# Worship List Update - December 2025

## Summary of Changes

This update addresses cross-device synchronization issues, adds drag-and-drop reordering for songs, and rebrands "Worship Planning" to "Worship List" throughout the application.

---

## 🎯 Main Features Added

### 1. **Fixed Cross-Device Song Adding** ✅

- **Problem**: Unable to add songs to worship plans from other devices
- **Solution**:
  - Backend now normalizes all ID comparisons using `.toString()` to handle both numeric IDs (from local storage) and UUID strings (from backend)
  - Added duplicate detection for song associations (prevents duplicate entries)
  - POST endpoints now preserve provided IDs from migration instead of always generating new UUIDs

### 2. **Drag-and-Drop Song Reordering** ✅

- **New Feature**: Songs in worship plans can now be reordered by:
  - **Dragging**: Click and drag songs with the ⋮⋮ handle
  - **Arrows**: Use ▲ ▼ buttons to move songs up or down
- **Visual Feedback**:
  - Songs highlight on hover with purple border
  - Cursor changes to "grabbing" during drag
  - Touch-friendly on mobile devices

### 3. **Worship Planning → Worship List Rebrand** ✅

- **Changed Throughout**:
  - Page title: "Worship List"
  - Navigation menu: "📋 Worship List" (both desktop and mobile)
  - Home page card: "Worship List"
  - Documentation files updated
- **Icon Change**: 📅 → 📋 (from calendar to clipboard)

---

## 🔧 Technical Changes

### Backend (`backend/server.js`)

#### ID Normalization (Songs)

```javascript
// POST - Preserve provided IDs
const incomingId = req.body.id != null ? req.body.id.toString() : uuid();
if (db.songs.find((s) => s.id?.toString() === incomingId)) {
  return res.status(409).json({ error: "Song ID already exists" });
}

// GET/PUT/DELETE - Normalize comparisons
db.songs.find((s) => s.id?.toString() === req.params.id)
```

#### ID Normalization (Profiles, Plans, Associations)

- All `profile_id`, `plan_id`, `song_id` comparisons now use `.toString()`
- Added duplicate prevention for:
  - `profileSongs` associations
  - `planSongs` associations

#### Export Endpoint Fix

```javascript
db.songs.find((s) => s.id?.toString() === ps.song_id?.toString())
```

### Frontend (`frontend/src/App.js`)

#### Profile Songs Mapping Enhancement

```javascript
export async function getProfileSongs(profileId) {
  // Map associations to full songs
  for (const ps of backend) {
    let song = await localStorageAPI.getSong(ps.song_id);
    if (!song) {
      // Fetch from backend if not in local cache
      const r = await fetch(`${API_BASE}/songs/${ps.song_id}`);
      if (r.ok) song = await r.json();
    }
    if (song) fullSongs.push(song);
  }
}
```

#### Drag-and-Drop Implementation

```javascript
function handleDragStart(e, index) {
  e.dataTransfer.effectAllowed = "move";
  e.dataTransfer.setData("text/plain", index.toString());
}

function handleDrop(e, dropIndex) {
  e.preventDefault();
  const dragIndex = parseInt(e.dataTransfer.getData("text/plain"));
  const newSongs = [...chosenSongs];
  const [removed] = newSongs.splice(dragIndex, 1);
  newSongs.splice(dropIndex, 0, removed);
  setChosenSongs(newSongs);
}
```

#### Force Migration Button

- Added "⚙️ Force Full Migration (Associations)" button in Settings
- Re-runs migration even when backend not empty
- Migrates missing `profileSongs` and `profileSongKeys`

### Migration Script (`frontend/src/migration.js`)

#### Key Fixes

```javascript
// Now uses correct localStorage keys
const allProfileSongs = JSON.parse(
  localStorage.getItem(STORAGE_KEYS.PROFILE_SONGS) || "[]"
);

// Keys stored as array entries
const profileSongKeysArr = JSON.parse(
  localStorage.getItem(STORAGE_KEYS.PROFILE_SONG_KEYS) || "[]"
);
```

#### Duplicate Prevention

- Checks existing backend data before posting
- Skips songs/profiles/plans already present
- Logs skipped items with ⏭️ emoji

---

## 📱 User Interface Changes

### Worship List Page

- ✨ **New Label**: "Chosen Songs (X) - Drag to reorder or use arrows"
- 🎨 **Visual Drag Handle**: ⋮⋮ appears on each song
- 🎯 **Hover Effects**: Songs highlight with purple border and shadow
- 📊 **Better Feedback**: Order numbers update instantly on reorder

### Navigation

- Desktop menu: "📋 Worship List"
- Mobile menu: "📋 Worship List"
- Consistent branding throughout

---

## 🔄 Migration Guide

### For Existing Users

1. **Restart Backend**:

   ```powershell
   cd backend
   node server.js
   ```

2. **Run Force Migration** (if needed):
   - Go to **Settings** → switch to **Online Mode**
   - Scroll to **Data Management** section
   - Click **"⚙️ Force Full Migration (Associations)"**
   - This will sync profile songs and keys to backend

3. **Verify on Other Devices**:
   - Open app on secondary device
   - Ensure **Online Mode** with correct backend IP
   - Profile saved songs should now display
   - Worship plan songs should be clickable and show titles

---

## ✅ Testing Checklist

- [x] Backend normalizes IDs correctly (songs, profiles, plans)
- [x] Profile songs display on other devices
- [x] Plan songs display with titles and are clickable
- [x] Adding songs to plan works from any device
- [x] Drag-and-drop reordering works
- [x] Arrow button reordering works
- [x] Force migration button copies associations
- [x] "Worship List" name appears throughout app
- [x] Navigation icons updated (📋 instead of 📅)
- [x] Duplicate associations prevented

---

## 🐛 Bug Fixes

1. **404 Errors on Song Lookup**
   - **Cause**: Numeric IDs (1, 2) not matching string comparisons
   - **Fix**: All ID comparisons now use `.toString()`

2. **Empty Profile Song Lists**
   - **Cause**: Backend had no profileSongs associations
   - **Fix**: Migration script now migrates associations; Force Migration button added

3. **Plan Songs Not Showing**
   - **Cause**: Export endpoint not finding songs with mixed ID types
   - **Fix**: Normalized comparisons in export logic

4. **Unable to Add Songs from Other Device**
   - **Cause**: Duplicate check failing due to ID type mismatch
   - **Fix**: Duplicate detection now compares stringified IDs

---

## 📝 Known Limitations

1. **Drag-and-Drop on Touch Devices**: HTML5 drag API has limited mobile support; arrow buttons remain primary method on phones/tablets
2. **Real-time Order Sync**: Order changes update on save; WebSocket doesn't broadcast reorder events (plan must be refreshed)
3. **Migration Required**: Existing users must run Force Migration once to populate backend associations

---

## 🚀 Future Enhancements

- [ ] Real-time collaborative editing (WebSocket song order updates)
- [ ] Touch-friendly drag library (React DnD or similar)
- [ ] Bulk song import from CSV
- [ ] Plan templates and recurring schedules
- [ ] Worship list history and version control

---

## 📞 Support

If you encounter issues:

1. Check backend is running: `http://localhost:5000/api/health`
2. Verify Online Mode settings match your backend IP
3. Run Force Migration to sync associations
4. Clear browser cache and localStorage if data seems stale
5. Check browser console for error messages

---

**Updated**: November 29, 2025
**Version**: 2.1.0
**Author**: GitHub Copilot
