import type { ErrorRequestHandler } from 'express';

import { toHttpError } from '../errors.js';
import {
  applyApiResponseHeaders,
  buildApiLogContext,
  wantsApiEnvelope,
} from '../http.js';

export const errorHandler: ErrorRequestHandler = (
  error,
  request,
  response,
  _next,
) => {
  const normalizedError = toHttpError(error);
  const meta = applyApiResponseHeaders(request, response);

  request.log?.error(
    {
      err: error,
      ...buildApiLogContext(request, response),
      user_id: request.userId ?? null,
      status: normalizedError.statusCode,
      error_code: normalizedError.code,
    },
    'request failed',
  );

  response.status(normalizedError.statusCode);

  const errorPayload = {
    code: normalizedError.code,
    message: normalizedError.message,
    ...(normalizedError.expose && normalizedError.details !== undefined
      ? { details: normalizedError.details }
      : {}),
  };

  if (wantsApiEnvelope(request)) {
    response.json({
      ok: false,
      data: null,
      error: errorPayload,
      meta,
    });
    return;
  }

  response.json({
    error: errorPayload,
    meta,
  });
};