// Copyright 2014-2016, Google, Inc.
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//    http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

import { DefaultTransporter } from 'google-auth-library';

/**
 * Build a string used to create a URL from the discovery doc provided URL.
 *
 * @private
 * @param  {String} input URL to build from
 * @return {String}       Resulting built URL
 */
function buildurl (input) {
  return ('\'' + input + '\'')
    // No * symbols
    .replace(/\*/g, '')
    // No + symbols
    .replace(/\+/g, '')
    // replace double slashes with single slash (except in https://)
    .replace(/([^:]\/)\/+/g, '$1')
    // No {/ symbols
    .replace(/\{\//g, '/{');
}

/**
 * Disable auto-escaping its output
 * @type {Boolean}
 */
(buildurl as any).safe = true;

/**
 * Handle error object with callback
 *
 * @private
 * @param  {Error}   err      Error object to return in callback
 * @param  {Function=} callback Optional callback function
 */
function handleError (err: Error, callback: Function) {
  if (callback && typeof callback === 'function') {
    callback(err, null);
  }
}

export default {
  DefaultTransporter: DefaultTransporter,
  buildurl: buildurl,
  handleError: handleError
}