# Task: Create Needyfy Chat Service (Real-time Messaging Mini Service)

## Summary
Created the Socket.IO-based real-time messaging mini service for the Needyfy Super App at `/home/z/my-project/mini-services/chat-service/`.

## Files Created

### 1. `/home/z/my-project/mini-services/chat-service/package.json`
- Name: `needyfy-chat-service`
- Script: `dev` → `bun --hot index.ts`
- Dependency: `socket.io@^4.7.0`

### 2. `/home/z/my-project/mini-services/chat-service/index.ts`
Full Socket.IO server implementation with:
- **Port**: 3003 (hardcoded, no env variable)
- **CORS**: All origins (`*`)
- **Path**: `/` (required by Caddy gateway)

#### Event Handlers:
| Event | Payload | Behavior |
|-------|---------|----------|
| `join` | `{ userId }` | Stores socket↔user mapping, joins personal room, emits `joined` + `presence` |
| `message` | `{ senderId, receiverId, content, messageType }` | Emits to receiver's room, sends `message-delivered` confirmation, stores in conversation history |
| `typing` | `{ senderId, receiverId }` | Notifies receiver that sender is typing |
| `stop-typing` | `{ senderId, receiverId }` | Notifies receiver that sender stopped typing |
| `read` | `{ senderId, receiverId, messageIds }` | Marks messages as read, notifies sender via `read` event |
| `disconnect` | — | Cleans up socket↔user mapping, broadcasts `presence` if user fully offline |

#### In-Memory Stores:
- `socketToUser`: Map<socketId, userId>
- `userToSockets`: Map<userId, Set<socketId>> (multi-device support)
- `messageStore`: Map<conversationKey, StoredMessage[]> (last 200 per conversation)

#### Features:
- Multi-device support (user can connect from multiple tabs/devices)
- Online presence tracking and broadcasting
- Delivery confirmation for messages
- Read receipt support
- Graceful shutdown (SIGTERM/SIGINT)
- Error handling with `error` event emissions
- Uncaught exception/unhandled rejection handlers

### 3. `/home/z/my-project/mini-services/chat-service/tsconfig.json`
Simple TypeScript config targeting ESNext with Bun types.

## Verification Results
- ✅ Service starts on port 3003
- ✅ Socket.IO polling handshake works (`/?EIO=4&transport=polling` returns proper SID)
- ✅ WebSocket upgrades supported
- ✅ Dependencies installed (socket.io@4.8.3)
- ✅ Service stays alive using bash wrapper process

## Frontend Connection
```typescript
import { io } from 'socket.io-client'
const socket = io('/?XTransformPort=3003', {
  transports: ['websocket', 'polling'],
  forceNew: true,
  reconnection: true,
})
```

## Notes
- The sandbox environment kills background processes; a bash wrapper is used to keep the service alive
- Service uses `bun --hot index.ts` for development (auto-restart on file changes)