add: resource patcher

Signed-off-by: oSumAtrIX <johan.melkonyan1@web.de>

src/main/kotlin/app/revanced/utils/filesystem/FileSystemUtils.kt

@@ -0,0 +1,66 @@
+package app.revanced.utils.filesystem
+
+import java.io.Closeable
+import java.io.File
+import java.nio.file.FileSystem
+import java.nio.file.FileSystems
+import java.nio.file.Files
+
+internal class FileSystemUtils(
+    file: File
+) : Closeable {
+    private var fileSystem: FileSystem
+
+    init {
+        fileSystem = FileSystems.newFileSystem(
+            file.toPath(),
+            null
+        )
+    }
+
+    private fun deleteDirectory(dirPath: String) {
+        val files = Files.walk(fileSystem.getPath("$dirPath/"))
+
+        files
+            .sorted(Comparator.reverseOrder())
+            .forEach {
+
+                Files.delete(it)
+            }
+
+        files.close()
+    }
+
+
+    internal fun replaceDirectory(replacement: File) {
+        if (!replacement.isDirectory) throw Exception("${replacement.name} is not a directory.")
+
+        // FIXME: make this delete the directory recursively
+        //deleteDirectory(replacement.name)
+        //val path = Files.createDirectory(fileSystem.getPath(replacement.name))
+
+        val excludeFromPath = replacement.path.removeSuffix(replacement.name)
+        for (path in Files.walk(replacement.toPath())) {
+            val file = path.toFile()
+            if (file.isDirectory) {
+                val relativePath = path.toString().removePrefix(excludeFromPath)
+                val fileSystemPath = fileSystem.getPath(relativePath)
+                if (!Files.exists(fileSystemPath)) Files.createDirectory(fileSystemPath)
+
+                continue
+            }
+
+            replaceFile(path.toString().removePrefix(excludeFromPath), file.readBytes())
+        }
+    }
+
+    internal fun replaceFile(sourceFile: String, content: ByteArray) {
+        val path = fileSystem.getPath(sourceFile)
+        Files.deleteIfExists(path)
+        Files.write(path, content)
+    }
+
+    override fun close() {
+        fileSystem.close()
+    }
+}