/* Copyright (c) 2006-2007 MetaCarta, Inc., published under a modified BSD licence.
 * See http://svn.openlayers.org/trunk/openlayers/repository-license.txt
 * for the full text of the license. */


/**
 * @requires OpenLayers/Layer/Grid.js
 *
 * Class: OpenLayers.Layer.WFSGrid
 *
 * Inherits from:
 *  - <OpenLayers.Layer.Grid>
 */
OpenLayers.Layer.WFSGrid = OpenLayers.Class(OpenLayers.Layer.Grid, OpenLayers.Layer.Markers, {

    /**
     * APIProperty: isBaseLayer
     * {Boolean}
     */
    isBaseLayer: false,

    tileSize: new OpenLayers.Size(512,512),
    buffer: 0,
    layername: "WFS",
    type: "txt",

    /**
     * APIProperty: tileOrigin
     * {<OpenLayers.Pixel>}
     */
    tileOrigin: null,

    /**
     * Constructor: OpenLayers.Layer.WFSGrid
     *
     * Parameters:
     * name - {String}
     * url - {String}
     * params - {Object}
     * options - {Object} Hashtable of extra options to tag onto the layer
     */
    initialize: function(name, url, options) {
//    		alert(name);
        var newArguments = [];
        newArguments.push(name, url, {}, options);
        OpenLayers.Layer.Grid.prototype.initialize.apply(this, newArguments);
        OpenLayers.Layer.Markers.prototype.initialize.apply(this, newArguments);
    },

    /**
     * APIMethod:destroy
     */
    destroy: function() {
        // for now, nothing special to do here.
        OpenLayers.Layer.Grid.prototype.destroy.apply(this, arguments);
        OpenLayers.Layer.Markers.prototype.destroy.apply(this, arguments);
    },


    /**
     * APIMethod: clone
     *
     * Parameters:
     * obj - {Object}
     *
     * Returns:
     * {<OpenLayers.Layer.WFSGrid>} An exact clone of this <OpenLayers.Layer.WFSGrid>
     */
    clone: function (obj) {

        if (obj == null) {
            obj = new OpenLayers.Layer.WFSGrid(this.name,
                                           this.url,
                                           this.options);
        }

        //get all additions from superclasses
        obj = OpenLayers.Layer.Grid.prototype.clone.apply(this, [obj]);

        // copy/set any non-init, non-simple values here

        return obj;
    },

    /**
     * Method: getUrl
     *
     * Parameters:
     * bounds - {<OpenLayers.Bounds>}
     *
     * Returns:
     * {String} A string with the layer's url and parameters and also the
     *          passed-in bounds and appropriate tile size specified as
     *          parameters
     */
    getURL: function (bounds) {
       	//alert("bounds.left: " + bounds.left);
        bounds = this.adjustBounds(bounds);
        var res = this.map.getResolution();
       	//alert("bounds.left: " + bounds.left + "bounds.bottom: " + bounds.bottom + "res: " + res + "lon: " + this.tileOrigin.lon + "lat: " + this.tileOrigin.lat);
        var x = Math.round((bounds.left - this.tileOrigin.lon) / (res * this.tileSize.w));
        var y = Math.round((bounds.bottom - this.tileOrigin.lat) / (res * this.tileSize.h));
        var z = this.map.getZoom();
        var path = "/" + this.layername + "/" + z + "/" + x + "/" + y + "." + this.type;
        var url = this.url;
        if (url instanceof Array) {
            url = this.selectUrl(path, url);
        }
        return url + path;
    },

    moveTo:function(bounds, zoomChanged, dragging) {
    	//alert(bounds);
        OpenLayers.Layer.Grid.prototype.moveTo.apply(this, arguments);
        OpenLayers.Layer.Markers.prototype.moveTo.apply(this, arguments);
    },


    /**
     * Method: addTile
     * addTile creates a tile, initializes it, and adds it to the layer div.
     *
     * Parameters:
     * bounds - {<OpenLayers.Bounds>}
     *
     * Returns:
     * {<OpenLayers.Tile.Image>} The added OpenLayers.Tile.Image
     */
    addTile:function(bounds,position) {
    	//alert(bounds);
        return new OpenLayers.Tile.WFS(this, position, bounds,
                                         null, this.tileSize);
    },


    /**
     * APIMethod: setMap
     * When the layer is added to a map, then we can fetch our origin
     *    (if we don't have one.)
     *
     * Parameters:
     * map - {<OpenLayers.Map>}
     */
    setMap: function(map) {
        OpenLayers.Layer.Grid.prototype.setMap.apply(this, arguments);
        if (!this.tileOrigin) {
            this.tileOrigin = new OpenLayers.LonLat(this.map.maxExtent.left,
                                                this.map.maxExtent.bottom);
        }
    },

    CLASS_NAME: "OpenLayers.Layer.WFSGrid"
});