/**
 * Google Maps hacks and utils.
 *
 * - displaying WMS map-data
 * - transparent WMS overlaying
 * - adding custom labels (TLabel)
 * - utility methods (speed, distance etc)
 *
 * Merge of several JS files (needs cleanup!).
 *
 * version: $Id: gmap.js,v 1.4 2006-03-08 17:12:04 just Exp $
 *
 */


/*
 * Create GoogleMap WMS (transparent) layers on any GoogleMap.
 *
 * Just van den Broecke - just AT justobjects.nl - www.justobjects.nl - www.geoskating.com
 *
 * This (experimental) code can be downloaded from
 * http://www.geotracing.com/gt/script/gmap.js
 *
 * CREDITS
 * This code is based on and inspired by:
 * Brian Flood - http://www.spatialdatalogic.com/cs/blogs/brian_flood/archive/2005/07/11/39.aspx and
 * Kyle Mulka - http://blog.kylemulka.com/?p=287
 * I have merely merged the two approaches taken by each of these great minds !
 *
 * EXAMPLE
 *   // Fake WMS server to be used for overlaying map with transparent GIF
 *   // Use a real WMS server here.
 *   var WMS_URL_ROUTE='http://www.geoskating.com/gmap/route-wms.jsp?';
 *
 *   // Create WMSSpec
 *   // need: wmsURL, gName, gShortName, wmsLayers, wmsStyles, wmsFormat, [wmsVersion], [wmsBgColor], [wmsSrs]
 *   var G_MAP_WMS_SPEC = createWMSSpec(WMS_URL_ROUTE, "MyWMS", "MyWMS", "routes", "default", "image/gif", "1.0.0");
 *
 *   // Use WMSSpec to create transparent overlay on a standard Google MapSpec
 *   var G_MAP_WMS_OVERLAY_SPEC = createWMSOverlaySpec(G_SATELLITE_TYPE, G_MAP_WMS_SPEC, "MyOvWMS", "MyOvWMS");
 *
 *   // Create mapspecs array
 *   var mapSpecs = [];
 *   mapSpecs.push(G_SATELLITE_TYPE);
 *   mapSpecs.push(G_MAP_WMS_SPEC);
 *   mapSpecs.push(G_MAP_WMS_OVERLAY_SPEC);
 *
 *   // Setup the map
 *   var map = new GMap(document.getElementById("map"), mapSpecs);
 *   map.addControl(new GMapTypeControl());
 *   map.addControl(new GSmallMapControl());
 *   map.setMapType(G_SATELLITE_TYPE);
 *   map.centerAndZoom(new GPoint(4.9, 52.35), 10);
 */


/** Create WMS type spec as a GMap Spec. */
function createWMSSpec(wmsURL, gName, gShortName, wmsLayers, wmsStyles, wmsFormat, wmsVersion, wmsBgColor, wmsSrs) {
	// Copy all GMap-spec object members (attrs+functions)
	var wmsSpec = new GGoogleMapMercSpec();

	// Override GmapSpec-specific attrs (not future-proof!)
	wmsSpec.Name = gName;
	wmsSpec.ShortName = gShortName;

	// Set internal WMS parameters
	wmsSpec.wmsURL = wmsURL;
	wmsSpec.wmsLayers = wmsLayers;
	wmsSpec.wmsStyles = wmsStyles;
	wmsSpec.wmsFormat = wmsFormat;

	// Optional projection/datum
	wmsSpec.wmsVersion = (wmsVersion ? wmsVersion : "1.1.1");
	wmsSpec.wmsBgColor = (wmsBgColor ? wmsBgColor : "0xFFFFFF");
	wmsSpec.wmsSrs = (wmsSrs ? wmsSrs : "EPSG:4326");
	wmsSpec.wmsTransparent = "TRUE";
	// ?? should be made optional parm ??

	// Override GmapSpec function: no overlay here.
	wmsSpec.hasOverlay = function () {
		return false;
	};

	// Override GmapSpec function: Gets URL for map tile image
	wmsSpec.getTileURL = function (x, y, zoom) {
		var ts = this.tileSize;
		var ul = this.getLatLng(x * ts, (y + 1) * ts, zoom);
		var lr = this.getLatLng((x + 1) * ts, y * ts, zoom);
		var bbox = ul.x + "," + ul.y + "," + lr.x + "," + lr.y;
		var url = this.wmsURL + "VERSION=" + this.wmsVersion + "&REQUEST=GetMap&LAYERS=" + this.wmsLayers + "&STYLES=" + this.wmsStyles + "&SRS=" + this.wmsSrs + "&BBOX=" + bbox + "&WIDTH=" + ts + "&HEIGHT=" + ts + "&FORMAT=" + this.wmsFormat + "&TRANSPARENT=" + this.wmsTransparent + '&EXCEPTIONS=INIMAGE';
		return url;
	};

	wmsSpec.getLinkText = function() {
		return this.Name;
	};

	wmsSpec.getShortLinkText = function() {
		return this.ShortName;
	};

	wmsSpec.getCopyright = function() {
		return ';-)';
	};

	return wmsSpec;
}

/** Create transparent WMS overlay layer on standard GMap Spec. */
function createWMSOverlaySpec(gSpec, wmsSpec, gName, gShortName) {
	// New object
	var overlaySpec = new Object();
	// Override with members of wmsSpec
	for (var m in wmsSpec) {
		overlaySpec[m] = wmsSpec[m];
	}

	// Copy all GMap-spec (e.g. G_SATELLITE_TYPE) object members (attrs+functions)
	for (var m in gSpec) {
		overlaySpec[m] = gSpec[m];
	}

	// Override GmapSpec-specific attrs (not future-proof!)
	overlaySpec.Name = gName;
	overlaySpec.ShortName = gShortName;

	// Override GmapSpec function: Having overlay is the whole purpose!
	overlaySpec.hasOverlay = function () {
		return true;
	};

	// Override GmapSpec function: Gets URL for overlayed tile
	overlaySpec.getOverlayURL = wmsSpec.getTileURL;

	overlaySpec.getLinkText = wmsSpec.getLinkText;

	overlaySpec.getShortLinkText = wmsSpec.getShortLinkText;

	overlaySpec.getCopyright = function() {
		return SIG;
	};

	return overlaySpec;
}

var SIG = '<a style="background-color:#555555; font:10px verdana;text-decoration:none;padding:2px;color:yellow;" href="#" onClick="window.open(\'http://www.geotracing.com\'); return false;">GeoTracing Powered</a>';

// Generic Google Map functions (may move this to generic file);
var GMAP = {

// Is GPoint within GBounds ?
	isInBox: function(pt, bounds) {
		return (pt.x > bounds.minX && pt.y > bounds.minY && pt.x < bounds.maxX && pt.y < bounds.maxY);
	},

// Calculate great-circle distance between GPoints
	distance: function(a, b) {
		// Could be...
		if (a.x == b.x && a.y == b.y) {
			return 0.0;
		}
		var rad = 0.01745566;
		Lo = Math.abs(a.x - b.x);
		Drad = Math.acos((Math.sin(a.y * rad) * Math.sin(b.y * rad)) + (Math.abs(Math.cos(a.y * rad)) * Math.abs(Math.cos(b.y * rad)) * Math.cos(Lo * rad)));

		Crad = Math.acos((Math.sin(b.y * rad) - (Math.sin(a.y * rad) * Math.cos(Drad))) / (Math.cos(a.y * rad) * Math.sin(Drad)));
		var Cdeg = Crad * 57.295779;
		return Drad * 57.295779 * 69.06 * 1.6094;
		// KIlometers Just
	},

// Calculate speed between GPoints
	speed: function(a, b) {
		return GCdistanceBetween(a, b) / ((b.time - a.time) / 3600000);
	}
}