websocket-demo/server/websocket.js

const { WebSocketServer } = require('ws');
const { createServer } = require('http');

const server = createServer();
const wss = new WebSocketServer({ server });

wss.on('connection', (ws) => {
  console.log('Client connected');
  
  // Send welcome message
  ws.send(JSON.stringify({
    type: 'welcome',
    message: 'Connected to WebSocket server!',
    timestamp: new Date().toISOString()
  }));
  
  // Handle incoming messages
  ws.on('message', (data) => {
    try {
      const message = JSON.parse(data.toString());
      console.log('Received:', message);
      
      // Broadcast to all connected clients
      wss.clients.forEach((client) => {
        if (client.readyState === 1) { // WebSocket.OPEN
          client.send(JSON.stringify({
            type: 'broadcast',
            message: message.message,
            sender: message.sender || 'Anonymous',
            timestamp: new Date().toISOString()
          }));
        }
      });
    } catch (error) {
      console.error('Error parsing message:', error);
    }
  });
  
  ws.on('close', () => {
    console.log('Client disconnected');
  });
  
  ws.on('error', (error) => {
    console.error('WebSocket error:', error);
  });
});

const PORT = process.env.WS_PORT || 8080;
server.listen(PORT, () => {
  console.log(`WebSocket server started on port ${PORT}`);
});

module.exports = { wss };