
+    override fun getValue(): Boolean = this.value
+
+    companion object {
+        fun BooleanEncodedValue.toMutable(): MutableBooleanEncodedValue = MutableBooleanEncodedValue(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/iface/value/MutableByteEncodedValue.kt

@@ -0,0 +1,17 @@
+package com.android.tools.smali.dexlib2.iface.value
+
+import com.android.tools.smali.dexlib2.base.value.BaseByteEncodedValue
+
+class MutableByteEncodedValue(byteEncodedValue: ByteEncodedValue) : BaseByteEncodedValue(), MutableEncodedValue {
+    private var value = byteEncodedValue.value
+
+    fun setValue(value: Byte) {
+        this.value = value
+    }
+
+    override fun getValue(): Byte = this.value
+
+    companion object {
+        fun ByteEncodedValue.toMutable(): MutableByteEncodedValue = MutableByteEncodedValue(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/iface/value/MutableCharEncodedValue.kt

@@ -0,0 +1,17 @@
+package com.android.tools.smali.dexlib2.iface.value
+
+import com.android.tools.smali.dexlib2.base.value.BaseCharEncodedValue
+
+class MutableCharEncodedValue(charEncodedValue: CharEncodedValue) : BaseCharEncodedValue(), MutableEncodedValue {
+    private var value = charEncodedValue.value
+
+    fun setValue(value: Char) {
+        this.value = value
+    }
+
+    override fun getValue(): Char = this.value
+
+    companion object {
+        fun CharEncodedValue.toMutable(): MutableCharEncodedValue = MutableCharEncodedValue(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/iface/value/MutableDoubleEncodedValue.kt

@@ -0,0 +1,19 @@
+package com.android.tools.smali.dexlib2.iface.value
+
+import com.android.tools.smali.dexlib2.base.value.BaseDoubleEncodedValue
+
+class MutableDoubleEncodedValue(doubleEncodedValue: DoubleEncodedValue) :
+    BaseDoubleEncodedValue(),
+    MutableEncodedValue {
+    private var value = doubleEncodedValue.value
+
+    fun setValue(value: Double) {
+        this.value = value
+    }
+
+    override fun getValue(): Double = this.value
+
+    companion object {
+        fun DoubleEncodedValue.toMutable(): MutableDoubleEncodedValue = MutableDoubleEncodedValue(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/iface/value/MutableEncodedValue.kt

@@ -0,0 +1,31 @@
+package com.android.tools.smali.dexlib2.iface.value
+
+import com.android.tools.smali.dexlib2.ValueType
+
+interface MutableEncodedValue : EncodedValue {
+    companion object {
+        fun EncodedValue.toMutable(): MutableEncodedValue {
+            return when (this.valueType) {
+                ValueType.TYPE -> MutableTypeEncodedValue(this as TypeEncodedValue)
+                ValueType.FIELD -> MutableFieldEncodedValue(this as FieldEncodedValue)
+                ValueType.METHOD -> MutableMethodEncodedValue(this as MethodEncodedValue)
+                ValueType.ENUM -> MutableEnumEncodedValue(this as EnumEncodedValue)
+                ValueType.ARRAY -> MutableArrayEncodedValue(this as ArrayEncodedValue)
+                ValueType.ANNOTATION -> MutableAnnotationEncodedValue(this as AnnotationEncodedValue)
+                ValueType.BYTE -> MutableByteEncodedValue(this as ByteEncodedValue)
+                ValueType.SHORT -> MutableShortEncodedValue(this as ShortEncodedValue)
+                ValueType.CHAR -> MutableCharEncodedValue(this as CharEncodedValue)
+                ValueType.INT -> MutableIntEncodedValue(this as IntEncodedValue)
+                ValueType.LONG -> MutableLongEncodedValue(this as LongEncodedValue)
+                ValueType.FLOAT -> MutableFloatEncodedValue(this as FloatEncodedValue)
+                ValueType.DOUBLE -> MutableDoubleEncodedValue(this as DoubleEncodedValue)
+                ValueType.METHOD_TYPE -> MutableMethodTypeEncodedValue(this as MethodTypeEncodedValue)
+                ValueType.METHOD_HANDLE -> MutableMethodHandleEncodedValue(this as MethodHandleEncodedValue)
+                ValueType.STRING -> MutableStringEncodedValue(this as StringEncodedValue)
+                ValueType.BOOLEAN -> MutableBooleanEncodedValue(this as BooleanEncodedValue)
+                ValueType.NULL -> MutableNullEncodedValue()
+                else -> this as MutableEncodedValue
+            }
+        }
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/iface/value/MutableEnumEncodedValue.kt

@@ -0,0 +1,18 @@
+package com.android.tools.smali.dexlib2.iface.value
+
+import com.android.tools.smali.dexlib2.base.value.BaseEnumEncodedValue
+import com.android.tools.smali.dexlib2.iface.reference.FieldReference
+
+class MutableEnumEncodedValue(enumEncodedValue: EnumEncodedValue) : BaseEnumEncodedValue(), MutableEncodedValue {
+    private var value = enumEncodedValue.value
+
+    fun setValue(value: FieldReference) {
+        this.value = value
+    }
+
+    override fun getValue(): FieldReference = this.value
+
+    companion object {
+        fun EnumEncodedValue.toMutable(): MutableEnumEncodedValue = MutableEnumEncodedValue(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/iface/value/MutableFieldEncodedValue.kt

@@ -0,0 +1,21 @@
+package com.android.tools.smali.dexlib2.iface.value
+
+import com.android.tools.smali.dexlib2.ValueType
+import com.android.tools.smali.dexlib2.base.value.BaseFieldEncodedValue
+import com.android.tools.smali.dexlib2.iface.reference.FieldReference
+
+class MutableFieldEncodedValue(fieldEncodedValue: FieldEncodedValue) : BaseFieldEncodedValue(), MutableEncodedValue {
+    private var value = fieldEncodedValue.value
+
+    fun setValue(value: FieldReference) {
+        this.value = value
+    }
+
+    override fun getValueType(): Int = ValueType.FIELD
+
+    override fun getValue(): FieldReference = this.value
+
+    companion object {
+        fun FieldEncodedValue.toMutable(): MutableFieldEncodedValue = MutableFieldEncodedValue(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/iface/value/MutableFloatEncodedValue.kt

@@ -0,0 +1,17 @@
+package com.android.tools.smali.dexlib2.iface.value
+
+import com.android.tools.smali.dexlib2.base.value.BaseFloatEncodedValue
+
+class MutableFloatEncodedValue(floatEncodedValue: FloatEncodedValue) : BaseFloatEncodedValue(), MutableEncodedValue {
+    private var value = floatEncodedValue.value
+
+    fun setValue(value: Float) {
+        this.value = value
+    }
+
+    override fun getValue(): Float = this.value
+
+    companion object {
+        fun FloatEncodedValue.toMutable(): MutableFloatEncodedValue = MutableFloatEncodedValue(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/iface/value/MutableIntEncodedValue.kt

@@ -0,0 +1,17 @@
+package com.android.tools.smali.dexlib2.iface.value
+
+import com.android.tools.smali.dexlib2.base.value.BaseIntEncodedValue
+
+class MutableIntEncodedValue(intEncodedValue: IntEncodedValue) : BaseIntEncodedValue(), MutableEncodedValue {
+    private var value = intEncodedValue.value
+
+    fun setValue(value: Int) {
+        this.value = value
+    }
+
+    override fun getValue(): Int = this.value
+
+    companion object {
+        fun IntEncodedValue.toMutable(): MutableIntEncodedValue = MutableIntEncodedValue(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/iface/value/MutableLongEncodedValue.kt

@@ -0,0 +1,17 @@
+package com.android.tools.smali.dexlib2.iface.value
+
+import com.android.tools.smali.dexlib2.base.value.BaseLongEncodedValue
+
+class MutableLongEncodedValue(longEncodedValue: LongEncodedValue) : BaseLongEncodedValue(), MutableEncodedValue {
+    private var value = longEncodedValue.value
+
+    fun setValue(value: Long) {
+        this.value = value
+    }
+
+    override fun getValue(): Long = this.value
+
+    companion object {
+        fun LongEncodedValue.toMutable(): MutableLongEncodedValue = MutableLongEncodedValue(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/iface/value/MutableMethodEncodedValue.kt

@@ -0,0 +1,20 @@
+package com.android.tools.smali.dexlib2.iface.value
+
+import com.android.tools.smali.dexlib2.base.value.BaseMethodEncodedValue
+import com.android.tools.smali.dexlib2.iface.reference.MethodReference
+
+class MutableMethodEncodedValue(methodEncodedValue: MethodEncodedValue) :
+    BaseMethodEncodedValue(),
+    MutableEncodedValue {
+    private var value = methodEncodedValue.value
+
+    fun setValue(value: MethodReference) {
+        this.value = value
+    }
+
+    override fun getValue(): MethodReference = this.value
+
+    companion object {
+        fun MethodEncodedValue.toMutable(): MutableMethodEncodedValue = MutableMethodEncodedValue(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/iface/value/MutableMethodHandleEncodedValue.kt

@@ -0,0 +1,20 @@
+package com.android.tools.smali.dexlib2.iface.value
+
+import com.android.tools.smali.dexlib2.base.value.BaseMethodHandleEncodedValue
+import com.android.tools.smali.dexlib2.iface.reference.MethodHandleReference
+
+class MutableMethodHandleEncodedValue(methodHandleEncodedValue: MethodHandleEncodedValue) :
+    BaseMethodHandleEncodedValue(),
+    MutableEncodedValue {
+    private var value = methodHandleEncodedValue.value
+
+    fun setValue(value: MethodHandleReference) {
+        this.value = value
+    }
+
+    override fun getValue(): MethodHandleReference = this.value
+
+    companion object {
+        fun MethodHandleEncodedValue.toMutable(): MutableMethodHandleEncodedValue = MutableMethodHandleEncodedValue(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/iface/value/MutableMethodTypeEncodedValue.kt

@@ -0,0 +1,18 @@
+package com.android.tools.smali.dexlib2.iface.value
+
+import com.android.tools.smali.dexlib2.base.value.BaseMethodTypeEncodedValue
+import com.android.tools.smali.dexlib2.iface.reference.MethodProtoReference
+
+class MutableMethodTypeEncodedValue(methodTypeEncodedValue: MethodTypeEncodedValue) : BaseMethodTypeEncodedValue(), MutableEncodedValue {
+    private var value = methodTypeEncodedValue.value
+
+    fun setValue(value: MethodProtoReference) {
+        this.value = value
+    }
+
+    override fun getValue(): MethodProtoReference = this.value
+
+    companion object {
+        fun MethodTypeEncodedValue.toMutable(): MutableMethodTypeEncodedValue = MutableMethodTypeEncodedValue(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/iface/value/MutableNullEncodedValue.kt

@@ -0,0 +1,9 @@
+package com.android.tools.smali.dexlib2.iface.value
+
+import com.android.tools.smali.dexlib2.base.value.BaseNullEncodedValue
+
+class MutableNullEncodedValue : BaseNullEncodedValue(), MutableEncodedValue {
+    companion object {
+        fun ByteEncodedValue.toMutable(): MutableByteEncodedValue = MutableByteEncodedValue(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/iface/value/MutableShortEncodedValue.kt

@@ -0,0 +1,19 @@
+package com.android.tools.smali.dexlib2.iface.value
+
+import com.android.tools.smali.dexlib2.base.value.BaseShortEncodedValue
+
+class MutableShortEncodedValue(shortEncodedValue: ShortEncodedValue) :
+    BaseShortEncodedValue(),
+    MutableEncodedValue {
+    private var value = shortEncodedValue.value
+
+    fun setValue(value: Short) {
+        this.value = value
+    }
+
+    override fun getValue(): Short = this.value
+
+    companion object {
+        fun ShortEncodedValue.toMutable(): MutableShortEncodedValue = MutableShortEncodedValue(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/iface/value/MutableStringEncodedValue.kt

@@ -0,0 +1,19 @@
+package com.android.tools.smali.dexlib2.iface.value
+
+import com.android.tools.smali.dexlib2.base.value.BaseStringEncodedValue
+
+class MutableStringEncodedValue(stringEncodedValue: StringEncodedValue) :
+    BaseStringEncodedValue(),
+    MutableEncodedValue {
+    private var value = stringEncodedValue.value
+
+    fun setValue(value: String) {
+        this.value = value
+    }
+
+    override fun getValue(): String = this.value
+
+    companion object {
+        fun ByteEncodedValue.toMutable(): MutableByteEncodedValue = MutableByteEncodedValue(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/iface/value/MutableTypeEncodedValue.kt

@@ -0,0 +1,17 @@
+package com.android.tools.smali.dexlib2.iface.value
+
+import com.android.tools.smali.dexlib2.base.value.BaseTypeEncodedValue
+
+class MutableTypeEncodedValue(typeEncodedValue: TypeEncodedValue) : BaseTypeEncodedValue(), MutableEncodedValue {
+    private var value = typeEncodedValue.value
+
+    fun setValue(value: String) {
+        this.value = value
+    }
+
+    override fun getValue() = this.value
+
+    companion object {
+        fun TypeEncodedValue.toMutable(): MutableTypeEncodedValue = MutableTypeEncodedValue(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/mutable/MutableAnnotation.kt

@@ -0,0 +1,21 @@
+package com.android.tools.smali.dexlib2.mutable
+
+import com.android.tools.smali.dexlib2.base.BaseAnnotation
+import com.android.tools.smali.dexlib2.iface.Annotation
+import com.android.tools.smali.dexlib2.mutable.MutableAnnotationElement.Companion.toMutable
+
+class MutableAnnotation(annotation: Annotation) : BaseAnnotation() {
+    private val visibility = annotation.visibility
+    private val type = annotation.type
+    private val _elements by lazy { annotation.elements.map { element -> element.toMutable() }.toMutableSet() }
+
+    override fun getType() = type
+
+    override fun getElements() = _elements
+
+    override fun getVisibility() = visibility
+
+    companion object {
+        fun Annotation.toMutable() = MutableAnnotation(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/mutable/MutableAnnotationElement.kt

@@ -0,0 +1,27 @@
+package com.android.tools.smali.dexlib2.mutable
+
+import com.android.tools.smali.dexlib2.base.BaseAnnotationElement
+import com.android.tools.smali.dexlib2.iface.AnnotationElement
+import com.android.tools.smali.dexlib2.iface.value.MutableEncodedValue
+import com.android.tools.smali.dexlib2.iface.value.MutableEncodedValue.Companion.toMutable
+
+class MutableAnnotationElement(annotationElement: AnnotationElement) : BaseAnnotationElement() {
+    private var name = annotationElement.name
+    private var value = annotationElement.value.toMutable()
+
+    fun setName(name: String) {
+        this.name = name
+    }
+
+    fun setValue(value: MutableEncodedValue) {
+        this.value = value
+    }
+
+    override fun getName() = name
+
+    override fun getValue() = value
+
+    companion object {
+        fun AnnotationElement.toMutable() = MutableAnnotationElement(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/mutable/MutableClassDef.kt

@@ -0,0 +1,76 @@
+package com.android.tools.smali.dexlib2.mutable
+
+import com.android.tools.smali.dexlib2.base.reference.BaseTypeReference
+import com.android.tools.smali.dexlib2.iface.ClassDef
+import com.android.tools.smali.dexlib2.mutable.MutableAnnotation.Companion.toMutable
+import com.android.tools.smali.dexlib2.mutable.MutableField.Companion.toMutable
+import com.android.tools.smali.dexlib2.mutable.MutableMethod.Companion.toMutable
+import com.android.tools.smali.dexlib2.util.FieldUtil
+import com.android.tools.smali.dexlib2.util.MethodUtil
+
+class MutableClassDef(classDef: ClassDef) : BaseTypeReference(), ClassDef {
+    // Class
+    private var type = classDef.type
+    private var sourceFile = classDef.sourceFile
+    private var accessFlags = classDef.accessFlags
+    private var superclass = classDef.superclass
+
+    private val _interfaces by lazy { classDef.interfaces.toMutableList() }
+    private val _annotations by lazy {
+        classDef.annotations.map { annotation -> annotation.toMutable() }.toMutableSet()
+    }
+
+    // Methods
+    private val _methods by lazy { classDef.methods.map { method -> method.toMutable() }.toMutableSet() }
+    private val _directMethods by lazy { methods.filter { method -> MethodUtil.isDirect(method) }.toMutableSet() }
+    private val _virtualMethods by lazy { methods.filter { method -> !MethodUtil.isDirect(method) }.toMutableSet() }
+
+    // Fields
+    private val _fields by lazy { classDef.fields.map { field -> field.toMutable() }.toMutableSet() }
+    private val _staticFields by lazy { _fields.filter { field -> FieldUtil.isStatic(field) }.toMutableSet() }
+    private val _instanceFields by lazy { _fields.filter { field -> !FieldUtil.isStatic(field) }.toMutableSet() }
+
+    fun setType(type: String) {
+        this.type = type
+    }
+
+    fun setSourceFile(sourceFile: String?) {
+        this.sourceFile = sourceFile
+    }
+
+    fun setAccessFlags(accessFlags: Int) {
+        this.accessFlags = accessFlags
+    }
+
+    fun setSuperClass(superclass: String?) {
+        this.superclass = superclass
+    }
+
+    override fun getType() = type
+
+    override fun getAccessFlags() = accessFlags
+
+    override fun getSourceFile() = sourceFile
+
+    override fun getSuperclass() = superclass
+
+    override fun getInterfaces() = _interfaces
+
+    override fun getAnnotations() = _annotations
+
+    override fun getStaticFields() = _staticFields
+
+    override fun getInstanceFields() = _instanceFields
+
+    override fun getFields() = _fields
+
+    override fun getDirectMethods() = _directMethods
+
+    override fun getVirtualMethods() = _virtualMethods
+
+    override fun getMethods() = _methods
+
+    companion object {
+        fun ClassDef.toMutable(): MutableClassDef = MutableClassDef(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/mutable/MutableField.kt

@@ -0,0 +1,56 @@
+package com.android.tools.smali.dexlib2.mutable
+
+import com.android.tools.smali.dexlib2.base.reference.BaseFieldReference
+import com.android.tools.smali.dexlib2.iface.Field
+import com.android.tools.smali.dexlib2.iface.value.MutableEncodedValue
+import com.android.tools.smali.dexlib2.iface.value.MutableEncodedValue.Companion.toMutable
+import com.android.tools.smali.dexlib2.mutable.MutableAnnotation.Companion.toMutable
+
+class MutableField(field: Field) : BaseFieldReference(), Field {
+    private var definingClass = field.definingClass
+    private var name = field.name
+    private var type = field.type
+    private var accessFlags = field.accessFlags
+
+    private var initialValue = field.initialValue?.toMutable()
+    private val _annotations by lazy { field.annotations.map { annotation -> annotation.toMutable() }.toMutableSet() }
+    private val _hiddenApiRestrictions by lazy { field.hiddenApiRestrictions }
+
+    fun setDefiningClass(definingClass: String) {
+        this.definingClass = definingClass
+    }
+
+    fun setName(name: String) {
+        this.name = name
+    }
+
+    fun setType(type: String) {
+        this.type = type
+    }
+
+    fun setAccessFlags(accessFlags: Int) {
+        this.accessFlags = accessFlags
+    }
+
+    fun setInitialValue(initialValue: MutableEncodedValue?) {
+        this.initialValue = initialValue
+    }
+
+    override fun getDefiningClass() = this.definingClass
+
+    override fun getName() = this.name
+
+    override fun getType() = this.type
+
+    override fun getAnnotations() = this._annotations
+
+    override fun getAccessFlags() = this.accessFlags
+
+    override fun getHiddenApiRestrictions() = this._hiddenApiRestrictions
+
+    override fun getInitialValue() = this.initialValue
+
+    companion object {
+        fun Field.toMutable() = MutableField(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/mutable/MutableMethod.kt

@@ -0,0 +1,63 @@
+package com.android.tools.smali.dexlib2.mutable
+
+import com.android.tools.smali.dexlib2.base.reference.BaseMethodReference
+import com.android.tools.smali.dexlib2.builder.MutableMethodImplementation
+import com.android.tools.smali.dexlib2.iface.Method
+import com.android.tools.smali.dexlib2.mutable.MutableAnnotation.Companion.toMutable
+import com.android.tools.smali.dexlib2.mutable.MutableMethodParameter.Companion.toMutable
+
+class MutableMethod(method: Method) : BaseMethodReference(), Method {
+    private var definingClass = method.definingClass
+    private var name = method.name
+    private var accessFlags = method.accessFlags
+    private var returnType = method.returnType
+
+    // TODO: Create own mutable MethodImplementation (due to not being able to change members like register count).
+    private var implementation = method.implementation?.let(::MutableMethodImplementation)
+    private val _annotations by lazy { method.annotations.map { annotation -> annotation.toMutable() }.toMutableSet() }
+    private val _parameters by lazy { method.parameters.map { parameter -> parameter.toMutable() }.toMutableList() }
+    private val _parameterTypes by lazy { method.parameterTypes.toMutableList() }
+    private val _hiddenApiRestrictions by lazy { method.hiddenApiRestrictions }
+
+    fun setDefiningClass(definingClass: String) {
+        this.definingClass = definingClass
+    }
+
+    fun setName(name: String) {
+        this.name = name
+    }
+
+    fun setAccessFlags(accessFlags: Int) {
+        this.accessFlags = accessFlags
+    }
+
+    fun setReturnType(returnType: String) {
+        this.returnType = returnType
+    }
+
+    fun setImplementation(implementation: MutableMethodImplementation?) {
+        this.implementation = implementation
+    }
+
+    override fun getDefiningClass() = definingClass
+
+    override fun getName() = name
+
+    override fun getParameterTypes() = _parameterTypes
+
+    override fun getReturnType() = returnType
+
+    override fun getAnnotations() = _annotations
+
+    override fun getAccessFlags() = accessFlags
+
+    override fun getHiddenApiRestrictions() = _hiddenApiRestrictions
+
+    override fun getParameters() = _parameters
+
+    override fun getImplementation() = implementation
+
+    companion object {
+        fun Method.toMutable() = MutableMethod(this)
+    }
+}

patcher/src/commonMain/kotlin/com/android/tools/smali/dexlib2/mutable/MutableMethodParameter.kt

@@ -0,0 +1,26 @@
+package com.android.tools.smali.dexlib2.mutable
+
+import com.android.tools.smali.dexlib2.base.BaseMethodParameter
+import com.android.tools.smali.dexlib2.iface.MethodParameter
+import com.android.tools.smali.dexlib2.mutable.MutableAnnotation.Companion.toMutable
+
+class MutableMethodParameter(parameter: MethodParameter) : BaseMethodParameter(), MethodParameter {
+    private var type = parameter.type
+    private var name = parameter.name
+    private var signature = parameter.signature
+    private val _annotations by lazy {
+        parameter.annotations.map { annotation -> annotation.toMutable() }.toMutableSet()
+    }
+
+    override fun getType() = type
+
+    override fun getName() = name
+
+    override fun getSignature() = signature
+
+    override fun getAnnotations() = _annotations
+
+    companion object {
+        fun MethodParameter.toMutable() = MutableMethodParameter(this)
+    }
+}

patcher/src/commonMain/kotlin/java/io/File.kt

@@ -0,0 +1,17 @@
+package java.io
+
+internal expect fun File.kmpResolve(child: String): File
+
+internal fun File.resolve(child: String) = kmpResolve(child)
+
+internal expect fun File.kmpDeleteRecursively(): Boolean
+
+internal fun File.deleteRecursively() = kmpDeleteRecursively()
+
+internal expect fun File.kmpInputStream(): InputStream
+
+internal fun File.inputStream() = kmpInputStream()
+
+internal expect fun File.kmpBufferedWriter(charset: java.nio.charset.Charset): BufferedWriter
+
+internal fun File.bufferedWriter(charset: java.nio.charset.Charset) = kmpBufferedWriter(charset)

patcher/src/jvmMain/kotlin/app/revanced/patcher/patch/Patch.jvm.kt

@@ -0,0 +1,32 @@
+package app.revanced.patcher.patch
+
+import java.io.File
+import java.net.URLClassLoader
+import java.util.jar.JarFile
+
+actual val Class<*>.isPatch get() = Patch::class.java.isAssignableFrom(this)
+
+/**
+ * Loads patches from JAR files declared as public static fields
+ * or returned by public static and non-parametrized methods.
+ * Patches with no name are not loaded. If a patches file fails to load,
+ * the [onFailedToLoad] callback is invoked with the file and the throwable
+ * and the loading continues for the other files.
+ *
+ * @param patchesFiles The JAR files to load the patches from.
+ * @param onFailedToLoad A callback invoked when a patches file fails to load.
+ *
+ * @return The loaded patches.
+ */
+actual fun loadPatches(
+    vararg patchesFiles: File,
+    onFailedToLoad: (patchesFile: File, throwable: Throwable) -> Unit,
+) = loadPatches(
+    patchesFiles = patchesFiles,
+    { file ->
+        JarFile(file).entries().toList().filter { it.name.endsWith(".class") }
+            .map { it.name.substringBeforeLast('.').replace('/', '.') }
+    },
+    URLClassLoader(patchesFiles.map { it.toURI().toURL() }.toTypedArray()),
+    onFailedToLoad = onFailedToLoad
+)

patcher/src/jvmMain/kotlin/collections/MutableMap.jvm.kt

@@ -0,0 +1,7 @@
+package collections
+
+internal actual fun <K, V> MutableMap<K, V>.kmpMerge(
+    key: K,
+    value: V,
+    remappingFunction: (oldValue: V, newValue: V) -> V
+) = merge(key, value, remappingFunction)

patcher/src/jvmMain/kotlin/java/io/File.jvm.kt

@@ -0,0 +1,9 @@
+package java.io
+
+import java.nio.charset.Charset
+
+
+internal actual fun File.kmpResolve(child: String) = resolve(child)
+internal actual fun File.kmpDeleteRecursively() = deleteRecursively()
+internal actual fun File.kmpInputStream() = inputStream()
+internal actual fun File.kmpBufferedWriter(charset: Charset) = bufferedWriter(charset)

patcher/src/jvmTest/kotlin/app/revanced/patcher/FingerprintTest.kt

@@ -0,0 +1,27 @@
+package app.revanced.patcher
+
+import org.junit.jupiter.api.BeforeAll
+import org.junit.jupiter.api.TestInstance
+import kotlin.test.Test
+import kotlin.test.assertNotNull
+import kotlin.test.assertNull
+
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
+internal class FingerprintTest : PatcherTestBase() {
+    @BeforeAll
+    fun setup() = setupMock()
+
+    @Test
+    fun `matches fingerprints correctly`() {
+        with(bytecodePatchContext) {
+            assertNotNull(
+                fingerprint { returns("V") }.originalMethodOrNull,
+                "Fingerprints should match correctly."
+            )
+            assertNull(
+                fingerprint { returns("does not exist") }.originalMethodOrNull,
+                "Fingerprints should match correctly."
+            )
+        }
+    }
+}

patcher/src/jvmTest/kotlin/app/revanced/patcher/MatchingTest.kt

@@ -0,0 +1,165 @@
+package app.revanced.patcher
+
+import app.revanced.patcher.BytecodePatchContextMethodMatching.firstMethod
+import app.revanced.patcher.BytecodePatchContextMethodMatching.firstMethodDeclarativelyOrNull
+import app.revanced.patcher.patch.bytecodePatch
+import com.android.tools.smali.dexlib2.Opcode
+import com.android.tools.smali.dexlib2.iface.instruction.TwoRegisterInstruction
+import com.android.tools.smali.dexlib2.iface.instruction.formats.Instruction22t
+import org.junit.jupiter.api.Assertions
+import org.junit.jupiter.api.BeforeAll
+import org.junit.jupiter.api.TestInstance
+import org.junit.jupiter.api.assertDoesNotThrow
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertFalse
+import kotlin.test.assertNotNull
+
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
+class MatchingTest : PatcherTestBase() {
+    @BeforeAll
+    fun setup() = setupMock()
+
+    @Test
+    fun `finds via builder api`() {
+        fun firstMethodComposite(fail: Boolean = false) = firstMethodComposite {
+            name("method")
+            definingClass("class")
+
+            if (fail) returnType("doesnt exist")
+
+            instructions(
+                at(Opcode.CONST_STRING()),
+                `is`<TwoRegisterInstruction>(),
+                noneOf(registers()),
+                string("test", String::contains),
+                after(1..3, allOf(Opcode.INVOKE_VIRTUAL(), registers(1, 0))),
+                allOf(),
+                type("PrintStream;", String::endsWith)
+            )
+        }
+
+        with(bytecodePatchContext) {
+            assertNotNull(firstMethodComposite().methodOrNull) { "Expected to find a method" }
+            Assertions.assertNull(firstMethodComposite(fail = true).immutableMethodOrNull) { "Expected to not find a method" }
+            Assertions.assertNotNull(
+                firstMethodComposite().match(classDefs.first()).methodOrNull
+            ) { "Expected to find a method matching in a specific class" }
+        }
+    }
+
+    @Test
+    fun `finds via declarative api`() {
+        bytecodePatch {
+            apply {
+                val method = firstMethodDeclarativelyOrNull {
+                    anyOf {
+                        predicate { name == "method" }
+                        add { false }
+                    }
+                    allOf {
+                        predicate { returnType == "V" }
+                    }
+                    predicate { definingClass == "class" }
+                }
+                assertNotNull(method) { "Expected to find a method" }
+            }
+        }()
+    }
+
+    @Test
+    fun `predicate api works correctly`() {
+        bytecodePatch {
+            apply {
+                assertDoesNotThrow("Should find method") { firstMethod { name == "method" } }
+            }
+        }
+    }
+
+    @Test
+    fun `matcher finds indices correctly`() {
+        val iterable = (1..10).toList()
+        val matcher = indexedMatcher<Int>()
+
+        matcher.apply {
+            +at<Int> { this > 5 }
+        }
+        assertFalse(
+            matcher(iterable),
+            "Should not match at any other index than first"
+        )
+        matcher.clear()
+
+        matcher.apply { +at<Int> { this == 1 } }(iterable)
+        assertEquals(
+            listOf(0),
+            matcher.indices,
+            "Should match at first index."
+        )
+        matcher.clear()
+
+        matcher.apply { add { _, _, _ -> this > 0 } }(iterable)
+        assertEquals(1, matcher.indices.size, "Should only match once.")
+        matcher.clear()
+
+        matcher.apply { add { _, _, _ -> this == 2 } }(iterable)
+        assertEquals(
+            listOf(1),
+            matcher.indices,
+            "Should find the index correctly."
+        )
+        matcher.clear()
+
+        matcher.apply {
+            +at<Int> { this == 1 }
+            add { _, _, _ -> this == 2 }
+            add { _, _, _ -> this == 4 }
+        }(iterable)
+        assertEquals(
+            listOf(0, 1, 3),
+            matcher.indices,
+            "Should match 1, 2 and 4 at indices 0, 1 and 3."
+        )
+        matcher.clear()
+
+        matcher.apply {
+            +after<Int> { this == 1 }
+        }(iterable)
+        assertEquals(
+            listOf(0),
+            matcher.indices,
+            "Should match index 0 after nothing"
+        )
+        matcher.clear()
+
+        matcher.apply {
+            +after<Int>(2..Int.MAX_VALUE) { this == 1 }
+        }
+        assertFalse(
+            matcher(iterable),
+            "Should not match, because 1 is out of range"
+        )
+        matcher.clear()
+
+        matcher.apply {
+            +after<Int>(1..1) { this == 2 }
+        }
+        assertFalse(
+            matcher(iterable),
+            "Should not match, because 2 is at index 1"
+        )
+        matcher.clear()
+
+        matcher.apply {
+            +at<Int> { this == 1 }
+            +after<Int>(2..5) { this == 4 }
+            add { _, _, _ -> this == 8 }
+            add { _, _, _ -> this == 9 }
+        }(iterable)
+        assertEquals(
+            listOf(0, 3, 7, 8),
+            matcher.indices,
+            "Should match indices correctly."
+        )
+    }
+}

patcher/src/jvmTest/kotlin/app/revanced/patcher/PatcherTest.kt

@@ -0,0 +1,80 @@
+package app.revanced.patcher
+
+import app.revanced.patcher.patch.Patch
+import app.revanced.patcher.patch.PatchException
+import app.revanced.patcher.patch.bytecodePatch
+import org.junit.jupiter.api.BeforeAll
+import org.junit.jupiter.api.TestInstance
+import org.junit.jupiter.api.assertThrows
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+@TestInstance(TestInstance.Lifecycle.PER_CLASS)
+internal class PatcherTest : PatcherTestBase() {
+    @BeforeAll
+    fun setup() = setupMock()
+
+    @Test
+    fun `applies patches in correct order`() {
+        val applied = mutableListOf<String>()
+
+        infix fun Patch.resultsIn(equals: List<String>) = this to equals
+        infix fun Pair<Patch, List<String>>.because(reason: String) {
+            runCatching { setOf(first)() }
+
+            assertEquals(second, applied, reason)
+
+            applied.clear()
+        }
+
+        bytecodePatch {
+            dependsOn(
+                bytecodePatch {
+                    apply { applied += "1" }
+                    afterDependents { applied += "-2" }
+                },
+                bytecodePatch { apply { applied += "2" } },
+            )
+            apply { applied += "3" }
+            afterDependents { applied += "-1" }
+        } resultsIn listOf("1", "2", "3", "-1", "-2") because
+                "Patches should apply in post-order and afterDependents in pre-order."
+
+        bytecodePatch {
+            dependsOn(
+                bytecodePatch {
+                    apply { throw PatchException("1") }
+                    afterDependents { applied += "-2" }
+                },
+            )
+            apply { applied += "2" }
+            afterDependents { applied += "-1" }
+        } resultsIn emptyList() because
+                "Patches that depend on a patched that failed to apply should not be applied."
+
+        bytecodePatch {
+            dependsOn(
+                bytecodePatch {
+                    apply { applied += "1" }
+                    afterDependents { applied += "-2" }
+                },
+            )
+            apply { throw PatchException("2") }
+            afterDependents { applied += "-1" }
+        } resultsIn listOf("1", "-2") because
+                "afterDependents of a patch should not be called if it failed to apply."
+
+        bytecodePatch {
+            dependsOn(
+                bytecodePatch {
+                    apply { applied += "1" }
+                    afterDependents { applied += "-2" }
+                },
+            )
+            apply { applied += "2" }
+            afterDependents { throw PatchException("-1") }
+        } resultsIn listOf("1", "2", "-2") because
+                "afterDependents of a patch should be called " +
+                "regardless of dependant patches failing."
+    }
+}

patcher/src/jvmTest/kotlin/app/revanced/patcher/PatcherTestBase.kt

@@ -0,0 +1,105 @@
+package app.revanced.patcher
+
+import app.revanced.patcher.extensions.toInstructions
+import app.revanced.patcher.patch.BytecodePatchContext
+import app.revanced.patcher.patch.Patch
+import app.revanced.patcher.patch.ResourcePatchContext
+import com.android.tools.smali.dexlib2.Opcodes
+import com.android.tools.smali.dexlib2.iface.DexFile
+import com.android.tools.smali.dexlib2.immutable.ImmutableClassDef
+import com.android.tools.smali.dexlib2.immutable.ImmutableMethod
+import com.android.tools.smali.dexlib2.immutable.ImmutableMethodImplementation
+import io.mockk.every
+import io.mockk.justRun
+import io.mockk.mockk
+import io.mockk.mockkStatic
+import lanchon.multidexlib2.MultiDexIO
+import java.io.File
+import java.io.InputStream
+
+abstract class PatcherTestBase {
+    protected lateinit var bytecodePatchContext: BytecodePatchContext
+    protected lateinit var resourcePatchContext: ResourcePatchContext
+
+    protected fun setupMock(
+        method: ImmutableMethod = ImmutableMethod(
+            "class",
+            "method",
+            emptyList(),
+            "V",
+            0,
+            null,
+            null,
+            ImmutableMethodImplementation(
+                2,
+                """
+                    const-string v0, "Hello, World!"
+                    iput-object v0, p0, Ljava/lang/System;->out:Ljava/io/PrintStream;
+                    iget-object v0, p0, Ljava/lang/System;->out:Ljava/io/PrintStream;
+                    return-void
+                    const-string v0, "This is a test."
+                    return-object v0
+                    invoke-virtual { p0, v0 }, Ljava/io/PrintStream;->println(Ljava/lang/String;)V
+                    invoke-static { p0 }, Ljava/lang/System;->currentTimeMillis()J
+                    check-cast p0, Ljava/io/PrintStream;
+                """.toInstructions(),
+                null,
+                null
+            ),
+        ),
+    ) {
+        resourcePatchContext = mockk<ResourcePatchContext>(relaxed = true)
+        bytecodePatchContext = mockk<BytecodePatchContext> bytecodePatchContext@{
+            mockkStatic(MultiDexIO::readDexFile)
+            every {
+                MultiDexIO.readDexFile(
+                    any(),
+                    any(),
+                    any(),
+                    any(),
+                    any()
+                )
+            } returns mockk<DexFile> {
+                every { classes } returns mutableSetOf(
+                    ImmutableClassDef(
+                        "class",
+                        0,
+                        null,
+                        null,
+                        null,
+                        null,
+                        null,
+                        listOf(method),
+                    )
+                )
+                every { opcodes } returns Opcodes.getDefault()
+            }
+
+            every { this@bytecodePatchContext.getProperty("apkFile") } returns mockk<File>()
+
+            every { this@bytecodePatchContext.classDefs } returns ClassDefs().apply {
+                javaClass.getDeclaredMethod($$"initializeCache$patcher").apply {
+                    isAccessible = true
+                }.invoke(this)
+            }
+
+            every { get() } returns emptySet()
+
+            justRun { this@bytecodePatchContext["extendWith"](any<InputStream>()) }
+        }
+    }
+
+    protected operator fun Set<Patch>.invoke() {
+        runCatching {
+            apply(
+                bytecodePatchContext,
+                resourcePatchContext
+            ) { }
+        }.fold(
+            { it.dexFiles },
+            { it.printStackTrace() }
+        )
+    }
+
+    protected operator fun Patch.invoke() = setOf(this)()
+}

patcher/src/jvmTest/kotlin/app/revanced/patcher/extensions/MethodExtensionsTest.kt

@@ -0,0 +1,253 @@
+package app.revanced.patcher.extensions
+
+import com.android.tools.smali.dexlib2.AccessFlags
+import com.android.tools.smali.dexlib2.Opcode
+import com.android.tools.smali.dexlib2.builder.BuilderOffsetInstruction
+import com.android.tools.smali.dexlib2.builder.MutableMethodImplementation
+import com.android.tools.smali.dexlib2.builder.instruction.BuilderInstruction21s
+import com.android.tools.smali.dexlib2.iface.instruction.OneRegisterInstruction
+import com.android.tools.smali.dexlib2.immutable.ImmutableMethod
+import com.android.tools.smali.dexlib2.mutable.MutableMethod
+import com.android.tools.smali.dexlib2.mutable.MutableMethod.Companion.toMutable
+import org.junit.jupiter.api.BeforeEach
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+internal class MethodExtensionsTest {
+    private val testInstructions = (0..9).map { i -> TestInstruction(i) }
+    private var method = ImmutableMethod(
+        "TestClass;",
+        "testMethod",
+        null,
+        "V",
+        AccessFlags.PUBLIC.value,
+        null,
+        null,
+        MutableMethodImplementation(16)
+    ).toMutable()
+
+    @BeforeEach
+    fun setup() {
+        method.instructions.clear()
+        method.addInstructions(testInstructions)
+    }
+
+    @Test
+    fun addInstructionsToImplementationIndexed() =
+        applyToImplementation {
+            addInstructions(5, getTestInstructions(5..6)).also {
+                assertRegisterIs(5, 5)
+                assertRegisterIs(6, 6)
+
+                assertRegisterIs(5, 7)
+            }
+        }
+
+    @Test
+    fun addInstructionsToImplementation() =
+        applyToImplementation {
+            addInstructions(getTestInstructions(10..11)).also {
+                assertRegisterIs(10, 10)
+                assertRegisterIs(11, 11)
+            }
+        }
+
+    @Test
+    fun removeInstructionsFromImplementationIndexed() =
+        applyToImplementation {
+            removeInstructions(5, 5).also { assertRegisterIs(4, 4) }
+        }
+
+    @Test
+    fun removeInstructionsFromImplementation() =
+        applyToImplementation {
+            removeInstructions(0).also { assertRegisterIs(9, 9) }
+            removeInstructions(1).also { assertRegisterIs(1, 0) }
+            removeInstructions(2).also { assertRegisterIs(3, 0) }
+        }
+
+    @Test
+    fun replaceInstructionsInImplementationIndexed() =
+        applyToImplementation {
+            replaceInstructions(5, getTestInstructions(0..1)).also {
+                assertRegisterIs(0, 5)
+                assertRegisterIs(1, 6)
+                assertRegisterIs(7, 7)
+            }
+        }
+
+    @Test
+    fun addInstructionToMethodIndexed() =
+        applyToMethod {
+            addInstruction(5, TestInstruction(0)).also { assertRegisterIs(0, 5) }
+        }
+
+    @Test
+    fun addInstructionToMethod() =
+        applyToMethod {
+            addInstruction(TestInstruction(0)).also { assertRegisterIs(0, 10) }
+        }
+
+    @Test
+    fun addSmaliInstructionToMethodIndexed() =
+        applyToMethod {
+            addInstruction(5, getTestSmaliInstruction(0)).also { assertRegisterIs(0, 5) }
+        }
+
+    @Test
+    fun addSmaliInstructionToMethod() =
+        applyToMethod {
+            addInstruction(getTestSmaliInstruction(0)).also { assertRegisterIs(0, 10) }
+        }
+
+    @Test
+    fun addInstructionsToMethodIndexed() =
+        applyToMethod {
+            addInstructions(5, getTestInstructions(0..1)).also {
+                assertRegisterIs(0, 5)
+                assertRegisterIs(1, 6)
+
+                assertRegisterIs(5, 7)
+            }
+        }
+
+    @Test
+    fun addInstructionsToMethod() =
+        applyToMethod {
+            addInstructions(getTestInstructions(0..1)).also {
+                assertRegisterIs(0, 10)
+                assertRegisterIs(1, 11)
+
+                assertRegisterIs(9, 9)
+            }
+        }
+
+    @Test
+    fun addSmaliInstructionsToMethodIndexed() =
+        applyToMethod {
+            addInstructionsWithLabels(5, getTestSmaliInstructions(0..1)).also {
+                assertRegisterIs(0, 5)
+                assertRegisterIs(1, 6)
+
+                assertRegisterIs(5, 7)
+            }
+        }
+
+    @Test
+    fun addSmaliInstructionsToMethod() =
+        applyToMethod {
+            addInstructions(getTestSmaliInstructions(0..1)).also {
+                assertRegisterIs(0, 10)
+                assertRegisterIs(1, 11)
+
+                assertRegisterIs(9, 9)
+            }
+        }
+
+    @Test
+    fun addSmaliInstructionsWithExternalLabelToMethodIndexed() =
+        applyToMethod {
+            val label = ExternalLabel("testLabel", getInstruction(5))
+
+            addInstructionsWithLabels(
+                5,
+                getTestSmaliInstructions(0..1).plus("\n").plus("goto :${label.name}"),
+                label,
+            ).also {
+                assertRegisterIs(0, 5)
+                assertRegisterIs(1, 6)
+                assertRegisterIs(5, 8)
+
+                val gotoTarget =
+                    getInstruction<BuilderOffsetInstruction>(7)
+                        .target.location.instruction as OneRegisterInstruction
+
+                assertEquals(5, gotoTarget.registerA)
+            }
+        }
+
+    @Test
+    fun removeInstructionFromMethodIndexed() =
+        applyToMethod {
+            removeInstruction(5).also {
+                assertRegisterIs(4, 4)
+                assertRegisterIs(6, 5)
+            }
+        }
+
+    @Test
+    fun removeInstructionsFromMethodIndexed() =
+        applyToMethod {
+            removeInstructions(5, 5).also { assertRegisterIs(4, 4) }
+        }
+
+    @Test
+    fun removeInstructionsFromMethod() =
+        applyToMethod {
+            removeInstructions(0).also { assertRegisterIs(9, 9) }
+            removeInstructions(1).also { assertRegisterIs(1, 0) }
+            removeInstructions(2).also { assertRegisterIs(3, 0) }
+        }
+
+    @Test
+    fun replaceInstructionInMethodIndexed() =
+        applyToMethod {
+            replaceInstruction(5, TestInstruction(0)).also { assertRegisterIs(0, 5) }
+        }
+
+    @Test
+    fun replaceInstructionsInMethodIndexed() =
+        applyToMethod {
+            replaceInstructions(5, getTestInstructions(0..1)).also {
+                assertRegisterIs(0, 5)
+                assertRegisterIs(1, 6)
+                assertRegisterIs(7, 7)
+            }
+        }
+
+    @Test
+    fun replaceSmaliInstructionsInMethodIndexed() =
+        applyToMethod {
+            replaceInstructions(5, getTestSmaliInstructions(0..1)).also {
+                assertRegisterIs(0, 5)
+                assertRegisterIs(1, 6)
+                assertRegisterIs(7, 7)
+            }
+        }
+
+    // region Helper methods
+
+    private fun applyToImplementation(block: MutableMethodImplementation.() -> Unit) {
+        method.implementation!!.apply(block)
+    }
+
+    private fun applyToMethod(block: MutableMethod.() -> Unit) {
+        method.apply(block)
+    }
+
+    private fun MutableMethodImplementation.assertRegisterIs(
+        register: Int,
+        atIndex: Int,
+    ) = assertEquals(
+        register,
+        getInstruction<OneRegisterInstruction>(atIndex).registerA,
+    )
+
+    private fun MutableMethod.assertRegisterIs(
+        register: Int,
+        atIndex: Int,
+    ) = implementation!!.assertRegisterIs(register, atIndex)
+
+    private fun getTestInstructions(range: IntRange) = range.map { TestInstruction(it) }
+
+    private fun getTestSmaliInstruction(register: Int) = "const/16 v$register, 0"
+
+    private fun getTestSmaliInstructions(range: IntRange) =
+        range.joinToString("\n") {
+            getTestSmaliInstruction(it)
+        }
+
+    // endregion
+
+    private class TestInstruction(register: Int) : BuilderInstruction21s(Opcode.CONST_16, register, 0)
+}

patcher/src/jvmTest/kotlin/app/revanced/patcher/patch/OptionsTest.kt

@@ -0,0 +1,146 @@
+package app.revanced.patcher.patch
+
+import org.junit.jupiter.api.assertDoesNotThrow
+import org.junit.jupiter.api.assertThrows
+import kotlin.reflect.typeOf
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertNull
+import kotlin.test.assertTrue
+
+internal object OptionsTest {
+    private val externalOption = stringOption("external", "default")
+
+    private val optionsTestPatch = bytecodePatch {
+        externalOption()
+
+        booleanOption("bool", true)
+
+        stringOption("required", "default", required = true)
+
+        stringsOption("list", listOf("1", "2"))
+
+        stringOption("choices", "value", values = mapOf("Valid option value" to "valid"))
+
+        stringOption("validated", "default") { it == "valid" }
+
+        stringOption("resettable", null, required = true)
+    }
+
+    @Test
+    fun `should not fail because default value is unvalidated`() = options {
+        assertDoesNotThrow { get("required") }
+    }
+
+    @Test
+    fun `should not allow setting custom value with validation`() = options {
+        // Getter validation on incorrect value.
+        assertThrows<OptionException.ValueValidationException> {
+            set("validated", get("validated"))
+        }
+
+        // Setter validation on incorrect value.
+        assertThrows<OptionException.ValueValidationException> {
+            set("validated", "invalid")
+        }
+
+        // Setter validation on correct value.
+        assertDoesNotThrow {
+            set("validated", "valid")
+        }
+    }
+
+    @Test
+    fun `should throw due to incorrect type`() = options {
+        assertThrows<OptionException.InvalidValueTypeException> {
+            set("bool", "not a boolean")
+        }
+    }
+
+    @Test
+    fun `should be nullable`() = options {
+        assertDoesNotThrow {
+            set("bool", null)
+        }
+    }
+
+    @Test
+    fun `option should not be found`() = options {
+        assertThrows<OptionException.OptionNotFoundException> {
+            set("this option does not exist", 1)
+        }
+    }
+
+    @Test
+    fun `should be able to add options manually`() = options {
+        assertDoesNotThrow {
+            bytecodePatch {
+                get("list")()
+            }.options["list"]
+        }
+    }
+
+    @Test
+    fun `should allow setting value from values`() = options {
+        @Suppress("UNCHECKED_CAST")
+        val option = get("choices") as Option<String>
+
+        option.value = option.values!!.values.last()
+
+        assertTrue(option.value == "valid")
+    }
+
+    @Test
+    fun `should allow setting custom value`() = options {
+        assertDoesNotThrow {
+            set("choices", "unknown")
+        }
+    }
+
+    @Test
+    fun `should allow resetting value`() = options {
+        assertDoesNotThrow {
+            set("choices", null)
+        }
+
+        assert(get("choices").value == null)
+    }
+
+    @Test
+    fun `reset should not fail`() = options {
+        assertDoesNotThrow {
+            set("resettable", "test")
+            get("resettable").reset()
+        }
+
+        assertThrows<OptionException.ValueRequiredException> {
+            get("resettable").value
+        }
+    }
+
+    @Test
+    fun `option types should be known`() = options {
+        assertEquals(typeOf<List<String>>(), get("list").type)
+    }
+
+    @Test
+    fun `getting default value should work`() = options {
+        assertDoesNotThrow {
+            assertNull(get("resettable").default)
+        }
+    }
+
+    @Test
+    fun `external option should be accessible`() {
+        assertDoesNotThrow {
+            externalOption.value = "test"
+        }
+    }
+
+    @Test
+    fun `should allow getting the external option from the patch`() {
+        assertEquals(optionsTestPatch.options["external"].value, externalOption.value)
+    }
+
+    private fun options(block: Options.() -> Unit) = optionsTestPatch.options.let(block)
+}

patcher/src/jvmTest/kotlin/app/revanced/patcher/patch/PatchTest.kt

@@ -0,0 +1,85 @@
+package app.revanced.patcher.patch
+
+import kotlin.reflect.jvm.javaField
+import kotlin.test.Test
+import kotlin.test.assertEquals
+
+internal object PatchTest {
+    @Test
+    fun `can create patch with name`() {
+        val patch = bytecodePatch(name = "Test") {}
+
+        assertEquals("Test", patch.name)
+    }
+
+    @Test
+    fun `can create patch with compatible packages`() {
+        val patch = bytecodePatch(name = "Test") {
+            compatibleWith(
+                "compatible.package"("1.0.0"),
+            )
+        }
+
+        assertEquals(1, patch.compatiblePackages!!.size)
+        assertEquals("compatible.package", patch.compatiblePackages!!.first().first)
+    }
+
+    @Test
+    fun `can create patch with dependencies`() {
+        val patch = bytecodePatch(name = "Test") {
+            dependsOn(resourcePatch {})
+        }
+
+        assertEquals(1, patch.dependencies.size)
+    }
+
+    @Test
+    fun `can create patch with options`() {
+        val patch = bytecodePatch(name = "Test") {
+            val print by stringOption("print")
+            val custom = option<String>("custom")()
+
+            this.apply {
+                println(print)
+                println(custom.value)
+            }
+        }
+
+        assertEquals(2, patch.options.size)
+    }
+
+    @Test
+    fun `loads patches correctly`() {
+        val patchesClass = ::Public.javaField!!.declaringClass.name
+        val classLoader = ::Public.javaClass.classLoader
+
+        val patches = getPatches(listOf(patchesClass), classLoader)
+
+        assertEquals(
+            2,
+            patches.size,
+            "Expected 2 patches to be loaded, " +
+                    "because there's only two named patches declared as public static fields " +
+                    "or returned by public static and non-parametrized methods.",
+        )
+    }
+}
+
+val publicUnnamedPatch = bytecodePatch {} // Not loaded, because it's unnamed.
+
+val Public by creatingBytecodePatch {} // Loaded, because it's named.
+
+private val privateUnnamedPatch = bytecodePatch {} // Not loaded, because it's private.
+
+private val Private by creatingBytecodePatch {}  // Not loaded, because it's private.
+
+fun publicUnnamedPatchFunction() = publicUnnamedPatch // Not loaded, because it's unnamed.
+
+fun publicNamedPatchFunction() = bytecodePatch("Public") { } // Loaded, because it's named.
+
+fun parameterizedFunction(@Suppress("UNUSED_PARAMETER") param: Any) =
+    publicNamedPatchFunction() // Not loaded, because it's parameterized.
+
+private fun privateUnnamedPatchFunction() = privateUnnamedPatch // Not loaded, because it's private.
+
+private fun privateNamedPatchFunction() = Private // Not loaded, because it's private.

patcher/src/jvmTest/kotlin/app/revanced/patcher/util/SmaliTest.kt

@@ -0,0 +1,76 @@
+package app.revanced.patcher.util
+
+import app.revanced.patcher.extensions.*
+import com.android.tools.smali.dexlib2.AccessFlags
+import com.android.tools.smali.dexlib2.builder.BuilderOffsetInstruction
+import com.android.tools.smali.dexlib2.builder.MutableMethodImplementation
+import com.android.tools.smali.dexlib2.builder.instruction.BuilderInstruction21t
+import com.android.tools.smali.dexlib2.immutable.ImmutableMethod
+import com.android.tools.smali.dexlib2.mutable.MutableMethod.Companion.toMutable
+import org.junit.jupiter.api.BeforeEach
+import kotlin.test.Test
+import kotlin.test.assertEquals
+import kotlin.test.assertTrue
+
+internal class SmaliTest {
+    val method = ImmutableMethod(
+        "Ldummy;",
+        "name",
+        emptyList(), // parameters
+        "V",
+        AccessFlags.PUBLIC.value,
+        null,
+        null,
+        MutableMethodImplementation(1),
+    ).toMutable()
+
+
+    @BeforeEach
+    fun setup() {
+        method.instructions.clear()
+    }
+
+    @Test
+    fun `own branches work`() {
+        method.addInstructionsWithLabels(
+            0,
+            """
+                :test
+                const/4 v0, 0x1
+                if-eqz v0, :test
+            """,
+        )
+
+        val targetLocationIndex = method.getInstruction<BuilderOffsetInstruction>(1).target.location.index
+
+        assertEquals(0, targetLocationIndex, "Label should point to index 0")
+    }
+
+    @Test
+    fun `external branches work`() {
+        val instructionIndex = 3
+        val labelIndex = 1
+
+        method.addInstructions(
+            """
+                const/4 v0, 0x1
+                const/4 v0, 0x0
+            """,
+        )
+
+        method.addInstructionsWithLabels(
+            method.instructions.size,
+            """
+                const/4 v0, 0x1
+                if-eqz v0, :test
+                return-void
+            """,
+            ExternalLabel("test", method.getInstruction(1)),
+        )
+
+        val instruction = method.getInstruction<BuilderInstruction21t>(instructionIndex)
+
+        assertTrue(instruction.target.isPlaced, "Label should be placed")
+        assertEquals(labelIndex, instruction.target.location.index)
+    }
+}

settings.gradle.kts

@@ -1 +1,24 @@
 rootProject.name = "revanced-patcher"
+enableFeaturePreview("TYPESAFE_PROJECT_ACCESSORS")
+
+pluginManagement {
+    repositories {
+        mavenCentral()
+        google()
+    }
+}
+
+dependencyResolutionManagement {
+    repositories {
+        mavenCentral()
+        google()
+        maven {
+            name = "githubPackages"
+            // A repository must be specified for some reason. "registry" is a dummy.
+            url = uri("https://maven.pkg.github.com/revanced/registry")
+            credentials(PasswordCredentials::class)
+        }
+    }
+}
+
+include(":patcher")