// 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 fs     = require('fs');
const yaml   = require('js-yaml');      // npm i js-yaml
const path   = require('path');

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

/* --------------------------------------------------------------------- */
/* ---------- 1. Load the YAML configuration file ---------------------- */
/* --------------------------------------------------------------------- */
let config = {};
try {
  const file = fs.readFileSync(path.resolve(__dirname, 'cosmostat_settings.yaml'), 'utf8');
  config = yaml.load(file);
} catch (e) {
  console.error('Failed to load config.yaml:', e);
  process.exit(1);
}

const API_PORT   = config.custom_api_port   || 5000;   // fallback to 5000
const API_HOST   = config.docker_gateway   || '192.168.37.1'; // fallback IP
const API_BASE   = `http://${API_HOST}:${API_PORT}`;

// ---------------------------------------------------------------------
// ---------- 2. 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(`${API_BASE}/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(`${API_BASE}/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);
    }
  });
});

/* --------------------------------------------------------------------- */
/* ---------- 3. Serve static files ----------------------------------- */
/* --------------------------------------------------------------------- */
app.use(express.static('public'));

/* --------------------------------------------------------------------- */
/* ---------- 4. 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));
})();

/* --------------------------------------------------------------------- */
/* ---------- 5. Start the HTTP server --------------------------------- */
/* --------------------------------------------------------------------- */
const PORT = process.env.PORT || 3000;
server.listen(PORT, () => {
  console.log(`Server listening on http://localhost:${PORT}`);
});