fix(Spotify): Add Spoof client patch to fix various issues by using a web platform access token (#5173)

Co-authored-by: Nuckyz <61953774+Nuckyz@users.noreply.github.com>
Co-authored-by: brosssh <tiabroch@gmail.com>
Co-authored-by: Dawid Krajcarz <80264606+drobotk@users.noreply.github.com>
Co-authored-by: LisoUseInAIKyrios <118716522+LisoUseInAIKyrios@users.noreply.github.com>

extensions/spotify/utils/src/main/antlr/app/revanced/extension/spotify/UserAgent.g4

@@ -0,0 +1,35 @@
+grammar UserAgent;
+
+@header { package app.revanced.extension.spotify; }
+
+userAgent
+    : product (WS product)* EOF
+    ;
+
+product
+    : name ('/' version)? (WS comment)?
+    ;
+
+name
+    : STRING
+    ;
+
+version
+    : STRING ('.' STRING)*
+    ;
+
+comment
+    : COMMENT
+    ;
+
+COMMENT
+    : '(' ~ ')'* ')'
+    ;
+
+STRING
+    : [a-zA-Z0-9]+
+    ;
+
+WS
+    : [ \r\n]+
+    ;

extensions/spotify/utils/src/main/java/app/revanced/extension/spotify/UserAgent.java

@@ -0,0 +1,60 @@
+package app.revanced.extension.spotify;
+
+import org.antlr.v4.runtime.CharStream;
+import org.antlr.v4.runtime.CharStreams;
+import org.antlr.v4.runtime.CommonTokenStream;
+import org.antlr.v4.runtime.TokenStreamRewriter;
+import org.antlr.v4.runtime.tree.ParseTreeWalker;
+
+public class UserAgent {
+    private final UserAgentParser.UserAgentContext tree;
+    private final TokenStreamRewriter rewriter;
+    private final ParseTreeWalker walker;
+
+    public UserAgent(String userAgentString) {
+        CharStream input = CharStreams.fromString(userAgentString);
+        UserAgentLexer lexer = new UserAgentLexer(input);
+        CommonTokenStream tokens = new CommonTokenStream(lexer);
+
+        tree = new UserAgentParser(tokens).userAgent();
+        walker = new ParseTreeWalker();
+        rewriter = new TokenStreamRewriter(tokens);
+    }
+
+    public UserAgent withoutProduct(String name) {
+        walker.walk(new UserAgentBaseListener() {
+            @Override
+            public void exitProduct(UserAgentParser.ProductContext ctx) {
+                if (!ctx.name().getText().contains(name)) return;
+
+                int startIndex = ctx.getStart().getTokenIndex();
+                if (startIndex != 0) startIndex -= 1; // Also remove the preceding whitespace.
+
+                int stopIndex = ctx.getStop().getTokenIndex();
+
+                
+                rewriter.delete(startIndex, stopIndex);
+            }
+        }, tree);
+
+        return new UserAgent(rewriter.getText().trim());
+    }
+
+    public UserAgent withCommentReplaced(String containing, String replacement) {
+        walker.walk(new UserAgentBaseListener() {
+            @Override
+            public void exitComment(UserAgentParser.CommentContext ctx) {
+                if (ctx.getText().contains(containing)) {
+                    rewriter.replace(ctx.getStart(), ctx.getStop(), "(" + replacement + ")");
+                }
+            }
+        }, tree);
+
+        return new UserAgent(rewriter.getText());
+    }
+
+    @Override
+    public String toString() {
+        return rewriter.getText();
+    }
+}