PWA_IMPLEMENTATION.md

# PWA Implementation Guide for Open Notebook

## What Was Implemented

Open Notebook has been successfully converted into a Progressive Web App (PWA) with the following features:

### Features Added

1. **Installable App**
   - Users can install Open Notebook to their home screen on mobile and desktop
   - Works on iOS, Android, Windows, Mac, and Linux
   - App appears in app launchers just like native apps

2. **Offline Support**
   - Service worker caching for faster load times
   - Graceful offline fallback page
   - API caching with Network-First strategy (5-minute cache)

3. **Smart Caching**
   - Static assets (JS, CSS, images) cached for 24 hours
   - Google Fonts cached for optimal performance
   - Next.js image optimization cached

4. **Install Prompt**
   - Smart install prompt appears after 30 seconds
   - Dismissible with 7-day cooldown
   - Auto-detects if already installed

5. **Mobile Optimized**
   - Apple Touch Icon support
   - Proper viewport and theme-color meta tags
   - App shortcuts for quick actions

## Files Modified/Created

### Modified Files
- `frontend/next.config.ts` - PWA configuration with caching strategies
- `frontend/src/app/layout.tsx` - Added PWA meta tags and install prompt
- `frontend/package.json` - Added next-pwa dependency

### New Files
- `frontend/public/manifest.json` - Web app manifest with app metadata
- `frontend/public/offline.html` - Offline fallback page
- `frontend/src/components/common/InstallPWA.tsx` - Install prompt component
- `frontend/generate-icons.js` - Icon generation script
- `frontend/public/icon-*.png` - PWA icons (9 sizes)
- `frontend/public/apple-touch-icon.png` - iOS home screen icon

## How to Test

### 1. Build and Start the App

```bash
cd /home/john/opennotebook/frontend
npm run build
npm start
```

Or with Docker:
```bash
cd /home/john/opennotebook
docker compose up --build
```

### 2. Test on Desktop (Chrome/Edge)

1. Open Chrome/Edge browser
2. Navigate to your Open Notebook URL (e.g., `http://localhost:8502`)
3. Look for the install icon in the address bar (⊕ or ⬇️)
4. Click it and select "Install"
5. The app will open in its own window

**Alternative:**
- Open DevTools (F12)
- Go to "Application" tab
- Click "Manifest" to verify manifest is loaded
- Check "Service Workers" to see if worker is active
- Use "Lighthouse" tab to run PWA audit

### 3. Test on Android

1. Open Chrome browser on Android
2. Navigate to your Open Notebook URL
3. Wait 30 seconds for the install prompt to appear
4. Or tap the menu (⋮) and select "Install app" or "Add to Home Screen"
5. Tap "Install"
6. Find the app icon on your home screen

**Testing Tips:**
- Use Chrome's Device Mode in DevTools to simulate mobile
- Remote debug using `chrome://inspect` on desktop
- Check console for any PWA-related errors

### 4. Test on iOS (Safari)

1. Open Safari on iOS
2. Navigate to your Open Notebook URL
3. Tap the Share button (square with arrow)
4. Scroll down and tap "Add to Home Screen"
5. Customize name if desired and tap "Add"
6. Find the app icon on your home screen

**Note:** iOS has limited PWA support:
- No automatic install prompt
- No background sync
- Limited push notification support

### 5. Test Offline Functionality

**Desktop:**
1. Open DevTools (F12)
2. Go to "Network" tab
3. Check "Offline" checkbox
4. Refresh the page
5. You should see the offline fallback page

**Mobile:**
1. Enable Airplane mode
2. Open the installed app
3. You should see cached content or offline page

### 6. Test PWA Features with Lighthouse

1. Open Chrome DevTools (F12)
2. Go to "Lighthouse" tab
3. Select "Progressive Web App" category
4. Click "Analyze page load"
5. Review the PWA score (should be 90+)

## PWA Configuration Details

### Caching Strategies

| Resource Type | Strategy | Cache Duration | Notes |
|--------------|----------|----------------|-------|
| API Calls | NetworkFirst | 5 minutes | Falls back to cache if network is slow (10s timeout) |
| Static JS/CSS | StaleWhileRevalidate | 24 hours | Always serves from cache, updates in background |
| Images | StaleWhileRevalidate | 24 hours | Cached for fast loading |
| Google Fonts | CacheFirst (webfonts) / StaleWhileRevalidate (CSS) | 365 days / 7 days | Optimal font loading |

### Manifest Features

- **Display Mode:** Standalone (looks like a native app)
- **Orientation:** Portrait-primary (mobile optimized)
- **Theme Color:** #000000 (customizable in manifest.json)
- **Background Color:** #ffffff (customizable in manifest.json)
- **App Shortcuts:** Quick access to New Notebook and Search

## Customization

### Change Theme Colors

Edit `frontend/public/manifest.json`:
```json
{
  "theme_color": "#667eea",
  "background_color": "#ffffff"
}
```

Also update in `frontend/src/app/layout.tsx`:
```tsx
<meta name="theme-color" content="#667eea" />
```

### Adjust Install Prompt Timing

Edit `frontend/src/components/common/InstallPWA.tsx`:
```tsx
// Change from 30 seconds (30000ms) to desired delay
setTimeout(() => {
  setShowInstallPrompt(true);
}, 30000); // Change this value
```

### Modify Caching Behavior

Edit `frontend/next.config.ts` in the `runtimeCaching` array:
- Change `handler` types: `NetworkFirst`, `CacheFirst`, `StaleWhileRevalidate`
- Adjust `maxAgeSeconds` for cache duration
- Modify `maxEntries` for cache size limits

### Disable PWA in Development

PWA is automatically disabled in development mode. To enable it, edit `next.config.ts`:
```tsx
disable: false, // Change from process.env.NODE_ENV === "development"
```

## Troubleshooting

### Install Button Not Showing

1. Check if already installed (look for standalone display mode)
2. PWA criteria not met - run Lighthouse audit
3. HTTPS required (except localhost)
4. Service worker may not be registered - check DevTools > Application > Service Workers

### Service Worker Not Updating

1. In DevTools > Application > Service Workers
2. Check "Update on reload"
3. Click "Unregister" and reload page
4. Or use "Skip waiting" button

### Icons Not Loading

1. Verify icons exist: `ls frontend/public/icon-*.png`
2. Regenerate if needed: `node frontend/generate-icons.js`
3. Check manifest.json paths match icon filenames
4. Clear cache and reinstall app

### Manifest Not Found

1. Check that manifest.json exists in `frontend/public/`
2. Verify build output includes public files
3. Check browser console for 404 errors
4. Ensure `manifest: "/manifest.json"` in layout.tsx

### App Not Working Offline

1. Service worker must be active (check DevTools)
2. Visit pages while online first to cache them
3. API calls require cached responses or fallbacks
4. Check offline.html is in public directory

## Production Deployment

### Important Considerations

1. **HTTPS Required**
   - PWAs require HTTPS (except localhost)
   - Ensure your production server has valid SSL certificate

2. **Cache Updates**
   - Service worker updates automatically on new deployments
   - Users get updates when they close and reopen the app

3. **Environment Variables**
   - `NODE_ENV=production` enables PWA features
   - `API_URL` must be set correctly for your deployment

4. **Docker Deployment**
   - PWA files are included in the standalone build
   - Icons and manifest are served from the public directory
   - No additional configuration needed

## Next Steps

### Optional Enhancements

1. **Push Notifications**
   - Add web push notification support
   - Requires backend integration for push subscriptions

2. **Background Sync**
   - Queue API requests when offline
   - Sync when connection is restored

3. **Share Target API**
   - Allow sharing content to Open Notebook from other apps
   - Add to manifest.json

4. **App Shortcuts**
   - Already configured in manifest
   - Can add more shortcuts for quick actions

5. **Screenshots**
   - Add app screenshots to manifest
   - Improves install prompt on some platforms

## Resources

- [PWA Documentation](https://web.dev/progressive-web-apps/)
- [next-pwa GitHub](https://github.com/shadowwalker/next-pwa)
- [Workbox Documentation](https://developers.google.com/web/tools/workbox)
- [Manifest Generator](https://www.simicart.com/manifest-generator.html/)
- [PWA Testing Tools](https://www.pwabuilder.com/)

## Support

For issues specific to Open Notebook PWA:
- Check browser console for errors
- Run Lighthouse audit for PWA compliance
- Verify service worker is active
- Test on different devices and browsers

---

**Implementation Date:** October 28, 2025
**Implemented By:** Claude Code Assistant
**Status:** ✅ Complete and Ready for Testing