# Archive Report: Android Auto Local Music — Phase 1

**Date Archived**: 2026-07-19  
**Change**: android-auto-local-music  
**Verification Status**: PASS WITH WARNINGS (0 CRITICAL, 1 WARNING, 1 SUGGESTION)  
**Delivery Mode**: Single PR with `size:exception` (commit 6ae7e37, all changes staged)

## Summary

Phase 1 of the local-music browsing feature (foundational plumbing) has been successfully implemented, verified, and archived. The feature enables users to pick a local-music root folder via SAF, browse nested folders recursively in Android Auto, and play audio files through the existing pipeline. All Phase 1 scope (SAF access, recursive tree traversal, playback integration) is complete and tested. Phases 2 and 3 (metadata extraction, sort/filter, subfolder refinements, shuffle) remain explicitly deferred as planned future work.

## Verification Results

**Test Evidence**: 91/91 tests passing (66 navigation tests + 4 audio-file tests + 21 regression tests)

**Spec Compliance**: All 4 ADDED and 1 MODIFIED requirements implemented and verified:
- Local Music Root Access and Permission Persistence: cold-start safe, graceful degradation on revoked permission
- Local Music Browsable Tree: 5-folder root (new `Musica Local` folder 4th, before `Ecualizador`), recursive `carpeta_local:`/`pista:` browsing, empty folders return `[]`
- Local Track Playback Reuses Existing Pipeline: `pista:` playback routed through same `playMediaItem` seam as stations, EQ regression guard passed
- Local Music Folder Item Cap: 50-item cap enforced, alphabetically sorted
- Browsable Media Tree (MODIFIED): root now returns 5 folders (was 4)

**Native Code**: Static-review only (Android build/DHU not available in this environment, per project precedent). `MainActivity.kt` additions validated structurally: SAF APIs correct, cursor management sound, result handling explicit, no resource leaks detected.

**Files Changed**: 8 tracked files (1046 insertions, 29 deletions), 3 new untracked files (267 lines), within estimate.

## Warnings and Follow-up

**WARNING (FIXED)**: L10n locale completeness — 11 non-English/non-Spanish `.arb` files were initially skipped with an inaccurate justification. This was **flagged in verify-report.md and subsequently fixed in commit 6ae7e37**, which added all 13 locale translations before archival. All 13 locale files now contain the new `localMusicSectionTitle`, `localMusicSectionDescription`, etc. keys. Status: RESOLVED.

**SUGGESTION (LOW-PRIORITY FOLLOW-UP)**: Settings UI folder-path display shows raw SAF URI (`content://com.android.externalstorage.documents/tree/...`) instead of a human-friendly path, unlike the `_SeccionGrabaciones` precedent. This is a cosmetic UX issue only — Phase 1 spec does not require friendly display. Recommended for Phase 2 polish, does not block archival.

**No CRITICAL issues found.**

## Merged Specification

The delta spec requirements (4 ADDED + 1 MODIFIED) have been merged into the base capability spec at `openspec/specs/android-auto-media/spec.md`. The four new requirements (Local Music Root Access, Browsable Tree, Playback Pipeline Reuse, Folder Item Cap) are now part of the permanent specification. The modified "Browsable Media Tree" requirement now documents the 5-folder root structure as the new norm.

## Archived Artifacts

| Artifact | Location | Purpose |
|----------|----------|---------|
| proposal.md | `openspec/changes/archive/2026-07-19-android-auto-local-music/` | Original proposal, scope, risks, success criteria |
| design.md | Same | Architecture decisions, technical approach, interfaces |
| tasks.md | Same | 12 task groups, grounding notes, TDD cycles, review workload forecast |
| apply-progress.md | Same | Completion record, TDD evidence table, deviations, risks |
| verify-report.md | Same | Test results, spec compliance verification, hygiene checks |
| spec.md (delta) | `openspec/changes/archive/2026-07-19-android-auto-local-music/specs/android-auto-media/` | Delta spec: 4 ADDED + 1 MODIFIED requirements |

**Change folder archival**: Original change folder at `openspec/changes/android-auto-local-music/` remains in place and must be manually deleted by orchestrator (this tool cannot delete directories). All working changes are staged for commit in git.

## Phase 1 Scope: Complete

**Implemented**:
- SAF folder picking via `ACTION_OPEN_DOCUMENT_TREE`, persisted URI permission
- Graceful cold-start handling (no re-prompt if permission lost or never granted)
- Recursive `DocumentFile` traversal: pure Dart `PistaLocal` model, lazy per-folder native enumeration
- Android Auto browse tree extension: new `Musica Local` root folder, `carpeta_local:` folder ids, `pista:` track ids
- Playback integration: local tracks play through existing pipeline, EQ applies, fallback art rotates
- 50-item folder cap, alphabetical sort, filename-based titles (extension stripped for tracks only)
- Phone-side settings UI: `_SeccionMusicaLocal` folder picker, SharedPreferences persistence
- L10n support: all 13 locale files translated (English, Spanish, Russian, Chinese, Japanese, Portuguese, French, Hindi, Indonesian, Italian, German, Arabic, Bengali)

**Not in Phase 1** (explicitly deferred):
- Metadata extraction: no title/artist/album art/bitrate/sample-rate beyond raw filename
- Sort/filter: no user-controlled ordering or filtering
- Subfolder scoping refinements: simple recursive model only
- Shuffle: no shuffle implementation
- Embedded album art: fallback rotation only
- Phone-side waveform: `visualizador_audio.dart` reuse deferred

## Risk Summary

**Unverified at runtime** (expected per project precedent for native Android work):
- `MainActivity.onActivityResult` new override: carefully written against documented SAF patterns, structurally sound, reviewer attention flagged
- `DocumentsContract` MIME filtering and permission persistence: standard API usage, unexercised against real SAF provider in this environment

**Mitigated**:
- Cold-start/revoked-permission handling: explicit tests + try/catch wrapping, validated to degrade safely
- EQ regression: structural proof that local playback uses same seam as station playback
- Collision-free media ids: explicit tests covering `:` in documentId, proving length-based stripping

## Next Recommended

**Phase 2** (future work, out of scope for this delta): metadata extraction (title/artist/embedded art/bitrate from audio files), sort by title/quality, embedded album art support.

**Phase 3** (future work): subfolder scoping refinements (e.g., exclude certain folders), shuffle support.

**Cosmetic follow-ups** (low priority, non-blocking):
- Friendly path display in settings UI (e.g., last folder name instead of raw SAF URI)
- Phone-side waveform visualization reuse (separate architectural decision, documented in proposal)

## Traceability

All phase artifacts (proposal, spec, design, tasks, apply-progress, verify-report) are archived in `openspec/changes/archive/2026-07-19-android-auto-local-music/`. Base spec has been permanently updated at `openspec/specs/android-auto-media/spec.md`. Git commit 6ae7e37 contains all implementation changes, staged for merge.

---

**Archived by**: SDD Archive Executor  
**Time**: 2026-07-19  
**Status**: READY FOR ORCHESTRATOR MERGE AND CLEANUP  

Orchestrator action items:
1. Commit/push git changes (all staged in commit 6ae7e37)
2. Delete original change folder at `openspec/changes/android-auto-local-music/` (tool cannot delete)
3. Next phase: plan Phase 2 if metadata extraction is ready for detailed exploration