namespace TSE {

    export const MESSAGE_ASSET_LOADER_ASSET_LOADED = "MESSAGE_ASSET_LOADER_ASSET_LOADED::";

    export class AssetManager {

        private static _loaders: IAssetLoader[] = [];
        private static _loadedAssets: { [name: string]: IAsset } = {};

        private constructor() {}

        public static initialize(): void {
            this.registerLoader(new ImageAssetLoader());
            this.registerLoader(new JsonAssetLoader());
        }

        public static registerLoader(loader: IAssetLoader): void {
            AssetManager._loaders.push(loader);
        }

        public static onAssetLoaded(asset: IAsset): void {
            AssetManager._loadedAssets[asset.name] = asset;
            Message.send(MESSAGE_ASSET_LOADER_ASSET_LOADED + asset.name, this, asset);
        }

        public static loadAsset(assetName: string): void {
            let extention = assetName.split('.').pop().toLowerCase();
            for (let loader of AssetManager._loaders) {
                if (loader.supportedExtensions.indexOf(extention) !== -1) {
                    loader.loadAsset(assetName);
                    return;
                }
            }

            console.warn("Unable to load asset with extention: '" + extention + "'. no loader was found.");
        }

        public static isAssetLoaded(assetName: string): boolean {
            return AssetManager._loadedAssets[assetName] !== undefined;
        }

        public static getAsset(assetName: string): IAsset {
            if (AssetManager.isAssetLoaded(assetName)) {
                return AssetManager._loadedAssets[assetName];
            } else {
                AssetManager.loadAsset(assetName);
            }

            return undefined;
        }

    }

}