/*
 * Copyright 2003-2006, 2009, 2017, 2020 United States Government, as represented
 * by the Administrator of the National Aeronautics and Space Administration.
 * All rights reserved.
 *
 * The NASAWorldWind/WebWorldWind platform 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.
 *
 * NASAWorldWind/WebWorldWind also contains the following 3rd party Open Source
 * software:
 *
 *    ES6-Promise – under MIT License
 *    libtess.js – SGI Free Software License B
 *    Proj4 – under MIT License
 *    JSZip – under MIT License
 *
 * A complete listing of 3rd Party software notices and licenses included in
 * WebWorldWind can be found in the WebWorldWind 3rd-party notices and licenses
 * PDF found in code  directory.
 */
define(function () {
    "use strict";

    var DatasetDropdown = function (controller) {
        var self = this;

        this.controller = controller;

        this.attachServer();
    };

    DatasetDropdown.prototype.attachServer = function () {
        var serverAddress = "https://neo.sci.gsfc.nasa.gov/wms/wms";

        var self = this,
            request = new XMLHttpRequest(),
            url = serverAddress + "?service=WMS&request=GetCapabilities&version=1.3.0";

        request.open("GET", url, true);
        request.onreadystatechange = function () {
            if (request.readyState === 4 && request.status === 200) {
                var xmlDom = request.responseXML;

                if (!xmlDom && request.responseText.indexOf("<?xml") === 0) {
                    xmlDom = new window.DOMParser().parseFromString(request.responseText, "text/xml");
                }

                if (!xmlDom) {
                    alert(serverAddress + " retrieval failed.");
                    return;
                }

                self.wmsCapsDoc = new WorldWind.WmsCapabilities(xmlDom);

                if (self.wmsCapsDoc.version) { // if no version, then the URL doesn't point to a caps doc.
                    self.fillDropdownList(self.wmsCapsDoc);
                } else {
                    alert("WMS capabilities document invalid.");
                }
            } else if (request.readyState === 4) {
                if (request.statusText) {
                    alert(request.responseURL + " " + request.status + " (" + request.statusText + ")");
                } else {
                    alert("Failed to retrieve WMS capabilities from " + serverAddress + ".");
                }
            }
        };

        request.send(null);
    };

    DatasetDropdown.prototype.fillDropdownList = function (wmsCapsDoc) {
        var layers = wmsCapsDoc.capability.layers[0].layers;

        var datasetList = $('#datasetDropdownList');

        for (var i = 0; i < layers.length; i++) {
            var layer = layers[i];

            var menuItem = $('<li><a>' + layer.title + '</a></li>');
            datasetList.append(menuItem);
        }

        var controller = this.controller;
        datasetList.find(" li").on("click", function (e) {
            controller.onDatasetClick(e);
        });
    };

    return DatasetDropdown;
});