/**
 *   Wechaty Chatbot SDK - https://github.com/wechaty/wechaty
 *
 *   @copyright 2016 Huan LI (李卓桓) <https://github.com/huan>, and
 *                   Wechaty Contributors <https://github.com/wechaty>.
 *
 *   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 portfinder from 'portfinder'

/**
 *
 * @param port is just a suggestion.
 * there's no grantuee for the number
 *
 * The IANA suggested ephemeral port range.
 * @see http://en.wikipedia.org/wiki/Ephemeral_ports
 *
 * const DEFAULT_IANA_RANGE = {min: 49152, max: 65535}
 *
 */
export async function getPort (
  basePort?: number,
): Promise<number> {
  if (basePort) {
    portfinder.basePort = basePort
  }
  return portfinder.getPortPromise()
}