const express = require('express');
const http = require('http');
const WebSocket = require('ws');
const multer = require('multer');
const sharp = require('sharp');
const path = require('path');
const fs = require('fs');
const crypto = require('crypto');

const app = express();
const server = http.createServer(app);
const wss = new WebSocket.Server({ server });

// --- Configuration ---
const PORT = process.env.PORT || 3000;
const PHOTOS_DIR = path.join(__dirname, 'data', 'photos');
const THUMBS_DIR = path.join(__dirname, 'data', 'thumbs');

// Creer les dossiers
fs.mkdirSync(PHOTOS_DIR, { recursive: true });
fs.mkdirSync(THUMBS_DIR, { recursive: true });

// --- Sessions evenement ---
// { eventId: { password, photos: [{name, timestamp}], createdAt } }
const sessions = new Map();

function genererPassword() {
  return crypto.randomInt(1000, 9999).toString();
}

function getSession(eventId) {
  if (!sessions.has(eventId)) {
    sessions.set(eventId, {
      password: genererPassword(),
      photos: [],
      createdAt: Date.now(),
    });
    // Creer le dossier
    fs.mkdirSync(path.join(PHOTOS_DIR, eventId), { recursive: true });
    fs.mkdirSync(path.join(THUMBS_DIR, eventId), { recursive: true });
  }
  return sessions.get(eventId);
}

// --- Upload photos depuis la borne ---
const upload = multer({
  storage: multer.memoryStorage(),
  limits: { fileSize: 20 * 1024 * 1024 }, // 20 Mo max
});

// API Key pour l'upload (simple)
const API_KEY = process.env.API_KEY || 'booth-secret-key';

function verifierApiKey(req, res, next) {
  const key = req.headers['x-api-key'] || req.query.key;
  if (key !== API_KEY) {
    return res.status(401).json({ error: 'Cle API invalide' });
  }
  next();
}

// --- Routes API ---

// Upload photo depuis la borne
app.post('/api/:eventId/upload', verifierApiKey, upload.single('photo'), async (req, res) => {
  try {
    const { eventId } = req.params;
    const session = getSession(eventId);
    const timestamp = Date.now();
    const filename = `${timestamp}.jpg`;

    // Sauvegarder la photo originale
    const photoPath = path.join(PHOTOS_DIR, eventId, filename);
    await sharp(req.file.buffer)
      .jpeg({ quality: 90 })
      .toFile(photoPath);

    // Creer la miniature
    const thumbPath = path.join(THUMBS_DIR, eventId, filename);
    await sharp(req.file.buffer)
      .resize(400, 400, { fit: 'cover' })
      .jpeg({ quality: 75 })
      .toFile(thumbPath);

    // Ajouter a la session
    const photoInfo = { name: filename, timestamp };
    session.photos.push(photoInfo);

    // Notifier les clients WebSocket
    broadcast(eventId, {
      type: 'new_photo',
      photo: photoInfo,
    });

    res.json({ ok: true, filename });
  } catch (err) {
    console.error('Erreur upload:', err);
    res.status(500).json({ error: 'Erreur upload' });
  }
});

// Info session (mot de passe pour la borne)
app.get('/api/:eventId/info', verifierApiKey, (req, res) => {
  const session = getSession(req.params.eventId);
  res.json({
    password: session.password,
    photoCount: session.photos.length,
  });
});

// Regenerer le mot de passe
app.post('/api/:eventId/reset-password', verifierApiKey, (req, res) => {
  const session = getSession(req.params.eventId);
  session.password = genererPassword();
  res.json({ password: session.password });
});

// --- Routes publiques (invites) ---

// Verifier le mot de passe
app.post('/api/:eventId/auth', express.json(), (req, res) => {
  const session = sessions.get(req.params.eventId);
  if (!session) {
    return res.status(404).json({ error: 'Evenement introuvable' });
  }
  if (req.body.password !== session.password) {
    return res.status(403).json({ error: 'Mot de passe incorrect' });
  }
  // Generer un token simple
  const token = crypto.randomBytes(16).toString('hex');
  session.token = session.token || new Set();
  session.token.add(token);
  res.json({ ok: true, token, photoCount: session.photos.length });
});

// Middleware pour verifier le token invite
function verifierToken(req, res, next) {
  const token = req.headers['x-token'] || req.query.token;
  const session = sessions.get(req.params.eventId);
  if (!session || !session.token || !session.token.has(token)) {
    return res.status(403).json({ error: 'Acces refuse' });
  }
  req.session = session;
  next();
}

// Liste des photos
app.get('/api/:eventId/photos', verifierToken, (req, res) => {
  res.json({ photos: req.session.photos });
});

// Servir les photos
app.get('/photos/:eventId/:filename', (req, res) => {
  const token = req.query.token;
  const session = sessions.get(req.params.eventId);
  if (!session || !session.token || !session.token.has(token)) {
    return res.status(403).send('Acces refuse');
  }
  const filePath = path.join(PHOTOS_DIR, req.params.eventId, req.params.filename);
  if (!fs.existsSync(filePath)) return res.status(404).send('Not found');
  res.sendFile(filePath);
});

// Servir les miniatures
app.get('/thumbs/:eventId/:filename', (req, res) => {
  const token = req.query.token;
  const session = sessions.get(req.params.eventId);
  if (!session || !session.token || !session.token.has(token)) {
    return res.status(403).send('Acces refuse');
  }
  const filePath = path.join(THUMBS_DIR, req.params.eventId, req.params.filename);
  if (!fs.existsSync(filePath)) return res.status(404).send('Not found');
  res.sendFile(filePath);
});

// --- WebSocket ---
wss.on('connection', (ws, req) => {
  const url = new URL(req.url, `http://localhost:${PORT}`);
  const eventId = url.searchParams.get('event');
  const token = url.searchParams.get('token');

  const session = sessions.get(eventId);
  if (!session || !session.token || !session.token.has(token)) {
    ws.close(4001, 'Acces refuse');
    return;
  }

  ws.eventId = eventId;
  ws.isAlive = true;

  ws.on('pong', () => { ws.isAlive = true; });
  ws.on('error', () => {});
});

function broadcast(eventId, data) {
  const msg = JSON.stringify(data);
  wss.clients.forEach(client => {
    if (client.eventId === eventId && client.readyState === WebSocket.OPEN) {
      client.send(msg);
    }
  });
}

// Ping pour garder les connexions
setInterval(() => {
  wss.clients.forEach(ws => {
    if (!ws.isAlive) return ws.terminate();
    ws.isAlive = false;
    ws.ping();
  });
}, 30000);

// --- Frontend statique ---
app.use(express.static(path.join(__dirname, 'public')));

// SPA fallback
app.get('/:eventId', (req, res) => {
  res.sendFile(path.join(__dirname, 'public', 'index.html'));
});

// --- Demarrage ---
server.listen(PORT, () => {
  console.log(`Booth gallery running on port ${PORT}`);
});