var prevOverlays = [];

function undo() {

	for (var i = 0; i < overlays.length; i++) {
		overlays[i].setMap(null);

	}
	if (prevOverlays.length != 0){
		overlays = [];
		console.log(prevOverlays);
		var prev_overlay = prevOverlays.pop();
		
		for (var i = 0; i < prev_overlay.length; i++) {
			overlays[i] = prev_overlay[i];
			overlays[i].setMap(map);
		}
		
	}
	
	//Deactivated at the moment
	if(enableSelectionFeature){
		selectedShapes = [];
		var i = 0;
		var lastEntry = prevOverlays[prevOverlays.length-1][i];
		console.log(prevOverlays[prevOverlays.length-1].length);
		
		for(var i = 0; i < lastEntry.length; i++){
			selectedShapes.push(prevOverlays)
			console.log("comes here");
		}
		
	}
	
	
}

function clonePath(path)
{
	var clone_path = [];
	
	for (var i = 0; i < path.length; i++) {
		var lati = path.getAt(i).lat();
		var lngi = path.getAt(i).lng();
		clone_lat_lng = {
			lat: lati,
			lng: lngi
		};
		clone_path.push(clone_lat_lng);
	}
	
	return clone_path;
}

function clonePolyline(polyline)
{
	var path          = polyline.getPath();
	var geodesic      = polyline.geodesic;
	var strokeColor   = polyline.strokeColor;
	var strokeOpacity = polyline.strokeOpacity;
	var strokeWeight  = polyline.strokeWeight;
	var clone_path    = clonePath(path);
	//var editable      = rect.editable;
	
	var clone_polyline = new google.maps.Polyline({
		geodesic: geodesic,
		strokeColor: strokeColor,
		strokeOpacity: strokeOpacity,
		strokeWeight: strokeWeight,
		path: clone_path,
		draggable: true,
		editable: false
	});
	
	clone_polyline.type = google.maps.drawing.OverlayType.POLYLINE;
	
	return clone_polyline;
}

function clonePolygon(polygon)
{
	var path          = polygon.getPath();
	var geodesic      = polygon.geodesic;
	var strokeColor   = polygon.strokeColor;
	var strokeOpacity = polygon.strokeOpacity;
	var strokeWeight  = polygon.strokeWeight;
	var fillColor     = polygon.fillColor;
	var fillOpacity   = polygon.fillOpacity;
	var clone_path    = clonePath(path);
	//var editable      = rect.editable;
	
	var clone_polygon = new google.maps.Polygon({
		geodesic: geodesic,
		strokeColor: strokeColor,
		strokeOpacity: strokeOpacity,
		strokeWeight: strokeWeight,
		fillColor: fillColor,
		fillOpacity: fillOpacity,
		path: clone_path,
		draggable: true,
		editable: false
	});
	
	clone_polygon.type = google.maps.drawing.OverlayType.POLYGON;
	
	return clone_polygon;
}

function cloneRectangle(rect)
{
	var strokeColor   = rect.strokeColor;
	var strokeOpacity = rect.strokeOpacity;
	var strokeWeight  = rect.strokeWeight;
	var fillColor     = rect.fillColor;
	var fillOpacity   = rect.fillOpacity;
	var bounds        = rect.getBounds();
	//var editable      = rect.editable;
	
	var clone_rect = new google.maps.Rectangle({
		strokeColor: strokeColor,
		strokeOpacity: strokeOpacity,
		strokeWeight: strokeWeight,
		fillColor: fillColor,
		fillOpacity: fillOpacity,
		bounds: bounds,
		draggable: true,
		editable: false
	});
	
	clone_rect.type = google.maps.drawing.OverlayType.RECTANGLE;
	
	return clone_rect;
}

function cloneCircle(circ)
{
	var strokeColor   = circ.strokeColor;
	var strokeOpacity = circ.strokeOpacity;
	var strokeWeight  = circ.strokeWeight;
	var fillColor     = circ.fillColor;
	var fillOpacity   = circ.fillOpacity;
	var center        = circ.center;
	var radius        = circ.radius;
	//var editable      = rect.editable;
	
	var clone_circ = new google.maps.Circle({
		strokeColor: strokeColor,
		strokeOpacity: strokeOpacity,
		strokeWeight: strokeWeight,
		fillColor: fillColor,
		fillOpacity: fillOpacity,
		center: center,
		radius: radius,
		draggable: true,
		editable: false
	});
	
	clone_circ.type = google.maps.drawing.OverlayType.CIRCLE;
	
	return clone_circ;
}


function cloneShape(shape)
{
	if (shape.type === google.maps.drawing.OverlayType.POLYLINE) {
		var clone_polyline = clonePolyline(shape);
		return clone_polyline;
	}
	else if (shape.type === google.maps.drawing.OverlayType.POLYGON) {
		var clone_polygon = clonePolygon(shape);
		return clone_polygon;
	}
	else if (shape.type === google.maps.drawing.OverlayType.RECTANGLE) {
		var clone_rect = cloneRectangle(shape);
		return clone_rect;
	
	}
	else if (shape.type === google.maps.drawing.OverlayType.CIRCLE) {
		var clone_circ = cloneCircle(shape);
		return clone_circ;
	
	}
	else {
		console.error("Unrecognized shape: " + shape);
		return null;
	}
}

function overlayItemIsShape(overlay_item)
{
	var type = overlay_item.type;
	
	is_shape = (type === google.maps.drawing.OverlayType.POLYLINE)
	 || (type === google.maps.drawing.OverlayType.POLYGON)
	 || (type === google.maps.drawing.OverlayType.RECTANGLE)
	 || (type === google.maps.drawing.OverlayType.CIRCLE);
	 
	 return is_shape;
}

function historyOverlayPush()
{
	console.log("comes here");
	var overlays_copy = [];
	for (var i = 0; i<overlays.length; i++) {
		var clone_shape = cloneShape(overlays[i]);
		if (overlayItemIsShape(clone_shape)) {
			addShapeListeners(clone_shape,null); // don't have an overlay event!
		}
		else {
			addMarkerListeners(clone_shape,null); // don't have an overlay event!
		}
		overlays_copy[i] = clone_shape;
	}
	
	prevOverlays.push(overlays_copy); 
}