const express = require('express');
const { createServer } = require('node:http');
const { Server } = require('socket.io');
const { SerialPort } = require('serialport');
const { ReadlineParser } = require('@serialport/parser-readline');
const { spawn } = require('child_process');

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

const PORT = 3000;
const SOUND_FILE = 'assets/sounds/muddy_files.mp3'; // chemin vers ton fichier mp3
let mpg123Process = null;
let lastPosition = null;
let lastTime = null;
let stopTimeout = null;

const arduinoCOMPort = '/dev/ttyUSB0'; // adapte si besoin
const arduinoSerialPort = new SerialPort({
  path: arduinoCOMPort,
  baudRate: 9600
});

// Lorsqu’on ouvre la connexion série
arduinoSerialPort.on('open', () => {
  console.log('Port série ouvert:', arduinoCOMPort);
});

const parser = arduinoSerialPort.pipe(new ReadlineParser({ delimiter: '\n' }));

// Middleware
app.use(express.static('assets'));

// Routes
app.get('/', (req, res) => {
  res.sendFile('assets/main.html', { root: __dirname });
});

// Socket.io
io.on('connection', (socket) => {
  console.log('Un client s\'est connecté');

  parser.on('data', (data) => {
    const position = parseInt(data.trim(), 10);
    if (isNaN(position)) return;

    socket.emit('position', position); // envoie au client pour l'animation

    const now = Date.now();
    if (lastPosition !== null && lastTime !== null) {
      const deltaPos = position - lastPosition;
      const deltaTime = (now - lastTime) / 1000;
      const speed = deltaPos / deltaTime;

      clearTimeout(stopTimeout);

      if (Math.abs(speed) < 5) {
        stopPlayback();
        return;
      }

      if (speed < 0) {
        stopPlayback(); // Rotation inverse = arrêt
      } else {
        // Rotation positive = jouer le son
        const rate = Math.min(Math.max(0.5 + speed / 400, 0.5), 1.5);
        startOrAdjustPlayback(rate);
      }
    }

    lastPosition = position;
    lastTime = now;

    stopTimeout = setTimeout(() => {
      stopPlayback();
    }, 300);
  });
});

// Fonctions de lecture audio
function startOrAdjustPlayback(speed = 1.0) {
  if (mpg123Process === null) {
    console.log(`⏯️ Lecture à ${speed.toFixed(2)}x`);
    mpg123Process = spawn('mpg123', ['-k', '0', SOUND_FILE]);

    mpg123Process.on('exit', (code) => {
      console.log(`🔇 mpg123 terminé (code ${code})`);
      mpg123Process = null;
    });
  } else {
    console.log(`⚙️ (Note : mpg123 ne supporte pas le changement de vitesse à chaud)`);
    // Pour changer la vitesse, il faudrait tuer et relancer mpg123 avec options spécifiques
  }
}

function stopPlayback() {
  if (mpg123Process !== null) {
    console.log('🛑 Arrêt de la lecture');
    mpg123Process.kill('SIGKILL');
    mpg123Process = null;
  }
}

server.listen(PORT, () => {
  console.log(`Serveur en écoute sur http://localhost:${PORT}`);
});