var map;
var centerLatitude = 38;
var centerLongitude = -95; 
var startZoom = 4;

var activeOverlays = {};

function addSideBarItem(title, id, func) {
	var listItem = document.createElement('li');
	var listItemLink = listItem.appendChild(document.createElement('a'));
	listItem.id = id;
	listItemLink.href = "#";
	listItemLink.innerHTML = title;
	listItemLink.onclick = func;
	document.getElementById('sidebar-list').appendChild(listItem);
	
	return listItemLink;
}

function regionListClickHandler() {
	var code = this.parentNode.id;
	if (!activeOverlays[code])
	{
		var tilelayer = new GTileLayer(new GCopyrightCollection(''));
		tilelayer.getTileUrl = function(tile, zoom) { return 'cache/' + code + '/' + tile.x + '-' + tile.y + '-' + zoom + '.gif'; }
		tilelayer.isPng = function() { return false; }
		tilelayer.getOpacity = function() { return 0.4; }
		activeOverlays[code] = new GTileLayerOverlay(tilelayer);
		map.addOverlay(activeOverlays[code]);
		this.parentNode.className = 'visible';
	}
	else
	{
		map.removeOverlay(activeOverlays[code]);
		activeOverlays[code] = null;
		this.parentNode.className = '';
	}
	
	return false;
}

function windowHeight() {
	// Standard browsers (Mozilla, Safari, etc.)
	if (self.innerHeight)
		return self.innerHeight;
	// IE 6
	if (document.documentElement && document.documentElement.clientHeight)
		return document.documentElement.clientHeight;
	// IE 5
	if (document.body)
		return document.body.clientHeight;
	// Just in case.
	return 0;
}

function handleResize() {
	var height = windowHeight() - document.getElementById('toolbar').offsetHeight - 30;
	document.getElementById('map').style.height = height + 'px';
	document.getElementById('sidebar').style.height = height + 'px';
}

function changeBodyClass(from, to) {
     document.body.className = document.body.className.replace(from, to);
     return false;
}

function init() {
	document.getElementById('button-sidebar-hide').onclick = function() { return changeBodyClass('sidebar-right', 'nosidebar'); };
	document.getElementById('button-sidebar-show').onclick = function() { return changeBodyClass('nosidebar', 'sidebar-right'); };
	handleResize();
	
	map = new GMap(document.getElementById("map"));
	map.addControl(new GSmallMapControl());
	map.setCenter(new GLatLng(centerLatitude, centerLongitude), startZoom);
	
	for(id in regions) {
		addSideBarItem(regions[id].title, regions[id].code, regionListClickHandler);
	}
}

window.onresize = handleResize;
window.onload = init;