Imported from mira-x/SicMu (AGENTS.md). Install upstream with npx skills add mira-x/SicMu. Copyright stays with the author.

SicMu Neo - Technical Overview for Agents

SicMu Neo is a file-based Android music player (Java 11, SDK 36, Min SDK 26).

Key Components & Architecture

• Main.java: Entry point Activity. Handles UI, permissions, and service binding.
• MusicService.java: Core playback engine using Media3 (ExoPlayer). Implements MediaBrowserServiceCompat.
• Data Model: Hierarchical tree structure using Row, RowGroup, and RowSong.
• Metadata: Uses a hard-forked org.jaudiotagger for audio tags.
• Persistence: Room Database (SongDatabase.java, Database.java) for metadata caching and configuration.
• UI: Minimalist, uses RowsAdapter.java for the main list. Supports dark/light themes via Theme.java.

Critical Patterns

• File System Centric: Primarily navigates via Path.java. Metadata mode is a secondary view of the same structure.
• Service Communication: Main activity communicates with MusicService via AIDL/Binder and MediaSession.
• Audio Processing: Custom BypassAudioProcessor and MergeAudioProcessor handle mono/stereo downmixing.

1. Think Before Coding -- Don't assume. Don't hide confusion. Surface tradeoffs. Before implementing:

• State your assumptions explicitly. If uncertain, ask.
• If multiple interpretations exist, present them - don't pick silently.
• If a simpler approach exists, say so. Push back when warranted.
• If something is unclear, stop. Name what's confusing. Ask.

2. Simplicity First -- Minimum code that solves the problem. Nothing speculative.

• No features beyond what was asked.
• No abstractions for single-use code.
• No "flexibility" or "configurability" that wasn't requested.
• No error handling for impossible scenarios.
• No fallback mechanisms that were'nt requested
• If you write 200 lines and it could be 50, rewrite it.

Ask yourself: "Would a team of the senior engineers Russ Cox, Rob Pike, Ken Thompson and Dennis Richie say this is overcomplicated?" If yes, simplify.

3. Surgical Changes -- Touch only what you must. Clean up only your own mess. When editing existing code:

• Don't "improve" adjacent code, comments, or formatting.
• Don't refactor things that aren't broken.
• Match existing style, even if you'd do it differently.
• If you notice unrelated dead code, mention it - don't delete it.

When your changes create orphans:

• Remove imports/variables/functions that YOUR changes made unused.
• Don't remove pre-existing dead code unless asked.

The test: Every changed line should trace directly to the user's request.

4. Goal-Driven Execution -- Define success criteria. Loop until verified. Transform tasks into verifiable goals:

• "Add validation" → "Write tests for invalid inputs, then make them pass"
• "Fix the bug" → "Write a test that reproduces it, then make it pass"
• "Refactor X" → "Ensure tests pass before and after"

For multi-step tasks, state a brief plan:

1. [Step] → verify: [check]
2. [Step] → verify: [check]
3. [Step] → verify: [check]

Strong success criteria let you loop independently. Weak criteria ("make it work") require constant clarification.