// 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 FauxtonAPI from "./base";
import Backbone from "backbone";
import _ from "lodash";

// This is not exposed externally as it should not need to be accessed or overridden
var Auth = function (options) {
  this._options = options;
  this.initialize.apply(this, arguments);
};

// Piggy-back on Backbone's self-propagating extend function,
Auth.extend = Backbone.Model.extend;

_.extend(Auth.prototype, Backbone.Events, {
  authDeniedCb: function () {},

  initialize: function () {
  },

  authHandlerCb : function () {
    var deferred = $.Deferred();
    deferred.resolve();
    return deferred;
  },

  registerAuth: function (authHandlerCb) {
    this.authHandlerCb = authHandlerCb;
  },

  registerAuthDenied: function (authDeniedCb) {
    this.authDeniedCb = authDeniedCb;
  },

  checkAccess: function (roles) {
    var requiredRoles = roles || [],
    that = this;

    if (!FauxtonAPI.session) {
      throw new Error("Fauxton.session is not configured.");
    }

    return FauxtonAPI.session.fetchUser().then(function () {
      return FauxtonAPI.when(that.authHandlerCb(FauxtonAPI.session, requiredRoles));
    });
  }
});

export default Auth;