import { HTTPError } from "ky";

export interface ApiErrorBody {
  message?: string;
  errors?: Record<string, string[]>;
}

/** 讀取 ky 已解析的 API 錯誤，不重複消耗 response body。 */
export function getApiErrorBody(error: unknown): ApiErrorBody | null {
  if (
    error instanceof HTTPError &&
    error.data &&
    typeof error.data === "object"
  ) {
    return error.data as ApiErrorBody;
  }

  return null;
}

export function getApiErrorStatus(error: unknown): number | null {
  return error instanceof HTTPError ? error.response.status : null;
}

export function getApiErrorMessage(
  error: unknown,
  fallback = "操作失敗，請稍後再試。",
): string {
  const body = getApiErrorBody(error);
  if (body?.message) {
    return body.message;
  }

  const firstFieldError = Object.values(body?.errors ?? {})[0]?.[0];
  if (firstFieldError) {
    return firstFieldError;
  }

  return error instanceof Error ? error.message : fallback;
}

export function isUnregisteredPhoneError(error: unknown): boolean {
  return (
    getApiErrorStatus(error) === 401 &&
    getApiErrorBody(error)?.message === "手機門號不存在或尚未註冊"
  );
}