/**
 * Error Handling Middleware
 * 統一的錯誤處理
 */

/**
 * 404 Not Found Handler
 */
export function notFoundHandler(req, res, next) {
  res.status(404).json({
    success: false,
    error: 'Not Found',
    message: `無法找到路徑: ${req.originalUrl}`
  });
}

/**
 * Global Error Handler
 */
export function errorHandler(err, req, res, next) {
  console.error('Error:', err);

  // 預設錯誤狀態碼
  const statusCode = err.statusCode || 500;

  // 錯誤訊息
  const message = err.message || '伺服器發生錯誤';

  // 開發環境返回完整錯誤堆疊
  const response = {
    success: false,
    error: err.name || 'Error',
    message: message
  };

  if (process.env.NODE_ENV === 'development') {
    response.stack = err.stack;
    response.details = err.details || null;
  }

  res.status(statusCode).json(response);
}

/**
 * Async Handler Wrapper
 * 包裝 async 函數以自動捕獲錯誤
 */
export function asyncHandler(fn) {
  return (req, res, next) => {
    Promise.resolve(fn(req, res, next)).catch(next);
  };
}

/**
 * Validation Error Handler
 */
export function validationErrorHandler(errors) {
  const error = new Error('驗證失敗');
  error.statusCode = 400;
  error.details = errors;
  return error;
}