var map, srs, extent;

require(["esri/map",
         "esri/geometry/Extent",
         "esri/geometry/Point",
         "esri/SpatialReference",
         "dojo/domReady!"],
        function (Map, Extent, Point, SpatialReference) {
            dojo.declare("WMSLayer", esri.layers.TiledMapServiceLayer, {
                //construct the layer
                constructor: function () {
                
                    // res = 2 * math.pi * 6378137) / (256 * 2**zoom)
                    //scale = (res * dpi) / 0.0254
                    //layer provides tile info                    
                    this.tileInfo = new esri.layers.TileInfo({
                        "rows": 256, "cols"  : 256,
                        "dpi" :  96, "format": "PNG8",
                        "compressionQuality" : 0,
                        "origin"             : { "x"   : -20037508.342787, "y": 20037508.342787 },
                        "spatialReference"   : { "wkid": 900913 },

                        "lods": [   { "level": 0, "resolution": 156543.033928, "scale": 591657527.591555 },
                                    { "level": 1, "resolution": 78271.5169639999, "scale": 295828763.795777 },
                                    { "level": 2, "resolution": 39135.7584820001, "scale": 147914381.897889 },
                                    { "level": 3, "resolution": 19567.8792409999, "scale": 73957190.948944 },
                                    { "level": 4, "resolution": 9783.93962049996, "scale": 36978595.474472 },
                                    { "level": 5, "resolution": 4891.96981024998, "scale": 18489297.737236 },
                                    { "level": 6, "resolution": 2445.98490512499, "scale": 9244648.868618 },
                                    { "level": 7, "resolution": 1222.99245256249, "scale": 4622324.434309 },
                                    { "level": 8, "resolution": 611.49622628138, "scale": 2311162.217155 },
                                    { "level": 9, "resolution": 305.748113140558, "scale": 1155581.108577 },
                                    { "level": 10, "resolution": 152.874056570411, "scale": 577790.554289 },
                                    { "level": 11, "resolution": 76.4370282850732, "scale": 288895.277144 },
                                    { "level": 12, "resolution": 38.2185141425366, "scale": 144447.638572 },
                                    { "level": 13, "resolution": 19.1092570712683, "scale": 72223.819286 },
                                    { "level": 14, "resolution": 9.55462853563415, "scale": 36111.909643 },
                                    { "level": 15, "resolution": 4.77731426794937, "scale": 18055.954822 },
                                    { "level": 16, "resolution": 2.38865713397468, "scale": 9027.977411 },
                                    { "level": 17, "resolution": 1.19432856685505, "scale": 4513.988705 },
                                    { "level": 18, "resolution": 0.59716428337097172, "scale": 2256.9943526 },
                                    { "level": 19, "resolution": 0.2985821416854858, "scale": 1128.497176344 },
                                    { "level": 20, "resolution": 0.1492910708694458, "scale": 564.248588172 },
                                    { "level": 21, "resolution": 0.0746455354347229, "scale": 282.124294086 }
                        ]

                    });

                    //layer provides initial extent & full extent.
                    this.fullExtent = new esri.geometry.Extent(-20037508.34,-20037508.34, 20037508.34, 20037508.34,
                          new esri.SpatialReference({ "wkid": 900913 }));

         
                    //set layer loaded property and fire onLoad event
                    this.loaded = true;
                    this.onLoad(this);
                },

         
                getTileUrl: function (level, row, col) {

                    var mercBounds = mercator.tileBounds(row, col, level);
                    url = "http://services.cuzk.cz/wms/wms.asp?&LAYERS=KN&REQUEST=GetMap&SERVICE=WMS&VERSION=1.3.0&FORMAT=image/png&TRANSPARENT=TRUE&STYLES=&CRS=EPSG:900913&WIDTH=256&HEIGHT=256&BBOX="+
                        Math.abs(mercBounds[1]) + "," +  Math.abs(mercBounds[2]) + "," + Math.abs(mercBounds[3]) + "," +   Math.abs(mercBounds[0]);
                    return url;
                }
            });

            map = new Map("map", {
                center: [15.376, 49.789],
                zoom: 17,
                basemap: 'topo'
            });

            layer1 = new WMSLayer();
            map.addLayer(layer1);

           
        });