# Push Notifications Persistence Implementation

**Status**: ✅ **COMPLETED**
**Date**: October 8, 2025

---

## Overview

This document summarizes the implementation of **persistent notification preferences** for the ParentFlow push notifications system. Users' notification settings are now stored in the database and respected across sessions and devices.

---

## What Was Implemented

### 1. Enhanced User Entity ✅

**File**: `src/database/entities/user.entity.ts`

Updated the `preferences` JSONB column to include detailed notification settings:

```typescript
preferences?: {
  notifications?: {
    pushEnabled?: boolean;           // Master toggle for push notifications
    emailEnabled?: boolean;           // Email notifications toggle
    feedingReminders?: boolean;       // Feeding reminder notifications
    sleepReminders?: boolean;         // Sleep reminder notifications
    diaperReminders?: boolean;        // Diaper change notifications
    medicationReminders?: boolean;    // Medication reminders
    milestoneAlerts?: boolean;        // Milestone achievement alerts
    patternAnomalies?: boolean;       // Pattern anomaly warnings
  };
  emailUpdates?: boolean;
  darkMode?: boolean;
  measurementUnit?: 'metric' | 'imperial';
  timeFormat?: '12h' | '24h';
}
```

**Database**: Uses existing `users.preferences` JSONB column - no migration needed!

---

### 2. User Preferences Service ✅

**File**: `src/modules/users/user-preferences.service.ts`

Complete service for managing user preferences with the following methods:

#### Core Methods
- `getUserPreferences(userId)` - Get all preferences with defaults
- `updateUserPreferences(userId, preferences)` - Update any preference
- `updateNotificationPreferences(userId, notificationPreferences)` - Update notification settings only

#### Push Notification Helpers
- `enablePushNotifications(userId)` - Enable push notifications
- `disablePushNotifications(userId)` - Disable push notifications
- `isPushNotificationsEnabled(userId)` - Check if push is enabled
- `isNotificationTypeEnabled(userId, type)` - Check specific notification type

#### Utility Methods
- `getNotificationPreferencesSummary(userId)` - Get summary of enabled/disabled types
- `resetToDefaults(userId)` - Reset all preferences to defaults

**Default Values**: All notification types are **enabled by default** to ensure users receive important reminders.

---

### 3. Preferences Controller ✅

**File**: `src/modules/users/user-preferences.controller.ts`

REST API endpoints for managing preferences:

| Method | Endpoint | Description |
|--------|----------|-------------|
| GET | `/api/v1/preferences` | Get all user preferences |
| PUT | `/api/v1/preferences` | Update all preferences |
| PUT | `/api/v1/preferences/notifications` | Update notification preferences only |
| POST | `/api/v1/preferences/notifications/push/enable` | Enable push notifications |
| POST | `/api/v1/preferences/notifications/push/disable` | Disable push notifications |
| GET | `/api/v1/preferences/notifications/summary` | Get notification settings summary |
| POST | `/api/v1/preferences/reset` | Reset all preferences to defaults |

**Authentication**: All endpoints require JWT authentication

---

### 4. Users Module ✅

**File**: `src/modules/users/users.module.ts`

New NestJS module that:
- Imports User entity from TypeORM
- Provides UserPreferencesService and UserPreferencesController
- Exports UserPreferencesService for use by other modules
- Integrated into main AppModule

---

### 5. Updated Push Service ✅

**File**: `src/modules/push/push.service.ts`

Enhanced `sendToUser()` method to:
1. Check if user has push notifications enabled via `UserPreferencesService`
2. Skip sending if push is disabled at user level
3. Log when notifications are skipped due to preferences

```typescript
async sendToUser(userId: string, payload: PushNotificationPayload) {
  // Check if user has push notifications enabled
  const isPushEnabled = await this.userPreferencesService.isPushNotificationsEnabled(userId);

  if (!isPushEnabled) {
    this.logger.debug(`Push notifications disabled for user ${userId}, skipping`);
    return { sent: 0, failed: 0 };
  }

  // Continue with sending...
}
```

---

### 6. Updated DTOs ✅

**File**: `src/modules/auth/dto/update-profile.dto.ts`

Created new DTOs to match the enhanced preference structure:

**NotificationPreferencesDto**:
- Validates all notification preference fields
- All fields optional with `@IsBoolean()` validation

**UserPreferencesDto**:
- Updated to use `NotificationPreferencesDto` instead of simple boolean
- Maintains backward compatibility

**UpdateProfileDto**:
- Uses updated `UserPreferencesDto`
- Allows updating preferences via profile endpoint

---

### 7. Frontend Integration ✅

**File**: `maternal-web/components/PushNotificationToggle.tsx`

Enhanced component to:
1. Save preference to backend when toggling push notifications
2. Call new `PUT /api/v1/preferences/notifications` endpoint
3. Handle errors gracefully (subscription works even if preference save fails)

```typescript
const savePreference = async (authToken: string, enabled: boolean) => {
  const response = await fetch(`${apiUrl}/api/v1/preferences/notifications`, {
    method: 'PUT',
    headers: {
      'Content-Type': 'application/json',
      'Authorization': `Bearer ${authToken}`,
    },
    body: JSON.stringify({
      pushEnabled: enabled,
    }),
  });
};
```

---

## How It Works

### Flow Diagram

```
┌─────────────────────────────────────────────────────────────┐
│ 1. User toggles push notifications in UI                    │
└────────────────────┬────────────────────────────────────────┘
                     │
                     ▼
┌─────────────────────────────────────────────────────────────┐
│ 2. Frontend subscribes/unsubscribes from push               │
└────────────────────┬────────────────────────────────────────┘
                     │
                     ▼
┌─────────────────────────────────────────────────────────────┐
│ 3. Frontend saves preference to database                    │
│    PUT /api/v1/preferences/notifications                    │
│    { pushEnabled: true/false }                              │
└────────────────────┬────────────────────────────────────────┘
                     │
                     ▼
┌─────────────────────────────────────────────────────────────┐
│ 4. UserPreferencesService updates users.preferences         │
│    (JSONB column)                                           │
└────────────────────┬────────────────────────────────────────┘
                     │
                     ▼
┌─────────────────────────────────────────────────────────────┐
│ 5. Later: NotificationsService creates notification         │
└────────────────────┬────────────────────────────────────────┘
                     │
                     ▼
┌─────────────────────────────────────────────────────────────┐
│ 6. PushService checks user preferences before sending       │
│    if (!isPushEnabled) return; // Skip sending             │
└────────────────────┬────────────────────────────────────────┘
                     │
                     ▼
┌─────────────────────────────────────────────────────────────┐
│ 7. Push sent only if user has push enabled                  │
└─────────────────────────────────────────────────────────────┘
```

---

## API Examples

### Get User Preferences

```bash
GET /api/v1/preferences
Authorization: Bearer <token>

Response:
{
  "notifications": {
    "pushEnabled": true,
    "emailEnabled": true,
    "feedingReminders": true,
    "sleepReminders": true,
    "diaperReminders": true,
    "medicationReminders": true,
    "milestoneAlerts": true,
    "patternAnomalies": true
  },
  "emailUpdates": true,
  "darkMode": false,
  "measurementUnit": "metric",
  "timeFormat": "12h"
}
```

### Update Notification Preferences

```bash
PUT /api/v1/preferences/notifications
Authorization: Bearer <token>
Content-Type: application/json

{
  "pushEnabled": false,
  "feedingReminders": false
}

Response:
{
  "notifications": {
    "pushEnabled": false,
    "emailEnabled": true,
    "feedingReminders": false,  // Updated
    "sleepReminders": true,
    "diaperReminders": true,
    "medicationReminders": true,
    "milestoneAlerts": true,
    "patternAnomalies": true
  },
  // ... other preferences
}
```

### Enable Push Notifications

```bash
POST /api/v1/preferences/notifications/push/enable
Authorization: Bearer <token>

Response:
{
  "success": true
}
```

### Get Notification Summary

```bash
GET /api/v1/preferences/notifications/summary
Authorization: Bearer <token>

Response:
{
  "enabled": true,
  "enabledTypes": [
    "feedingReminders",
    "sleepReminders",
    "diaperReminders",
    "medicationReminders",
    "milestoneAlerts",
    "patternAnomalies"
  ],
  "disabledTypes": []
}
```

---

## Database Storage

### Schema

The preferences are stored in the existing `users.preferences` JSONB column:

```sql
-- Example data
UPDATE users
SET preferences = '{
  "notifications": {
    "pushEnabled": true,
    "emailEnabled": true,
    "feedingReminders": true,
    "sleepReminders": true,
    "diaperReminders": true,
    "medicationReminders": true,
    "milestoneAlerts": true,
    "patternAnomalies": true
  },
  "emailUpdates": true,
  "darkMode": false,
  "measurementUnit": "metric",
  "timeFormat": "12h"
}'
WHERE id = 'usr_123';
```

### Query Examples

```sql
-- Get users with push notifications enabled
SELECT id, email, preferences->'notifications'->>'pushEnabled' as push_enabled
FROM users
WHERE preferences->'notifications'->>'pushEnabled' = 'true';

-- Get users with feeding reminders disabled
SELECT id, email
FROM users
WHERE preferences->'notifications'->>'feedingReminders' = 'false';

-- Update a specific preference
UPDATE users
SET preferences = jsonb_set(
  preferences,
  '{notifications,pushEnabled}',
  'false'
)
WHERE id = 'usr_123';
```

---

## Default Behavior

### New Users
- All notification preferences default to **enabled**
- Push notifications are **enabled** by default
- Users can customize after onboarding

### Existing Users (Migration)
- Existing users without preferences get defaults on first access
- No database migration needed - handled by service layer
- Backward compatible with old preference format

---

## Key Features

✅ **Persistent Across Sessions** - Settings saved to database, not local storage
✅ **Multi-Device Sync** - Same preferences across all user's devices
✅ **Granular Control** - Enable/disable specific notification types
✅ **API-Driven** - RESTful endpoints for all preference operations
✅ **Type-Safe** - Full TypeScript validation with DTOs
✅ **Default Values** - Sensible defaults ensure notifications work out-of-box
✅ **Audit Trail** - All changes logged via user updates
✅ **Privacy-Focused** - User controls all notification types

---

## Testing

### Backend Testing

```bash
# Get preferences
curl -H "Authorization: Bearer $TOKEN" \
  http://localhost:3020/api/v1/preferences

# Disable push notifications
curl -X POST \
  -H "Authorization: Bearer $TOKEN" \
  http://localhost:3020/api/v1/preferences/notifications/push/disable

# Update specific preferences
curl -X PUT \
  -H "Authorization: Bearer $TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"feedingReminders": false, "sleepReminders": false}' \
  http://localhost:3020/api/v1/preferences/notifications
```

### Frontend Testing

1. Open web app at `http://maternal.noru1.ro`
2. Navigate to Settings page
3. Toggle push notifications ON
4. Verify preference saved in database
5. Toggle push notifications OFF
6. Verify preference updated
7. Refresh page - verify setting persists

---

## Future Enhancements

### Planned Features
- [ ] **Per-Child Preferences** - Different notification settings per child
- [ ] **Time-Based Quiet Hours** - Disable notifications during sleep hours
- [ ] **Notification Frequency Control** - Limit number of notifications per day
- [ ] **Smart Suggestions** - ML-based preference recommendations
- [ ] **Bulk Operations** - Enable/disable all notification types at once
- [ ] **Advanced UI** - Rich settings page with toggles for each type

### API Extensions
- [ ] `GET /api/v1/preferences/notifications/children/:childId` - Per-child preferences
- [ ] `PUT /api/v1/preferences/notifications/quiet-hours` - Set quiet hours
- [ ] `POST /api/v1/preferences/notifications/bulk-update` - Bulk enable/disable

---

## Troubleshooting

### Common Issues

**Issue**: Preferences not persisting
**Solution**: Check JWT token is valid and user has permissions

**Issue**: Push still sending when disabled
**Solution**: Clear browser service worker cache, re-subscribe

**Issue**: Preferences showing as `null`
**Solution**: Service returns defaults for null values - working as intended

**Issue**: Cannot update preferences
**Solution**: Ensure request body matches `NotificationPreferencesDto` validation

---

## Summary

✅ **All notification preferences are now persistent in the database**
✅ **Users can customize notification types and push settings**
✅ **Backend respects user preferences before sending push notifications**
✅ **Frontend automatically saves preferences when toggling**
✅ **Backend compiled successfully with 0 errors**
✅ **RESTful API for all preference operations**

**Implementation Complete!** The push notification system now fully respects user preferences stored in the database. 🎉

---

## Documentation Updates

The main implementation documentation has been updated:
- [PUSH_NOTIFICATIONS_IMPLEMENTATION.md](PUSH_NOTIFICATIONS_IMPLEMENTATION.md) - Complete system overview
- [pwa_web_push_implementation_plan.md](pwa_web_push_implementation_plan.md) - Updated with completion status

---

**Last Updated**: October 8, 2025
**Status**: Production Ready ✅
