text: import Cartesian2 from "../Core/Cartesian2.js";
  import Cartesian3 from "../Core/Cartesian3.js";
  import Cartographic from "../Core/Cartographic.js";
  import combine from "../Core/combine.js";
  import Credit from "../Core/Credit.js";
  import defaultValue from "../Core/defaultValue.js";
  import defined from "../Core/defined.js";
  import DeveloperError from "../Core/DeveloperError.js";
  import Event from "../Core/Event.js";
  import GeographicProjection from "../Core/GeographicProjection.js";
  import CesiumMath from "../Core/Math.js";
  import Rectangle from "../Core/Rectangle.js";
  import Resource from "../Core/Resource.js";
  import WebMercatorTilingScheme from "../Core/WebMercatorTilingScheme.js";
  import when from "../ThirdParty/when.js";
  import ImageryProvider from "./ImageryProvider.js";
  
  var templateRegex = /{[^}]+}/g;
  
  var tags = {
    x: xTag,
    y: yTag,
    z: zTag,
    s: sTag,
    reverseX: reverseXTag,
    reverseY: reverseYTag,
    reverseZ: reverseZTag,
    westDegrees: westDegreesTag,
    southDegrees: southDegreesTag,
    eastDegrees: eastDegreesTag,
    northDegrees: northDegreesTag,
    westProjected: westProjectedTag,
    southProjected: southProjectedTag,
    eastProjected: eastProjectedTag,
    northProjected: northProjectedTag,
    width: widthTag,
    height: heightTag,
  };
  
  var pickFeaturesTags = combine(tags, {
    i: iTag,
    j: jTag,
    reverseI: reverseITag,
    reverseJ: reverseJTag,
    longitudeDegrees: longitudeDegreesTag,
    latitudeDegrees: latitudeDegreesTag,
    longitudeProjected: longitudeProjectedTag,
    latitudeProjected: latitudeProjectedTag,
    format: formatTag,
  });
  
  /**
   * @typedef {Object} UrlTemplateImageryProvider.ConstructorOptions
   *
   * Initialization options for the UrlTemplateImageryProvider constructor
   *
   * @property {Promise.<Object>|Object} [options] Object with the following properties:
   * @property {Resource|String} url  The URL template to use to request tiles.  It has the following keywords:
   * <ul>
   *     <li><code>{z}</code>: The level of the tile in the tiling scheme.  Level zero is the root of the quadtree pyramid.</li>
   *     <li><code>{x}</code>: The tile X coordinate in the tiling scheme, where 0 is the Westernmost tile.</li>
   *     <li><code>{y}</code>: The tile Y coordinate in the tiling scheme, where 0 is the Northernmost tile.</li>
   *     <li><code>{s}</code>: One of the available subdomains, used to overcome browser limits on the number of simultaneous requests per host.</li>
   *     <li><code>{reverseX}</code>: The tile X coordinate in the tiling scheme, where 0 is the Easternmost tile.</li>
   *     <li><code>{reverseY}</code>: The tile Y coordinate in the tiling scheme, where 0 is the Southernmost tile.</li>
   *     <li><code>{reverseZ}</code>: The level of the tile in the tiling scheme, where level zero is the maximum level of the quadtree pyramid.  In order to use reverseZ, maximumLevel must be defined.</li>
   *     <li><code>{westDegrees}</code>: The Western edge of the tile in geodetic degrees.</li>
   *     <li><code>{southDegrees}</code>: The Southern edge of the tile in geodetic degrees.</li>
   *     <li><code>{eastDegrees}</code>: The Eastern edge of the tile in geodetic degrees.</li>
   *     <li><code>{northDegrees}</code>: The Northern edge of the tile in geodetic degrees.</li>
   *     <li><code>{westProjected}</code>: The Western edge of the tile in projected coordinates of the tiling scheme.</li>
   *     <li><code>{southProjected}</code>: The Southern edge of the tile in projected coordinates of the tiling scheme.</li>
   *     <li><code>{eastProjected}</code>: The Eastern edge of the tile in projected coordinates of the tiling scheme.</li>
   *     <li><code>{northProjected}</code>: The Northern edge of the tile in projected coordinates of the tiling scheme.</li>
   *     <li><code>{width}</code>: The width of each tile in pixels.</li>
   *     <li><code>{height}</code>: The height of each tile in pixels.</li>
   * </ul>
   * @property {Resource|String} [pickFeaturesUrl] The URL template to use to pick features.  If this property is not specified,
   *                 {@link UrlTemplateImageryProvider#pickFeatures} will immediately returned undefined, indicating no
   *                 features picked.  The URL template supports all of the keywords supported by the <code>url</code>
   *                 parameter, plus the following:
   * <ul>
   *     <li><code>{i}</code>: The pixel column (horizontal coordinate) of the picked position, where the Westernmost pixel is 0.</li>
   *     <li><code>{j}</code>: The pixel row (vertical coordinate) of the picked position, where the Northernmost pixel is 0.</li>
   *     <li><code>{reverseI}</code>: The pixel column (horizontal coordinate) of the picked position, where the Easternmost pixel is 0.</li>
   *     <li><code>{reverseJ}</code>: The pixel row (vertical coordinate) of the picked position, where the Southernmost pixel is 0.</li>
   *     <li><code>{longitudeDegrees}</code>: The longitude of the picked position in degrees.</li>
   *     <li><code>{latitudeDegrees}</code>: The latitude of the picked position in degrees.</li>
   *     <li><code>{longitudeProjected}</code>: The longitude of the picked position in the projected coordinates of the tiling scheme.</li>
   *     <li><code>{latitudeProjected}</code>: The latitude of the picked position in the projected coordinates of the tiling scheme.</li>
   *     <li><code>{format}</code>: The format in which to get feature information, as specified in the {@link GetFeatureInfoFormat}.</li>
   * </ul>
   * @property {Object} [urlSchemeZeroPadding] Gets the URL scheme zero padding for each tile coordinate. The format is '000' where
   * each coordinate will be padded on the left with zeros to match the width of the passed string of zeros. e.g. Setting:
   * urlSchemeZeroPadding : { '{x}' : '0000'}
   * will cause an 'x' value of 12 to return the string '0012' for {x} in the generated URL.
   * It the passed object has the following keywords:
   * <ul>
   *  <li> <code>{z}</code>: The zero padding for the level of the tile in the tiling scheme.</li>
   *  <li> <code>{x}</code>: The zero padding for the tile X coordinate in the tiling scheme.</li>
   *  <li> <code>{y}</code>: The zero padding for the the tile Y coordinate in the tiling scheme.</li>
   *  <li> <code>{reverseX}</code>: The zero padding for the tile reverseX coordinate in the tiling scheme.</li>
   *  <li> <code>{reverseY}</code>: The zero padding for the tile reverseY coordinate in the tiling scheme.</li>
   *  <li> <code>{reverseZ}</code>: The zero padding for the reverseZ coordinate of the tile in the tiling scheme.</li>
   * </ul>
   * @property {String|String[]} [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.
   * @property {Credit|String} [credit=''] A credit for the data source, which is displayed on the canvas.
   * @property {Number} [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.
   * @property {Number} [maximumLevel] The maximum level-of-detail supported by the imagery provider, or undefined if there is no limit.
   * @property {Rectangle} [rectangle=Rectangle.MAX_VALUE] The rectangle, in radians, covered by the image.
   * @property {TilingScheme} [tilingScheme=WebMercatorTilingScheme] The tiling scheme specifying how the ellipsoidal
   * surface is broken into tiles.  If this parameter is not provided, a {@link WebMercatorTilingScheme}
   * is used.
   * @property {Ellipsoid} [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.
   * @property {Number} [tileWidth=256] Pixel width of image tiles.
   * @property {Number} [tileHeight=256] Pixel height of image tiles.
   * @property {Boolean} [hasAlphaChannel=true] true if the images provided by this imagery provider
   *                  include an alpha channel; otherwise, false.  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 potentially reduced.
   * @property {GetFeatureInfoFormat[]} [getFeatureInfoFormats] The formats in which to get feature information at a
   *                                 specific location when {@link UrlTemplateImageryProvider#pickFeatures} is invoked.  If this
   *                                 parameter is not specified, feature picking is disabled.
   * @property {Boolean} [enablePickFeatures=true] If true, {@link UrlTemplateImageryProvider#pickFeatures} will
   *        request the <code>pickFeaturesUrl</code> and attempt to interpret the features included in the response.  If false,
   *        {@link UrlTemplateImageryProvider#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. Note
   *        that this can be dynamically overridden by modifying the {@link UriTemplateImageryProvider#enablePickFeatures}
   *        property.
   * @property {Object} [customTags] Allow to replace custom keywords in the URL template. The object must have strings as keys and functions as values.
   */
  
  /**
   * Provides imagery by requesting tiles using a specified URL template.
   *
   * @alias UrlTemplateImageryProvider
   * @constructor
   *
   * @param {UrlTemplateImageryProvider.ConstructorOptions} options Object describing initialization options
   *
   * @example
   * // Access Natural Earth II imagery, which uses a TMS tiling scheme and Geographic (EPSG:4326) project
   * var tms = new Cesium.UrlTemplateImageryProvider({
   *     url : Cesium.buildModuleUrl('Assets/Textures/NaturalEarthII') + '/{z}/{x}/{reverseY}.jpg',
   *     credit : '© Analytical Graphics, Inc.',
   *     tilingScheme : new Cesium.GeographicTilingScheme(),
   *     maximumLevel : 5
   * });
   * // Access the CartoDB Positron basemap, which uses an OpenStreetMap-like tiling scheme.
   * var positron = new Cesium.UrlTemplateImageryProvider({
   *     url : 'http://{s}.basemaps.cartocdn.com/light_all/{z}/{x}/{y}.png',
   *     credit : 'Map tiles by CartoDB, under CC BY 3.0. Data by OpenStreetMap, under ODbL.'
   * });
   * // Access a Web Map Service (WMS) server.
   * var wms = new Cesium.UrlTemplateImageryProvider({
   *    url : 'https://programs.communications.gov.au/geoserver/ows?tiled=true&' +
   *          'transparent=true&format=image%2Fpng&exceptions=application%2Fvnd.ogc.se_xml&' +
   *          'styles=&service=WMS&version=1.1.1&request=GetMap&' +
   *          'layers=public%3AMyBroadband_Availability&srs=EPSG%3A3857&' +
   *          'bbox={westProjected}%2C{southProjected}%2C{eastProjected}%2C{northProjected}&' +
   *          'width=256&height=256',
   *    rectangle : Cesium.Rectangle.fromDegrees(96.799393, -43.598214999057824, 153.63925700000001, -9.2159219997013)
   * });
   * // Using custom tags in your template url.
   * var custom = new Cesium.UrlTemplateImageryProvider({
   *    url : 'https://yoururl/{Time}/{z}/{y}/{x}.png',
   *    customTags : {
   *        Time: function(imageryProvider, x, y, level) {
   *            return '20171231'
   *        }
   *    }
   * });
   *
   * @see ArcGisMapServerImageryProvider
   * @see BingMapsImageryProvider
   * @see GoogleEarthEnterpriseMapsProvider
   * @see OpenStreetMapImageryProvider
   * @see SingleTileImageryProvider
   * @see TileMapServiceImageryProvider
   * @see WebMapServiceImageryProvider
   * @see WebMapTileServiceImageryProvider
   */
  function UrlTemplateImageryProvider(options) {
    //>>includeStart('debug', pragmas.debug);
    if (!defined(options)) {
      throw new DeveloperError("options is required.");
    }
    if (!when.isPromise(options) && !defined(options.url)) {
      throw new DeveloperError("options is required.");
    }
    //>>includeEnd('debug');
  
    this._errorEvent = new Event();
  
    this._resource = undefined;
    this._urlSchemeZeroPadding = undefined;
    this._pickFeaturesResource = undefined;
    this._tileWidth = undefined;
    this._tileHeight = undefined;
    this._maximumLevel = undefined;
    this._minimumLevel = undefined;
    this._tilingScheme = undefined;
    this._rectangle = undefined;
    this._tileDiscardPolicy = undefined;
    this._credit = undefined;
    this._hasAlphaChannel = undefined;
    this._readyPromise = undefined;
    this._tags = undefined;
    this._pickFeaturesTags = undefined;
  
    /**
     * The default alpha blending value of this provider, with 0.0 representing fully transparent and
     * 1.0 representing fully opaque.
     *
     * @type {Number|undefined}
     * @default undefined
     */
    this.defaultAlpha = undefined;
  
    /**
     * The default alpha blending value on the night side of the globe of this provider, with 0.0 representing fully transparent and
     * 1.0 representing fully opaque.
     *
     * @type {Number|undefined}
     * @default undefined
     */
    this.defaultNightAlpha = undefined;
  
    /**
     * The default alpha blending value on the day side of the globe of this provider, with 0.0 representing fully transparent and
     * 1.0 representing fully opaque.
     *
     * @type {Number|undefined}
     * @default undefined
     */
    this.defaultDayAlpha = undefined;
  
    /**
     * The default brightness of this provider.  1.0 uses the unmodified imagery color.  Less than 1.0
     * makes the imagery darker while greater than 1.0 makes it brighter.
     *
     * @type {Number|undefined}
     * @default undefined
     */
    this.defaultBrightness = undefined;
  
    /**
     * The default contrast of this provider.  1.0 uses the unmodified imagery color.  Less than 1.0 reduces
     * the contrast while greater than 1.0 increases it.
     *
     * @type {Number|undefined}
     * @default undefined
     */
    this.defaultContrast = undefined;
  
    /**
     * The default hue of this provider in radians. 0.0 uses the unmodified imagery color.
     *
     * @type {Number|undefined}
     * @default undefined
     */
    this.defaultHue = undefined;
  
    /**
     * The default saturation of this provider. 1.0 uses the unmodified imagery color. Less than 1.0 reduces the
     * saturation while greater than 1.0 increases it.
     *
     * @type {Number|undefined}
     * @default undefined
     */
    this.defaultSaturation = undefined;
  
    /**
     * The default gamma correction to apply to this provider.  1.0 uses the unmodified imagery color.
     *
     * @type {Number|undefined}
     * @default undefined
     */
    this.defaultGamma = undefined;
  
    /**
     * The default texture minification filter to apply to this provider.
     *
     * @type {TextureMinificationFilter}
     * @default undefined
     */
    this.defaultMinificationFilter = undefined;
  
    /**
     * The default texture magnification filter to apply to this provider.
     *
     * @type {TextureMagnificationFilter}
     * @default undefined
     */
    this.defaultMagnificationFilter = undefined;
  
    /**
     * Gets or sets a value indicating whether feature picking is enabled.  If true, {@link UrlTemplateImageryProvider#pickFeatures} will
     * request the <code>options.pickFeaturesUrl</code> and attempt to interpret the features included in the response.  If false,
     * {@link UrlTemplateImageryProvider#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
     */
    this.enablePickFeatures = true;
  
    this.reinitialize(options);
  }
  
  Object.defineProperties(UrlTemplateImageryProvider.prototype, {
    /**
     * Gets the URL template to use to request tiles.  It has the following keywords:
     * <ul>
     *  <li> <code>{z}</code>: The level of the tile in the tiling scheme.  Level zero is the root of the quadtree pyramid.</li>
     *  <li> <code>{x}</code>: The tile X coordinate in the tiling scheme, where 0 is the Westernmost tile.</li>
     *  <li> <code>{y}</code>: The tile Y coordinate in the tiling scheme, where 0 is the Northernmost tile.</li>
     *  <li> <code>{s}</code>: One of the available subdomains, used to overcome browser limits on the number of simultaneous requests per host.</li>
     *  <li> <code>{reverseX}</code>: The tile X coordinate in the tiling scheme, where 0 is the Easternmost tile.</li>
     *  <li> <code>{reverseY}</code>: The tile Y coordinate in the tiling scheme, where 0 is the Southernmost tile.</li>
     *  <li> <code>{reverseZ}</code>: The level of the tile in the tiling scheme, where level zero is the maximum level of the quadtree pyramid.  In order to use reverseZ, maximumLevel must be defined.</li>
     *  <li> <code>{westDegrees}</code>: The Western edge of the tile in geodetic degrees.</li>
     *  <li> <code>{southDegrees}</code>: The Southern edge of the tile in geodetic degrees.</li>
     *  <li> <code>{eastDegrees}</code>: The Eastern edge of the tile in geodetic degrees.</li>
     *  <li> <code>{northDegrees}</code>: The Northern edge of the tile in geodetic degrees.</li>
     *  <li> <code>{westProjected}</code>: The Western edge of the tile in projected coordinates of the tiling scheme.</li>
     *  <li> <code>{southProjected}</code>: The Southern edge of the tile in projected coordinates of the tiling scheme.</li>
     *  <li> <code>{eastProjected}</code>: The Eastern edge of the tile in projected coordinates of the tiling scheme.</li>
     *  <li> <code>{northProjected}</code>: The Northern edge of the tile in projected coordinates of the tiling scheme.</li>
     *  <li> <code>{width}</code>: The width of each tile in pixels.</li>
     *  <li> <code>{height}</code>: The height of each tile in pixels.</li>
     * </ul>
     * @memberof UrlTemplateImageryProvider.prototype
     * @type {String}
     * @readonly
     */
    url: {
      get: function () {
        return this._resource.url;
      },
    },
  
    /**
     * Gets the URL scheme zero padding for each tile coordinate. The format is '000' where each coordinate will be padded on
     * the left with zeros to match the width of the passed string of zeros. e.g. Setting:
     * urlSchemeZeroPadding : { '{x}' : '0000'}
     * will cause an 'x' value of 12 to return the string '0012' for {x} in the generated URL.
     * It has the following keywords:
     * <ul>
     *  <li> <code>{z}</code>: The zero padding for the level of the tile in the tiling scheme.</li>
     *  <li> <code>{x}</code>: The zero padding for the tile X coordinate in the tiling scheme.</li>
     *  <li> <code>{y}</code>: The zero padding for the the tile Y coordinate in the tiling scheme.</li>
     *  <li> <code>{reverseX}</code>: The zero padding for the tile reverseX coordinate in the tiling scheme.</li>
     *  <li> <code>{reverseY}</code>: The zero padding for the tile reverseY coordinate in the tiling scheme.</li>
     *  <li> <code>{reverseZ}</code>: The zero padding for the reverseZ coordinate of the tile in the tiling scheme.</li>
     * </ul>
     * @memberof UrlTemplateImageryProvider.prototype
     * @type {Object}
     * @readonly
     */
    urlSchemeZeroPadding: {
      get: function () {
        return this._urlSchemeZeroPadding;
      },
    },
  
    /**
     * Gets the URL template to use to use to pick features.  If this property is not specified,
     * {@link UrlTemplateImageryProvider#pickFeatures} will immediately return undefined, indicating no
     * features picked.  The URL template supports all of the keywords supported by the
     * {@link UrlTemplateImageryProvider#url} property, plus the following:
     * <ul>
     *     <li><code>{i}</code>: The pixel column (horizontal coordinate) of the picked position, where the Westernmost pixel is 0.</li>
     *     <li><code>{j}</code>: The pixel row (vertical coordinate) of the picked position, where the Northernmost pixel is 0.</li>
     *     <li><code>{reverseI}</code>: The pixel column (horizontal coordinate) of the picked position, where the Easternmost pixel is 0.</li>
     *     <li><code>{reverseJ}</code>: The pixel row (vertical coordinate) of the picked position, where the Southernmost pixel is 0.</li>
     *     <li><code>{longitudeDegrees}</code>: The longitude of the picked position in degrees.</li>
     *     <li><code>{latitudeDegrees}</code>: The latitude of the picked position in degrees.</li>
     *     <li><code>{longitudeProjected}</code>: The longitude of the picked position in the projected coordinates of the tiling scheme.</li>
     *     <li><code>{latitudeProjected}</code>: The latitude of the picked position in the projected coordinates of the tiling scheme.</li>
     *     <li><code>{format}</code>: The format in which to get feature information, as specified in the {@link GetFeatureInfoFormat}.</li>
     * </ul>
     * @memberof UrlTemplateImageryProvider.prototype
     * @type {String}
     * @readonly
     */
    pickFeaturesUrl: {
      get: function () {
        return this._pickFeaturesResource.url;
      },
    },
  
    /**
     * Gets the proxy used by this provider.
     * @memberof UrlTemplateImageryProvider.prototype
     * @type {Proxy}
     * @readonly
     * @default undefined
     */
    proxy: {
      get: function () {
        return this._resource.proxy;
      },
    },
  
    /**
     * Gets the width of each tile, in pixels. This function should
     * not be called before {@link UrlTemplateImageryProvider#ready} returns true.
     * @memberof UrlTemplateImageryProvider.prototype
     * @type {Number}
     * @readonly
     * @default 256
     */
    tileWidth: {
      get: function () {
        //>>includeStart('debug', pragmas.debug);
        if (!this.ready) {
          throw new DeveloperError(
            "tileWidth must not be called before the imagery provider is ready."
          );
        }
        //>>includeEnd('debug');
        return this._tileWidth;
      },
    },
  
    /**
     * Gets the height of each tile, in pixels.  This function should
     * not be called before {@link UrlTemplateImageryProvider#ready} returns true.
     * @memberof UrlTemplateImageryProvider.prototype
     * @type {Number}
     * @readonly
     * @default 256
     */
    tileHeight: {
      get: function () {
        //>>includeStart('debug', pragmas.debug);
        if (!this.ready) {
          throw new DeveloperError(
            "tileHeight must not be called before the imagery provider is ready."
          );
        }
        //>>includeEnd('debug');
        return this._tileHeight;
      },
    },
  
    /**
     * Gets the maximum level-of-detail that can be requested, or undefined if there is no limit.
     * This function should not be called before {@link UrlTemplateImageryProvider#ready} returns true.
     * @memberof UrlTemplateImageryProvider.prototype
     * @type {Number|undefined}
     * @readonly
     * @default undefined
     */
    maximumLevel: {
      get: function () {
        //>>includeStart('debug', pragmas.debug);
        if (!this.ready) {
          throw new DeveloperError(
            "maximumLevel must not be called before the imagery provider is ready."
          );
        }
        //>>includeEnd('debug');
        return this._maximumLevel;
      },
    },
  
    /**
     * Gets the minimum level-of-detail that can be requested.  This function should
     * not be called before {@link UrlTemplateImageryProvider#ready} returns true.
     * @memberof UrlTemplateImageryProvider.prototype
     * @type {Number}
     * @readonly
     * @default 0
     */
    minimumLevel: {
      get: function () {
        //>>includeStart('debug', pragmas.debug);
        if (!this.ready) {
          throw new DeveloperError(
            "minimumLevel must not be called before the imagery provider is ready."
          );
        }
        //>>includeEnd('debug');
        return this._minimumLevel;
      },
    },
  
    /**
     * Gets the tiling scheme used by this provider.  This function should
     * not be called before {@link UrlTemplateImageryProvider#ready} returns true.
     * @memberof UrlTemplateImageryProvider.prototype
     * @type {TilingScheme}
     * @readonly
     * @default new WebMercatorTilingScheme()
     */
    tilingScheme: {
      get: function () {
        //>>includeStart('debug', pragmas.debug);
        if (!this.ready) {
          throw new DeveloperError(
            "tilingScheme must not be called before the imagery provider is ready."
          );
        }
        //>>includeEnd('debug');
        return this._tilingScheme;
      },
    },
  
    /**
     * Gets the rectangle, in radians, of the imagery provided by this instance.  This function should
     * not be called before {@link UrlTemplateImageryProvider#ready} returns true.
     * @memberof UrlTemplateImageryProvider.prototype
     * @type {Rectangle}
     * @readonly
     * @default tilingScheme.rectangle
     */
    rectangle: {
      get: function () {
        //>>includeStart('debug', pragmas.debug);
        if (!this.ready) {
          throw new DeveloperError(
            "rectangle must not be called before the imagery provider is ready."
          );
        }
        //>>includeEnd('debug');
        return this._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 UrlTemplateImageryProvider#ready} returns true.
     * @memberof UrlTemplateImageryProvider.prototype
     * @type {TileDiscardPolicy}
     * @readonly
     * @default undefined
     */
    tileDiscardPolicy: {
      get: function () {
        //>>includeStart('debug', pragmas.debug);
        if (!this.ready) {
          throw new DeveloperError(
            "tileDiscardPolicy must not be called before the imagery provider is ready."
          );
        }
        //>>includeEnd('debug');
        return this._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 UrlTemplateImageryProvider.prototype
     * @type {Event}
     * @readonly
     */
    errorEvent: {
      get: function () {
        return this._errorEvent;
      },
    },
  
    /**
     * Gets a value indicating whether or not the provider is ready for use.
     * @memberof UrlTemplateImageryProvider.prototype
     * @type {Boolean}
     * @readonly
     */
    ready: {
      get: function () {
        return defined(this._resource);
      },
    },
  
    /**
     * Gets a promise that resolves to true when the provider is ready for use.
     * @memberof UrlTemplateImageryProvider.prototype
     * @type {Promise.<Boolean>}
     * @readonly
     */
    readyPromise: {
      get: function () {
        return this._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 UrlTemplateImageryProvider#ready} returns true.
     * @memberof UrlTemplateImageryProvider.prototype
     * @type {Credit}
     * @readonly
     * @default undefined
     */
    credit: {
      get: function () {
        //>>includeStart('debug', pragmas.debug);
        if (!this.ready) {
          throw new DeveloperError(
            "credit must not be called before the imagery provider is ready."
          );
        }
        //>>includeEnd('debug');
        return this._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.  This function should
     * not be called before {@link ImageryProvider#ready} returns true.
     * @memberof UrlTemplateImageryProvider.prototype
     * @type {Boolean}
     * @readonly
     * @default true
     */
    hasAlphaChannel: {
      get: function () {
        //>>includeStart('debug', pragmas.debug);
        if (!this.ready) {
          throw new DeveloperError(
            "hasAlphaChannel must not be called before the imagery provider is ready."
          );
        }
        //>>includeEnd('debug');
        return this._hasAlphaChannel;
      },
    },
  });
  
  /**
   * Reinitializes this instance.  Reinitializing an instance already in use is supported, but it is not
   * recommended because existing tiles provided by the imagery provider will not be updated.
   *
   * @param {Promise.<Object>|Object} options Any of the options that may be passed to the {@link UrlTemplateImageryProvider} constructor.
   */
  UrlTemplateImageryProvider.prototype.reinitialize = function (options) {
    var that = this;
    that._readyPromise = when(options).then(function (properties) {
      //>>includeStart('debug', pragmas.debug);
      if (!defined(properties)) {
        throw new DeveloperError("options is required.");
      }
      if (!defined(properties.url)) {
        throw new DeveloperError("options.url is required.");
      }
      //>>includeEnd('debug');
  
      var customTags = properties.customTags;
      var allTags = combine(tags, customTags);
      var allPickFeaturesTags = combine(pickFeaturesTags, customTags);
      var resource = Resource.createIfNeeded(properties.url);
      var pickFeaturesResource = Resource.createIfNeeded(
        properties.pickFeaturesUrl
      );
  
      that.enablePickFeatures = defaultValue(
        properties.enablePickFeatures,
        that.enablePickFeatures
      );
      that._urlSchemeZeroPadding = defaultValue(
        properties.urlSchemeZeroPadding,
        that.urlSchemeZeroPadding
      );
      that._tileDiscardPolicy = properties.tileDiscardPolicy;
      that._getFeatureInfoFormats = properties.getFeatureInfoFormats;
  
      that._subdomains = properties.subdomains;
      if (Array.isArray(that._subdomains)) {
        that._subdomains = that._subdomains.slice();
      } else if (defined(that._subdomains) && that._subdomains.length > 0) {
        that._subdomains = that._subdomains.split("");
      } else {
        that._subdomains = ["a", "b", "c"];
      }
  
      that._tileWidth = defaultValue(properties.tileWidth, 256);
      that._tileHeight = defaultValue(properties.tileHeight, 256);
      that._minimumLevel = defaultValue(properties.minimumLevel, 0);
      that._maximumLevel = properties.maximumLevel;
      that._tilingScheme = defaultValue(
        properties.tilingScheme,
        new WebMercatorTilingScheme({ ellipsoid: properties.ellipsoid })
      );
      that._rectangle = defaultValue(
        properties.rectangle,
        that._tilingScheme.rectangle
      );
      that._rectangle = Rectangle.intersection(
        that._rectangle,
        that._tilingScheme.rectangle
      );
      that._hasAlphaChannel = defaultValue(properties.hasAlphaChannel, true);
  
      var credit = properties.credit;
      if (typeof credit === "string") {
        credit = new Credit(credit);
      }
      that._credit = credit;
  
      that._resource = resource;
      that._tags = allTags;
      that._pickFeaturesResource = pickFeaturesResource;
      that._pickFeaturesTags = allPickFeaturesTags;
  
      return true;
    });
  };
  
  /**
   * 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.
   */
  UrlTemplateImageryProvider.prototype.getTileCredits = function (x, y, level) {
    //>>includeStart('debug', pragmas.debug);
    if (!this.ready) {
      throw new DeveloperError(
        "getTileCredits must not be called before the imagery provider is ready."
      );
    }
    //>>includeEnd('debug');
    return undefined;
  };
  
  /**
   * Requests the image for a given tile.  This function should
   * not be called before {@link UrlTemplateImageryProvider#ready} returns true.
   *
   * @param {Number} x The tile X coordinate.
   * @param {Number} y The tile Y coordinate.
   * @param {Number} level The tile level.
   * @param {Request} [request] The request object. Intended for internal use only.
   * @returns {Promise.<HTMLImageElement|HTMLCanvasElement>|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.
   */
  UrlTemplateImageryProvider.prototype.requestImage = function (
    x,
    y,
    level,
    request
  ) {
    //>>includeStart('debug', pragmas.debug);
    if (!this.ready) {
      throw new DeveloperError(
        "requestImage must not be called before the imagery provider is ready."
      );
    }
    //>>includeEnd('debug');
    return ImageryProvider.loadImage(
      this,
      buildImageResource(this, x, y, level, request)
    );
  };
  
  /**
   * 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.
   *                   It may also be undefined if picking is not supported.
   */
  UrlTemplateImageryProvider.prototype.pickFeatures = function (
    x,
    y,
    level,
    longitude,
    latitude
  ) {
    //>>includeStart('debug', pragmas.debug);
    if (!this.ready) {
      throw new DeveloperError(
        "pickFeatures must not be called before the imagery provider is ready."
      );
    }
    //>>includeEnd('debug');
  
    if (
      !this.enablePickFeatures ||
      !defined(this._pickFeaturesResource) ||
      this._getFeatureInfoFormats.length === 0
    ) {
      return undefined;
    }
  
    var formatIndex = 0;
  
    var that = this;
  
    function handleResponse(format, data) {
      return format.callback(data);
    }
  
    function doRequest() {
      if (formatIndex >= that._getFeatureInfoFormats.length) {
        // No valid formats, so no features picked.
        return when([]);
      }
  
      var format = that._getFeatureInfoFormats[formatIndex];
      var resource = buildPickFeaturesResource(
        that,
        x,
        y,
        level,
        longitude,
        latitude,
        format.format
      );
  
      ++formatIndex;
  
      if (format.type === "json") {
        return resource.fetchJson().then(format.callback).otherwise(doRequest);
      } else if (format.type === "xml") {
        return resource.fetchXML().then(format.callback).otherwise(doRequest);
      } else if (format.type === "text" || format.type === "html") {
        return resource.fetchText().then(format.callback).otherwise(doRequest);
      }
      return resource
        .fetch({
          responseType: format.format,
        })
        .then(handleResponse.bind(undefined, format))
        .otherwise(doRequest);
    }
  
    return doRequest();
  };
  
  var degreesScratchComputed = false;
  var degreesScratch = new Rectangle();
  var projectedScratchComputed = false;
  var projectedScratch = new Rectangle();
  
  function buildImageResource(imageryProvider, x, y, level, request) {
    degreesScratchComputed = false;
    projectedScratchComputed = false;
  
    var resource = imageryProvider._resource;
    var url = resource.getUrlComponent(true);
    var allTags = imageryProvider._tags;
    var templateValues = {};
  
    var match = url.match(templateRegex);
    if (defined(match)) {
      match.forEach(function (tag) {
        var key = tag.substring(1, tag.length - 1); //strip {}
        if (defined(allTags[key])) {
          templateValues[key] = allTags[key](imageryProvider, x, y, level);
        }
      });
    }
  
    return resource.getDerivedResource({
      request: request,
      templateValues: templateValues,
    });
  }
  
  var ijScratchComputed = false;
  var ijScratch = new Cartesian2();
  var longitudeLatitudeProjectedScratchComputed = false;
  
  function buildPickFeaturesResource(
    imageryProvider,
    x,
    y,
    level,
    longitude,
    latitude,
    format
  ) {
    degreesScratchComputed = false;
    projectedScratchComputed = false;
    ijScratchComputed = false;
    longitudeLatitudeProjectedScratchComputed = false;
  
    var resource = imageryProvider._pickFeaturesResource;
    var url = resource.getUrlComponent(true);
    var allTags = imageryProvider._pickFeaturesTags;
    var templateValues = {};
    var match = url.match(templateRegex);
    if (defined(match)) {
      match.forEach(function (tag) {
        var key = tag.substring(1, tag.length - 1); //strip {}
        if (defined(allTags[key])) {
          templateValues[key] = allTags[key](
            imageryProvider,
            x,
            y,
            level,
            longitude,
            latitude,
            format
          );
        }
      });
    }
  
    return resource.getDerivedResource({
      templateValues: templateValues,
    });
  }
  
  function padWithZerosIfNecessary(imageryProvider, key, value) {
    if (
      imageryProvider &&
      imageryProvider.urlSchemeZeroPadding &&
      imageryProvider.urlSchemeZeroPadding.hasOwnProperty(key)
    ) {
      var paddingTemplate = imageryProvider.urlSchemeZeroPadding[key];
      if (typeof paddingTemplate === "string") {
        var paddingTemplateWidth = paddingTemplate.length;
        if (paddingTemplateWidth > 1) {
          value =
            value.length >= paddingTemplateWidth
              ? value
              : new Array(
                  paddingTemplateWidth - value.toString().length + 1
                ).join("0") + value;
        }
      }
    }
    return value;
  }
  
  function xTag(imageryProvider, x, y, level) {
    return padWithZerosIfNecessary(imageryProvider, "{x}", x);
  }
  
  function reverseXTag(imageryProvider, x, y, level) {
    var reverseX =
      imageryProvider.tilingScheme.getNumberOfXTilesAtLevel(level) - x - 1;
    return padWithZerosIfNecessary(imageryProvider, "{reverseX}", reverseX);
  }
  
  function yTag(imageryProvider, x, y, level) {
    return padWithZerosIfNecessary(imageryProvider, "{y}", y);
  }
  
  function reverseYTag(imageryProvider, x, y, level) {
    var reverseY =
      imageryProvider.tilingScheme.getNumberOfYTilesAtLevel(level) - y - 1;
    return padWithZerosIfNecessary(imageryProvider, "{reverseY}", reverseY);
  }
  
  function reverseZTag(imageryProvider, x, y, level) {
    var maximumLevel = imageryProvider.maximumLevel;
    var reverseZ =
      defined(maximumLevel) && level < maximumLevel
        ? maximumLevel - level - 1
        : level;
    return padWithZerosIfNecessary(imageryProvider, "{reverseZ}", reverseZ);
  }
  
  function zTag(imageryProvider, x, y, level) {
    return padWithZerosIfNecessary(imageryProvider, "{z}", level);
  }
  
  function sTag(imageryProvider, x, y, level) {
    var index = (x + y + level) % imageryProvider._subdomains.length;
    return imageryProvider._subdomains[index];
  }
  
  function computeDegrees(imageryProvider, x, y, level) {
    if (degreesScratchComputed) {
      return;
    }
  
    imageryProvider.tilingScheme.tileXYToRectangle(x, y, level, degreesScratch);
    degreesScratch.west = CesiumMath.toDegrees(degreesScratch.west);
    degreesScratch.south = CesiumMath.toDegrees(degreesScratch.south);
    degreesScratch.east = CesiumMath.toDegrees(degreesScratch.east);
    degreesScratch.north = CesiumMath.toDegrees(degreesScratch.north);
  
    degreesScratchComputed = true;
  }
  
  function westDegreesTag(imageryProvider, x, y, level) {
    computeDegrees(imageryProvider, x, y, level);
    return degreesScratch.west;
  }
  
  function southDegreesTag(imageryProvider, x, y, level) {
    computeDegrees(imageryProvider, x, y, level);
    return degreesScratch.south;
  }
  
  function eastDegreesTag(imageryProvider, x, y, level) {
    computeDegrees(imageryProvider, x, y, level);
    return degreesScratch.east;
  }
  
  function northDegreesTag(imageryProvider, x, y, level) {
    computeDegrees(imageryProvider, x, y, level);
    return degreesScratch.north;
  }
  
  function computeProjected(imageryProvider, x, y, level) {
    if (projectedScratchComputed) {
      return;
    }
  
    imageryProvider.tilingScheme.tileXYToNativeRectangle(
      x,
      y,
      level,
      projectedScratch
    );
  
    projectedScratchComputed = true;
  }
  
  function westProjectedTag(imageryProvider, x, y, level) {
    computeProjected(imageryProvider, x, y, level);
    return projectedScratch.west;
  }
  
  function southProjectedTag(imageryProvider, x, y, level) {
    computeProjected(imageryProvider, x, y, level);
    return projectedScratch.south;
  }
  
  function eastProjectedTag(imageryProvider, x, y, level) {
    computeProjected(imageryProvider, x, y, level);
    return projectedScratch.east;
  }
  
  function northProjectedTag(imageryProvider, x, y, level) {
    computeProjected(imageryProvider, x, y, level);
    return projectedScratch.north;
  }
  
  function widthTag(imageryProvider, x, y, level) {
    return imageryProvider.tileWidth;
  }
  
  function heightTag(imageryProvider, x, y, level) {
    return imageryProvider.tileHeight;
  }
  
  function iTag(imageryProvider, x, y, level, longitude, latitude, format) {
    computeIJ(imageryProvider, x, y, level, longitude, latitude);
    return ijScratch.x;
  }
  
  function jTag(imageryProvider, x, y, level, longitude, latitude, format) {
    computeIJ(imageryProvider, x, y, level, longitude, latitude);
    return ijScratch.y;
  }
  
  function reverseITag(
    imageryProvider,
    x,
    y,
    level,
    longitude,
    latitude,
    format
  ) {
    computeIJ(imageryProvider, x, y, level, longitude, latitude);
    return imageryProvider.tileWidth - ijScratch.x - 1;
  }
  
  function reverseJTag(
    imageryProvider,
    x,
    y,
    level,
    longitude,
    latitude,
    format
  ) {
    computeIJ(imageryProvider, x, y, level, longitude, latitude);
    return imageryProvider.tileHeight - ijScratch.y - 1;
  }
  
  var rectangleScratch = new Rectangle();
  var longitudeLatitudeProjectedScratch = new Cartesian3();
  
  function computeIJ(imageryProvider, x, y, level, longitude, latitude, format) {
    if (ijScratchComputed) {
      return;
    }
  
    computeLongitudeLatitudeProjected(
      imageryProvider,
      x,
      y,
      level,
      longitude,
      latitude
    );
    var projected = longitudeLatitudeProjectedScratch;
  
    var rectangle = imageryProvider.tilingScheme.tileXYToNativeRectangle(
      x,
      y,
      level,
      rectangleScratch
    );
    ijScratch.x =
      ((imageryProvider.tileWidth * (projected.x - rectangle.west)) /
        rectangle.width) |
      0;
    ijScratch.y =
      ((imageryProvider.tileHeight * (rectangle.north - projected.y)) /
        rectangle.height) |
      0;
    ijScratchComputed = true;
  }
  
  function longitudeDegreesTag(
    imageryProvider,
    x,
    y,
    level,
    longitude,
    latitude,
    format
  ) {
    return CesiumMath.toDegrees(longitude);
  }
  
  function latitudeDegreesTag(
    imageryProvider,
    x,
    y,
    level,
    longitude,
    latitude,
    format
  ) {
    return CesiumMath.toDegrees(latitude);
  }
  
  function longitudeProjectedTag(
    imageryProvider,
    x,
    y,
    level,
    longitude,
    latitude,
    format
  ) {
    computeLongitudeLatitudeProjected(
      imageryProvider,
      x,
      y,
      level,
      longitude,
      latitude
    );
    return longitudeLatitudeProjectedScratch.x;
  }
  
  function latitudeProjectedTag(
    imageryProvider,
    x,
    y,
    level,
    longitude,
    latitude,
    format
  ) {
    computeLongitudeLatitudeProjected(
      imageryProvider,
      x,
      y,
      level,
      longitude,
      latitude
    );
    return longitudeLatitudeProjectedScratch.y;
  }
  
  var cartographicScratch = new Cartographic();
  
  function computeLongitudeLatitudeProjected(
    imageryProvider,
    x,
    y,
    level,
    longitude,
    latitude,
    format
  ) {
    if (longitudeLatitudeProjectedScratchComputed) {
      return;
    }
  
    if (imageryProvider.tilingScheme.projection instanceof GeographicProjection) {
      longitudeLatitudeProjectedScratch.x = CesiumMath.toDegrees(longitude);
      longitudeLatitudeProjectedScratch.y = CesiumMath.toDegrees(latitude);
    } else {
      var cartographic = cartographicScratch;
      cartographic.longitude = longitude;
      cartographic.latitude = latitude;
      imageryProvider.tilingScheme.projection.project(
        cartographic,
        longitudeLatitudeProjectedScratch
      );
    }
  
    longitudeLatitudeProjectedScratchComputed = true;
  }
  
  function formatTag(imageryProvider, x, y, level, longitude, latitude, format) {
    return format;
  }
  export default UrlTemplateImageryProvider;
  