const express = require('express');
const cookieParser = require('cookie-parser');
const jwt = require('jsonwebtoken');
const bcrypt = require('bcryptjs');
const path = require('path');
const db = require('./db');
const posClient = require('./posClient');

const app = express();
const PORT = process.env.PORT || 80;

app.use(express.json());
app.use(express.urlencoded({ extended: true }));
app.use(cookieParser());

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

// Favicon dummy damit kein 502/404 geloggt wird
app.get('/favicon.ico', (req, res) => res.status(204).end());

// JWT Auth Middleware
function getSecret() {
  const row = db.prepare('SELECT value FROM config WHERE key = ?').get('jwt_secret');
  return row ? row.value : 'default_secret_key';
}

function authMiddleware(req, res, next) {
  const token = req.cookies.admin_token || req.headers.authorization?.replace('Bearer ', '');
  if (!token) {
    return res.status(401).json({ error: 'Nicht authentifiziert' });
  }
  try {
    const decoded = jwt.verify(token, getSecret());
    req.user = decoded;
    next();
  } catch (err) {
    res.status(401).json({ error: 'Ungültige Session' });
  }
}

// ==================== Öffentliche API ====================

// 1. Produkte, Gruppen & Theme Settings für die Speisekarte
app.get('/api/menu', (req, res) => {
  const groups = db.prepare('SELECT * FROM product_groups ORDER BY sort_order ASC, name ASC').all();
  const products = db.prepare('SELECT id, text1, text2, langtext1, langtext2, langtext3, langtext4, group_id, preis1, unit FROM products WHERE active = 1 ORDER BY sort_order ASC, text1 ASC').all();

  // Globale Einstellungen laden
  const configRows = db.prepare('SELECT key, value FROM config').all();
  const settings = {};
  for (const r of configRows) {
    if (r.key.startsWith('site_') || r.key.startsWith('theme_')) {
      settings[r.key] = r.value;
    }
  }

  const groupMap = {};
  for (const g of groups) {
    groupMap[g.id] = {
      id: g.id,
      name: g.name,
      items: []
    };
  }

  const ungrouped = [];
  for (const p of products) {
    if (p.group_id && groupMap[p.group_id]) {
      groupMap[p.group_id].items.push(p);
    } else {
      ungrouped.push(p);
    }
  }

  const result = Object.values(groupMap).filter(g => g.items.length > 0);
  if (ungrouped.length > 0) {
    result.push({
      id: 'other',
      name: 'Weitere Spezialitäten',
      items: ungrouped
    });
  }

  res.json({ categories: result, allProducts: products, settings });
});

// ==================== Admin Auth ====================

// 2. Login
app.post('/api/admin/login', (req, res) => {
  const { username, password } = req.body;
  const adminUserRow = db.prepare('SELECT value FROM config WHERE key = ?').get('admin_user');
  const hashRow = db.prepare('SELECT value FROM config WHERE key = ?').get('admin_password_hash');

  const adminUser = adminUserRow ? adminUserRow.value : 'admin';
  const hash = hashRow ? hashRow.value : '';

  if (username === adminUser && bcrypt.compareSync(password, hash)) {
    const token = jwt.sign({ user: username }, getSecret(), { expiresIn: '30d' });
    res.cookie('admin_token', token, { httpOnly: true, maxAge: 30 * 24 * 60 * 60 * 1000, sameSite: 'lax' });
    return res.json({ success: true, message: 'Erfolgreich eingeloggt' });
  }

  res.status(401).json({ error: 'Benutzername oder Passwort falsch' });
});

// 3. Logout
app.post('/api/admin/logout', (req, res) => {
  res.clearCookie('admin_token');
  res.json({ success: true });
});

// 4. Auth-Check
app.get('/api/admin/check', authMiddleware, (req, res) => {
  res.json({ authenticated: true, user: req.user.user });
});

// ==================== Admin POS Settings, Theme & Sync ====================

// 5. Config abrufen
app.get('/api/admin/config', authMiddleware, (req, res) => {
  const config = posClient.getConfig();
  delete config.admin_password_hash;
  delete config.jwt_secret;
  res.json(config);
});

// 6. Config / Theme / Texte speichern
app.post('/api/admin/config', authMiddleware, (req, res) => {
  const updates = req.body;
  const upsert = db.prepare('INSERT INTO config (key, value) VALUES (?, ?) ON CONFLICT(key) DO UPDATE SET value = excluded.value');

  for (const [key, val] of Object.entries(updates)) {
    if (key === 'new_admin_password') {
      if (val && val.trim().length > 0) {
        const newHash = bcrypt.hashSync(val.trim(), 10);
        upsert.run('admin_password_hash', newHash);
      }
    } else if (val !== undefined && val !== null) {
      upsert.run(key, String(val));
    }
  }

  res.json({ success: true, message: 'Einstellungen erfolgreich gespeichert' });
});

// 7. QR-Code Setup Handshake
app.post('/api/admin/qr-setup', authMiddleware, async (req, res) => {
  const { qrContent } = req.body;
  if (!qrContent) {
    return res.status(400).json({ error: 'Kein QR-Code Inhalt übergeben' });
  }

  try {
    const result = await posClient.processQrSetup(qrContent);
    res.json({ success: true, message: 'ServicePass erfolgreich registriert und aktiviert!', result });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

// 8. Sync auslösen
app.post('/api/admin/sync', authMiddleware, async (req, res) => {
  const { type } = req.body; // 'ERSTEINRICHTUNG' oder 'AENDERUNGEN'
  try {
    const result = await posClient.performSync(type || 'ERSTEINRICHTUNG');
    res.json({ success: true, result });
  } catch (err) {
    db.prepare('INSERT INTO sync_logs (status, message) VALUES (?, ?)').run('ERROR', err.message);
    res.status(500).json({ error: err.message });
  }
});

// 9. Logs & Produkte im Admin anzeigen
app.get('/api/admin/data', authMiddleware, (req, res) => {
  const products = db.prepare('SELECT * FROM products ORDER BY updated_at DESC').all();
  const groups = db.prepare('SELECT * FROM product_groups').all();
  const logs = db.prepare('SELECT * FROM sync_logs ORDER BY timestamp DESC LIMIT 20').all();
  res.json({ products, groups, logs });
});

// 10. Manueller Import (Test/Demo)
app.post('/api/admin/mock-import', authMiddleware, (req, res) => {
  const mockData = req.body;
  const count = posClient.importJsonData(mockData);
  res.json({ success: true, imported: count });
});

// Admin Route Frontend
app.get('/admin', (req, res) => {
  res.sendFile(path.join(__dirname, 'public', 'admin.html'));
});

// Server Start
app.listen(PORT, '0.0.0.0', () => {
  console.log(`Server läuft auf Port ${PORT}`);
});