adopt-a-street/NOTIFICATION_IMPLEMENTATION.md

# Notification Toast System - Implementation Summary

## Overview
Implemented a comprehensive real-time notification toast system for the Adopt-a-Street frontend application. The system integrates Socket.IO events with react-toastify to provide user-friendly notifications for all real-time events.

## Files Created

### 1. NotificationProvider Component
**Path:** `frontend/src/context/NotificationProvider.js`
- Integrates with SocketContext and AuthContext
- Automatically listens to Socket.IO events and displays toasts
- Provides `notify` utility for manual toast triggering
- Handles connection status, events, tasks, streets, achievements, and social updates

### 2. Custom Toast Styles
**Path:** `frontend/src/styles/toastStyles.css`
- Custom CSS matching Bootstrap theme colors
- Mobile-responsive design (full-width on screens ≤480px)
- Support for success, error, info, and warning toast types
- Smooth animations and hover effects
- Dark mode support

### 3. Usage Examples
**Path:** `frontend/src/examples/notificationExamples.js`
- Comprehensive examples of using the notification system
- Demonstrates notify utility, toast API, promises, and async patterns
- Example component showing real-world usage

### 4. Documentation
**Path:** `NOTIFICATION_SYSTEM.md`
- Complete documentation of the notification system
- Usage instructions and examples
- Socket.IO event mappings
- Configuration options
- Troubleshooting guide

### 5. Tests
**Path:** `frontend/src/__tests__/context/NotificationProvider.test.js`
- 16 passing tests covering all functionality
- Tests for event subscriptions, toast triggering, cleanup
- Tests for notify utility functions

## Files Modified

### 1. App.js
**Changes:**
- Added import for `NotificationProvider` and custom styles
- Wrapped Router with NotificationProvider
- Enhanced ToastContainer configuration:
  - Increased autoClose to 5000ms
  - Set newestOnTop to true
  - Added theme="light"
  - Added limit={5} to prevent toast spam

### 2. setupTests.js
**Changes:**
- Added global axios mock to prevent test import errors

## How to Trigger Toasts from Components

### Method 1: Using notify utility (Recommended)
```javascript
import { notify } from "../context/NotificationProvider";

notify.success("Operation completed!");
notify.error("Something went wrong!");
notify.info("Here's some info");
notify.warning("Be careful!");
```

### Method 2: Using toast directly
```javascript
import { toast } from "react-toastify";

toast.success("Success message");
toast.error("Error message", { autoClose: 3000 });
```

### Method 3: For async operations
```javascript
const toastId = toast.loading("Processing...");
// ... do work ...
toast.update(toastId, {
  render: "Completed!",
  type: "success",
  isLoading: false,
});
```

## Socket.IO Events That Trigger Notifications

### Connection Events
- `connect` → Success: "Connected to real-time updates"
- `disconnect` → Error/Warning: Connection lost messages
- `reconnect` → Success: "Reconnected to server"
- `reconnect_error` → Error: "Failed to reconnect"

### Event Updates (`eventUpdate`)
- `new_event` → Info: "New event: [event title]"
- `event_updated` → Info: "Event details have been updated"
- `event_deleted` → Warning: "An event has been cancelled"

### Task Updates (`taskUpdate`)
- `new_task` → Info: "New task available: [task description]"
- `task_completed` → Success: "Task completed by another user"
- `task_updated` → Info: "A task has been updated"
- `task_deleted` → Warning: "A task has been removed"

### Street Updates (`streetUpdate`)
- `street_adopted` → Info: "[Street] was adopted by [User]"
- `street_unadopted` → Info: "[Street] is now available"

### Achievements
- `achievementUnlocked` → Success: Custom achievement toast with badge details
- `badgeUnlocked` → Success: Custom badge toast with details

### Social Updates
- `newPost` → Info: "[User] created a new post"
- `newComment` → Info: "[User] commented on a post"

### Generic Notifications
- `notification` → Type-based: Fallback for custom notifications

## Configuration Options

### ToastContainer Options (in App.js)
- **position**: `top-right` (also available: top-left, top-center, bottom-*)
- **autoClose**: `5000` (5 seconds, set to `false` for persistent)
- **hideProgressBar**: `false` (show progress bar)
- **newestOnTop**: `true` (stack newest on top)
- **limit**: `5` (max 5 toasts at once)
- **theme**: `light` (also available: dark, colored)
- **pauseOnHover**: `true` (pause auto-dismiss on hover)
- **draggable**: `true` (can drag to dismiss)

### Individual Toast Options
```javascript
notify.success("Message", {
  autoClose: 3000,
  position: "bottom-right",
  toastId: "unique-id", // Prevent duplicates
  pauseOnHover: false,
  closeOnClick: true,
});
```

## Mobile Responsiveness
- **Desktop**: Positioned in top-right corner with 320px width
- **Mobile (≤480px)**: Full-width toasts at the top of screen
- Touch-friendly dismissal
- Optimized animations for mobile

## Testing
All tests passing (16/16):
```bash
cd frontend && npm test -- --testPathPattern="NotificationProvider" --watchAll=false
```

## Build Status
✅ Production build successful
✅ No errors or breaking changes
✅ All existing tests still passing

## Next Steps (Optional Enhancements)
1. Add notification sound effects (configurable)
2. Add notification history/center
3. Add user preferences for notification types
4. Add desktop notifications API integration
5. Add notification grouping for similar events
6. Add undo/action buttons in toasts

## Backend Integration Notes
To trigger notifications from backend, emit Socket.IO events:

```javascript
const io = req.app.get("io");

// Notify all users
io.emit("notification", {
  type: "info",
  message: "System maintenance in 5 minutes",
});

// Notify specific user
io.to(userSocketId).emit("achievementUnlocked", {
  badge: { name: "Badge Name", description: "Description" },
});

// Notify room
io.to(`event_${eventId}`).emit("eventUpdate", {
  type: "participants_updated",
  eventId,
  participants: [...],
});
```

## Resources
- Full documentation: `NOTIFICATION_SYSTEM.md`
- Usage examples: `frontend/src/examples/notificationExamples.js`
- Tests: `frontend/src/__tests__/context/NotificationProvider.test.js`
- react-toastify docs: https://fkhadra.github.io/react-toastify/