Socket.io Framework

// Install Socket.io
npm install socket.io

// Socket.io server with Express
const express = require('express');
const http = require('http');
const socketIo = require('socket.io');

const app = express();
const server = http.createServer(app);
const io = socketIo(server, {
    cors: {
        origin: "http://localhost:3000",
        methods: ["GET", "POST"]
    }
});

// Connection handling
io.on('connection', (socket) => {
    console.log('User connected:', socket.id);

    // Join a room
    socket.on('join-room', (roomName) => {
        socket.join(roomName);
        socket.to(roomName).emit('user-joined', {
            userId: socket.id,
            message: 'A new user joined the room'
        });
        console.log(`User ${socket.id} joined room: ${roomName}`);
    });

    // Handle chat messages
    socket.on('send-message', (data) => {
        socket.to(data.room).emit('receive-message', {
            userId: socket.id,
            message: data.message,
            timestamp: new Date().toISOString()
        });
    });

    // Handle typing indicators
    socket.on('typing', (data) => {
        socket.to(data.room).emit('user-typing', {
            userId: socket.id,
            isTyping: true
        });
    });

    socket.on('stop-typing', (data) => {
        socket.to(data.room).emit('user-typing', {
            userId: socket.id,
            isTyping: false
        });
    });

    // Handle disconnection
    socket.on('disconnect', () => {
        console.log('User disconnected:', socket.id);
    });
});

// Middleware for authentication
io.use((socket, next) => {
    const token = socket.handshake.auth.token;
    if (token) {
        // Verify token here
        socket.userId = 'user-' + Math.random();
        next();
    } else {
        next(new Error('Authentication error'));
    }
});

server.listen(3001, () => {
    console.log('Socket.io server running on port 3001');
});

// Socket.io client
import { io } from 'socket.io-client';

const socket = io('http://localhost:3001', {
    auth: {
        token: 'your-auth-token'
    }
});

// Connection events
socket.on('connect', () => {
    console.log('Connected to server');
    console.log('Socket ID:', socket.id);
});

socket.on('disconnect', () => {
    console.log('Disconnected from server');
});

socket.on('connect_error', (error) => {
    console.error('Connection error:', error);
});

// Join a room
function joinRoom(roomName) {
    socket.emit('join-room', roomName);
}

// Send a message
function sendMessage(roomName, message) {
    socket.emit('send-message', {
        room: roomName,
        message: message
    });
}

// Listen for messages
socket.on('receive-message', (data) => {
    console.log('New message:', data);
    // Update UI with new message
});

// Listen for user join/leave
socket.on('user-joined', (data) => {
    console.log('User joined:', data);
    // Update UI to show new user
});

socket.on('user-left', (data) => {
    console.log('User left:', data);
    // Update UI to show user left
});

// Typing indicators
function startTyping(roomName) {
    socket.emit('typing', { room: roomName });
}

function stopTyping(roomName) {
    socket.emit('stop-typing', { room: roomName });
}

socket.on('user-typing', (data) => {
    console.log('User typing:', data);
    // Show typing indicator in UI
});

// Reconnection handling
socket.on('reconnect', (attemptNumber) => {
    console.log('Reconnected after', attemptNumber, 'attempts');
});

socket.on('reconnect_attempt', (attemptNumber) => {
    console.log('Reconnection attempt:', attemptNumber);
});