/**
 * The image factory takes care that we only make requests for Image URLs which we have not already started downloading
 * @param graphics
 * @param apiImageFactory
 * @param progressCallback
 * @returns {GameLib.D3.ImageFactory}
 * @constructor
 */
GameLib.D3.ImageFactory = function (
    graphics,
    apiImageFactory,
    progressCallback
) {
    graphics.isNotThreeThrow();
    this.graphics = graphics;

    if (GameLib.Utils.UndefinedOrNull(apiImageFactory)) {
        apiImageFactory = {};
    }

	if (apiImageFactory instanceof GameLib.D3.ImageFactory) {
		return apiImageFactory;
	}

    GameLib.D3.API.ImageFactory.call(
        this,
        apiImageFactory.id,
        apiImageFactory.name,
        apiImageFactory.baseUrl,
        apiImageFactory.parentEntity
    );

    if (GameLib.Utils.UndefinedOrNull(progressCallback)) {
        progressCallback = null;
    }
    this.progressCallback = progressCallback;

    GameLib.Component.call(
        this,
        GameLib.Component.COMPONENT_IMAGE_FACTORY
    );
    
    this.promiseList = {};
};

GameLib.D3.ImageFactory.prototype = Object.create(GameLib.D3.API.ImageFactory.prototype);
GameLib.D3.ImageFactory.prototype.constructor = GameLib.D3.ImageFactory;

GameLib.D3.ImageFactory.prototype.createInstance = function(update) {

    if (!this.loaded) {
        console.log('Attempted to create an instance but the runtime object is not fully loaded : ' + this.name);
        return null;
    }

    var instance = null;
    
    if (update) {
        instance = this.instance;
    } else {
        instance = new THREE.ImageLoader();
    }
    
    instance.crossOrigin = '';
    
    return instance;
};

/**
 * Update instance
 */
GameLib.D3.ImageFactory.prototype.updateInstance = function() {
    this.instance = this.createInstance(true);
};


/**
 * Loads an image, either returns the image immediately if already loaded, or a promise to load the image
 * @param imagePath
 * @returns {*}
 * @constructor
 */
GameLib.D3.ImageFactory.prototype.loadImage = function(
    imagePath,
    force
) {

    imagePath = imagePath.replace(new RegExp('\/*'), '/');

    if (!imagePath) {
        console.log('Attempted to download bad URL : ' + imagePath);
        throw new Error('Bad URL : ' + imagePath);
    }

    if (!force && this.promiseList[imagePath]) {
        return this.promiseList[imagePath];
    }

    var defer = Q.defer();

    this.promiseList[imagePath] = defer.promise;
    
    this.instance.load(
        this.baseUrl + imagePath + '?ts=' + Date.now(),
        function (image) {

            GameLib.Event.Emit(
                GameLib.Event.IMAGE_LOADED,
                {
                    imagePath : imagePath,
                    imageInstance : image
                }
            );

            defer.resolve(image);
        }.bind(this),
        function onProgress(xhr) {
            if (this.progressCallback) {
                this.progressCallback((xhr.loaded / xhr.total * 100));
            }
        }.bind(this),
        function onError() {
            defer.reject('Failed to download image : ' + this.baseUrl + imagePath);
        }.bind(this)
    );
    
    return this.promiseList[imagePath];
};

/**
 * Converts a GameLib.D3.ImageFactory to a GameLib.D3.API.ImageFactory
 * @returns {GameLib.D3.API.ImageFactory}
 */
GameLib.D3.ImageFactory.prototype.toApiObject = function() {
    return new GameLib.D3.API.ImageFactory(
        this.id,
        this.name,
        this.baseUrl,
        GameLib.Utils.IdOrNull(this.parentEntity)
    );
};

/**
 * Returns a new GameLib.D3.ImageFactory from a GameLib.D3.API.ImageFactory
 * @param graphics GameLib.D3.Graphics
 * @param objectImageFactory GameLib.D3.API.ImageFactory
 * @returns {GameLib.D3.ImageFactory}
 */
GameLib.D3.ImageFactory.FromObject = function(graphics, objectImageFactory) {

    return new GameLib.D3.ImageFactory(
        graphics,
        GameLib.D3.API.ImageFactory.FromObject(objectImageFactory)
    );

};