/*****************************************************************************
 * Open MCT Web, Copyright (c) 2014-2015, United States Government
 * as represented by the Administrator of the National Aeronautics and Space
 * Administration. All rights reserved.
 *
 * Open MCT Web 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 Web 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.
 *****************************************************************************/
/*global define*/

define(
    [],
    function () {
        "use strict";

        /**
         * The CompositeController supports the "composite" control type,
         * which provides an array of other controls. It is used specifically
         * to support validation when a particular row is not marked as
         * required; in this case, empty input should be allowed, but partial
         * input (where some but not all of the composite controls have been
         * filled in) should be disallowed. This is enforced in the template
         * by an ng-required directive, but that is supported by the
         * isNonEmpty check that this controller provides.
         * @constructor
         */
        function CompositeController() {
            // Check if an element is defined; the map step of isNonEmpty
            function isDefined(element) {
                return typeof element !== 'undefined';
            }

            // Boolean or; the reduce step of isNonEmpty
            function or(a, b) {
                return a || b;
            }

            return {
                /**
                 * Check if an array contains anything other than
                 * undefined elements.
                 * @param {Array} value the array to check
                 * @returns {boolean} true if any non-undefined
                 *          element is in the array
                 */
                isNonEmpty: function (value) {
                    return Array.isArray(value) &&
                        value.map(isDefined).reduce(or, false);
                }
            };
        }

        return CompositeController;

    }
);