var authExpirationHandler,
    errorHandler;

function catchUnauthorizedResponses(data) {
  if (data.status === 401 && !maybeLocalStorage.getItem("token")) {
    // ensure the in-memory session really is expired before destroying it
    return axios.get("/api/auth/session").then(
      (response) => {
        // we ARE still auth'd, so just throw the error down the chain
        throw data;
      }, (err) => {
        // local session is invalid, so invoke handler and throw the original error
        authExpirationHandler ? authExpirationHandler.call(null) : null;
        // TODO: remove self from interceptors chain
        throw data;
      });
  } else {
    throw data;
  }
}

function authHeader(email, token) {
  return "Bearer email=\"" + email + "\", token=\"" + token + "\"";
}

function authorizeAxiosRequests(config) {
  if (session) {
    config.headers.Authorization = authHeader(email, token);
  }
  return config;
}

function catchAllErrorResponses(data) {
 // maybe don't call errorHandler if (!!authExpirationHandler && data.status === 401) ?? i dunno.
 errorHandler.call(null, data.status);
}


module.exports = {
  addErrorInterceptors (handler) {
   errorHandler = handler;
   // TODO: add catchAllErrorResponses to the interceptors chain
  },
  
  addAuthInterceptors (email, token, handler) {
   authExpirationHandler = handler;
   // TODO: add catchUnauthorizedResponses to the interceptors chain
   // TODO: add authorizeAxiosRequests to the interceptors chain
  }
}