const logger = require('../utils/logger');

const errorHandler = (err, req, res, next) => {
  let error = { ...err };
  error.message = err.message;

  // Log error
  logger.logError(err, {
    method: req.method,
    url: req.originalUrl,
    ip: req.ip,
    userAgent: req.get('User-Agent')
  });

  // Mongoose bad ObjectId
  if (err.name === 'CastError') {
    const message = 'Invalid ID format';
    error = {
      message,
      statusCode: 400
    };
  }

  // Mongoose duplicate key
  if (err.code === 11000) {
    const field = Object.keys(err.keyValue)[0];
    const message = `${field} already exists`;
    error = {
      message,
      statusCode: 400
    };
  }

  // Mongoose validation error
  if (err.name === 'ValidationError') {
    const message = Object.values(err.errors).map(val => val.message).join(', ');
    error = {
      message,
      statusCode: 400
    };
  }

  // JWT errors
  if (err.name === 'JsonWebTokenError') {
    const message = 'Invalid token';
    error = {
      message,
      statusCode: 401
    };
  }

  if (err.name === 'TokenExpiredError') {
    const message = 'Token expired';
    error = {
      message,
      statusCode: 401
    };
  }

  // Stripe errors
  if (err.type && err.type.startsWith('Stripe')) {
    const message = 'Payment processing error';
    error = {
      message,
      statusCode: 400
    };
  }

  res.status(error.statusCode || 500).json({
    success: false,
    message: error.message || 'Server Error',
    ...(process.env.NODE_ENV === 'development' && { stack: err.stack })
  });
};

module.exports = errorHandler;