/**
 * Thin axios wrapper for the Webex Service App.
 *
 * - Pulls the current access token from WebexServiceAppAuth on each call.
 * - Retries transient failures via utils/retry.withRetry.
 * - On a 401 response (token revoked between cache and call), forces a single
 *   refresh and retries once. Repeated 401s after that surface as errors so
 *   the caller can degrade gracefully.
 */

const axios = require('axios');
const config = require('../config');
const WebexServiceAppAuth = require('../integrations/webex/WebexServiceAppAuth');
const { withRetry } = require('../utils/retry');
const logger = require('../utils/logger');

const BASE_URL = 'https://webexapis.com/v1';
const RETRY_OPTS = { retries: 2, initialDelayMs: 500 };

let _auth = null;
function auth() {
  if (!_auth) {
    _auth = WebexServiceAppAuth.getInstance({
      clientId: config.webexServiceApp.clientId,
      clientSecret: config.webexServiceApp.clientSecret,
      tokensFilePath: config.webexServiceApp.tokensPath,
    });
  }
  return _auth;
}

function resetAuthForTests() {
  _auth = null;
}

/**
 * Issue a Webex Service App request. Returns response.data (or an empty
 * object) on success; throws axios errors on hard failures.
 *
 * @param {('GET'|'POST'|'PUT'|'DELETE'|'PATCH')} method
 * @param {string} pathSuffix - Webex API path relative to /v1 (e.g. "people").
 * @param {object|null} body - JSON body for non-GET methods.
 * @param {object|null} params - querystring params.
 */
async function request(method, pathSuffix, body = null, params = null) {
  const url = `${BASE_URL}/${String(pathSuffix).replace(/^\/+/, '')}`;
  const a = auth();

  const doRequest = async (forceRefresh = false) => {
    const token = forceRefresh ? await a.forceRefresh() : await a.getAccessToken();
    return axios({
      method,
      url,
      data: body || undefined,
      params: params || undefined,
      headers: {
        Authorization: `Bearer ${token}`,
        'Content-Type': 'application/json',
      },
      timeout: 15000,
    });
  };

  try {
    const res = await withRetry(() => doRequest(false), RETRY_OPTS);
    return res.data ?? {};
  } catch (err) {
    if (err.response?.status === 401) {
      logger.warn('Webex returned 401 — refreshing and retrying once', { url });
      try {
        const retry = await doRequest(true);
        return retry.data ?? {};
      } catch (retryErr) {
        logger.error('Webex request failed after forced refresh', {
          url,
          status: retryErr.response?.status,
          error: retryErr.message,
        });
        throw retryErr;
      }
    }
    throw err;
  }
}

module.exports = { request, resetAuthForTests, BASE_URL };