grants/server/middleware/errorHandler.ts

import type { Request, Response, NextFunction } from "express";
import createHttpError from "http-errors";
import logger from "./logger";

/**
 * Global error handler middleware.
 * - Logs errors with full context
 * - Returns sanitized error responses in production
 * - Returns detailed errors in development
 */

export function errorHandler(err: any, req: Request, res: Response, next: NextFunction) {
  // Log the error
  logger.error(
    {
      err,
      path: req.path,
      method: req.method,
      body: req.body,
    },
    "request error"
  );

  // Determine status code
  const status = err.status || err.statusCode || 500;

  // Build response
  const response: any = {
    ok: false,
    error: err.message || "Internal server error",
  };

  // In development, include stack trace
  if (process.env.NODE_ENV !== "production") {
    response.stack = err.stack;
    response.details = err.details;
  }

  // Add request ID if available
  const reqId = res.getHeader("X-Request-ID");
  if (reqId) {
    response.requestId = reqId;
  }

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

// 404 handler
export function notFoundHandler(req: Request, res: Response, next: NextFunction) {
  next(createHttpError(404, `Not found: ${req.method} ${req.path}`));
}