require('dotenv').config();

const { SECURITY, SERVER, CRON } = require('./config/constants');

// ============ SECURITY VALIDATION ============
// Validate JWT_SECRET at startup
if (!process.env.JWT_SECRET || process.env.JWT_SECRET.length < SECURITY.JWT_MIN_SECRET_LENGTH) {
  console.error(`JWT_SECRET must be at least ${SECURITY.JWT_MIN_SECRET_LENGTH} characters!`);
  process.exit(1);
}

const express = require('express');
const cors = require('cors');
const helmet = require('helmet');
const rateLimit = require('express-rate-limit');
const path = require('path');
const cron = require('node-cron');
const apiRouter = require('./routes/api');
const authRouter = require('./routes/auth');
const beneficiariesRouter = require('./routes/beneficiaries');
const deploymentsRouter = require('./routes/deployments');
const invitationsRouter = require('./routes/invitations');
const pushTokensRouter = require('./routes/push-tokens');
const notificationSettingsRouter = require('./routes/notification-settings');
const ordersRouter = require('./routes/orders');
const stripeRouter = require('./routes/stripe');
const webhookRouter = require('./routes/webhook');
const adminRouter = require('./routes/admin');
const mqttRouter = require('./routes/mqtt');
const { syncAllSubscriptions } = require('./services/subscription-sync');
const mqttService = require('./services/mqtt');
const logger = require('./utils/logger');

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

// Trust proxy for correct IP when behind nginx
app.set('trust proxy', SERVER.TRUST_PROXY_LEVEL);

// ============ SECURITY ============

// Helmet - добавляет security headers
app.use(helmet({
  contentSecurityPolicy: false // отключаем для admin panel
}));

// CORS - разрешаем только наши домены
const allowedOrigins = [
  'https://wellnuo.smartlaunchhub.com',
  'https://wellnuo.com',
  'http://localhost:3000',
  'http://localhost:8081',  // Expo dev
  'exp://192.168.1.*'       // Expo local
];

app.use(cors({
  origin: function(origin, callback) {
    // Разрешаем запросы без origin (mobile apps, Postman)
    if (!origin) return callback(null, true);

    // Проверяем разрешённые домены
    if (allowedOrigins.some(allowed => {
      if (allowed.includes('*')) {
        const regex = new RegExp(allowed.replace('*', '.*'));
        return regex.test(origin);
      }
      return allowed === origin;
    })) {
      return callback(null, true);
    }

    callback(new Error('Not allowed by CORS'));
  },
  credentials: true
}));

// Rate Limiting - защита от DDoS
const limiter = rateLimit({
  windowMs: SECURITY.RATE_LIMIT.WINDOW_MS,
  max: SECURITY.RATE_LIMIT.MAX_REQUESTS,
  message: { error: 'Too many requests, please try again later' },
  standardHeaders: true,
  legacyHeaders: false
});

// Лимит для auth endpoints
const authLimiter = rateLimit({
  windowMs: SECURITY.RATE_LIMIT.WINDOW_MS,
  max: SECURITY.RATE_LIMIT.AUTH_MAX_REQUESTS,
  message: { error: 'Too many login attempts, please try again later' },
  // Пропускаем админов без лимита
  skip: (req) => {
    const adminEmails = ['serter2069@gmail.com', 'ezmrzli@gmail.com', 'apple@zmrinc.com'];
    return adminEmails.includes(req.body?.email?.toLowerCase());
  }
});

// Применяем rate limiting
app.use(limiter);
app.use('/api/auth', authLimiter); // Auth endpoints
app.use('/function/well-api/api', authLimiter); // Legacy API с auth

// Stripe webhooks need raw body for signature verification
// Must be before express.json()
app.use('/api/webhook/stripe', express.raw({ type: 'application/json' }));

// JSON body parser for other routes
// Increased limit for base64 avatar uploads
app.use(express.json({ limit: SERVER.JSON_BODY_LIMIT }));
app.use(express.urlencoded({ extended: true, limit: SERVER.JSON_BODY_LIMIT }));

// ============ ROUTES ============

// Legacy API route - matches old API structure
// POST /function/well-api/api with function parameter
app.use('/function/well-api/api', apiRouter);

// New REST API routes
app.use('/api/auth', authRouter);
app.use('/api/me/beneficiaries', beneficiariesRouter);
app.use('/api/me', deploymentsRouter); // Deployment routes
app.use('/api/invitations', invitationsRouter);
app.use('/api/push-tokens', pushTokensRouter);
app.use('/api/notification-settings', notificationSettingsRouter);
app.use('/api/orders', ordersRouter);
app.use('/api/stripe', stripeRouter);
app.use('/api/webhook', webhookRouter);
app.use('/api/admin', adminRouter);
app.use('/api/mqtt', mqttRouter);

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

// Health check
app.get('/health', (req, res) => {
  res.json({
    status: 'ok',
    timestamp: new Date().toISOString(),
    stripe: process.env.STRIPE_SECRET_KEY ? 'configured' : 'missing'
  });
});

// API info
app.get('/api', (req, res) => {
  res.json({
    name: 'WellNuo API',
    version: '2.0.0',
    endpoints: {
      auth: '/api/auth',
      beneficiaries: '/api/me/beneficiaries',
      deployments: '/api/me/beneficiaries/:id/deployments',
      invitations: '/api/invitations',
      pushTokens: '/api/push-tokens',
      notificationSettings: '/api/notification-settings',
      orders: '/api/orders',
      stripe: '/api/stripe',
      webhook: '/api/webhook/stripe',
      admin: '/api/admin',
      mqtt: '/api/mqtt',
      legacy: '/function/well-api/api'
    }
  });
});

// ============ CRON JOBS ============

// Sync subscriptions from Stripe every hour
cron.schedule(CRON.SYNC_CRON_SCHEDULE, async () => {
  logger.info('CRON', 'Running subscription sync...');
  const result = await syncAllSubscriptions();
  logger.info('CRON', 'Subscription sync result', result);
});

// Run sync on startup (after delay to let everything initialize)
setTimeout(async () => {
  logger.info('STARTUP', 'Running initial subscription sync...');
  const result = await syncAllSubscriptions();
  logger.info('STARTUP', 'Initial sync result', result);
}, SERVER.INITIAL_SYNC_DELAY_MS);

// Manual sync endpoint (for admin)
app.post('/api/admin/sync-subscriptions', async (req, res) => {
  logger.info('ADMIN', 'Manual subscription sync requested');
  const result = await syncAllSubscriptions();
  res.json(result);
});

app.listen(PORT, () => {
  logger.info('SERVER', `WellNuo API running on port ${PORT}`);
  logger.info('SERVER', `Stripe: ${process.env.STRIPE_SECRET_KEY ? 'configured' : 'missing'}`);

  // Initialize MQTT connection
  mqttService.init();

  // Subscribe to ALL active deployments from database
  setTimeout(async () => {
    const deployments = await mqttService.subscribeToAllDeployments();
    logger.info('MQTT', `Subscribed to ${deployments.length} deployments`, { deployments });
  }, SERVER.MQTT_SUBSCRIBE_DELAY_MS);
});

// Graceful shutdown
process.on('SIGTERM', () => {
  logger.info('SERVER', 'SIGTERM received, shutting down gracefully...');
  mqttService.shutdown();
  process.exit(0);
});

process.on('SIGINT', () => {
  logger.info('SERVER', 'SIGINT received, shutting down gracefully...');
  mqttService.shutdown();
  process.exit(0);
});