const express = require('express');
const session = require('express-session');
const path = require('path');
const fs = require('fs');

// Load .env if present
try {
  const envFile = fs.readFileSync(path.join(__dirname, '..', '.env'), 'utf8');
  envFile.split('\n').forEach(line => {
    const match = line.match(/^([^#=]+)=(.*)$/);
    if (match) {
      process.env[match[1].trim()] = match[2].trim();
    }
  });
} catch (e) { /* .env file is optional */ }

// Ensure data dirs exist
const dataDir = path.dirname(process.env.DB_PATH || './data/loot-hunt.db');
const uploadsDir = process.env.UPLOADS_DIR || './data/uploads';
[dataDir, uploadsDir].forEach(dir => {
  if (!fs.existsSync(dir)) fs.mkdirSync(dir, { recursive: true });
});

// Initialize database (async — schema creation happens in background)
const db = require('./config/database');

const { loadUser } = require('./middleware/auth');

// ─── SQLite Session Store ─────────────────────────────────
class SQLiteSessionStore extends session.Store {
  constructor() {
    super();
  }

  get(sid, callback) {
    try {
      const row = db.prepare('SELECT sess FROM sessions WHERE sid = ? AND expired > datetime(\'now\')').get(sid);
      if (row) {
        callback(null, JSON.parse(row.sess));
      } else {
        callback(null, null);
      }
    } catch (err) { callback(err); }
  }

  set(sid, sess, callback) {
    try {
      const maxAge = sess.cookie && sess.cookie.maxAge ? sess.cookie.maxAge : 86400000;
      const expiredDate = new Date(Date.now() + maxAge).toISOString();
      const sessStr = JSON.stringify(sess);
      // upsert
      db.prepare('DELETE FROM sessions WHERE sid = ?').run(sid);
      db.prepare('INSERT INTO sessions (sid, sess, expired) VALUES (?, ?, ?)').run(sid, sessStr, expiredDate);
      callback(null);
    } catch (err) { callback(err); }
  }

  destroy(sid, callback) {
    try {
      db.prepare('DELETE FROM sessions WHERE sid = ?').run(sid);
      callback(null);
    } catch (err) { callback(err); }
  }

  // Clean up expired sessions periodically
  touch(sid, sess, callback) {
    this.set(sid, sess, callback);
  }
}

// ─── Start app once DB is ready ───────────────────────────
async function start() {
  await db.ready;

  const app = express();
  const PORT = process.env.PORT || 3000;

  // View engine
  app.set('view engine', 'ejs');
  app.set('views', path.join(__dirname, 'views'));

  // Body parsing
  app.use(express.urlencoded({ extended: true }));
  app.use(express.json());

  // Static files
  app.use(express.static(path.join(__dirname, '..', 'public')));
  app.use('/uploads', express.static(path.resolve(uploadsDir)));

  // Sessions
  app.use(session({
    store: new SQLiteSessionStore(),
    secret: process.env.SESSION_SECRET || 'loot-hunt-dev-secret-change-me',
    resave: false,
    saveUninitialized: false,
    cookie: {
      maxAge: 30 * 24 * 60 * 60 * 1000, // 30 days
      httpOnly: true,
      secure: process.env.NODE_ENV === 'production' && process.env.TRUST_PROXY === 'true'
    }
  }));

  // Trust proxy if behind nginx
  if (process.env.TRUST_PROXY === 'true') {
    app.set('trust proxy', 1);
  }

  // Load current user into all views
  app.use(loadUser);

  // Flash-like messages via session
  app.use((req, res, next) => {
    res.locals.flash = req.session.flash || null;
    delete req.session.flash;
    next();
  });

  // Routes
  app.use('/auth', require('./routes/auth'));
  app.use('/admin', require('./routes/admin'));
  app.use('/loot', require('./routes/loot'));
  app.use('/', require('./routes/hunts'));

  // QR Scanner
  app.get('/scanner', (req, res) => {
    res.render('scanner', { title: 'QR Scanner' });
  });

  // Home page
  app.get('/', (req, res) => {
    const { Hunts, Scans } = require('./models');
    const hunts = Hunts.getAll();
    const recentActivity = Scans.getRecentActivity(5);
    res.render('home', { title: 'Loot Hunt', hunts, recentActivity });
  });

  // 404 handler
  app.use((req, res) => {
    res.status(404).render('error', { title: 'Not Found', message: 'The page you are looking for does not exist.' });
  });

  // Error handler
  app.use((err, req, res, next) => {
    console.error(err.stack);
    res.status(500).render('error', { title: 'Error', message: 'Something went wrong.' });
  });

  app.listen(PORT, '0.0.0.0', () => {
    console.log(`🎯 Loot Hunt running on port ${PORT}`);
  });
}

start().catch(err => {
  console.error('Failed to start:', err);
  process.exit(1);
});