/**
* @name MarkerClusterer
* @version 1.0
* @author Xiaoxi Wu
* @copyright (c) 2009 Xiaoxi Wu
* @fileoverview
* This javascript library creates and manages per-zoom-level 
* clusters for large amounts of markers (hundreds or thousands).
* This library was inspired by the <a href="http://www.maptimize.com">
* Maptimize</a> hosted clustering solution.
* <br /><br/>
* <b>How it works</b>:<br/>
* The <code>MarkerClusterer</code> will group markers into clusters according to
* their distance from a cluster's center. When a marker is added,
* the marker cluster will find a position in all the clusters, and 
* if it fails to find one, it will create a new cluster with the marker.
* The number of markers in a cluster will be displayed
* on the cluster marker. When the map viewport changes,
* <code>MarkerClusterer</code> will destroy the clusters in the viewport 
* and regroup them into new clusters.
*
*/

/*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
*     http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/


/**
* @name MarkerClustererOptions
* @class This class represents optional arguments to the {@link MarkerClusterer}
* constructor.
* @property {Number} [maxZoom] The max zoom level monitored by a
* marker cluster. If not given, the marker cluster assumes the maximum map
* zoom level. When maxZoom is reached or exceeded all markers will be shown
* without cluster.
* @property {Number} [gridSize=60] The grid size of a cluster in pixel. Each
* cluster will be a square. If you want the algorithm to run faster, you can set
* this value larger.
* @property {Array of MarkerStyleOptions} [styles]
* Custom styles for the cluster markers.
* The array should be ordered according to increasing cluster size,
* with the style for the smallest clusters first, and the style for the
* largest clusters last.
*/

/**
* @name MarkerStyleOptions
* @class An array of these is passed into the {@link MarkerClustererOptions}
* styles option.
* @property {String} [url] Image url.
* @property {Number} [height] Image height.
* @property {Number} [height] Image width.
* @property {Array of Number} [opt_anchor] Anchor for label text, like [24, 12]. 
*    If not set, the text will align center and middle.
* @property {String} [opt_textColor="black"] Text color.
*/

/**
* Creates a new MarkerClusterer to cluster markers on the map.
*
* @constructor
* @param {GMap2} map The map that the markers should be added to.
* @param {Array of GMarker} opt_markers Initial set of markers to be clustered.
* @param {MarkerClustererOptions} opt_opts A container for optional arguments.
*/
function MarkerClusterer(map, opt_markers, opt_opts) {
    // private members
    var clusters_ = [];
    var map_ = map;
    var maxZoom_ = null;
    var me_ = this;
    var gridSize_ = 60;
    var sizes = [53, 56, 66, 78, 90];
    var styles_ = [];
    var leftMarkers_ = [];
    var mcfn_ = null;

    var i = 0;
    for (i = 1; i <= 5; ++i) {
        styles_.push({
            'url': "http://gmaps-utility-library.googlecode.com/svn/trunk/markerclusterer/images/m" + i + ".png",
            'height': sizes[i - 1],
            'width': sizes[i - 1]
        });
    }

    if (typeof opt_opts === "object" && opt_opts !== null) {
        if (typeof opt_opts.gridSize === "number" && opt_opts.gridSize > 0) {
            gridSize_ = opt_opts.gridSize;
        }
        if (typeof opt_opts.maxZoom === "number") {
            maxZoom_ = opt_opts.maxZoom;
        }
        if (typeof opt_opts.styles === "object" && opt_opts.styles !== null && opt_opts.styles.length !== 0) {
            styles_ = opt_opts.styles;
        }
    }

    /**
    * When we add a marker, the marker may not in the viewport of map, then we don't deal with it, instead
    * we add the marker into a array called leftMarkers_. When we reset MarkerClusterer we should add the
    * leftMarkers_ into MarkerClusterer.
    */
    function addLeftMarkers_() {
        if (leftMarkers_.length === 0) {
            return;
        }
        var leftMarkers = [];
        for (i = 0; i < leftMarkers_.length; ++i) {
            me_.addMarker(leftMarkers_[i], true, null, null, true);
        }
        leftMarkers_ = leftMarkers;
    }

    /**
    * Get cluster marker images of this marker cluster. Mostly used by {@link Cluster}
    * @private
    * @return {Array of String}
    */
    this.getStyles_ = function() {
        return styles_;
    };

    /**
    * Remove all markers from MarkerClusterer.
    */
    this.clearMarkers = function() {
        for (var i = 0; i < clusters_.length; ++i) {
            if (typeof clusters_[i] !== "undefined" && clusters_[i] !== null) {
                clusters_[i].clearMarkers();
            }
        }
        clusters_ = [];
        leftMarkers_ = [];
        GEvent.removeListener(mcfn_);
    };

    /**
    * Check a marker, whether it is in current map viewport.
    * @private
    * @return {Boolean} if it is in current map viewport
    */
    function isMarkerInViewport_(marker) {
        return map_.getBounds().containsLatLng(marker.getLatLng());
    }

    /**
    * When reset MarkerClusterer, there will be some markers get out of its cluster.
    * These markers should be add to new clusters.
    * @param {Array of GMarker} markers Markers to add.
    */
    function reAddMarkers_(markers) {
        var len = markers.length;
        var clusters = [];
        for (var i = len - 1; i >= 0; --i) {
            me_.addMarker(markers[i].marker, true, markers[i].isAdded, clusters, true);
        }
        addLeftMarkers_();
    }

    /**
    * Add a marker.
    * @private
    * @param {GMarker} marker Marker you want to add
    * @param {Boolean} opt_isNodraw Whether redraw the cluster contained the marker
    * @param {Boolean} opt_isAdded Whether the marker is added to map. Never use it.
    * @param {Array of Cluster} opt_clusters Provide a list of clusters, the marker
    *     cluster will only check these cluster where the marker should join.
    */
    this.addMarker = function(marker, opt_isNodraw, opt_isAdded, opt_clusters, opt_isNoCheck) {
        if (opt_isNoCheck !== true) {
            if (!isMarkerInViewport_(marker)) {
                leftMarkers_.push(marker);
                return;
            }
        }

        var isAdded = opt_isAdded;
        var clusters = opt_clusters;
        var pos = map_.fromLatLngToDivPixel(marker.getLatLng());

        if (typeof isAdded !== "boolean") {
            isAdded = false;
        }
        if (typeof clusters !== "object" || clusters === null) {
            clusters = clusters_;
        }

        var length = clusters.length;
        var cluster = null;
        for (var i = length - 1; i >= 0; i--) {
            cluster = clusters[i];
            var center = cluster.getCenter();
            if (center === null) {
                continue;
            }
            center = map_.fromLatLngToDivPixel(center);

            // Found a cluster which contains the marker.
            if (pos.x >= center.x - gridSize_ && pos.x <= center.x + gridSize_ &&
          pos.y >= center.y - gridSize_ && pos.y <= center.y + gridSize_) {
                cluster.addMarker({
                    'isAdded': isAdded,
                    'marker': marker
                });
                if (!opt_isNodraw) {
                    cluster.redraw_();
                }
                return;
            }
        }

        // No cluster contain the marker, create a new cluster.
        cluster = new Cluster(this, map);
        cluster.addMarker({
            'isAdded': isAdded,
            'marker': marker
        });
        if (!opt_isNodraw) {
            cluster.redraw_();
        }

        // Add this cluster both in clusters provided and clusters_
        clusters.push(cluster);
        if (clusters !== clusters_) {
            clusters_.push(cluster);
        }
    };

    /**
    * Remove a marker.
    *
    * @param {GMarker} marker The marker you want to remove.
    */

    this.removeMarker = function(marker) {
        for (var i = 0; i < clusters_.length; ++i) {
            if (clusters_[i].remove(marker)) {
                clusters_[i].redraw_();
                return;
            }
        }
    };

    /**
    * Redraw all clusters in viewport.
    */
    this.redraw_ = function() {
        var clusters = this.getClustersInViewport_();
        for (var i = 0; i < clusters.length; ++i) {
            clusters[i].redraw_(true);
        }
    };

    /**
    * Get all clusters in viewport.
    * @return {Array of Cluster}
    */
    this.getClustersInViewport_ = function() {
        var clusters = [];
        var curBounds = map_.getBounds();
        for (var i = 0; i < clusters_.length; i++) {
            if (clusters_[i].isInBounds(curBounds)) {
                clusters.push(clusters_[i]);
            }
        }
        return clusters;
    };

    /**
    * Get max zoom level.
    * @private
    * @return {Number}
    */
    this.getMaxZoom_ = function() {
        return maxZoom_;
    };

    /**
    * Get map object.
    * @private
    * @return {GMap2}
    */
    this.getMap_ = function() {
        return map_;
    };

    /**
    * Get grid size
    * @private
    * @return {Number}
    */
    this.getGridSize_ = function() {
        return gridSize_;
    };

    /**
    * Get total number of markers.
    * @return {Number}
    */
    this.getTotalMarkers = function() {
        var result = 0;
        for (var i = 0; i < clusters_.length; ++i) {
            result += clusters_[i].getTotalMarkers();
        }
        return result;
    };

    /**
    * Get total number of clusters.
    * @return {int}
    */
    this.getTotalClusters = function() {
        return clusters_.length;
    };

    /**
    * Collect all markers of clusters in viewport and regroup them.
    */
    this.resetViewport = function() {
        var clusters = this.getClustersInViewport_();
        var tmpMarkers = [];
        var removed = 0;

        for (var i = 0; i < clusters.length; ++i) {
            var cluster = clusters[i];
            var oldZoom = cluster.getCurrentZoom();
            if (oldZoom === null) {
                continue;
            }
            var curZoom = map_.getZoom();
            if (curZoom !== oldZoom) {

                // If the cluster zoom level changed then destroy the cluster
                // and collect its markers.
                var mks = cluster.getMarkers();
                for (var j = 0; j < mks.length; ++j) {
                    var newMarker = {
                        'isAdded': false,
                        'marker': mks[j].marker
                    };
                    tmpMarkers.push(newMarker);
                }
                cluster.clearMarkers();
                removed++;
                for (j = 0; j < clusters_.length; ++j) {
                    if (cluster === clusters_[j]) {
                        clusters_.splice(j, 1);
                    }
                }
            }
        }

        // Add the markers collected into marker cluster to reset
        reAddMarkers_(tmpMarkers);
        this.redraw_();
    };


    /**
    * Add a set of markers.
    *
    * @param {Array of GMarker} markers The markers you want to add.
    */
    this.addMarkers = function(markers) {
        for (var i = 0; i < markers.length; ++i) {
            this.addMarker(markers[i], true);
        }
        this.redraw_();
    };

    // initialize
    if (typeof opt_markers === "object" && opt_markers !== null) {
        this.addMarkers(opt_markers);
    }

    // when map move end, regroup.
    mcfn_ = GEvent.addListener(map_, "moveend", function() {
        me_.resetViewport();
    });
}

/**
* Create a cluster to collect markers.
* A cluster includes some markers which are in a block of area.
* If there are more than one markers in cluster, the cluster
* will create a {@link ClusterMarker_} and show the total number
* of markers in cluster.
*
* @constructor
* @private
* @param {MarkerClusterer} markerClusterer The marker cluster object
*/
function Cluster(markerClusterer) {
    var center_ = null;
    var markers_ = [];
    var markerClusterer_ = markerClusterer;
    var map_ = markerClusterer.getMap_();
    var clusterMarker_ = null;
    var zoom_ = map_.getZoom();

    /**
    * Get markers of this cluster.
    *
    * @return {Array of GMarker}
    */
    this.getMarkers = function() {
        return markers_;
    };

    /**
    * If this cluster intersects certain bounds.
    *
    * @param {GLatLngBounds} bounds A bounds to test
    * @return {Boolean} Is this cluster intersects the bounds
    */
    this.isInBounds = function(bounds) {
        if (center_ === null) {
            return false;
        }

        if (!bounds) {
            bounds = map_.getBounds();
        }
        var sw = map_.fromLatLngToDivPixel(bounds.getSouthWest());
        var ne = map_.fromLatLngToDivPixel(bounds.getNorthEast());

        var centerxy = map_.fromLatLngToDivPixel(center_);
        var inViewport = true;
        var gridSize = markerClusterer.getGridSize_();
        if (zoom_ !== map_.getZoom()) {
            var dl = map_.getZoom() - zoom_;
            gridSize = Math.pow(2, dl) * gridSize;
        }
        if (ne.x !== sw.x && (centerxy.x + gridSize < sw.x || centerxy.x - gridSize > ne.x)) {
            inViewport = false;
        }
        if (inViewport && (centerxy.y + gridSize < ne.y || centerxy.y - gridSize > sw.y)) {
            inViewport = false;
        }
        return inViewport;
    };

    /**
    * Get cluster center.
    *
    * @return {GLatLng}
    */
    this.getCenter = function() {
        return center_;
    };

    /**
    * Add a marker.
    *
    * @param {Object} marker An object of marker you want to add:
    *   {Boolean} isAdded If the marker is added on map.
    *   {GMarker} marker The marker you want to add.
    */
    this.addMarker = function(marker) {
        if (center_ === null) {
            /*var pos = marker['marker'].getLatLng();
            pos = map.fromLatLngToContainerPixel(pos);
            pos.x = parseInt(pos.x - pos.x % (GRIDWIDTH * 2) + GRIDWIDTH);
            pos.y = parseInt(pos.y - pos.y % (GRIDWIDTH * 2) + GRIDWIDTH);
            center = map.fromContainerPixelToLatLng(pos);*/
            center_ = marker.marker.getLatLng();
        }
        markers_.push(marker);
    };

    /**
    * Remove a marker from cluster.
    *
    * @param {GMarker} marker The marker you want to remove.
    * @return {Boolean} Whether find the marker to be removed.
    */
    this.removeMarker = function(marker) {
        for (var i = 0; i < markers_.length; ++i) {
            if (marker === markers_[i].marker) {
                if (markers_[i].isAdded) {
                    map_.removeOverlay(markers_[i].marker);
                }
                markers_.splice(i, 1);
                return true;
            }
        }
        return false;
    };

    /**
    * Get current zoom level of this cluster.
    * Note: the cluster zoom level and map zoom level not always the same.
    *
    * @return {Number}
    */
    this.getCurrentZoom = function() {
        return zoom_;
    };

    /**
    * Redraw a cluster.
    * @private
    * @param {Boolean} isForce If redraw by force, no matter if the cluster is
    *     in viewport.
    */
    this.redraw_ = function(isForce) {
        if (!isForce && !this.isInBounds()) {
            return;
        }

        // Set cluster zoom level.
        zoom_ = map_.getZoom();
        var i = 0;
        var mz = markerClusterer.getMaxZoom_();
        if (mz === null) {
            mz = map_.getCurrentMapType().getMaximumResolution();
        }
        if (zoom_ >= mz || this.getTotalMarkers() === 1) {

            // If current zoom level is beyond the max zoom level or the cluster
            // have only one marker, the marker(s) in cluster will be showed on map.
            for (i = 0; i < markers_.length; ++i) {
                if (markers_[i].isAdded) {
                    if (markers_[i].marker.isHidden()) {
                        markers_[i].marker.show();
                    }
                } else {
                    map_.addOverlay(markers_[i].marker);
                    markers_[i].isAdded = true;
                }
            }
            if (clusterMarker_ !== null) {
                clusterMarker_.hide();
            }
        } else {
            // Else add a cluster marker on map to show the number of markers in
            // this cluster.
            for (i = 0; i < markers_.length; ++i) {
                if (markers_[i].isAdded && (!markers_[i].marker.isHidden())) {
                    markers_[i].marker.hide();
                }
            }
            if (clusterMarker_ === null) {
                clusterMarker_ = new ClusterMarker_(center_, this.getTotalMarkers(), markerClusterer_.getStyles_(), markerClusterer_.getGridSize_());
                map_.addOverlay(clusterMarker_);
            } else {
                if (clusterMarker_.isHidden()) {
                    clusterMarker_.show();
                }
                clusterMarker_.redraw(true);
            }
        }
    };

    /**
    * Remove all the markers from this cluster.
    */
    this.clearMarkers = function() {
        if (clusterMarker_ !== null) {
            map_.removeOverlay(clusterMarker_);
        }
        for (var i = 0; i < markers_.length; ++i) {
            if (markers_[i].isAdded) {
                map_.removeOverlay(markers_[i].marker);
            }
        }
        markers_ = [];
    };

    /**
    * Get number of markers.
    * @return {Number}
    */
    this.getTotalMarkers = function() {
        return markers_.length;
    };
}

/**
* ClusterMarker_ creates a marker that shows the number of markers that
* a cluster contains.
*
* @constructor
* @private
* @param {GLatLng} latlng Marker's lat and lng.
* @param {Number} count Number to show.
* @param {Array of Object} styles The image list to be showed:
*   {String} url Image url.
*   {Number} height Image height.
*   {Number} width Image width.
*   {Array of Number} anchor Text anchor of image left and top.
*   {String} textColor text color.
* @param {Number} padding Padding of marker center.
*/
function ClusterMarker_(latlng, count, styles, padding) {
    var index = 0;
    var dv = count;
    while (dv !== 0) {
        dv = parseInt(dv / 10, 10);
        index++;
    }

    if (styles.length < index) {
        index = styles.length;
    }
    this.url_ = styles[index - 1].url;
    this.height_ = styles[index - 1].height;
    this.width_ = styles[index - 1].width;
    this.textColor_ = styles[index - 1].opt_textColor;
    this.anchor_ = styles[index - 1].opt_anchor;
    this.latlng_ = latlng;
    this.index_ = index;
    this.styles_ = styles;
    this.text_ = count;
    this.padding_ = padding;
}

ClusterMarker_.prototype = new GOverlay();

/**
* Initialize cluster marker.
* @private
*/
ClusterMarker_.prototype.initialize = function(map) {
    this.map_ = map;
    var div = document.createElement("div");
    var latlng = this.latlng_;
    var pos = map.fromLatLngToDivPixel(latlng);
    pos.x -= parseInt(this.width_ / 2, 10);
    pos.y -= parseInt(this.height_ / 2, 10);
    var mstyle = "";
    if (document.all) {
        mstyle = 'filter:progid:DXImageTransform.Microsoft.AlphaImageLoader(sizingMethod=scale,src="' + this.url_ + '");';
    } else {
        mstyle = "background:url(" + this.url_ + ");";
    }
    if (typeof this.anchor_ === "object") {
        if (typeof this.anchor_[0] === "number" && this.anchor_[0] > 0 && this.anchor_[0] < this.height_) {
            mstyle += 'height:' + (this.height_ - this.anchor_[0]) + 'px;padding-top:' + this.anchor_[0] + 'px;';
        } else {
            mstyle += 'height:' + this.height_ + 'px;line-height:' + this.height_ + 'px;';
        }
        if (typeof this.anchor_[1] === "number" && this.anchor_[1] > 0 && this.anchor_[1] < this.width_) {
            mstyle += 'width:' + (this.width_ - this.anchor_[1]) + 'px;padding-left:' + this.anchor_[1] + 'px;';
        } else {
            mstyle += 'width:' + this.width_ + 'px;text-align:center;';
        }
    } else {
        mstyle += 'height:' + this.height_ + 'px;line-height:' + this.height_ + 'px;';
        mstyle += 'width:' + this.width_ + 'px;text-align:center;';
    }
    var txtColor = this.textColor_ ? this.textColor_ : 'black';

    div.style.cssText = mstyle + 'cursor:pointer;top:' + pos.y + "px;left:" +
      pos.x + "px;color:" + txtColor + ";position:absolute;font-size:11px;" +
      'font-family:Arial,sans-serif;font-weight:bold';
    div.innerHTML = this.text_;
    map.getPane(G_MAP_MAP_PANE).appendChild(div);
    var padding = this.padding_;
    GEvent.addDomListener(div, "click", function() {
        var pos = map.fromLatLngToDivPixel(latlng);
        var sw = new GPoint(pos.x - padding, pos.y + padding);
        sw = map.fromDivPixelToLatLng(sw);
        var ne = new GPoint(pos.x + padding, pos.y - padding);
        ne = map.fromDivPixelToLatLng(ne);
        var zoom = map.getBoundsZoomLevel(new GLatLngBounds(sw, ne), map.getSize());
        map.setCenter(latlng, zoom);
    });
    this.div_ = div;
};

/**
* Remove this overlay.
* @private
*/
ClusterMarker_.prototype.remove = function() {
    this.div_.parentNode.removeChild(this.div_);
};

/**
* Copy this overlay.
* @private
*/
ClusterMarker_.prototype.copy = function() {
    return new ClusterMarker_(this.latlng_, this.index_, this.text_, this.styles_, this.padding_);
};

/**
* Redraw this overlay.
* @private
*/
ClusterMarker_.prototype.redraw = function(force) {
    if (!force) {
        return;
    }
    var pos = this.map_.fromLatLngToDivPixel(this.latlng_);
    pos.x -= parseInt(this.width_ / 2, 10);
    pos.y -= parseInt(this.height_ / 2, 10);
    this.div_.style.top = pos.y + "px";
    this.div_.style.left = pos.x + "px";
};

/**
* Hide this cluster marker.
*/
ClusterMarker_.prototype.hide = function() {
    this.div_.style.display = "none";
};

/**
* Show this cluster marker.
*/
ClusterMarker_.prototype.show = function() {
    this.div_.style.display = "";
};

/**
* Get whether the cluster marker is hidden.
* @return {Boolean}
*/
ClusterMarker_.prototype.isHidden = function() {
    return this.div_.style.display === "none";
};
