const express = require('express');
const WebSocket = require('ws');
const http = require('http');

const app = express();
const server = http.createServer(app);
const wss = new WebSocket.Server({ server, path: '/counter-ws' });

let counter = 0; // In-memory counter (resets on server restart)

app.use(express.json());

// API endpoint to get current counter value
app.get('/api/counter', (req, res) => {
  res.json({ value: counter });
});

// API endpoint to increment counter
app.post('/api/counter/increment', (req, res) => {
  counter += 1;
  res.json({ value: counter });

  // Broadcast update to all connected WebSocket clients
  wss.clients.forEach(client => {
    if (client.readyState === WebSocket.OPEN) {
      client.send(JSON.stringify({ type: 'counter-update', value: counter }));
    }
  });
});

// WebSocket connection handling
wss.on('connection', (ws) => {
  console.log('Client connected');

  ws.on('message', (message) => {
    console.log('Received:', Buffer.from(message).toString());
  });

  ws.on('error', (error) => {
    console.log('WebSocket error:', error);
  });

  ws.on('close', (code, reason) => {
    console.log('Client disconnected', 'Code:', code, 'Reason:', reason.toString());
  });
});

const PORT = 3001; // API and WebSocket server port
server.listen(PORT, '127.0.0.1', () => {
  console.log(`Server running on http://127.0.0.1:${PORT}`);
});