const express = require('express');
const cors = require('cors');
const helmet = require('helmet');
const compression = require('compression');
const path = require('path');
const cron = require('node-cron');
require('dotenv').config();

const logger = require('./utils/logger');
const db = require('./models/db');
const apiRoutes = require('./routes/api');

const app = express();
const PORT = process.env.PORT || 3003;

// Trust proxy for Docker/reverse proxy environments
app.set('trust proxy', ['127.0.0.1', '::1', '172.16.0.0/12', '192.168.0.0/16', '10.0.0.0/8']);

// Compression middleware
app.use(compression());

// Security middleware - disable upgrade-insecure-requests and HSTS for HTTP-only access
app.use(helmet({
  contentSecurityPolicy: {
    directives: {
      defaultSrc: ["'self'"],
      styleSrc: ["'self'", "'unsafe-inline'", "https://unpkg.com", "https://fonts.googleapis.com"],
      scriptSrc: ["'self'", "'unsafe-inline'", "https://unpkg.com", "https://cdn.jsdelivr.net"],
      imgSrc: ["'self'", "data:", "https:", "blob:"],
      connectSrc: ["'self'", "https://unpkg.com", "https://tile.openstreetmap.org", "https://*.tile.openstreetmap.org", "https://router.project-osrm.org"],
      fontSrc: ["'self'", "https://fonts.gstatic.com", "https://unpkg.com"],
      upgradeInsecureRequests: null, // Disable for HTTP-only access
    },
  },
  hsts: false, // Disable HSTS for HTTP-only access (will be enabled by Cloudflare tunnel)
  crossOriginOpenerPolicy: false, // Disable for HTTP access
  originAgentCluster: false, // Disable for consistent behavior across HTTP/Tailscale access
}));

// Middleware
app.use(cors());
app.use(express.json());
app.use(express.urlencoded({ extended: true }));

// Request logging
app.use((req, res, next) => {
  const start = Date.now();
  res.on('finish', () => {
    const duration = Date.now() - start;
    logger.info(`${req.method} ${req.path}`, {
      status: res.statusCode,
      duration: `${duration}ms`,
      ip: req.ip
    });
  });
  next();
});

// Static files
app.use(express.static(path.join(__dirname, 'public'), {
  maxAge: process.env.NODE_ENV === 'production' ? '1d' : 0,
  etag: true
}));

// Health check endpoint
app.get('/api/health', async (req, res) => {
  try {
    await db.query('SELECT 1');
    res.json({
      status: 'healthy',
      timestamp: new Date().toISOString(),
      uptime: process.uptime()
    });
  } catch (error) {
    logger.error('Health check failed', { error: error.message });
    res.status(503).json({
      status: 'unhealthy',
      error: error.message,
      timestamp: new Date().toISOString()
    });
  }
});

// API routes
app.use('/api', apiRoutes);

// Serve main page
app.get('/', (req, res) => {
  res.sendFile(path.join(__dirname, 'public', 'index.html'));
});

// Resource detail page
app.get('/resource/:id', (req, res) => {
  res.sendFile(path.join(__dirname, 'public', 'index.html'));
});

// Weekly scraper cron job (runs every Sunday at 2 AM)
if (process.env.ENABLE_CRON === 'true') {
  cron.schedule('0 2 * * 0', async () => {
    logger.info('Starting weekly data scrape');
    try {
      const { runAllScrapers } = require('./scrapers/run-all');
      await runAllScrapers();
      logger.info('Weekly data scrape completed');
    } catch (error) {
      logger.error('Weekly data scrape failed', { error: error.message });
    }
  });
  logger.info('Weekly cron job scheduled for Sundays at 2 AM');
}

// Error handling middleware
app.use((err, req, res, next) => {
  logger.error('Application error', {
    error: err.message,
    stack: err.stack,
    path: req.path
  });
  res.status(err.status || 500).json({
    error: 'Something went wrong',
    message: process.env.NODE_ENV === 'development' ? err.message : 'Internal server error'
  });
});

// 404 handler
app.use((req, res) => {
  res.status(404).json({ error: 'Route not found' });
});

// Graceful shutdown
process.on('SIGTERM', () => {
  logger.info('SIGTERM received, shutting down');
  server.close(() => {
    db.end();
    process.exit(0);
  });
});

const server = app.listen(PORT, () => {
  logger.info('Server started', {
    port: PORT,
    environment: process.env.NODE_ENV
  });
});

module.exports = app;