Church-Music/legacy-site/documentation/md-files/MONGODB_QUICK_REFERENCE.md

# 🚀 MongoDB System - Quick Reference

## ✅ System Status

**Database:** MongoDB Community Server (Local)  
**Backend:** Flask + PyMongo  
**Status:** ✅ OPERATIONAL  

**Data:**

- 39 Songs
- 5 Profiles  
- Cross-device access enabled

---

## 🌐 Access URLs

### PC/Desktop

- **Frontend:** <http://localhost:3000>
- **Backend API:** <http://localhost:5000>

### Mobile/Tablet (Same WiFi)

- **Frontend:** <http://192.168.10.178:3000>
- **Backend API:** <http://192.168.10.178:5000>

---

## ⚡ Quick Commands

### Start Backend

```powershell
cd "E:\Documents\Website Projects\Church_SongLyric\backend"
.\venv\Scripts\python.exe app.py
```

### Check MongoDB Service

```powershell
Get-Service MongoDB
```

### Start MongoDB (if stopped)

```powershell
Start-Service MongoDB
```

### Test API

```powershell
Invoke-RestMethod http://localhost:5000/api/health
```

### Check Data Count

```powershell
cd backend
.\venv\Scripts\python.exe check_mongo_data.py
```

---

## 🔧 Troubleshooting

### Frontend shows "Offline"

Open browser console (F12) and run:

```javascript
localStorage.setItem("api_settings", JSON.stringify({
  protocol: "http",
  hostname: "localhost",  // or "192.168.10.178" for mobile
  port: "5000",
  useLocalStorage: false
}));
location.reload(true);
```

### Backend not responding

```powershell
# Check if backend is running
Get-Process python -ErrorAction SilentlyContinue

# Restart backend
cd "E:\Documents\Website Projects\Church_SongLyric\backend"
.\venv\Scripts\python.exe app.py
```

### MongoDB not running

```powershell
# Check service
Get-Service MongoDB

# Start if stopped
Start-Service MongoDB

# If service doesn't exist, reinstall MongoDB Community Server
```

### Data missing

```powershell
# Re-run migration (safe, skips duplicates)
cd "E:\Documents\Website Projects\Church_SongLyric\backend"
.\venv\Scripts\python.exe migrate_to_mongodb.py
```

---

## 📁 Important Files

### Configuration

- `backend/.env` - Database connection settings
- `backend/mongodb_models.py` - Database schema

### Backups (in `backend/._archived_sqlite/`)

- `app.db` - Original SQLite database
- `models.py` - Old SQLAlchemy models
- `app_sqlite_backup.py` - Pre-migration backend

### Documentation

- `MONGODB_MIGRATION_COMPLETE.md` - Full migration details
- `MONGODB_ATLAS_SETUP.md` - Cloud setup guide (future)

---

## 🎯 Key Features

✅ **Cross-Device Sync** - All devices use same database  
✅ **Real-Time Updates** - Changes visible immediately  
✅ **Connection Pooling** - Handles multiple devices  
✅ **Automatic Indexes** - Fast song search  
✅ **Data Safety** - Old SQLite backed up  

---

## 📊 API Endpoints

All endpoints working with MongoDB:

| Endpoint | Methods | Purpose |
|----------|---------|---------|
| `/api/health` | GET | Health check |
| `/api/profiles` | GET, POST | List/create profiles |
| `/api/profiles/<id>` | PUT, DELETE | Edit/delete profile |
| `/api/songs` | GET, POST | List/create songs (search with ?q=) |
| `/api/songs/<id>` | GET, PUT, DELETE | View/edit/delete song |
| `/api/plans` | GET, POST | List/create plans |
| `/api/profiles/<id>/songs` | GET, POST | Profile song library |
| `/api/search_external` | GET | Search ChartLyrics |

---

## 🔄 If You Need to Rollback

**(Only if something goes wrong - not recommended)**

```powershell
cd "E:\Documents\Website Projects\Church_SongLyric\backend"

# Stop current backend (Ctrl+C or close window)

# Restore old files
Copy-Item "._archived_sqlite\app.db" "app.db" -Force
Copy-Item "._archived_sqlite\app_sqlite_backup.py" "app.py" -Force
Copy-Item "._archived_sqlite\models.py" "models.py" -Force

# Restart backend with SQLite
.\venv\Scripts\python.exe app.py
```

**Note:** Rollback will lose any data added after migration!

---

## 💡 Tips

1. **Keep MongoDB Service Running**
   - Set to start automatically (already configured)
   - Don't stop MongoDB service

2. **Backend Must Run for Access**
   - PC must have backend running
   - Mobile/tablet connect to PC's backend

3. **Same WiFi Required**
   - All devices need same network
   - Use 192.168.10.178 for LAN access

4. **Future: Migrate to Cloud**
   - Follow `MONGODB_ATLAS_SETUP.md`
   - Enables access without PC running
   - Works from anywhere with internet

---

## 📞 Need Help?

Check these in order:

1. Is MongoDB service running? `Get-Service MongoDB`
2. Is backend running? `Get-Process python`
3. Can you access API? `Invoke-RestMethod http://localhost:5000/api/health`
4. Check browser console (F12) for errors
5. Review `MONGODB_MIGRATION_COMPLETE.md` for detailed info

---

## ✅ Success Checklist

- [x] MongoDB installed and running
- [x] 39 songs in database
- [x] 5 profiles in database
- [x] Backend API working
- [x] Old files archived safely
- [ ] Frontend tested (check now!)
- [ ] Mobile tested (try on phone)

**Your MongoDB migration is complete and operational!** 🎉