text: /*global define*/
  define([
          '../Core/combine',
          '../Core/defaultValue',
          '../Core/defined',
          '../Core/defineProperties',
          '../Core/DeveloperError',
          '../Core/freezeObject',
          '../Core/GeographicTilingScheme',
          '../Core/objectToQuery',
          '../Core/queryToObject',
          '../Core/WebMercatorTilingScheme',
          '../ThirdParty/Uri',
          './GetFeatureInfoFormat',
          './UrlTemplateImageryProvider'
      ], function(
          combine,
          defaultValue,
          defined,
          defineProperties,
          DeveloperError,
          freezeObject,
          GeographicTilingScheme,
          objectToQuery,
          queryToObject,
          WebMercatorTilingScheme,
          Uri,
          GetFeatureInfoFormat,
          UrlTemplateImageryProvider) {
      'use strict';
  
      /**
       * Provides tiled imagery hosted by a Web Map Service (WMS) server.
       *
       * @alias WebMapServiceImageryProvider
       * @constructor
       *
       * @param {Object} options Object with the following properties:
       * @param {String} options.url The URL of the WMS service. The URL supports the same keywords as the {@link UrlTemplateImageryProvider}.
       * @param {String} options.layers The layers to include, separated by commas.
       * @param {Object} [options.parameters=WebMapServiceImageryProvider.DefaultParameters] Additional parameters
       *        to pass to the WMS server in the GetMap URL.
       * @param {Object} [options.getFeatureInfoParameters=WebMapServiceImageryProvider.GetFeatureInfoDefaultParameters] Additional
       *        parameters to pass to the WMS server in the GetFeatureInfo URL.
       * @param {Boolean} [options.enablePickFeatures=true] If true, {@link WebMapServiceImageryProvider#pickFeatures} will invoke
       *        the GetFeatureInfo operation on the WMS server and return the features included in the response.  If false,
       *        {@link WebMapServiceImageryProvider#pickFeatures} will immediately return undefined (indicating no pickable features)
       *        without communicating with the server.  Set this property to false if you know your WMS server does not support
       *        GetFeatureInfo or if you don't want this provider's features to be pickable. Note that this can be dynamically
       *        overridden by modifying the WebMapServiceImageryProvider#enablePickFeatures property.
       * @param {GetFeatureInfoFormat[]} [options.getFeatureInfoFormats=WebMapServiceImageryProvider.DefaultGetFeatureInfoFormats] The formats
       *        in which to try WMS GetFeatureInfo requests.
       * @param {Rectangle} [options.rectangle=Rectangle.MAX_VALUE] The rectangle of the layer.
       * @param {TilingScheme} [options.tilingScheme=new GeographicTilingScheme()] The tiling scheme to use to divide the world into tiles.
       * @param {Ellipsoid} [options.ellipsoid] The ellipsoid.  If the tilingScheme is specified,
       *        this parameter is ignored and the tiling scheme's ellipsoid is used instead. If neither
       *        parameter is specified, the WGS84 ellipsoid is used.
       * @param {Number} [options.tileWidth=256] The width of each tile in pixels.
       * @param {Number} [options.tileHeight=256] The height of each tile in pixels.
       * @param {Number} [options.minimumLevel=0] The minimum level-of-detail supported by the imagery provider.  Take care when
       *        specifying this that the number of tiles at the minimum level is small, such as four or less.  A larger number is
       *        likely to result in rendering problems.
       * @param {Number} [options.maximumLevel] The maximum level-of-detail supported by the imagery provider, or undefined if there is no limit.
       *        If not specified, there is no limit.
       * @param {Credit|String} [options.credit] A credit for the data source, which is displayed on the canvas.
       * @param {Object} [options.proxy] A proxy to use for requests. This object is
       *        expected to have a getURL function which returns the proxied URL, if needed.
       * @param {String|String[]} [options.subdomains='abc'] The subdomains to use for the <code>{s}</code> placeholder in the URL template.
       *                          If this parameter is a single string, each character in the string is a subdomain.  If it is
       *                          an array, each element in the array is a subdomain.
       *
       * @see ArcGisMapServerImageryProvider
       * @see BingMapsImageryProvider
       * @see GoogleEarthImageryProvider
       * @see createOpenStreetMapImageryProvider
       * @see SingleTileImageryProvider
       * @see createTileMapServiceImageryProvider
       * @see WebMapTileServiceImageryProvider
       * @see UrlTemplateImageryProvider
       *
       * @see {@link http://resources.esri.com/help/9.3/arcgisserver/apis/rest/|ArcGIS Server REST API}
       * @see {@link http://www.w3.org/TR/cors/|Cross-Origin Resource Sharing}
       *
       * @example
       * var provider = new Cesium.WebMapServiceImageryProvider({
       *     url: '//sampleserver1.arcgisonline.com/ArcGIS/services/Specialty/ESRI_StatesCitiesRivers_USA/MapServer/WMSServer',
       *     layers : '0',
       *     proxy: new Cesium.DefaultProxy('/proxy/')
       * });
       *
       * viewer.imageryLayers.addImageryProvider(provider);
       */
      function WebMapServiceImageryProvider(options) {
          options = defaultValue(options, defaultValue.EMPTY_OBJECT);
  
          //>>includeStart('debug', pragmas.debug);
          if (!defined(options.url)) {
              throw new DeveloperError('options.url is required.');
          }
          if (!defined(options.layers)) {
              throw new DeveloperError('options.layers is required.');
          }
          //>>includeEnd('debug');
  
          this._url = options.url;
          this._layers = options.layers;
  
          var getFeatureInfoFormats = defaultValue(options.getFeatureInfoFormats, WebMapServiceImageryProvider.DefaultGetFeatureInfoFormats);
  
          // Build the template URLs for tiles and pickFeatures.
          var uri = new Uri(options.url);
          var queryOptions = queryToObject(defaultValue(uri.query, ''));
          var parameters = combine(objectToLowercase(defaultValue(options.parameters, defaultValue.EMPTY_OBJECT)), WebMapServiceImageryProvider.DefaultParameters);
          queryOptions = combine(parameters, queryOptions);
  
          var pickFeaturesUri;
          var pickFeaturesQueryOptions;
  
          pickFeaturesUri = new Uri(options.url);
          pickFeaturesQueryOptions = queryToObject(defaultValue(pickFeaturesUri.query, ''));
          var pickFeaturesParameters = combine(objectToLowercase(defaultValue(options.getFeatureInfoParameters, defaultValue.EMPTY_OBJECT)), WebMapServiceImageryProvider.GetFeatureInfoDefaultParameters);
          pickFeaturesQueryOptions = combine(pickFeaturesParameters, pickFeaturesQueryOptions);
  
          function setParameter(name, value) {
              if (!defined(queryOptions[name])) {
                  queryOptions[name] = value;
              }
  
              if (defined(pickFeaturesQueryOptions) && !defined(pickFeaturesQueryOptions[name])) {
                  pickFeaturesQueryOptions[name] = value;
              }
          }
  
          setParameter('layers', options.layers);
          setParameter('srs', options.tilingScheme instanceof WebMercatorTilingScheme ? 'EPSG:3857' : 'EPSG:4326');
          setParameter('bbox', '{westProjected},{southProjected},{eastProjected},{northProjected}');
          setParameter('width', '{width}');
          setParameter('height', '{height}');
  
          uri.query = objectToQuery(queryOptions);
  
          // objectToQuery escapes the placeholders.  Undo that.
          var templateUrl = uri.toString().replace(/%7B/g, '{').replace(/%7D/g, '}');
  
          var pickFeaturesTemplateUrl;
          if (defined(pickFeaturesQueryOptions)) {
              if (!defined(pickFeaturesQueryOptions.query_layers)) {
                  pickFeaturesQueryOptions.query_layers = options.layers;
              }
  
              if (!defined(pickFeaturesQueryOptions.x)) {
                  pickFeaturesQueryOptions.x = '{i}';
              }
  
              if (!defined(pickFeaturesQueryOptions.y)) {
                  pickFeaturesQueryOptions.y = '{j}';
              }
  
              if (!defined(pickFeaturesQueryOptions.info_format)) {
                  pickFeaturesQueryOptions.info_format = '{format}';
              }
  
              pickFeaturesUri.query = objectToQuery(pickFeaturesQueryOptions);
              pickFeaturesTemplateUrl = pickFeaturesUri.toString().replace(/%7B/g, '{').replace(/%7D/g, '}');
          }
  
          // Let UrlTemplateImageryProvider do the actual URL building.
          this._tileProvider = new UrlTemplateImageryProvider({
              url : templateUrl,
              pickFeaturesUrl : pickFeaturesTemplateUrl,
              tilingScheme : defaultValue(options.tilingScheme, new GeographicTilingScheme({ ellipsoid : options.ellipsoid})),
              rectangle : options.rectangle,
              tileWidth : options.tileWidth,
              tileHeight : options.tileHeight,
              minimumLevel : options.minimumLevel,
              maximumLevel : options.maximumLevel,
              proxy : options.proxy,
              subdomains: options.subdomains,
              tileDiscardPolicy : options.tileDiscardPolicy,
              credit : options.credit,
              getFeatureInfoFormats : getFeatureInfoFormats,
              enablePickFeatures: options.enablePickFeatures
          });
      }
  
      defineProperties(WebMapServiceImageryProvider.prototype, {
          /**
           * Gets the URL of the WMS server.
           * @memberof WebMapServiceImageryProvider.prototype
           * @type {String}
           * @readonly
           */
          url : {
              get : function() {
                  return this._url;
              }
          },
  
          /**
           * Gets the proxy used by this provider.
           * @memberof WebMapServiceImageryProvider.prototype
           * @type {Proxy}
           * @readonly
           */
          proxy : {
              get : function() {
                  return this._tileProvider.proxy;
              }
          },
  
          /**
           * Gets the names of the WMS layers, separated by commas.
           * @memberof WebMapServiceImageryProvider.prototype
           * @type {String}
           * @readonly
           */
          layers : {
              get : function() {
                  return this._layers;
              }
          },
  
          /**
           * Gets the width of each tile, in pixels. This function should
           * not be called before {@link WebMapServiceImageryProvider#ready} returns true.
           * @memberof WebMapServiceImageryProvider.prototype
           * @type {Number}
           * @readonly
           */
          tileWidth : {
              get : function() {
                  return this._tileProvider.tileWidth;
              }
          },
  
          /**
           * Gets the height of each tile, in pixels.  This function should
           * not be called before {@link WebMapServiceImageryProvider#ready} returns true.
           * @memberof WebMapServiceImageryProvider.prototype
           * @type {Number}
           * @readonly
           */
          tileHeight : {
              get : function() {
                  return this._tileProvider.tileHeight;
              }
          },
  
          /**
           * Gets the maximum level-of-detail that can be requested.  This function should
           * not be called before {@link WebMapServiceImageryProvider#ready} returns true.
           * @memberof WebMapServiceImageryProvider.prototype
           * @type {Number}
           * @readonly
           */
          maximumLevel : {
              get : function() {
                  return this._tileProvider.maximumLevel;
              }
          },
  
          /**
           * Gets the minimum level-of-detail that can be requested.  This function should
           * not be called before {@link WebMapServiceImageryProvider#ready} returns true.
           * @memberof WebMapServiceImageryProvider.prototype
           * @type {Number}
           * @readonly
           */
          minimumLevel : {
              get : function() {
                  return this._tileProvider.minimumLevel;
              }
          },
  
          /**
           * Gets the tiling scheme used by this provider.  This function should
           * not be called before {@link WebMapServiceImageryProvider#ready} returns true.
           * @memberof WebMapServiceImageryProvider.prototype
           * @type {TilingScheme}
           * @readonly
           */
          tilingScheme : {
              get : function() {
                  return this._tileProvider.tilingScheme;
              }
          },
  
          /**
           * Gets the rectangle, in radians, of the imagery provided by this instance.  This function should
           * not be called before {@link WebMapServiceImageryProvider#ready} returns true.
           * @memberof WebMapServiceImageryProvider.prototype
           * @type {Rectangle}
           * @readonly
           */
          rectangle : {
              get : function() {
                  return this._tileProvider.rectangle;
              }
          },
  
          /**
           * Gets the tile discard policy.  If not undefined, the discard policy is responsible
           * for filtering out "missing" tiles via its shouldDiscardImage function.  If this function
           * returns undefined, no tiles are filtered.  This function should
           * not be called before {@link WebMapServiceImageryProvider#ready} returns true.
           * @memberof WebMapServiceImageryProvider.prototype
           * @type {TileDiscardPolicy}
           * @readonly
           */
          tileDiscardPolicy : {
              get : function() {
                  return this._tileProvider.tileDiscardPolicy;
              }
          },
  
          /**
           * Gets an event that is raised when the imagery provider encounters an asynchronous error.  By subscribing
           * to the event, you will be notified of the error and can potentially recover from it.  Event listeners
           * are passed an instance of {@link TileProviderError}.
           * @memberof WebMapServiceImageryProvider.prototype
           * @type {Event}
           * @readonly
           */
          errorEvent : {
              get : function() {
                  return this._tileProvider.errorEvent;
              }
          },
  
          /**
           * Gets a value indicating whether or not the provider is ready for use.
           * @memberof WebMapServiceImageryProvider.prototype
           * @type {Boolean}
           * @readonly
           */
          ready : {
              get : function() {
                  return this._tileProvider.ready;
              }
          },
  
          /**
           * Gets a promise that resolves to true when the provider is ready for use.
           * @memberof WebMapServiceImageryProvider.prototype
           * @type {Promise.<Boolean>}
           * @readonly
           */
          readyPromise : {
              get : function() {
                  return this._tileProvider.readyPromise;
              }
          },
  
          /**
           * Gets the credit to display when this imagery provider is active.  Typically this is used to credit
           * the source of the imagery.  This function should not be called before {@link WebMapServiceImageryProvider#ready} returns true.
           * @memberof WebMapServiceImageryProvider.prototype
           * @type {Credit}
           * @readonly
           */
          credit : {
              get : function() {
                  return this._tileProvider.credit;
              }
          },
  
          /**
           * Gets a value indicating whether or not the images provided by this imagery provider
           * include an alpha channel.  If this property is false, an alpha channel, if present, will
           * be ignored.  If this property is true, any images without an alpha channel will be treated
           * as if their alpha is 1.0 everywhere.  When this property is false, memory usage
           * and texture upload time are reduced.
           * @memberof WebMapServiceImageryProvider.prototype
           * @type {Boolean}
           * @readonly
           */
          hasAlphaChannel : {
              get : function() {
                  return this._tileProvider.hasAlphaChannel;
              }
          },
  
          /**
           * Gets or sets a value indicating whether feature picking is enabled.  If true, {@link WebMapServiceImageryProvider#pickFeatures} will
           * invoke the <code>GetFeatureInfo</code> service on the WMS server and attempt to interpret the features included in the response.  If false,
           * {@link WebMapServiceImageryProvider#pickFeatures} will immediately return undefined (indicating no pickable
           * features) without communicating with the server.  Set this property to false if you know your data
           * source does not support picking features or if you don't want this provider's features to be pickable.
           * @type {Boolean}
           * @default true
           */
          enablePickFeatures : {
              get : function() {
                  return this._tileProvider.enablePickFeatures;
              },
              set : function(enablePickFeatures)  {
                  this._tileProvider.enablePickFeatures = enablePickFeatures;
              }
          }
      });
  
      /**
       * Gets the credits to be displayed when a given tile is displayed.
       *
       * @param {Number} x The tile X coordinate.
       * @param {Number} y The tile Y coordinate.
       * @param {Number} level The tile level;
       * @returns {Credit[]} The credits to be displayed when the tile is displayed.
       *
       * @exception {DeveloperError} <code>getTileCredits</code> must not be called before the imagery provider is ready.
       */
      WebMapServiceImageryProvider.prototype.getTileCredits = function(x, y, level) {
          return this._tileProvider.getTileCredits(x, y, level);
      };
  
      /**
       * Requests the image for a given tile.  This function should
       * not be called before {@link WebMapServiceImageryProvider#ready} returns true.
       *
       * @param {Number} x The tile X coordinate.
       * @param {Number} y The tile Y coordinate.
       * @param {Number} level The tile level.
       * @returns {Promise.<Image|Canvas>|undefined} A promise for the image that will resolve when the image is available, or
       *          undefined if there are too many active requests to the server, and the request
       *          should be retried later.  The resolved image may be either an
       *          Image or a Canvas DOM object.
       *
       * @exception {DeveloperError} <code>requestImage</code> must not be called before the imagery provider is ready.
       */
      WebMapServiceImageryProvider.prototype.requestImage = function(x, y, level) {
          return this._tileProvider.requestImage(x, y, level);
      };
  
      /**
       * Asynchronously determines what features, if any, are located at a given longitude and latitude within
       * a tile.  This function should not be called before {@link ImageryProvider#ready} returns true.
       *
       * @param {Number} x The tile X coordinate.
       * @param {Number} y The tile Y coordinate.
       * @param {Number} level The tile level.
       * @param {Number} longitude The longitude at which to pick features.
       * @param {Number} latitude  The latitude at which to pick features.
       * @return {Promise.<ImageryLayerFeatureInfo[]>|undefined} A promise for the picked features that will resolve when the asynchronous
       *                   picking completes.  The resolved value is an array of {@link ImageryLayerFeatureInfo}
       *                   instances.  The array may be empty if no features are found at the given location.
       *
       * @exception {DeveloperError} <code>pickFeatures</code> must not be called before the imagery provider is ready.
       */
      WebMapServiceImageryProvider.prototype.pickFeatures = function(x, y, level, longitude, latitude) {
          return this._tileProvider.pickFeatures(x, y, level, longitude, latitude);
      };
  
      /**
       * The default parameters to include in the WMS URL to obtain images.  The values are as follows:
       *    service=WMS
       *    version=1.1.1
       *    request=GetMap
       *    styles=
       *    format=image/jpeg
       *
       * @constant
       */
      WebMapServiceImageryProvider.DefaultParameters = freezeObject({
          service : 'WMS',
          version : '1.1.1',
          request : 'GetMap',
          styles : '',
          format : 'image/jpeg'
      });
  
      /**
       * The default parameters to include in the WMS URL to get feature information.  The values are as follows:
       *     service=WMS
       *     version=1.1.1
       *     request=GetFeatureInfo
       *
       * @constant
       */
      WebMapServiceImageryProvider.GetFeatureInfoDefaultParameters = freezeObject({
          service : 'WMS',
          version : '1.1.1',
          request : 'GetFeatureInfo'
      });
  
      WebMapServiceImageryProvider.DefaultGetFeatureInfoFormats = freezeObject([
          freezeObject(new GetFeatureInfoFormat('json', 'application/json')),
          freezeObject(new GetFeatureInfoFormat('xml', 'text/xml')),
          freezeObject(new GetFeatureInfoFormat('text', 'text/html'))
      ]);
  
      function objectToLowercase(obj) {
          var result = {};
          for ( var key in obj) {
              if (obj.hasOwnProperty(key)) {
                  result[key.toLowerCase()] = obj[key];
              }
          }
          return result;
      }
  
      return WebMapServiceImageryProvider;
  });
  