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

export function errorHandler(err: any, req: Request, res: Response, next: NextFunction) {
  console.error(`[ERROR] ${err.message}`, err.stack);

  if (err.name === 'ZodError') {
    return res.status(400).json({
      error: 'Validation error',
      details: err.errors
    });
  }

  if (err.code === 'P2002') {
    return res.status(409).json({ error: 'Resource already exists' });
  }

  if (err.code === 'P2025') {
    return res.status(404).json({ error: 'Resource not found' });
  }

  const status = err.status || 500;
  res.status(status).json({
    error: status === 500 ? 'Internal server error' : err.message
  });
}