backend/src/middleware/errorHandler.ts

import { Request, Response, NextFunction } from "express";
import { AppError } from "../utils/AppError";
import { createChildLogger } from "../config/logger";

const log = createChildLogger({ module: "error" });

export const errorHandler = (err: Error, req: Request, res: Response, _next: NextFunction) => {
  if (err instanceof AppError) {
    log.warn(`${err.message}`, { statusCode: err.statusCode, url: req.originalUrl });
    return res.status(err.statusCode).json({
      success: false,
      message: err.message,
    });
  }

  log.error("Unhandled error", {
    message: err.message,
    stack: err.stack,
    url: req.originalUrl,
    method: req.method,
  });

  return res.status(500).json({
    success: false,
    message: process.env.NODE_ENV === "production" ? "Internal Server Error" : err.message,
  });
};