// Server
app.get('/events', (req, res) => {
  res.setHeader('Content-Type', 'text/event-stream');
  res.setHeader('Cache-Control', 'no-cache');
  res.setHeader('Connection', 'keep-alive');

  const sendEvent = (event: string, data: object) => {
    res.write(`event: ${event}\n`);
    res.write(`data: ${JSON.stringify(data)}\n\n`);
  };

  // Send initial data
  sendEvent('connected', { timestamp: Date.now() });

  // Subscribe to updates
  const unsubscribe = eventEmitter.on('update', (data) => {
    sendEvent('update', data);
  });

  req.on('close', () => {
    unsubscribe();
  });
});

// Client
const eventSource = new EventSource('/events');

eventSource.addEventListener('update', (event) => {
  const data = JSON.parse(event.data);
  console.log('Update:', data);
});