/* Copyright (c) 2007-2008 MetaCarta, Inc., published under the Clear BSD
 * license.  See http://svn.openlayers.org/trunk/openlayers/license.txt for the
 * full text of the license. */

/**
 * LayerSwitcherPlus: it hopefully doesn't suck
 */


/** 
 * @requires OpenLayers/Control.js
 */

/**
 * Class: OpenLayers.Control.LayerSwitcher
 * The LayerSwitcher control displays a table of contents for the map. This 
 * allows the user interface to switch between BaseLasyers and to show or hide
 * Overlays. By default the switcher is shown minimized on the right edge of 
 * the map, the user may expand it by clicking on the handle.
 *
 * To create the LayerSwitcher outside of the map, pass the Id of a html div 
 * as the first argument to the constructor.
 * 
 * Inherits from:
 *  - <OpenLayers.Control>
 */
OpenLayers.Control.LayerSwitcherPlus = 
  OpenLayers.Class(OpenLayers.Control, {
    /**
     * Property: styles
     * {Array(Object)} An arry of styles which can be applied to layers
     */
    styles: null,

    style_rows: 5,

    style_columns: 5,



    /**  
     * Property: layerStates 
     * {Array(Object)} Basically a copy of the "state" of the map's layers 
     *     the last time the control was drawn. We have this in order to avoid
     *     unnecessarily redrawing the control.
     */
    layerStates: null,
    

  // DOM Elements
  
    /**
     * Property: layersDiv
     * {DOMElement} 
     */
    layersDiv: null,
    
    /** 
     * Property: baseLayersDiv
     * {DOMElement}
     */
    baseLayersDiv: null,

    /** 
     * Property: baseLayers
     * {Array(<OpenLayers.Layer>)}
     */
    baseLayers: null,
    
    
    /** 
     * Property: dataLbl
     * {DOMElement} 
     */
    dataLbl: null,
    
    /** 
     * Property: dataLayersDiv
     * {DOMElement} 
     */
    dataLayersDiv: null,

    /** 
     * Property: dataLayers
     * {Array(<OpenLayers.Layer>)} 
     */
    dataLayers: null,


    /** 
     * Property: minimizeDiv
     * {DOMElement} 
     */
    minimizeDiv: null,

    /** 
     * Property: maximizeDiv
     * {DOMElement} 
     */
    maximizeDiv: null,
    
    /**
     * APIProperty: ascending
     * {Boolean} 
     */
    ascending: true,
 
    /**
     * Constructor: OpenLayers.Control.LayerSwitcher
     * 
     * Parameters:
     * options - {Object}
     */
    initialize: function(options) {
        OpenLayers.Control.prototype.initialize.apply(this, arguments);
        this.layerStates = [];
    },

    /**
     * Method: styleMapToCSS
     *
     * Parameters:
     * styleMap {OpenLayers.StyleMap}
     *
     * Returns:
     * {Object} An object with css properties and values that can
     *    be applied to an element
     *
     */
    styleMapToCSS: function(styleMap) {
        css = new Object;
        default_style = styleMap.styles['default'].defaultStyle;
                                
        if (default_style['fillColor'] == 'transparent' && 
          typeof default_style['externalGraphic'] != 'undefined') {
          css['background-image'] = 'url('+default_style['externalGraphic']+')';
          css['background-repeat'] = 'no-repeat';
          css['background-color'] = 'transparent';
          css['width'] = default_style['pointRadius']*2;
          css['height'] = default_style['pointRadius']*2;
        }
        else {
          css['background-color'] = default_style['fillColor'];
        }
        if(default_style.strokeWidth > 0) {
          css['border-color'] = default_style['strokeColor'];
        }
        return css;
    },

    chooseStyle: function() {
        this.layer.styleMap = this.styleMap;
        $(this.styleDiv.style_holder).remove();
        $(this.styleDiv).css(this.styleDiv.ls.styleMapToCSS(this.styleMap));
        delete this.styleDiv.style_holder;
        this.layer.redraw();
    },

    /**
     * Method: toggleStyleChooser
     * 
     * Called when the a legend graphic or block is clicked, this
     * makes the styleChooser and makes it visible.
     */
    toggleStyleChooser: function() {
        if(typeof this.style_holder != 'undefined') {
          $(this.style_holder).remove();
          delete this.style_holder;
          return;
        }
        style_holder = document.createElement('div');
        style_holder.setAttribute('class', 'style_holder');
        position = $(this).position();
        for(style in this.ls.styles) {
          style_div = document.createElement('div');
          
          /**
           * Assign lots of pointers to the styleDiv
           * so that onclick it can still look up the chain.
           * These should be simplified to just the last line.
           */
          style_div.styleMap = this.ls.styles[style];
          style_div.style_name = style;
          style_div.layer = this.layer;
          style_div.styleDiv = this;

          style_css = this.ls.styleMapToCSS(this.ls.styles[style]);
          $(style_div).css(style_css);

          $(style_div).click(chooseStyle);
          style_div.setAttribute('class', 'styleDiv');
          // Make sure that the element is visible even though empty
          style_div.innerHTML = '&nbsp;';
          style_holder.appendChild(style_div);
        }
        this.parentNode.appendChild(style_holder);
        width = $(style_holder).width();
        $(style_holder).css('left',  position.left - width - 4);
        $(style_holder).css('top', position.top - 1);
        this.style_holder = style_holder;
    },
    /**
     * APIMethod: destroy 
     */    
    destroy: function() {
        
        OpenLayers.Event.stopObservingElement(this.div);

        OpenLayers.Event.stopObservingElement(this.minimizeDiv);
        OpenLayers.Event.stopObservingElement(this.maximizeDiv);

        //clear out layers info and unregister their events 
        this.clearLayersArray("base");
        this.clearLayersArray("data");
        
        this.map.events.un({
            "addlayer": this.redraw,
            "changelayer": this.redraw,
            "removelayer": this.redraw,
            "changebaselayer": this.redraw,
            scope: this
        });
        
        OpenLayers.Control.prototype.destroy.apply(this, arguments);
    },

    /** 
     * Method: setMap
     *
     * Properties:
     * map - {<OpenLayers.Map>} 
     */
    setMap: function(map) {
        OpenLayers.Control.prototype.setMap.apply(this, arguments);

        this.map.events.on({
            "addlayer": this.redraw,
            "changelayer": this.redraw,
            "removelayer": this.redraw,
            "changebaselayer": this.redraw,
            scope: this
        });
    },

    /**
     * Method: draw
     *
     * Returns:
     * {DOMElement} A reference to the DIV DOMElement containing the 
     *     switcher tabs.
     */  
    draw: function() {
        OpenLayers.Control.prototype.draw.apply(this);

        // create layout divs
        this.loadContents();

        // set mode to minimize
        if(!this.outsideViewport) {
            this.minimizeControl();
        }

        // populate div with current info
        this.redraw();    

        return this.div;
    },

    /** 
     * Method: clearLayersArray
     * User specifies either "base" or "data". we then clear all the
     *     corresponding listeners, the div, and reinitialize a new array.
     * 
     * Parameters:
     * layersType - {String}  
     */
    clearLayersArray: function(layersType) {
        var layers = this[layersType + "Layers"];
        if (layers) {
            for(var i=0, len=layers.length; i<len ; i++) {
                var layer = layers[i];
                OpenLayers.Event.stopObservingElement(layer.inputElem);
                OpenLayers.Event.stopObservingElement(layer.labelSpan);
            }
        }
        this[layersType + "LayersDiv"].innerHTML = "";
        this[layersType + "Layers"] = [];
    },


    /**
     * Method: checkRedraw
     * Checks if the layer state has changed since the last redraw() call.
     * 
     * Returns:
     * {Boolean} The layer state changed since the last redraw() call. 
     */
    checkRedraw: function() {
        var redraw = false;
        if ( !this.layerStates.length ||
             (this.map.layers.length != this.layerStates.length) ) {
            redraw = true;
        } else {
            for (var i=0, len=this.layerStates.length; i<len; i++) {
                var layerState = this.layerStates[i];
                var layer = this.map.layers[i];
                if ( (layerState.name != layer.name) || 
                     (layerState.inRange != layer.inRange) || 
                     (layerState.id != layer.id) || 
                     (layerState.visibility != layer.visibility) ) {
                    redraw = true;
                    break;
                }    
            }
        }    
        return redraw;
    },

    /** 
     * Method: redraw
     * Goes through and takes the current state of the Map and rebuilds the
     *     control to display that state. Groups base layers into a 
     *     radio-button group and lists each data layer with a checkbox.
     *
     * Returns: 
     * {DOMElement} A reference to the DIV DOMElement containing the control
     */  
    redraw: function() {
        //if the state hasn't changed since last redraw, no need 
        // to do anything. Just return the existing div.
        if (!this.checkRedraw()) { 
            return this.div; 
        } 

        //clear out previous layers 
        this.clearLayersArray("base");
        this.clearLayersArray("data");
        
        var containsOverlays = false;
        var containsBaseLayers = false;
        
        // Save state -- for checking layer if the map state changed.
        // We save this before redrawing, because in the process of redrawing
        // we will trigger more visibility changes, and we want to not redraw
        // and enter an infinite loop.
        var len = this.map.layers.length;
        this.layerStates = new Array(len);
        for (var i=0; i <len; i++) {
            var layer = this.map.layers[i];
            this.layerStates[i] = {
                'name': layer.name, 
                'visibility': layer.visibility,
                'inRange': layer.inRange,
                'id': layer.id
            };
        }    

        var layers = this.map.layers.slice();
        if (!this.ascending) { layers.reverse(); }
        for(var i=0, len=layers.length; i<len; i++) {
            var layer = layers[i];
            var baseLayer = layer.isBaseLayer;

            if (layer.displayInLayerSwitcher) {

                if (baseLayer) {
                    containsBaseLayers = true;
                } else {
                    containsOverlays = true;
                }    

                // only check a baselayer if it is *the* baselayer, check data
                //  layers if they are visible
                var checked = (baseLayer) ? (layer == this.map.baseLayer)
                                          : layer.getVisibility();
    
                // create input element
                var inputElem = document.createElement("input");
                inputElem.id = this.id + "_input_" + layer.name;
                inputElem.name = (baseLayer) ? "baseLayers" : layer.name;
                inputElem.type = (baseLayer) ? "radio" : "checkbox";
                inputElem.value = layer.name;
                inputElem.checked = checked;
                inputElem.defaultChecked = checked;

                if (!baseLayer && !layer.inRange) {
                    inputElem.disabled = true;
                }
                var context = {
                    'inputElem': inputElem,
                    'layer': layer,
                    'layerSwitcher': this
                };
                OpenLayers.Event.observe(inputElem, "mouseup", 
                    OpenLayers.Function.bindAsEventListener(this.onInputClick,
                                                            context)
                );
                
                // create span
                var labelSpan = document.createElement("span");
                labelSpan.setAttribute('class', 'labelSpan');
                if(baseLayer) {
                  labelSpan.setAttribute('class', 'baseLayer');
                }
                if (!baseLayer && !layer.inRange) {
                    labelSpan.style.color = "gray";
                }
                labelSpan.innerHTML = layer.title;
                labelSpan.style.verticalAlign = (baseLayer) ? "bottom" 
                                                            : "baseline";
                OpenLayers.Event.observe(labelSpan, "click", 
                    OpenLayers.Function.bindAsEventListener(this.onInputClick,
                                                            context)
                );
                // create line break
                // TODO: remove this
                var br = document.createElement("br");
                                
                if(layer.styleMap && !layer.isBaseLayer) {
                                                      
                  var styleDiv = document.createElement("div");
                  styleDiv.setAttribute('class', 'styleDiv');
                  styleDiv.innerHTML = '&nbsp;';
                  // TODO: these are dirty hacks, must be improved
                  styleDiv.layer = layer;
                  styleDiv.ls = this;
                  css = this.styleMapToCSS(layer.styleMap);
                  // TODO: make styleDiv look clickable
                  // TODO: move this functionality into another control
                  $(styleDiv).click(this.toggleStyleChooser);
                  $(styleDiv).css(css);
                }
                else {
                  styleDiv = false; // this is mostly so that in looping, they won't be reused
                }
                
                var groupArray = (baseLayer) ? this.baseLayers
                                             : this.dataLayers;
                groupArray.push({
                    'layer': layer,
                    'inputElem': inputElem,
                    'labelSpan': labelSpan
                });

                layerDiv = document.createElement('div');
                layerDiv.setAttribute('class', 'layerDiv');
    
                var groupDiv = (baseLayer) ? this.baseLayersDiv
                                           : this.dataLayersDiv;
                layerDiv.appendChild(inputElem);
                layerDiv.appendChild(labelSpan);
                if(styleDiv != false) {
                  layerDiv.appendChild(styleDiv);
                }
                groupDiv.appendChild(layerDiv);
            }
        }

        // if no overlays, dont display the overlay label
        this.dataLbl.style.display = (containsOverlays) ? "" : "none";        
        
        // if no baselayers, dont display the baselayer label
        this.baseLbl.style.display = (containsBaseLayers) ? "" : "none";        

        return this.div;
    },

    /** 
     * Method:
     * A label has been clicked, check or uncheck its corresponding input
     * 
     * Parameters:
     * e - {Event} 
     *
     * Context:  
     *  - {DOMElement} inputElem
     *  - {<OpenLayers.Control.LayerSwitcher>} layerSwitcher
     *  - {<OpenLayers.Layer>} layer
     */

    onInputClick: function(e) {

        if (!this.inputElem.disabled) {
            if (this.inputElem.type == "radio") {
                this.inputElem.checked = true;
                this.layer.map.setBaseLayer(this.layer);
            } else {
                this.inputElem.checked = !this.inputElem.checked;
                this.layerSwitcher.updateMap();
            }
        }
        OpenLayers.Event.stop(e);
    },
    
    /**
     * Method: onLayerClick
     * Need to update the map accordingly whenever user clicks in either of
     *     the layers.
     * 
     * Parameters: 
     * e - {Event} 
     */
    onLayerClick: function(e) {
        this.updateMap();
    },


    /** 
     * Method: updateMap
     * Cycles through the loaded data and base layer input arrays and makes
     *     the necessary calls to the Map object such that that the map's 
     *     visual state corresponds to what the user has selected in 
     *     the control.
     */
    updateMap: function() {

        // set the newly selected base layer        
        for(var i=0, len=this.baseLayers.length; i<len; i++) {
            var layerEntry = this.baseLayers[i];
            if (layerEntry.inputElem.checked) {
                this.map.setBaseLayer(layerEntry.layer, false);
            }
        }

        // set the correct visibilities for the overlays
        for(var i=0, len=this.dataLayers.length; i<len; i++) {
            var layerEntry = this.dataLayers[i];   
            layerEntry.layer.setVisibility(layerEntry.inputElem.checked);
        }

    },

    /** 
     * Method: maximizeControl
     * Set up the labels and divs for the control
     * 
     * Parameters:
     * e - {Event} 
     */
    maximizeControl: function(e) {

        //HACK HACK HACK - find a way to auto-size this layerswitcher
        this.div.style.width = "20em";
        this.div.style.height = "";

        this.showControls(false);

        if (e != null) {
            OpenLayers.Event.stop(e);                                            
        }
    },
    
    /** 
     * Method: minimizeControl
     * Hide all the contents of the control, shrink the size, 
     *     add the maximize icon
     *
     * Parameters:
     * e - {Event} 
     */
    minimizeControl: function(e) {

        this.div.style.width = "0px";
        this.div.style.height = "0px";

        this.showControls(true);

        if (e != null) {
            OpenLayers.Event.stop(e);                                            
        }
    },

    /**
     * Method: showControls
     * Hide/Show all LayerSwitcher controls depending on whether we are
     *     minimized or not
     * 
     * Parameters:
     * minimize - {Boolean}
     */
    showControls: function(minimize) {

        this.maximizeDiv.style.display = minimize ? "" : "none";
        this.minimizeDiv.style.display = minimize ? "none" : "";

        this.layersDiv.style.display = minimize ? "none" : "";
    },
    
    /** 
     * Method: loadContents
     * Set up the labels and divs for the control
     */
    loadContents: function() {
        OpenLayers.Event.observe(this.div, "mouseup", 
            OpenLayers.Function.bindAsEventListener(this.mouseUp, this));
        OpenLayers.Event.observe(this.div, "click",
                      this.ignoreEvent);
        OpenLayers.Event.observe(this.div, "mousedown",
            OpenLayers.Function.bindAsEventListener(this.mouseDown, this));
        OpenLayers.Event.observe(this.div, "dblclick", this.ignoreEvent);


        // layers list div        
        this.layersDiv = document.createElement("div");
        this.layersDiv.setAttribute('class', 'layersDiv');
        this.layersDiv.id = this.id + "_layersDiv";

        // had to set width/height to get transparency in IE to work.
        // thanks -- http://jszen.blogspot.com/2005/04/ie6-opacity-filter-caveat.html
        //


        this.baseLbl = document.createElement("div");
        this.baseLbl.setAttribute('class', 'baseLbl');
        this.baseLbl.innerHTML = OpenLayers.i18n("baseLayer");
        
        this.baseLayersDiv = document.createElement("div");
        this.baseLayersDiv.setAttribute('class', 'baseLayersDiv');
        /*OpenLayers.Event.observe(this.baseLayersDiv, "click", 
            OpenLayers.Function.bindAsEventListener(this.onLayerClick, this));
        */
                     

        this.dataLbl = document.createElement("div");
        this.dataLbl.setAttribute('class', 'dataLbl');
        this.dataLbl.innerHTML = OpenLayers.i18n("overlays");
                
        this.dataLayersDiv = document.createElement("div");
        this.dataLayersDiv.setAttribute('class', 'dataLayersDiv');

        if (this.ascending) {
            this.layersDiv.appendChild(this.baseLbl);
            this.layersDiv.appendChild(this.baseLayersDiv);
            this.layersDiv.appendChild(this.dataLbl);
            this.layersDiv.appendChild(this.dataLayersDiv);
        } else {
            this.layersDiv.appendChild(this.dataLbl);
            this.layersDiv.appendChild(this.dataLayersDiv);
            this.layersDiv.appendChild(this.baseLbl);
            this.layersDiv.appendChild(this.baseLayersDiv);
        }    
 
        this.div.appendChild(this.layersDiv);

        var imgLocation = OpenLayers.Util.getImagesLocation();
        var sz = new OpenLayers.Size(18,18);        

        // maximize button div
        var img = imgLocation + 'layer-switcher-maximize.png';
        this.maximizeDiv = OpenLayers.Util.createAlphaImageDiv(
                                    "OpenLayers_Control_MaximizeDiv", 
                                    null, 
                                    sz, 
                                    img, 
                                    "absolute");
        this.maximizeDiv.setAttribute('class', 'maximizeDiv');
        this.maximizeDiv.style.display = "none";
        OpenLayers.Event.observe(this.maximizeDiv, "click", 
            OpenLayers.Function.bindAsEventListener(this.maximizeControl, this)
        );
        
        this.div.appendChild(this.maximizeDiv);

        // minimize button div
        var img = imgLocation + 'layer-switcher-minimize.png';
        var sz = new OpenLayers.Size(18,18);        
        this.minimizeDiv = OpenLayers.Util.createAlphaImageDiv(
                                    "OpenLayers_Control_MinimizeDiv", 
                                    null, 
                                    sz, 
                                    img, 
                                    "absolute");
        this.minimizeDiv.setAttribute('class', 'minimizeDiv');
        this.minimizeDiv.style.display = "none";
        OpenLayers.Event.observe(this.minimizeDiv, "click", 
            OpenLayers.Function.bindAsEventListener(this.minimizeControl, this)
        );

        this.div.appendChild(this.minimizeDiv);
    },
    
    /** 
     * Method: ignoreEvent
     * 
     * Parameters:
     * evt - {Event} 
     */
    ignoreEvent: function(evt) {
        OpenLayers.Event.stop(evt);
    },

    /** 
     * Method: mouseDown
     * Register a local 'mouseDown' flag so that we'll know whether or not
     *     to ignore a mouseUp event
     * 
     * Parameters:
     * evt - {Event}
     */
    mouseDown: function(evt) {
        this.isMouseDown = true;
        this.ignoreEvent(evt);
    },

    /** 
     * Method: mouseUp
     * If the 'isMouseDown' flag has been set, that means that the drag was 
     *     started from within the LayerSwitcher control, and thus we can 
     *     ignore the mouseup. Otherwise, let the Event continue.
     *  
     * Parameters:
     * evt - {Event} 
     */
    mouseUp: function(evt) {
        if (this.isMouseDown) {
            this.isMouseDown = false;
            this.ignoreEvent(evt);
        }
    },

    CLASS_NAME: "OpenLayers.Control.LayerSwitcherPlus"
});