require('dotenv').config();
const express = require('express');
const session = require('express-session');
const path = require('path');
const bcrypt = require('bcryptjs');
const db = require('./config/database');

const app = express();

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

// Static Files
app.use(express.static(path.join(__dirname, 'public')));

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

// Session
app.use(session({
  secret: process.env.SESSION_SECRET || 'plusfit24-secret',
  resave: false,
  saveUninitialized: false,
  cookie: {
    secure: false, // auf true setzen wenn HTTPS direkt (nicht via Proxy)
    maxAge: 24 * 60 * 60 * 1000 // 24 Stunden
  }
}));

// Routen
const indexRouter = require('./routes/index');
const adminRouter = require('./routes/admin');
const apiRouter = require('./routes/api');
const billingRouter = require('./routes/billing');
const financeRouter = require('./routes/finance');
const renewalRouter  = require('./routes/renewal');
const contractsRouter = require('./routes/contracts');
const mailingRouter   = require('./routes/mailing');
const cron = require('node-cron');

app.use('/', indexRouter);
app.use('/admin', adminRouter);
app.use('/api', apiRouter);
app.use('/admin/billing', billingRouter);
app.use('/admin/finance', financeRouter);
app.use('/', renewalRouter);
app.use('/admin/contracts', contractsRouter);
app.use('/admin/mailing', mailingRouter);

// 404 Handler
app.use((req, res) => {
  res.status(404).render('error', { message: 'Seite nicht gefunden' });
});

// Fehler Handler
app.use((err, req, res, next) => {
  console.error(err.stack);
  res.status(500).render('error', { message: 'Ein Fehler ist aufgetreten' });
});

// Admin Account beim Start erstellen falls keiner existiert
async function initAdmin() {
  try {
    const [rows] = await db.query('SELECT COUNT(*) as count FROM admins');
    if (rows[0].count === 0) {
      const hash = await bcrypt.hash(process.env.ADMIN_PASSWORD || 'Admin1234!', 12);
      await db.query(
        'INSERT INTO admins (username, password_hash) VALUES (?, ?)',
        [process.env.ADMIN_USER || 'admin', hash]
      );
      console.log('✅ Admin Account erstellt:', process.env.ADMIN_USER || 'admin');
    }
  } catch (err) {
    console.error('❌ Fehler beim Erstellen des Admin Accounts:', err.message);
  }
}

// Verlängerungs-E-Mails: täglich um 08:00 Uhr prüfen (60 Tage vorher)
cron.schedule('0 8 * * *', async () => {
  console.log('⏰ Prüfe auslaufende Verträge (60 Tage)...');
  try {
    const [expiring] = await db.query(`
      SELECT m.* FROM memberships m
      WHERE m.status = 'active'
        AND m.effective_end BETWEEN CURDATE() AND DATE_ADD(CURDATE(), INTERVAL 61 DAY)
        AND m.id NOT IN (
          SELECT membership_id FROM renewal_requests
          WHERE status IN ('pending','completed')
            AND sent_at >= DATE_SUB(NOW(), INTERVAL 70 DAY)
        )
    `);
    if (expiring.length > 0) {
      const { renewalEmailHtml } = require('./routes/renewal');
      const mailer = require('./config/mailer');
      const crypto = require('crypto');
      const [tariffs] = await db.query('SELECT * FROM tariffs WHERE active = 1 ORDER BY price_monthly ASC');
      for (const member of expiring) {
        try {
          const token = crypto.randomBytes(32).toString('hex');
          const expiresAt = new Date(Date.now() + 30 * 24 * 60 * 60 * 1000);
          await db.query(
            'INSERT INTO renewal_requests (membership_id, token, expires_at) VALUES (?,?,?)',
            [member.id, token, expiresAt]
          );
          const baseUrl = process.env.APP_URL || 'https://plusfit24.software-joksch.com';
          const link = baseUrl + '/renew/' + token;
          await mailer.sendMail({
            from: process.env.MAIL_FROM,
            to: member.email,
            subject: `Deine PlusFit24 Mitgliedschaft läuft bald ab`,
            html: renewalEmailHtml(member, tariffs, link, member.effective_end || member.contract_end)
          });
          await db.query(
            'INSERT INTO email_log (membership_id, type, recipient, subject, status) VALUES (?,?,?,?,?)',
            [member.id, 'renewal_auto', member.email, 'Mitgliedschaft läuft ab', 'sent']
          );
          console.log('📧 Verlängerungs-E-Mail gesendet an:', member.email);
        } catch (err) {
          console.error('❌ E-Mail Fehler für', member.email, ':', err.message);
        }
      }
    } else {
      console.log('✅ Keine auslaufenden Verträge heute.');
    }
  } catch (err) {
    console.error('❌ Cron Fehler:', err.message);
  }
});

// Auto-Abrechnungslauf jeden 1. des Monats um 06:00 Uhr
cron.schedule('0 6 1 * *', async () => {
  const { currentPeriod } = require('./routes/billing');
  const period = currentPeriod();
  console.log(`⏰ Auto-Abrechnungslauf gestartet für ${period}`);
  try {
    const [existing] = await db.query('SELECT COUNT(*) as c FROM invoices WHERE period = ?', [period]);
    if (existing[0].c > 0) {
      console.log(`⏭ Abrechnungslauf für ${period} bereits vorhanden – übersprungen`);
      return;
    }
    const [members] = await db.query(`
      SELECT m.*, t.price_monthly FROM memberships m
      JOIN tariffs t ON m.tariff_id = t.id
      WHERE m.status IN ('active','paused')
        AND m.contract_start <= LAST_DAY(STR_TO_DATE(CONCAT(?, '-01'), '%Y-%m-%d'))
        AND (m.contract_end IS NULL OR m.contract_end >= STR_TO_DATE(CONCAT(?, '-01'), '%Y-%m-%d'))
    `, [period, period]);
    const [runResult] = await db.query(
      'INSERT INTO billing_runs (run_date, period, created_by) VALUES (CURDATE(), ?, ?)',
      [period, 'system-auto']
    );
    let total = 0, count = 0;
    for (const m of members) {
      const firstPeriod = m.first_payment_date ? m.first_payment_date.toISOString().substring(0,7) : null;
      const amount = firstPeriod === period && m.first_payment_amt ? parseFloat(m.first_payment_amt) : parseFloat(m.price_monthly);
      await db.query(
        'INSERT IGNORE INTO invoices (billing_run_id, membership_id, period, amount, description, iban, account_holder, bank_name) VALUES (?,?,?,?,?,?,?,?)',
        [runResult.insertId, m.id, period, amount, `Mitgliedsbeitrag ${period}`, m.iban||'', m.account_holder||'', m.bank_name||'']
      );
      total += amount; count++;
    }
    await db.query('UPDATE billing_runs SET total_amount=?, invoice_count=? WHERE id=?', [total, count, runResult.insertId]);
    console.log(`✅ Auto-Abrechnungslauf abgeschlossen: ${count} Rechnungen, ${total.toFixed(2)} €`);
  } catch (err) {
    console.error('❌ Auto-Abrechnungslauf Fehler:', err.message);
  }
});

const PORT = process.env.PORT || 3100;
app.listen(PORT, async () => {
  console.log(`🚀 PlusFit24 Server läuft auf Port ${PORT}`);
  await initAdmin();
});