/**
 * namespace to deal with oauth
 * @namespace Oauth
 */
var Goth = (function(ns) {

  /**
   * get a goa or fail
   * @param {string} packageName the package name
   * @param {PropertiesService} [props=ScriptProperties]
   * @return {Goa} a goa
   */
  ns.getGoa = function (packageName,props) {

    return cGoa.GoaApp.createGoa(
      packageName,
      props || PropertiesService.getScriptProperties()
    ).execute();

  }

  /**
   * get a token or fail
   * @param {string} packageName the package name
   * @param {PropertiesService} [props=ScriptProperties]
   * @return {Goa} a goa
   */
  ns.getToken = function (packageName,props) {

    var goa = ns.getGoa (packageName, props);

    if (!goa.hasToken()) {
      throw 'no token retrieved';
    }
    return goa.getToken();
  }

  return ns;
}) (Goth || {});