import { AppErrorCode } from '@documenso/lib/errors/app-error';

import { cscJsonPost, joinCscUrl } from './http';
import { type TCscInfoRequest, type TCscInfoResponse, ZCscInfoResponseSchema } from './types';

type CscInfoOptions = TCscInfoRequest & {
  /**
   * Base URI of the CSC service (e.g. `https://service.example.org/csc/v1`).
   * Per §7.2, `info` is mounted relative to the service base URI; the OAuth
   * base URI returned in `oauth2` is discovered from this call.
   */
  baseUrl: string;
  signal?: AbortSignal;
};

/**
 * `info` (§11.1) — discovery method every CSC-conformant TSP MUST implement.
 *
 * Used at startup to:
 *
 * 1. Learn the OAuth 2.0 base URI (`oauth2`) for subsequent token / revoke
 *    calls. Per §11.1, this MAY differ from the API base URI.
 * 2. Enumerate supported methods (`methods`) so the caller can fail fast
 *    when a required endpoint is absent.
 * 3. Surface `signatures/timestamp` capability for the B-LTA seal step.
 *
 * Unauthenticated — `info` requires no bearer token. Failures throw
 * `CSC_PROVIDER_INFO_FAILED` per the spec's startup-discovery error code.
 */
export const cscInfo = async (opts: CscInfoOptions): Promise<TCscInfoResponse> => {
  const { baseUrl, lang, signal } = opts;

  return await cscJsonPost(
    {
      url: joinCscUrl({ baseUrl, path: 'info' }),
      body: lang ? { lang } : {},
      errorCode: AppErrorCode.CSC_PROVIDER_INFO_FAILED,
      signal,
    },
    ZCscInfoResponseSchema,
  );
};