text: define([
          '../Core/Credit',
          '../Core/decodeGoogleEarthEnterpriseData',
          '../Core/defaultValue',
          '../Core/defined',
          '../Core/defineProperties',
          '../Core/deprecationWarning',
          '../Core/DeveloperError',
          '../Core/Event',
          '../Core/GeographicTilingScheme',
          '../Core/GoogleEarthEnterpriseMetadata',
          '../Core/loadImageFromTypedArray',
          '../Core/Math',
          '../Core/Rectangle',
          '../Core/Request',
          '../Core/Resource',
          '../Core/RuntimeError',
          '../Core/TileProviderError',
          '../ThirdParty/protobuf-minimal',
          '../ThirdParty/when'
      ], function(
          Credit,
          decodeGoogleEarthEnterpriseData,
          defaultValue,
          defined,
          defineProperties,
          deprecationWarning,
          DeveloperError,
          Event,
          GeographicTilingScheme,
          GoogleEarthEnterpriseMetadata,
          loadImageFromTypedArray,
          CesiumMath,
          Rectangle,
          Request,
          Resource,
          RuntimeError,
          TileProviderError,
          protobuf,
          when) {
      'use strict';
  
      function GoogleEarthEnterpriseDiscardPolicy() {
          this._image = new Image();
      }
  
      /**
       * Determines if the discard policy is ready to process images.
       * @returns {Boolean} True if the discard policy is ready to process images; otherwise, false.
       */
      GoogleEarthEnterpriseDiscardPolicy.prototype.isReady = function() {
          return true;
      };
  
      /**
       * Given a tile image, decide whether to discard that image.
       *
       * @param {Image} image An image to test.
       * @returns {Boolean} True if the image should be discarded; otherwise, false.
       */
      GoogleEarthEnterpriseDiscardPolicy.prototype.shouldDiscardImage = function(image) {
          return (image === this._image);
      };
  
      /**
       * Provides tiled imagery using the Google Earth Enterprise REST API.
       *
       * Notes: This provider is for use with the 3D Earth API of Google Earth Enterprise,
       *        {@link GoogleEarthEnterpriseMapsProvider} should be used with 2D Maps API.
       *
       * @alias GoogleEarthEnterpriseImageryProvider
       * @constructor
       *
       * @param {Object} options Object with the following properties:
       * @param {Resource|String} options.url The url of the Google Earth Enterprise server hosting the imagery.
       * @param {GoogleEarthEnterpriseMetadata} options.metadata A metadata object that can be used to share metadata requests with a GoogleEarthEnterpriseTerrainProvider.
       * @param {Ellipsoid} [options.ellipsoid] The ellipsoid.  If not specified, the WGS84 ellipsoid is used.
       * @param {TileDiscardPolicy} [options.tileDiscardPolicy] The policy that determines if a tile
       *        is invalid and should be discarded. If this value is not specified, a default
       *        is to discard tiles that fail to download.
       * @param {Credit|String} [options.credit] A credit for the data source, which is displayed on the canvas.
       *
       * @see GoogleEarthEnterpriseTerrainProvider
       * @see ArcGisMapServerImageryProvider
       * @see GoogleEarthEnterpriseMapsProvider
       * @see createOpenStreetMapImageryProvider
       * @see SingleTileImageryProvider
       * @see createTileMapServiceImageryProvider
       * @see WebMapServiceImageryProvider
       * @see WebMapTileServiceImageryProvider
       * @see UrlTemplateImageryProvider
       *
       *
       * @example
       * var geeMetadata = new GoogleEarthEnterpriseMetadata('http://www.earthenterprise.org/3d');
       * var gee = new Cesium.GoogleEarthEnterpriseImageryProvider({
       *     metadata : geeMetadata
       * });
       *
       * @see {@link http://www.w3.org/TR/cors/|Cross-Origin Resource Sharing}
       */
      function GoogleEarthEnterpriseImageryProvider(options) {
          options = defaultValue(options, defaultValue.EMPTY_OBJECT);
  
          //>>includeStart('debug', pragmas.debug);
          if (!(defined(options.url) || defined(options.metadata))) {
              throw new DeveloperError('options.url or options.metadata is required.');
          }
          //>>includeEnd('debug');
  
          if (defined(options.proxy)) {
              deprecationWarning('GoogleEarthEnterpriseImageryProvider.proxy', 'The options.proxy parameter has been deprecated. Specify options.url as a Resource instance and set the proxy property there.');
          }
  
          var metadata;
          if (defined(options.metadata)) {
              metadata = options.metadata;
          } else {
              var resource = Resource.createIfNeeded(options.url, {
                  proxy: options.proxy
              });
              metadata = new GoogleEarthEnterpriseMetadata(resource);
          }
          this._metadata = metadata;
          this._tileDiscardPolicy = options.tileDiscardPolicy;
  
          this._tilingScheme = new GeographicTilingScheme({
              numberOfLevelZeroTilesX : 2,
              numberOfLevelZeroTilesY : 2,
              rectangle : new Rectangle(-CesiumMath.PI, -CesiumMath.PI, CesiumMath.PI, CesiumMath.PI),
              ellipsoid : options.ellipsoid
          });
  
          var credit = options.credit;
          if (typeof credit === 'string') {
              credit = new Credit({text: credit});
          }
          this._credit = credit;
  
          this._tileWidth = 256;
          this._tileHeight = 256;
          this._maximumLevel = 23;
  
          // Install the default tile discard policy if none has been supplied.
          if (!defined(this._tileDiscardPolicy)) {
              this._tileDiscardPolicy = new GoogleEarthEnterpriseDiscardPolicy();
          }
  
          this._errorEvent = new Event();
  
          this._ready = false;
          var that = this;
          var metadataError;
          this._readyPromise = metadata.readyPromise
              .then(function(result) {
                  if (!metadata.imageryPresent) {
                      var e = new RuntimeError('The server ' + metadata.url + ' doesn\'t have imagery');
                      metadataError = TileProviderError.handleError(metadataError, that, that._errorEvent, e.message, undefined, undefined, undefined, e);
                      return when.reject(e);
                  }
  
                  TileProviderError.handleSuccess(metadataError);
                  that._ready = result;
                  return result;
              })
              .otherwise(function(e) {
                  metadataError = TileProviderError.handleError(metadataError, that, that._errorEvent, e.message, undefined, undefined, undefined, e);
                  return when.reject(e);
              });
      }
  
      defineProperties(GoogleEarthEnterpriseImageryProvider.prototype, {
          /**
           * Gets the name of the Google Earth Enterprise server url hosting the imagery.
           * @memberof GoogleEarthEnterpriseImageryProvider.prototype
           * @type {String}
           * @readonly
           */
          url : {
              get : function() {
                  return this._metadata.url;
              }
          },
  
          /**
           * Gets the proxy used by this provider.
           * @memberof GoogleEarthEnterpriseImageryProvider.prototype
           * @type {Proxy}
           * @readonly
           */
          proxy : {
              get : function() {
                  return this._metadata.proxy;
              }
          },
  
          /**
           * Gets the width of each tile, in pixels. This function should
           * not be called before {@link GoogleEarthEnterpriseImageryProvider#ready} returns true.
           * @memberof GoogleEarthEnterpriseImageryProvider.prototype
           * @type {Number}
           * @readonly
           */
          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 GoogleEarthEnterpriseImageryProvider#ready} returns true.
           * @memberof GoogleEarthEnterpriseImageryProvider.prototype
           * @type {Number}
           * @readonly
           */
          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.  This function should
           * not be called before {@link GoogleEarthEnterpriseImageryProvider#ready} returns true.
           * @memberof GoogleEarthEnterpriseImageryProvider.prototype
           * @type {Number}
           * @readonly
           */
          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 GoogleEarthEnterpriseImageryProvider#ready} returns true.
           * @memberof GoogleEarthEnterpriseImageryProvider.prototype
           * @type {Number}
           * @readonly
           */
          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 0;
              }
          },
  
          /**
           * Gets the tiling scheme used by this provider.  This function should
           * not be called before {@link GoogleEarthEnterpriseImageryProvider#ready} returns true.
           * @memberof GoogleEarthEnterpriseImageryProvider.prototype
           * @type {TilingScheme}
           * @readonly
           */
          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 GoogleEarthEnterpriseImageryProvider#ready} returns true.
           * @memberof GoogleEarthEnterpriseImageryProvider.prototype
           * @type {Rectangle}
           * @readonly
           */
          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._tilingScheme.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 GoogleEarthEnterpriseImageryProvider#ready} returns true.
           * @memberof GoogleEarthEnterpriseImageryProvider.prototype
           * @type {TileDiscardPolicy}
           * @readonly
           */
          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 GoogleEarthEnterpriseImageryProvider.prototype
           * @type {Event}
           * @readonly
           */
          errorEvent : {
              get : function() {
                  return this._errorEvent;
              }
          },
  
          /**
           * Gets a value indicating whether or not the provider is ready for use.
           * @memberof GoogleEarthEnterpriseImageryProvider.prototype
           * @type {Boolean}
           * @readonly
           */
          ready : {
              get : function() {
                  return this._ready;
              }
          },
  
          /**
           * Gets a promise that resolves to true when the provider is ready for use.
           * @memberof GoogleEarthEnterpriseImageryProvider.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 GoogleEarthEnterpriseImageryProvider#ready} returns true.
           * @memberof GoogleEarthEnterpriseImageryProvider.prototype
           * @type {Credit}
           * @readonly
           */
          credit : {
              get : function() {
                  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.  Setting this property to false reduces memory usage
           * and texture upload time.
           * @memberof GoogleEarthEnterpriseImageryProvider.prototype
           * @type {Boolean}
           * @readonly
           */
          hasAlphaChannel : {
              get : function() {
                  return false;
              }
          }
      });
  
      /**
       * 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.
       */
      GoogleEarthEnterpriseImageryProvider.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');
  
          var metadata = this._metadata;
          var info = metadata.getTileInformation(x, y, level);
          if (defined(info)) {
              var credit = metadata.providers[info.imageryProvider];
              if (defined(credit)) {
                  return [credit];
              }
          }
  
          return undefined;
      };
  
      /**
       * Requests the image for a given tile.  This function should
       * not be called before {@link GoogleEarthEnterpriseImageryProvider#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.<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.
       */
      GoogleEarthEnterpriseImageryProvider.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');
  
          var invalidImage = this._tileDiscardPolicy._image; // Empty image or undefined depending on discard policy
          var metadata = this._metadata;
          var quadKey = GoogleEarthEnterpriseMetadata.tileXYToQuadKey(x, y, level);
          var info = metadata.getTileInformation(x, y, level);
          if (!defined(info)) {
              if (metadata.isValid(quadKey)) {
                  var metadataRequest = new Request({
                      throttle : request.throttle,
                      throttleByServer : request.throttleByServer,
                      type : request.type,
                      priorityFunction : request.priorityFunction
                  });
                  metadata.populateSubtree(x, y, level, metadataRequest);
                  return undefined; // No metadata so return undefined so we can be loaded later
              }
              return invalidImage; // Image doesn't exist
          }
  
          if (!info.hasImagery()) {
              // Already have info and there isn't any imagery here
              return invalidImage;
          }
          var promise = buildImageResource(this, info, x, y, level, request).fetchArrayBuffer();
          if (!defined(promise)) {
              return undefined; // Throttled
          }
  
          return promise
              .then(function(image) {
                  decodeGoogleEarthEnterpriseData(metadata.key, image);
                  var a = new Uint8Array(image);
                  var type;
  
                  var protoImagery = metadata.protoImagery;
                  if (!defined(protoImagery) || !protoImagery) {
                      type = getImageType(a);
                  }
  
                  if (!defined(type) && (!defined(protoImagery) || protoImagery)) {
                      var message = decodeEarthImageryPacket(a);
                      type = message.imageType;
                      a = message.imageData;
                  }
  
                  if (!defined(type) || !defined(a)) {
                      return invalidImage;
                  }
  
                  return loadImageFromTypedArray(a, type);
              });
      };
  
      /**
       * Picking features is not currently supported by this imagery provider, so this function simply returns
       * undefined.
       *
       * @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.
       */
      GoogleEarthEnterpriseImageryProvider.prototype.pickFeatures = function(x, y, level, longitude, latitude) {
          return undefined;
      };
  
      //
      // Functions to handle imagery packets
      //
      function buildImageResource(imageryProvider, info, x, y, level, request) {
          var quadKey = GoogleEarthEnterpriseMetadata.tileXYToQuadKey(x, y, level);
          var version = info.imageryVersion;
          version = (defined(version) && version > 0) ? version : 1;
  
          return imageryProvider._metadata.resource.getDerivedResource({
              url: 'flatfile?f1-0' + quadKey + '-i.' + version.toString(),
              request: request
          });
      }
  
      // Detects if a Uint8Array is a JPEG or PNG
      function getImageType(image) {
          var jpeg = 'JFIF';
          if (image[6] === jpeg.charCodeAt(0) && image[7] === jpeg.charCodeAt(1) &&
              image[8] === jpeg.charCodeAt(2) && image[9] === jpeg.charCodeAt(3)) {
              return 'image/jpeg';
          }
  
          var png = 'PNG';
          if (image[1] === png.charCodeAt(0) && image[2] === png.charCodeAt(1) && image[3] === png.charCodeAt(2)) {
              return 'image/png';
          }
  
          return undefined;
      }
  
      // Decodes an Imagery protobuf into the message
      // Partially generated with the help of protobuf.js static generator
      function decodeEarthImageryPacket(data) {
          var reader = protobuf.Reader.create(data);
          var end = reader.len;
          var message = {};
          while (reader.pos < end) {
              var tag = reader.uint32();
              switch (tag >>> 3) {
                  case 1:
                      message.imageType = reader.uint32();
                      break;
                  case 2:
                      message.imageData = reader.bytes();
                      break;
                  case 3:
                      message.alphaType = reader.uint32();
                      break;
                  case 4:
                      message.imageAlpha = reader.bytes();
                      break;
                  case 5:
                      var copyrightIds = message.copyrightIds;
                      if (!defined(copyrightIds)) {
                          copyrightIds = message.copyrightIds = [];
                      }
                      if ((tag & 7) === 2) {
                          var end2 = reader.uint32() + reader.pos;
                          while (reader.pos < end2) {
                              copyrightIds.push(reader.uint32());
                          }
                      } else {
                          copyrightIds.push(reader.uint32());
                      }
                      break;
                  default:
                      reader.skipType(tag & 7);
                      break;
              }
          }
  
          var imageType = message.imageType;
          if (defined(imageType)) {
              switch (imageType) {
                  case 0:
                      message.imageType = 'image/jpeg';
                      break;
                  case 4:
                      message.imageType = 'image/png';
                      break;
                  default:
                      throw new RuntimeError('GoogleEarthEnterpriseImageryProvider: Unsupported image type.');
              }
          }
  
          var alphaType = message.alphaType;
          if (defined(alphaType) && alphaType !== 0) {
              console.log('GoogleEarthEnterpriseImageryProvider: External alpha not supported.');
              delete message.alphaType;
              delete message.imageAlpha;
          }
  
          return message;
      }
  
      return GoogleEarthEnterpriseImageryProvider;
  });
  