const http = require('http');
const express = require('express');
const { createClient } = require('redis');
const { Server } = require('socket.io');

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

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

// ---------- Redis subscriber ----------
const redisClient = createClient({
  url: 'redis://172.17.0.1:6379'
});
redisClient.on('error', err => console.error('Redis error', err));

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

  // Subscribe to the channel that sends disk lists
  const sub = redisClient.duplicate(); // duplicate to keep separate pub/sub
  await sub.connect();

  await sub.subscribe(
    ['attached_disks', 'host_stats'],
    (message, channel) => {            // <-- single handler
      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));  
})();

// ---------- Socket.io ----------
io.on('connection', socket => {
  console.log('client connected:', socket.id);
  // Optional: send the current state on connect if you keep it cached
});

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