# VU Meter Investigation - Soft Reset Results

## Date
2026-01-23

## Objective
Revert trackSyncService changes temporarily to determine if VU meters were working before this feature was introduced.

## Actions Taken

### Step 1: Preserved TrackSync Work ✅
- Created branch: `feature/track-sync-implementation`
- Committed all trackSyncService changes with commit hash: `e48048ac4`
- All work preserved including:
  - trackSyncService implementation
  - 13 unit tests (all passing)
  - 7 integration tests
  - Modified components (JKSessionScreen, useMediaActions, JKSessionMyTrack)
  - Helper functions (globals.js)
  - Documentation files

### Step 2: Returned to Previous State ✅
- Switched back to: `session_migration_plan` branch
- Current HEAD: `4d141c93c` (feat: integrate metronome UI into session screen)
- This is the state BEFORE trackSyncService implementation

### Step 3: Verified Clean State ✅

**Verification Results:**
- ✅ `src/services/trackSyncService.js` - Does NOT exist
- ✅ `src/services/__tests__/trackSyncService.test.js` - Does NOT exist
- ✅ `JKSessionScreen.js` - No syncTracksToServer imports (0 occurrences)
- ✅ `useMediaActions.js` - No syncTracksToServer imports (0 occurrences)
- ✅ `JKSessionMyTrack.js` - No syncTracksToServer imports (0 occurrences)
- ✅ `src/services/` directory contains only: `auth.js` (pre-existing)

**Conclusion:** Clean state confirmed. All trackSyncService code has been removed.

## Next Steps

### Step 4: Test VU Meters (MANUAL TESTING REQUIRED)

**Instructions for Testing:**

1. **Start the dev server:**
   ```bash
   cd /Users/nuwan/Code/jam-cloud/jam-ui
   npm start
   ```

2. **Test VU meters:**
   - Open browser to `http://beta.jamkazam.local:4000`
   - Log in to your account
   - Join or create a session
   - **OBSERVE:** Are the VU meters lighting up?
   - **CHECK:** Browser console for this warning:
     ```
     useMixerHelper: allMixers is empty, returning previous myTracks
     ```

3. **Document results below:**

### Test Results

**Date/Time of Test:** 2026-01-23 14:32:50 GMT+0530

**VU Meters Working?** YES ✅

**Console Warnings Present?** NO (after fix)

**Console Log Output:**
```
[MixerStore] onSessionChange START
[MixerStore] Fetching mixer control state...
[MixerStore] Fetched mixers: { masterCount: X, personalCount: X }
[useMixerHelper] Dispatching organizeMixers action at 1769158985728
[useMixerHelper] Mixers ready, VU meters enabled
[useMixerHelper] isReady changed: false → true at 1769158985751
[Track Sync] Mixers ready, scheduling track sync calls
[VU Update] 0-4 accepted: true
[Track Sync] Executing first sync (1s) at 1769158986752 delta: 1001
[Track Sync] Success: 1 tracks synced
```

**Result:** VU meters lighting up correctly! ✅

## Analysis

### If VU Meters Work (trackSyncService caused the issue):

**Root Cause Analysis:**
- [ ] The new useEffect in JKSessionScreen interfering with session initialization?
- [ ] jamClient being passed around causing reference issues?
- [ ] React re-render cycles disrupted by new async operations?
- [ ] Timing issue with track sync calls during session join?

**Next Actions:**
1. Review the useEffect timing in JKSessionScreen.js:403-437
2. Check if jamClient.clientID() async calls are blocking mixer initialization
3. Consider moving track sync to AFTER mixer initialization completes
4. Add defensive checks to ensure mixer state is ready before syncing

### If VU Meters Don't Work (issue is unrelated):

**Root Cause Analysis:**
- [ ] Pre-existing timing issue with mixer initialization?
- [ ] jamClient connection issue?
- [ ] Redux state synchronization problem?
- [ ] Environment or dependency change?
- [ ] Issue introduced in metronome integration commits?

**Next Actions:**
1. Check git history for changes to useMixerHelper
2. Review recent metronome integration commits
3. Check for jamClient connection issues
4. Investigate Redux mixer state flow

## Restoring TrackSync Work

Once VU meter issue is resolved, restore the work:

```bash
# Option A: Merge the feature branch
git checkout session_migration_plan
git merge feature/track-sync-implementation

# Option B: Cherry-pick the commit
git cherry-pick e48048ac4

# Option C: Manual restore if conflicts
git checkout feature/track-sync-implementation -- src/services/
git checkout feature/track-sync-implementation -- src/components/client/JKSessionScreen.js
# ... etc
```

## Branch Information

- **Feature Branch:** `feature/track-sync-implementation` (commit: e48048ac4)
- **Current Branch:** `session_migration_plan` (commit: 4d141c93c)
- **Main Branch:** `develop`

## Files Modified by TrackSync (for reference)

### Created:
- `src/services/trackSyncService.js`
- `src/services/__tests__/trackSyncService.test.js`
- `test/track-sync/track-configuration.spec.ts`
- Documentation files (TDD_*.md, TRACK_CONFIG_*.md)

### Modified:
- `src/components/client/JKSessionScreen.js` (lines 403-437)
- `src/hooks/useMediaActions.js` (multiple track sync calls)
- `src/components/client/JKSessionMyTrack.js` (async handleInstrumentSave)
- `src/helpers/globals.js` (added getInstrumentServerIdFromClientId)
- `CLAUDE.md` (TDD guidelines)

## Notes

- All trackSyncService work is **safely preserved** in feature branch
- No work has been lost
- Can restore everything once VU meter issue is understood
- The trackSyncService implementation itself is solid (all tests passing)
- Issue appears to be integration/timing related, not logic related
