/*****************************************************************************
 * Open MCT, Copyright (c) 2014-2018, United States Government
 * as represented by the Administrator of the National Aeronautics and Space
 * Administration. All rights reserved.
 *
 * Open MCT is 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.
 *
 * Open MCT includes source code licensed under additional open source
 * licenses. See the Open Source Licenses file (LICENSES.md) included with
 * this source code distribution or the Licensing information page available
 * at runtime from the About dialog for additional information.
 *****************************************************************************/

define(
    function () {

        /**
         * The "Cancel" action; the action triggered by clicking Cancel from
         * Edit Mode. Exits the editing user interface and invokes object
         * capabilities to persist the changes that have been made.
         * @constructor
         * @memberof platform/commonUI/edit
         * @implements {Action}
         */
        function CancelAction(context) {
            this.domainObject = context.domainObject;
        }

        /**
         * Cancel editing.
         *
         * @returns {Promise} a promise that will be fulfilled when
         *          cancellation has completed
         */
        CancelAction.prototype.perform = function () {
            var domainObject = this.domainObject;

            function returnToBrowse() {
                var parent;

                //If the object existed already, navigate to refresh view
                // with previous object state.
                if (domainObject.getModel().persisted) {
                    return domainObject.getCapability("action").perform("navigate");
                } else {
                    //If the object was new, and user has cancelled, then
                    //navigate back to parent because nothing to show.
                    return domainObject.getCapability("location").getOriginal().then(function (original) {
                        parent = original.getCapability("context").getParent();
                        return parent.getCapability("action").perform("navigate");
                    });
                }
            }

            function cancel() {
                return domainObject.getCapability("editor").finish();
            }

            //Do navigation first in order to trigger unsaved changes dialog
            return returnToBrowse()
                .then(cancel);
        };

        /**
         * Check if this action is applicable in a given context.
         * This will ensure that a domain object is present in the context,
         * and that this domain object is in Edit mode.
         * @returns {boolean} true if applicable
         */
        CancelAction.appliesTo = function (context) {
            var domainObject = (context || {}).domainObject;
            return domainObject !== undefined &&
                domainObject.hasCapability('editor') &&
                domainObject.getCapability('editor').isEditContextRoot();
        };

        return CancelAction;
    }
);