import Check from '../Core/Check.js';
import defaultValue from '../Core/defaultValue.js';
import defined from '../Core/defined.js';
import defineProperties from '../Core/defineProperties.js';
import DeveloperError from '../Core/DeveloperError.js';
import Event from '../Core/Event.js';
import IonResource from '../Core/IonResource.js';
import RuntimeError from '../Core/RuntimeError.js';
import when from '../ThirdParty/when.js';
import ArcGisMapServerImageryProvider from './ArcGisMapServerImageryProvider.js';
import BingMapsImageryProvider from './BingMapsImageryProvider.js';
import TileMapServiceImageryProvider from './TileMapServiceImageryProvider.js';
import GoogleEarthEnterpriseMapsProvider from './GoogleEarthEnterpriseMapsProvider.js';
import MapboxImageryProvider from './MapboxImageryProvider.js';
import SingleTileImageryProvider from './SingleTileImageryProvider.js';
import UrlTemplateImageryProvider from './UrlTemplateImageryProvider.js';
import WebMapServiceImageryProvider from './WebMapServiceImageryProvider.js';
import WebMapTileServiceImageryProvider from './WebMapTileServiceImageryProvider.js';

    function createFactory(Type) {
        return function(options) {
            return new Type(options);
        };
    }

    // These values are the list of supported external imagery
    // assets in the Cesium ion beta. They are subject to change.
    var ImageryProviderMapping = {
        ARCGIS_MAPSERVER: createFactory(ArcGisMapServerImageryProvider),
        BING: createFactory(BingMapsImageryProvider),
        GOOGLE_EARTH: createFactory(GoogleEarthEnterpriseMapsProvider),
        MAPBOX: createFactory(MapboxImageryProvider),
        SINGLE_TILE: createFactory(SingleTileImageryProvider),
        TMS: createFactory(TileMapServiceImageryProvider),
        URL_TEMPLATE: createFactory(UrlTemplateImageryProvider),
        WMS: createFactory(WebMapServiceImageryProvider),
        WMTS: createFactory(WebMapTileServiceImageryProvider)
    };

    /**
     * Provides tiled imagery using the Cesium ion REST API.
     *
     * @alias IonImageryProvider
     * @constructor
     *
     * @param {Object} options Object with the following properties:
     * @param {Number} options.assetId An ion imagery asset ID;
     * @param {String} [options.accessToken=Ion.defaultAccessToken] The access token to use.
     * @param {String|Resource} [options.server=Ion.defaultServer] The resource to the Cesium ion API server.
     *
     * @example
     * viewer.imageryLayers.addImageryProvider(new Cesium.IonImageryProvider({ assetId : 23489024 }));
     */
    function IonImageryProvider(options) {
        options = defaultValue(options, defaultValue.EMPTY_OBJECT);

        var assetId = options.assetId;
        //>>includeStart('debug', pragmas.debug);
        Check.typeOf.number('options.assetId', assetId);
        //>>includeEnd('debug');

        /**
         * The default alpha blending value of this provider, with 0.0 representing fully transparent and
         * 1.0 representing fully opaque.
         *
         * @type {Number}
         * @default undefined
         */
        this.defaultAlpha = 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}
         * @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}
         * @default undefined
         */
        this.defaultContrast = undefined;

        /**
         * The default hue of this provider in radians. 0.0 uses the unmodified imagery color.
         *
         * @type {Number}
         * @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}
         * @default undefined
         */
        this.defaultSaturation = undefined;

        /**
         * The default gamma correction to apply to this provider.  1.0 uses the unmodified imagery color.
         *
         * @type {Number}
         * @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;

        this._ready = false;
        this._tileCredits = undefined;
        this._errorEvent = new Event();

        var that = this;
        var endpointResource = IonResource._createEndpointResource(assetId, options);

        // A simple cache to avoid making repeated requests to ion for endpoints we've
        // already retrieved. This exists mainly to support Bing caching to reduce
        // world imagery sessions, but provides a small boost of performance in general
        // if constantly reloading assets
        var cacheKey = options.assetId.toString() + options.accessToken + options.server;
        var promise = IonImageryProvider._endpointCache[cacheKey];
        if (!defined(promise)) {
            promise = endpointResource.fetchJson();
            IonImageryProvider._endpointCache[cacheKey] = promise;
        }

        this._readyPromise = promise
            .then(function(endpoint) {
                if (endpoint.type !== 'IMAGERY') {
                    return when.reject(new RuntimeError('Cesium ion asset ' + assetId + ' is not an imagery asset.'));
                }

                var imageryProvider;
                var externalType = endpoint.externalType;
                if (!defined(externalType)) {
                    imageryProvider = new TileMapServiceImageryProvider({
                        url: new IonResource(endpoint, endpointResource)
                    });
                } else {
                    var factory = ImageryProviderMapping[externalType];

                    if (!defined(factory)) {
                        return when.reject(new RuntimeError('Unrecognized Cesium ion imagery type: ' + externalType));
                    }
                    imageryProvider = factory(endpoint.options);
                }

                that._tileCredits = IonResource.getCreditsFromEndpoint(endpoint, endpointResource);

                imageryProvider.errorEvent.addEventListener(function(tileProviderError) {
                    //Propagate the errorEvent but set the provider to this instance instead
                    //of the inner instance.
                    tileProviderError.provider = that;
                    that._errorEvent.raiseEvent(tileProviderError);
                });

                that._imageryProvider = imageryProvider;
                return imageryProvider.readyPromise.then(function() {
                    that._ready = true;
                    return true;
                });
            });
    }

    defineProperties(IonImageryProvider.prototype, {
        /**
         * Gets a value indicating whether or not the provider is ready for use.
         * @memberof IonImageryProvider.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 IonImageryProvider.prototype
         * @type {Promise.<Boolean>}
         * @readonly
         */
        readyPromise : {
            get: function() {
                return this._readyPromise;
            }
        },

        /**
         * Gets the rectangle, in radians, of the imagery provided by the instance.  This function should
         * not be called before {@link IonImageryProvider#ready} returns true.
         * @memberof IonImageryProvider.prototype
         * @type {Rectangle}
         * @readonly
         */
        rectangle: {
            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._imageryProvider.rectangle;
            }
        },

        /**
         * Gets the width of each tile, in pixels.  This function should
         * not be called before {@link IonImageryProvider#ready} returns true.
         * @memberof IonImageryProvider.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._imageryProvider.tileWidth;
            }
        },

        /**
         * Gets the height of each tile, in pixels.  This function should
         * not be called before {@link IonImageryProvider#ready} returns true.
         * @memberof IonImageryProvider.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._imageryProvider.tileHeight;
            }
        },

        /**
         * Gets the maximum level-of-detail that can be requested.  This function should
         * not be called before {@link IonImageryProvider#ready} returns true.
         * @memberof IonImageryProvider.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._imageryProvider.maximumLevel;
            }
        },

        /**
         * Gets the minimum level-of-detail that can be requested.  This function should
         * not be called before {@link IonImageryProvider#ready} returns true. Generally,
         * a minimum level should only be used when the rectangle of the imagery is small
         * enough that the number of tiles at the minimum level is small.  An imagery
         * provider with more than a few tiles at the minimum level will lead to
         * rendering problems.
         * @memberof IonImageryProvider.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 this._imageryProvider.minimumLevel;
            }
        },

        /**
         * Gets the tiling scheme used by the provider.  This function should
         * not be called before {@link IonImageryProvider#ready} returns true.
         * @memberof IonImageryProvider.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._imageryProvider.tilingScheme;
            }
        },

        /**
         * 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 IonImageryProvider#ready} returns true.
         * @memberof IonImageryProvider.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._imageryProvider.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 IonImageryProvider.prototype
         * @type {Event}
         * @readonly
         */
        errorEvent : {
            get: function() {
                return this._errorEvent;
            }
        },

        /**
         * 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 IonImageryProvider#ready} returns true.
         * @memberof IonImageryProvider.prototype
         * @type {Credit}
         * @readonly
         */
        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._imageryProvider.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 IonImageryProvider.prototype
         * @type {Boolean}
         * @readonly
         */
        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._imageryProvider.hasAlphaChannel;
            }
        }
    });

    /**
     * Gets the credits to be displayed when a given tile is displayed.
     * @function
     *
     * @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.
     */
    IonImageryProvider.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 innerCredits = this._imageryProvider.getTileCredits(x, y, level);
        if (!defined(innerCredits)) {
            return this._tileCredits;
        }

        return this._tileCredits.concat(innerCredits);
    };

    /**
     * Requests the image for a given tile.  This function should
     * not be called before {@link IonImageryProvider#ready} returns true.
     * @function
     *
     * @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.
     */
    IonImageryProvider.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 this._imageryProvider.requestImage(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 IonImageryProvider#ready} returns true.
     * This function is optional, so it may not exist on all ImageryProviders.
     *
     * @function
     *
     * @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.
     *
     * @exception {DeveloperError} <code>pickFeatures</code> must not be called before the imagery provider is ready.
     */
    IonImageryProvider.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');
        return this._imageryProvider.pickFeatures(x, y, level, longitude, latitude);
    };

    //exposed for testing
    IonImageryProvider._endpointCache = {};
export default IonImageryProvider;