/**
 * @requires OpenLayers/Layer/Grid.js
 * @requires OpenLayers/Tile/Image.js
 */

/**
 * Class: OpenLayers.Layer.WMTS
 * Instances of OpenLayers.Layer.WMS are used to display data from OGC Web
 *     Mapping Tiling Services. Create a new WMTS layer with the <OpenLayers.Layer.WMTS>
 *     constructor.
 * 
 * Inherits from:
 *  - <OpenLayers.Layer.Grid>
 *
 * @Author Ignacio Gámez Ramírez
 */
OpenLayers.Layer.WMTS = OpenLayers.Class(OpenLayers.Layer.GridOGC, {

    /**
     * Constant: DEFAULT_PARAMS
     * {Object} Hashtable of default parameter key/value pairs 
     */
    DEFAULT_PARAMS: { service: "WMTS",
                      version: "1.1.1",
                      request: "GETTILE",
                      style: "default",
                      exceptions: "application/vnd.ogc.se_inimage",
                      format: "image/png"
                     },
    
    /**
     * Property: reproject
     * *Deprecated*. See http://trac.openlayers.org/wiki/SphericalMercator
     * for information on the replacement for this functionality. 
     * {Boolean} Try to reproject this layer if its coordinate reference system
     *           is different than that of the base layer.  Default is true.  
     *           Set this in the layer options.  Should be set to false in 
     *           most cases.
     */
    reproject: false,
 
    /**
     * APIProperty: isBaseLayer
     * {Boolean} Default is true for WMS layer
     */
    isBaseLayer: true,
    
    /**
     * APIProperty: encodeBBOX
     * {Boolean} Should the BBOX commas be encoded? The WMS spec says 'no', 
     * but some services want it that way. Default false.
     */
    encodeBBOX: false,
 
    /**
     * Constructor: OpenLayers.Layer.WMS
     * Create a new WMS layer object
     *
     * Example:
     * (code)
     * var wms = new OpenLayers.Layer.WMS("NASA Global Mosaic",
     *                                    "http://wms.jpl.nasa.gov/wms.cgi", 
     *                                    {layers: "modis,global_mosaic"});
     * (end)
     *
     * Parameters:
     * name - {String} A name for the layer
     * url - {String} Base url for the WMS
     *                (e.g. http://wms.jpl.nasa.gov/wms.cgi)
     * params - {Object} An object with key/value pairs representing the
     *                   GetMap query string parameters and parameter values.
     * options - {Ojbect} Hashtable of extra options to tag onto the layer
     */
    initialize: function(name, url, params, options) {
        var newArguments = [];
        //uppercase params
        params = OpenLayers.Util.upperCaseObject(params);
        newArguments.push(name, url, params, options);
        OpenLayers.Layer.GridOGC.prototype.initialize.apply(this, newArguments);
        OpenLayers.Util.applyDefaults(
                       this.params, 
                       OpenLayers.Util.upperCaseObject(this.DEFAULT_PARAMS)
                       );


        //layer is transparent        
        if (this.params.TRANSPARENT && 
            this.params.TRANSPARENT.toString().toLowerCase() == "true") {
            
            // unless explicitly set in options, make layer an overlay
            if ( (options == null) || (!options.isBaseLayer) ) {
                this.isBaseLayer = false;
            } 
            
            // jpegs can never be transparent, so intelligently switch the 
            //  format, depending on teh browser's capabilities
            if (this.params.FORMAT == "image/jpeg") {
                this.params.FORMAT = OpenLayers.Util.alphaHack() ? "image/gif"
                                                                 : "image/png";
            }
        }

    },    

    /**
     * Method: destroy
     * Destroy this layer
     */
    destroy: function() {
        // for now, nothing special to do here. 
        OpenLayers.Layer.GridOGC.prototype.destroy.apply(this, arguments);  
    },

    
    /**
     * Method: clone
     * Create a clone of this layer
     *
     * Returns:
     * {<OpenLayers.Layer.WMS>} An exact clone of this layer
     */
    clone: function (obj) {
        
        if (obj == null) {
            obj = new OpenLayers.Layer.WMTS(this.name,
                                           this.url,
                                           this.params,
                                           this.options);
        }

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

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

        return obj;
    },    
    
    /**
     * Method: getURL
     * Return a GetMap query string for this layer
     *
     * Parameters:
     * bounds - {<OpenLayers.Bounds>} A bounds representing the bbox for the
     *                                request.
     *
     * 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) {
    
      bounds = this.adjustBounds(bounds);
      var bbox=this.maxExtent;
      //var anchoTotal = bbox.right - bbox.left;
      //var altoTotal = bbox.bottom -bbox.top;
      var anchoTileX = bounds.right - bounds.left;
      var anchoTileY = bounds.top - bounds.bottom;
      var zoom = this.map.getZoom();
      var actualScale = Math.round(this.resolutions[zoom] / 0.00028);          
      var tileX = Math.round((bounds.left - bbox.left)/anchoTileX);
      var tileY = Math.round((bbox.top - bounds.top)/anchoTileY);
      
      /* DEBUGGER */
      /*
      var comentarios = document.getElementById('Comentarios');
      comentarios.innerHTML = "<b>zoom:</b> "+ zoom+"<b></br>Resolutions:</b>"+this.map.getResolution()+"<b></br>MAX_EXTENT:</b>"+bbox+"<b></br>bounds:</b>"+bounds+"</br><b>tileROW</b>:"+tileY+"</br><b>tileCOL:</b>"+tileX;
      */
      var newParams = {
            'SCALE': actualScale,
            'TILEROW': tileY,
            'TILECOL': tileX
        };
      var requestString = this.getFullRequestString(newParams);
      return requestString;
    
    },

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

    /**
     * APIMethod: mergeNewParams
     * Catch changeParams and uppercase the new params to be merged in
     *     before calling changeParams on the super class.
     * 
     *     Once params have been changed, we will need to re-init our tiles.
     * 
     * Parameters:
     * newParams - {Object} Hashtable of new params to use
     */
    mergeNewParams:function(newParams) {
        var upperParams = OpenLayers.Util.upperCaseObject(newParams);
        var newArguments = [upperParams];
        return OpenLayers.Layer.GridOGC.prototype.mergeNewParams.apply(this, 
                                                             newArguments);
    },

    /** 
     * Method: getFullRequestString
     * Combine the layer's url with its params and these newParams. 
     *   
     *     Add the SRS parameter from projection -- this is probably
     *     more eloquently done via a setProjection() method, but this 
     *     works for now and always.
     *
     * Parameters:
     * newParams - {Object}
     * altUrl - {String} Use this as the url instead of the layer's url
     * 
     * Returns:
     * {String} 
     */
    getFullRequestString:function(newParams, altUrl) {
        var projectionCode = this.map.getProjection();
        this.params.SRS = (projectionCode == "none") ? null : projectionCode;

        return OpenLayers.Layer.GridOGC.prototype.getFullRequestString.apply(
                                                    this, arguments);
    },
    
    // IGámez: METODOS ESPECIFICOS DEL SERVICIO WEB MAP SERVICE TILING
    // IMPORTANTE: Hay que añadir las distintas resoluciones despues de 
    // insertar la capa en el mapa porque en dicho momento, el objeto 'map'
    // recalcula las resoluciones y modifica dichos valores.
    setResolutions:function(resolutions){
      this.resolutions = resolutions;
    },
    
    setMaxExtent:function(maxExtent){
    this.maxExtent = maxExtent;
    },
    
    CLASS_NAME: "OpenLayers.Layer.WMTS"
});