src/middleware/errorHandler.ts

import { Request, Response, NextFunction } from 'express';

export interface AppError extends Error {
  statusCode?: number;
  isOperational?: boolean;
}

export const errorHandler = (

  error: AppError,

  req: Request,

  res: Response,

  next: NextFunction

) => {
  const statusCode = error.statusCode || 500;
  const message = error.message || 'Internal Server Error';

  // Log error for debugging
  console.error('Error:', error);

  // Don't leak error details in production
  const isDevelopment = process.env.NODE_ENV === 'development';

  res.status(statusCode).json({
    error: message,
    ...(isDevelopment && { stack: error.stack })
  });
};