# Push Notifications Setup Guide

## Quick Start

### 1. Install Dependencies

```bash
npm install
```

This will install `web-push` which is now in package.json.

### 2. Generate VAPID Keys

```bash
npm run vapid:generate
```

Copy the output and add to your `.env` file:

```env
VAPID_PUBLIC_KEY=your-generated-public-key
VAPID_PRIVATE_KEY=your-generated-private-key
VAPID_SUBJECT=mailto:your-email@example.com
```

### 3. Update Database Schema

```bash
npx prisma db push
```

This adds the `PushSubscription` table to your database.

### 4. Add Notification Settings to Profile Page

Add the `NotificationSettings` component to your profile page:

```tsx
import NotificationSettings from '@/components/NotificationSettings';

export default function ProfilePage() {
  return (
    <div>
      {/* Your existing profile content */}
      
      <NotificationSettings />
    </div>
  );
}
```

### 5. Integrate Notifications into Your Actions

Update your existing action files to send notifications:

#### In `lib/actions.ts` (or wherever you handle items):

```typescript
import { notifyItemAdded, notifyItemRemoved, notifyItemCompleted } from '@/lib/notification-helpers';

// After creating an item:
export async function createItem(listId: string, data: ItemData) {
  // ... your existing code to create item
  const item = await prisma.item.create({ ... });
  
  // Send notification
  await notifyItemAdded(listId, item.title, session.user.id);
  
  return item;
}

// After deleting an item:
export async function deleteItem(itemId: string) {
  const item = await prisma.item.findUnique({ where: { id: itemId } });
  // ... your existing delete code
  
  if (item) {
    await notifyItemRemoved(item.listId, item.title, session.user.id);
  }
}

// After completing an item:
export async function toggleItemComplete(itemId: string) {
  const item = await prisma.item.update({ ... });
  
  if (item.completed) {
    await notifyItemCompleted(item.listId, item.title, session.user.id);
  }
}
```

#### In `lib/sharing-actions.ts`:

```typescript
import { notifyListInvitation, notifyInvitationAccepted, notifyRemovedFromList } from '@/lib/notification-helpers';

// After creating an invitation:
export async function inviteToList(listId: string, email: string, permission: string) {
  // ... your existing code
  const invitation = await prisma.invitation.create({ ... });
  
  // Send notification
  await notifyListInvitation(invitation.id, email);
  
  return invitation;
}

// After accepting an invitation:
export async function acceptInvitation(invitationId: string) {
  // ... your existing code
  
  await notifyInvitationAccepted(invitationId);
}

// After removing a collaborator:
export async function removeCollaborator(listId: string, userId: string) {
  const list = await prisma.list.findUnique({ where: { id: listId } });
  // ... your existing code
  
  if (list) {
    await notifyRemovedFromList(userId, list.title, session.user.id);
  }
}
```

## How It Works

### Architecture

1. **Client requests permission** → User clicks "Enable" in NotificationSettings
2. **Service worker subscribes** → Browser creates a push subscription
3. **Subscription saved to DB** → Stored in PushSubscription table
4. **Events trigger notifications** → Server sends push via web-push library
5. **Service worker displays** → User sees notification

### Self-Hosted Solution

This implementation uses **VAPID** (Voluntary Application Server Identification), which means:
- ✅ No external services required (no Firebase, no third-party APIs)
- ✅ Works entirely from your own server
- ✅ Free and open-source
- ✅ Full control over your data

### Browser Support

- ✅ Chrome/Edge (Desktop & Android)
- ✅ Firefox (Desktop & Android)
- ✅ Safari 16.4+ (iOS & macOS) - **Must be installed to home screen on iOS**
- ❌ Safari < 16.4

## Testing

### Local Testing (Desktop)

1. Start your dev server: `npm run dev`
2. Open Chrome DevTools → Application → Service Workers
3. Go to your profile page and enable notifications
4. Trigger an action (add item, invite someone, etc.)
5. You should see a notification appear

### iOS Testing (Real Device Required)

1. Deploy to a server with HTTPS (required for PWA)
2. Open Safari on iOS 16.4+
3. Tap Share → Add to Home Screen
4. Open the installed app
5. Enable notifications in profile
6. Test by triggering actions from another device

### Testing Push Manually

Use Chrome DevTools to simulate a push:

1. DevTools → Application → Service Workers
2. Find your service worker
3. Click "Push" to simulate receiving a notification

## Notification Events

The following events trigger notifications:

| Event | Recipient | Trigger |
|-------|-----------|---------|
| Item Added | All list collaborators (except adder) | Someone adds an item to a shared list |
| Item Removed | All list collaborators (except remover) | Someone removes an item |
| Item Completed | All list collaborators (except completer) | Someone marks an item complete |
| List Invitation | Invitee | Someone invites you to a list |
| Invitation Accepted | Inviter | Someone accepts your invitation |
| Removed from List | Removed user | Owner removes you from a list |

## Customization

### Notification Content

Edit `lib/notification-helpers.ts` to customize notification titles, bodies, and icons.

### Notification Preferences

To add per-list notification preferences:

1. Add a `notificationsEnabled` field to the `Collaborator` model
2. Update `NotificationSettings` to show per-list toggles
3. Check this field in `notifyListCollaborators` before sending

### Notification Sounds

Add to service worker push event:

```javascript
const options = {
  // ... existing options
  silent: false,
  sound: '/notification-sound.mp3',
};
```

## Troubleshooting

### "Push notifications not configured" error
- Check that VAPID keys are in `.env`
- Restart your dev server after adding keys

### Notifications not appearing
- Check browser permission (should be "granted")
- Verify service worker is active (DevTools → Application)
- Check browser console for errors
- Ensure you're testing on HTTPS (or localhost)

### iOS notifications not working
- Must be iOS 16.4 or later
- Must be installed to home screen (not in Safari browser)
- Check Settings → [Your App] → Notifications

### Subscription fails
- Verify VAPID public key matches between client and server
- Check service worker is registered and active
- Ensure you're on HTTPS (or localhost)

## Security Notes

- ⚠️ **Never commit VAPID_PRIVATE_KEY to git**
- ✅ VAPID keys are like JWT secrets - keep them secure
- ✅ Subscriptions are tied to users - no cross-user notification access
- ✅ Expired subscriptions are automatically cleaned up

## Production Checklist

- [ ] Generate production VAPID keys
- [ ] Add VAPID keys to production environment variables
- [ ] Run database migration: `npx prisma db push`
- [ ] Test on actual iOS device (if targeting iOS)
- [ ] Verify HTTPS is working (required for push)
- [ ] Test notification delivery
- [ ] Monitor for expired subscriptions in logs

## Performance

- Notifications are sent asynchronously (non-blocking)
- Failed subscriptions are automatically removed
- Multiple devices per user are supported
- TTL is set to 24 hours (notifications expire if not delivered)

## Next Steps

Consider adding:
- Notification preferences per list
- Quiet hours (don't notify during certain times)
- Notification history/inbox
- Rich notifications with action buttons
- Notification grouping/batching
if