export class LoadProgress {
    public url: string;
    public completedCount: number;
    public totalCount: number;
    public item: any;
    public cb?: Function;
}

export default class ResHelper {
    /** 加载进度 */
    public static loadProgress = new LoadProgress();

    /** 加载资源 */
    public static loadResAsync<T>(url: string, type: typeof cc.Asset, progressCallback?: (completedCount: number, totalCount: number, item: any) => void): Promise<T>{
        if (!url || !type) {
            cc.error("参数错误", url, type);
            return;
        }
        ResHelper.loadProgress.url = url;
        if(progressCallback) {
            this.loadProgress.cb = progressCallback;
        }
        return new Promise((resolve, reject) => {
            //cc.assetManager.downloader.download(url)
            cc.resources.load(url,type,this._progressCallback,function(err,prefab:any){
                if (err) {
                    cc.error(`${url} [资源加载] 错误 ${err}`);
                    resolve(null);
                }else {
                    resolve(prefab);
                }
                // 加载完毕了，清理进度数据
                ResHelper.loadProgress.url = '';
                ResHelper.loadProgress.completedCount = 0;
                ResHelper.loadProgress.totalCount = 0;
                ResHelper.loadProgress.item = null;
                ResHelper.loadProgress.cb = null;
            })
        });
    }
    /** 
     * 加载进度
     * cb方法 其实目的是可以将loader方法的progress
     */
    private static _progressCallback(completedCount: number, totalCount: number, item: any) {
        ResHelper.loadProgress.completedCount = completedCount;
        ResHelper.loadProgress.totalCount = totalCount;
        ResHelper.loadProgress.item = item;
        ResHelper.loadProgress.cb && ResHelper.loadProgress.cb(completedCount, totalCount, item);
    }
}