const express = require('express');
const cors = require('cors');
const helmet = require('helmet');
const securityConfig = require('./config/security');
const { apiLimiter } = require('./middleware/rateLimiter');

const app = express();

// Security Headers (helmet)
app.use(helmet({
  contentSecurityPolicy: {
    directives: {
      defaultSrc: ["'self'"],
      styleSrc: ["'self'", "'unsafe-inline'", "https://ui-avatars.com"],
      scriptSrc: ["'self'"],
      imgSrc: ["'self'", "data:", "https:", "https://ui-avatars.com"],
      connectSrc: ["'self'"],
      fontSrc: ["'self'"],
      objectSrc: ["'none'"],
      mediaSrc: ["'self'"],
      frameSrc: ["'none'"],
    },
  },
  hsts: {
    maxAge: 31536000,
    includeSubDomains: true,
    preload: true,
  },
  noSniff: true,
  xssFilter: true,
  hidePoweredBy: true,
}));

// CORS
app.use(cors({
  origin: (origin, callback) => {
    const allowedOrigins = securityConfig.cors.origin;

    // Allow requests with no origin (mobile apps, curl, etc.)
    if (!origin) return callback(null, true);

    if (allowedOrigins.includes(origin)) {
      callback(null, true);
    } else {
      callback(new Error('Not allowed by CORS'));
    }
  },
  credentials: securityConfig.cors.credentials,
  maxAge: 86400, // 24 hours
}));

// Body parsing with size limits
app.use(express.json({ limit: securityConfig.bodyLimit }));
app.use(express.urlencoded({ extended: true, limit: securityConfig.bodyLimit }));

// Request logging middleware
app.use((req, res, next) => {
  console.log(`${new Date().toISOString()} - ${req.method} ${req.path}`);
  next();
});

// Health check endpoint
app.get('/api/health', (req, res) => {
  res.status(200).json({
    status: 'ok',
    message: 'Backend is running',
    timestamp: new Date().toISOString(),
    environment: process.env.NODE_ENV || 'development'
  });
});

// Apply rate limiting to all API routes
app.use('/api/', apiLimiter);

// API routes
app.use('/api/auth', require('./routes/auth'));
app.use('/api/users', require('./routes/users'));
app.use('/api/events', require('./routes/events'));
app.use('/api/wsdc', require('./routes/wsdc'));
app.use('/api/divisions', require('./routes/divisions'));
app.use('/api/competition-types', require('./routes/competitionTypes'));
app.use('/api/matches', require('./routes/matches'));
// app.use('/api/ratings', require('./routes/ratings'));

// 404 handler
app.use((req, res) => {
  res.status(404).json({
    error: 'Not Found',
    message: `Cannot ${req.method} ${req.path}`
  });
});

// Error handler
app.use((err, req, res, next) => {
  // Log full error for debugging
  console.error('Error:', err);

  // Determine if we should show detailed errors
  const isDevelopment = process.env.NODE_ENV === 'development';

  // Generic error response
  const errorResponse = {
    success: false,
    error: isDevelopment ? err.message : 'Internal Server Error',
  };

  // Add stack trace only in development
  if (isDevelopment && err.stack) {
    errorResponse.stack = err.stack;
  }

  res.status(err.status || 500).json(errorResponse);
});

module.exports = app;