/**
* @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";
};