/**
 * Created by WEIWEI on 2017/10/10.
 */
(function($){
    function Preload(imgs,options){
    //    瀹氫箟
        this.imgs = (typeof imgs === 'string')?[imgs]:imgs;//淇濊瘉imgs涓烘暟缁
        this.opts = $.extend({},Preload.DEFAULTS,options)//鐢╫ptions鍘昏鐩栭粯璁ゅ€
    //    璋冪敤鍔犺浇鏂规硶
        if(this.opts.order == "ordered"){//鏈夊簭鍔犺浇
            this._orderedLoad();
        }else {
            this._unOrdered();//鏃犲簭鍔犺浇
        }
    //    Preload鐨勯粯璁ゅ€
        Preload.DEFAULTS = {
            order:"ordered",//榛樿鏈夊簭鍔犺浇
            each:null,//姣忓紶鍥剧墖鍔犺浇瀹屾垚鍚庤皟鐢ㄦ鏂规硶
            all:null//鍥剧墖鍔犺浇瀹屾瘯璋冪敤姝ゆ柟娉
        };
    }
    //    鏈夊簭鍔犺浇
        Preload.prototype._orderedLoad = function(){
            var imgs = this.imgs;
            var opts = this.opts;
            var count = 0;
            var len = imgs.length;

            function load(){
                var imgObj = new Image();
                imgObj.src = imgs[count];
                $(imgObj).on("load error",function(){
                    if(count > len-1){
                        opts.all && opts.all();//鍏ㄩ儴鍔犺浇瀹屾垚
                    }else {
                        opts.each && opts.each(count);
                        load();
                    }
                    count ++ ;
                })
            }
            load();
        };
    //    鏃犻渶鍔犺浇
        Preload.prototype._unOrdered = function(){
            var imgs = this.imgs;
            var opts = this.opts;
            var count = 0; // 璁℃暟鍣
            var len = imgs.length;
            $.each(imgs, function (index, src) {
                if (typeof src != 'string') { // src璺緞涓嶆槸瀛楃涓插垯涓嶅線涓嬫墽琛
                    console.error('璇蜂紶鍏ュ瓧绗︿覆褰㈠紡鐨勫浘鐗囪矾寰?);
                    return;
                }
                var imgObj = new Image();
                imgObj.src = src;

                $(imgObj).on('load error', function () {
                    opts.each && opts.each(count); // 棣栧厛鍒ゆ柇each灞炴€ф槸鍚﹀瓨鍦紝瀛樺湪鍒欐墽琛

                    if (count >= len -1) {
                        opts.all && opts.all(); // 鍚岀悊锛屼笉杩囨槸鍦ㄥ浘鐗囧姞杞藉畬鎴愪箣鍚庤皟鐢
                    }

                    count++;
                });
            });
        };


    //     鎸傝浇鍒癹Query瀵硅薄涓
    $.extend({
        preload: function (imgs, opts) { // 鍛藉悕涓簆reload
            new Preload(imgs, opts);
        }
    });
})(jQuery);