define([
    "dojo/_base/declare",
    "dijit/Dialog",
    "dijit/_WidgetBase",
    "dijit/_TemplatedMixin",
    "esri/layers/TiledMapServiceLayer",
    "esri/SpatialReference",
    "esri/geometry/Extent",
    "esri/layers/TileInfo"], 
    function (declare,
              Dialog,
              _WidgetBase,
              _TemplatedMixin,
              TiledMapServiceLayer,
              SpatialReference,
              Extent,
              TileInfo) {
    return declare("GoogleLayer", TiledMapServiceLayer, {
        // create WMTSLayer by extending esri.layers.TiledMapServiceLayer
        type: "myLayer",
        tileType: "png",
        constructor: function (options) {
            this.spatialReference = new SpatialReference({
                wkid: 102100
            });
            if(options){
                this.baseUrl = options.url || this.baseUrl;
            }
            this.initialExtent = new Extent(-20037508.342787, -20037508.342787, 20037508.342787, 20037508.342787, this.spatialReference);
            this.fullExtent = new Extent(-20037508.342787, -20037508.342787, 20037508.342787, 20037508.342787, this.spatialReference);
            this.tileInfo = new TileInfo({
                "dpi": "90.71428571427429",
                "format": "image/png",
                "compressionQuality": 0,
                "spatialReference": {
                    "wkid": "3857"
                },
                "rows": 256,
                "cols": 256,
                "origin": {
                    "x": -20037508.342787,
                    "y": 20037508.342787
                },
                // Scales in DPI 96
                "lods": [{
                    "level": 0, "scale": 591657527.591555, "resolution": 156543.033928
                }, {
                    "level": 1, "scale": 295828763.795777, "resolution": 78271.5169639999
                }, {
                    "level": 2, "scale": 147914381.897889, "resolution": 39135.7584820001
                }, {
                    "level": 3, "scale": 73957190.948944, "resolution": 19567.8792409999
                }, {
                    "level": 4, "scale": 36978595.474472, "resolution": 9783.93962049996
                }, {
                    "level": 5, "scale": 18489297.737236, "resolution": 4891.96981024998
                }, {
                    "level": 6, "scale": 9244648.868618, "resolution": 2445.98490512499
                }, {
                    "level": 7, "scale": 4622324.434309, "resolution": 1222.99245256249
                }, {
                    "level": 8, "scale": 2311162.217155, "resolution": 611.49622628138
                }, {
                    "level": 9, "scale": 1155581.108577, "resolution": 305.748113140558
                }, {
                    "level": 10, "scale": 577790.554289, "resolution": 152.874056570411
                }, {
                    "level": 11, "scale": 288895.277144, "resolution": 76.4370282850732
                }, {
                    "level": 12, "scale": 144447.638572, "resolution": 38.2185141425366
                }, {
                    "level": 13, "scale": 72223.819286, "resolution": 19.1092570712683
                }, {
                    "level": 14, "scale": 36111.909643, "resolution": 9.55462853563415
                }, {
                    "level": 15, "scale": 18055.954822, "resolution": 4.77731426794937
                }, {
                    "level": 16, "scale": 9027.977411, "resolution": 2.38865713397468
                }, {
                    "level": 17, "scale": 4513.988705, "resolution": 1.19432856685505
                }, {
                    "level": 18, "scale": 2256.994353, "resolution": 0.597164283559817
                }, {
                    "level": 19, "scale": 1128.497176, "resolution": 0.298582141647617
                }]
            });
            this.loaded = true;
            this.onLoad(this);
        },
        getTileUrl: function (level, row, col) {
            // The tile images are stored using hex values on disk.
            var x = 'C' + this.zeroPad(col, 8, 16);
            var y = 'R' + this.zeroPad(row, 8, 16);
            // 瓦片路径中小写转大写，解决3级以上地图http请求识别不到的bug
            if(level > 3){
                x = x.toUpperCase();
                y = y.toUpperCase();
            }
            var z = 'L' + this.zeroPad(level, 2, 10); // 改用10进制，否则第10级，转换后变为0a，无法找到对应级别切片
            var url = ampURL + '/' + z + '/' + y + '/' + x + '.' + this.tileType;
            return url;
        },
        /**
         * Method: zeroPad
         * Create a zero padded string optionally with a radix for casting numbers.
         *
         * Parameters:
         * num - {Number} The number to be zero padded.
         * len - {Number} The length of the string to be returned.
         * radix - {Number} An integer between 2 and 36 specifying the base to use
         *     for representing numeric values.
         */
        zeroPad: function(num, len, radix) {
            var str = num.toString(radix || 10);
            while (str.length < len) {
                str = "0" + str;
            }
            return str;
        }
    });
});