// server.js
const http   = require('http');
const express = require('express');
const { createClient } = require('redis');
const { Server } = require('socket.io');
const fetch  = require('node-fetch');   // npm i node-fetch@2

const app    = express();
const server = http.createServer(app);
const io     = new Server(server);

// ---------- Socket.io ----------
io.on('connection', async socket => {
  console.log('client connected:', socket.id);

  // Call the external API every time a client connects
  try {
    const resp = await fetch('http://192.168.37.1:5000/start_timer', {
      method: 'GET'
    });

    const data = await resp.json();
    console.log('API responded to connect:', data);
  } catch (err) {
    console.error('Failed to hit start_timer endpoint:', err);
  }

  // Listen for tableRendered event from the client
  socket.on('tableRendered', async () => {
    console.log('Client reported table rendered - starting timer');
    try {
      const resp = await fetch('http://192.168.37.1:5000/start_timer', {
        method: 'GET'
      });
      const text = await resp.text();
      console.log('Timer endpoint responded:', text);
    } catch (err) {
      console.error('Failed to hit start_timer:', err);
    }
  });
});

// Serve static files (index.html, etc.)
app.use(express.static('public'));

// ---------- Redis subscriber ----------
const redisClient = createClient({ url: 'redis://192.168.37.1:6379' });

redisClient.on('error', err => console.error('Redis error', err));

(async () => {
  await redisClient.connect();

  const sub = redisClient.duplicate(); // duplicate to keep separate pub/sub
  await sub.connect();

  // Subscribe to the channel that sends host stats
  await sub.subscribe(
    ['host_metrics'],
    (message, channel) => {
      let payload;
      try {
        payload = JSON.parse(message); // message is a JSON string
      } catch (e) {
        console.error(`Failed to parse ${channel}`, e);
        return;
      }
      io.emit(channel, payload);
    }
  );

  sub.on('error', err => console.error('Subscriber error', err));
})();

// ---------- Start ----------
const PORT = process.env.PORT || 3000;
server.listen(PORT, () => {
  console.log(`Server listening on http://localhost:${PORT}`);
});