var redolog = [], map,restore=0, GDir1, GDir2, normalProj, waypoints=[], gpolys=[], routeNodes=[], init_route=[], myNode, markerDragged, isDragged, lastIndex, prevIndex;

function reverse(wh) {
	var tmp = [];
	for (var a=wh.length-1;a>=0 ;a-- )	{
		tmp.push(wh[a]);
	}
	return tmp;
}
function save() {
    var rows = [];
    var point;
    var pl = (gpolys.length);
    for (var a = 0; a < gpolys.length; a++) {
      var len = gpolys[a].getVertexCount()||0;
      for(var i=0; i<len; i++){
          point = gpolys[a].getVertex(i);
          rows.push(point.lng().toFixed(6)+","+point.lat().toFixed(6)+",0");
      }
    }
	byid('trackCoords').value = rows.join(' ');
	return true;
}

function undo() {
	if (redolog.length > 1) {
		redolog.pop();
		var va = reverse(redolog[redolog.length-1]);
		restore=va.length;
		for (var a=0;a<va.length;a++ ) {
			var point = new GLatLng(va[a].lat(), va[a].lng());
			init_route.push(point);
		}
		if (init_route.length > 0) {
			InitRoute(init_route);
		}
	}
}

function writelog() {
	if (restore > 0) {
		restore--;
	} else {
		var tmp = [];
		for (var i = 0; i < waypoints.length; i++) {
			tmp.push(waypoints[i].getPoint());
		}
		redolog.push(tmp);
	}
}

function InitRoute(route_points) {
	if (!map) {
		return;
	}

	init_route = route_points; //global array, so GDir1.load can construct initial route

	// clear existing lines and nodes
	while (gpolys.length > 0) {
		map.removeOverlay(gpolys.pop());
	}
	while (waypoints.length > 0) {
		map.removeOverlay(waypoints.pop());
	}

	routeNodes=[];
	lastIndex=0;
	prevIndex=0;

	if (init_route.length > 0) {
		var point = init_route.pop();
		GDir1.loadFromWaypoints([point, point], {getPolyline:true}); //put the first point, and GDir1.load will continue to add points from init_route array
	}
}

if (!GBrowserIsCompatible()) {
    alert("Sorry, the Google Maps API is not compatible with this browser");
}
else {
	// Display the map with some controls and set the initial location
	map = new GMap2(document.getElementById("mapDiv"), {draggableCursor:"crosshair"});
	map.setCenter(new GLatLng(59.43, 24.75), 12);
	map.enableDoubleClickZoom();
	map.enableScrollWheelZoom();
	map.enableContinuousZoom();
	map.addMapType(G_SATELLITE_3D_MAP);

	map.addControl(new GMapTypeControl());
	map.addControl(new GLargeMapControl());
	map.addControl(new GScaleControl());

	normalProj = G_NORMAL_MAP.getProjection(); // for conversion between LatLng and screen pixels

	GDir1 = new GDirections(); // for extending route to additional point
	GDir2 = new GDirections(); // for recalculating of route when dragging line

	//GEvent.addListener(GDir1, "error", function() {	alert("Directions Failed: "+GDir1.getStatus().code); });
	//GEvent.addListener(GDir2, "error", function() {	alert("Directions Failed: "+GDir2.getStatus().code); });

	GEvent.addListener(map, 'mousemove', getProximity); // for detecting if mouse is above displayed route

	GEvent.addListener(map, "zoomend", function() {
		routeNodes = []; // clear cached coordinates in pixels of displayed route vertexes, the coordinates have to be recalculated on new zoom level
	});

	GEvent.addListener(map, "click", function(overlay, point) {
		if (point) {
			if (waypoints.length == 0) { // no waypoints exist yet - map was clicked for start of the route
				GDir1.loadFromWaypoints([point.toUrlValue(6), point.toUrlValue(6)], {getPolyline:true}); // get directions from that point to itself to snap it to street
			}
			else { // map was clicked for additional waypoint
				GDir1.loadFromWaypoints([waypoints[waypoints.length-1].getPoint(), point.toUrlValue(6)], {getPolyline:true}); //get directions from last waypoint to clicked point
			}
		}
	});

	iconNode = new GIcon();	iconNode.image = '/gfx/icons/trackmarker.png';
	iconNode.shadow = ''; iconNode.iconSize = new GSize(10,10); iconNode.shadowSize = new GSize(0,0);
	iconNode.iconAnchor = new GPoint(5,5); iconNode.infoWindowAnchor = new GPoint(5,5);
	iconNode.dragCrossImage = 'empty.gif'; // undocumented String: indicates an image to be used as the drag cross. If you set it to the null string, you get the default drag_cross_67_16.png image.
	iconNode.dragCrossSize = GSize(1, 1); //undocumented GSize(): indicates the size of the drag cross.
	iconNode.maxHeight = 1; //undocumented integer: The maximum difference in height between the marker anchor and the drag cross anchor during dragging. Setting the maxHeight to zero causes it to use the default 13.

	// create marker for displaying and dragging when mouse is over displayed route
	myNode = new GMarker(map.getCenter(), {icon:iconNode, draggable:true, bouncy:false, zIndexProcess:function(marker,b) {return 1;}});
	map.addOverlay(myNode);
	myNode.show(); // sometimes .hide() does not work without .show() at first ???
	myNode.hide(); // hide this marker initially

	GEvent.addListener(myNode, "drag", function() { // mouse was over displayed route and user drags the displayed marker
		myNode.show();

		if (isDragged == 2) { // already waiting for GDir2.load to complete - so just remember that marker was dragged again
			markerDragged = myNode; // remember which marker was dragged
			return;
		}

		if (myNode.MyIndex < waypoints.length) {
			isDragged = 2; // tag that GDir2.load is started
			markerDragged = false;

			lastIndex = myNode.MyIndex;
			prevIndex = -1;
			// recalculate route between waypoints before and after myNode on the displayed line
			GDir2.loadFromWaypoints([waypoints[lastIndex].getPoint(), myNode.getPoint().toUrlValue(6), waypoints[lastIndex + 1].getPoint()], {getPolyline:true});
		}
	});
	GEvent.addListener(myNode, "dragend", function() { // when user finished dragging the line, create new waypoint with permanent marker at the location
		var point = myNode.getPoint();
		var marker = new GMarker(point, {icon:iconNode, draggable:true, dragCrossMove:false, bouncy:false, zIndexProcess:function(marker,b) {return 1;}});
		waypoints.splice(myNode.MyIndex + 1, 0, marker); //insert new waypoint into waypoints array

		for (var i = myNode.MyIndex; i < waypoints.length; i++) // reindex next waypoints
			waypoints[i].MyIndex = i;

		var dummy = new GPolyline([point]); // insert empty segment into route segments array - GDir2.load will replace it with new route segment
		map.addOverlay(dummy);
		gpolys.splice(myNode.MyIndex + 1, 0, dummy);

		// add event listeners for marker of new waypoint - so route will be recalculated when user drags waypoint
		GEvent.addListener(marker, "dragstart", function() { isDragged = 1; myNode.hide(); });
		GEvent.addListener(marker, "dragend", function() { writelog(); isDragged = 0; } );
		GEvent.addListener(marker, "drag", dragMarker);

		map.addOverlay(marker);

		if (myNode.MyIndex < waypoints.length) {
			lastIndex = myNode.MyIndex + 1; prevIndex = lastIndex - 1;
			// recalculate route between previous and next waypoints going through new inserted waypoint
			GDir2.loadFromWaypoints([waypoints[lastIndex - 1].getPoint(),point.toUrlValue(6), waypoints[lastIndex + 1].getPoint()], {getPolyline:true});
			writelog();
		}
	});

	GEvent.addListener(GDir1, "load", function() {
		var gp = GDir1.getPolyline();
		var point = gp.getVertex(gp.getVertexCount() - 1); // snap to last vertex in the polyline
		var marker = new GMarker(point, {icon:iconNode, draggable:true, dragCrossMove:false, bouncy:false, zIndexProcess:function(marker,b) {return 1;}});

		if (waypoints.length == 0) {
			marker.title = GDir1.getRoute(0).getStartGeocode().address;
		}
		else {
			waypoints[waypoints.length-1].title = GDir1.getRoute(0).getStartGeocode().address;
			marker.title = GDir1.getRoute(0).getEndGeocode().address
		}

		GEvent.addListener(marker, "dragstart", function() { isDragged = 1; myNode.hide(); });
		GEvent.addListener(marker, "drag", dragMarker);
		GEvent.addListener(marker, "dragend", function() { writelog(); isDragged = 0; });

		marker.MyIndex = waypoints.length;
		waypoints.push(marker);
		map.addOverlay(marker);

		if (waypoints.length > 1) { // if this was not the first waypoint - display the route to this waypoint
			map.addOverlay(gp);
			gpolys.push(gp);

			routeNodes = [];
			getProximity();
		}

		if (init_route.length>0) {
			GDir1.loadFromWaypoints([marker.getPoint(), init_route.pop()], {getPolyline:true});
		}
		else {
			StoreToURL(waypoints);
			writelog();
		}
	});

	GEvent.addListener(GDir2, "load", function() {
		var gp = GDir2.getPolyline();

		map.removeOverlay(gpolys[lastIndex]);

		if (prevIndex >= 0) { // not the last waypoint was dragged
			map.removeOverlay(gpolys[lastIndex-1]);

			var minD, minI, points=[];
			var p0 = waypoints[lastIndex].getPoint();

			for (var i = 0; i < gp.getVertexCount(); i++) { // search closest vertex to dragged waypoint for splitting received route at it into two routes between waypoints
				var p = gp.getVertex(i);
				points.push(p);

				var d = p0.distanceFrom(p);

				if (i == 0 || minD > d) {
					minD = d;
					minI = i;
				}
			}

			gpolys[lastIndex - 1] = new GPolyline(points.slice(0, minI + 1)); //+1,  because slice extracts up to, but not including, the 'end' element
			gpolys[lastIndex] = new GPolyline(points.slice(minI, points.length));

			map.addOverlay(gpolys[lastIndex - 1]);

			waypoints[lastIndex-1].title = GDir2.getRoute(0).getStartGeocode().address;
			waypoints[lastIndex].title = GDir2.getRoute(0).getEndGeocode().address;
			waypoints[lastIndex+1].title = GDir2.getRoute(1).getEndGeocode().address;
		}
		else { // last waypoint was dragged
			gpolys[lastIndex] = gp;
			waypoints[lastIndex].title = GDir2.getRoute(0).getStartGeocode().address;
			waypoints[lastIndex+1].title = GDir2.getRoute(0).getEndGeocode().address;
		}
		map.addOverlay(gpolys[lastIndex]);

		routeNodes = [];
		getProximity();

		isDragged = 0; // tag that there is no dragged waypoints or waiting for GDir to complete
		StoreToURL(waypoints);

		if (markerDragged) { // marker was dragged again until GDir2 was loaded
			isDragged = 1; // tag that there is dragged waypoint
			setTimeout(function() {GEvent.trigger(markerDragged, 'drag');}, 200); // trigger recalculation of route
		}
	});
}

function StoreToURL(waypoints) {
	var s = [];

	for (var i = 0; i < waypoints.length; i++) {
		s.push(waypoints[i].getPoint().toUrlValue(6));
	}

//	window.location.hash = "#" + s.join(",");
}

function dragMarker() { // when waypoint marker is being dragged, start calculation of new route
	if (isDragged == 2) { // exit if already waiting for GDir2.load to complete
		markerDragged = this;
		return;
	}
	isDragged = 2; // tag that calculation of new route is started

	if (markerDragged) { //determine which marker triggered the recalculation
		marker = markerDragged;
		markerDragged = false;
	}
	else {
		marker = this;
	}

	lastIndex = marker.MyIndex;
	var point = marker.getPoint();

	if (lastIndex > 0) {
		if (lastIndex < waypoints.length - 1) {
			prevIndex = lastIndex - 1;
			GDir2.loadFromWaypoints([waypoints[lastIndex - 1].getPoint(),point.toUrlValue(6),waypoints[lastIndex + 1].getPoint()],{getPolyline:true});
		}
		else {
			prevIndex = -1; lastIndex = lastIndex - 1; // recalculate path to this point
			GDir2.loadFromWaypoints([waypoints[lastIndex].getPoint(),point.toUrlValue(6)],{getPolyline:true});
		}
	}
	else if (waypoints.length > 1) {
		prevIndex = -1;
		GDir2.loadFromWaypoints([point.toUrlValue(6),waypoints[1].getPoint()],{getPolyline:true});
	}
}

function getProximity(mouseLatLng) {
// displays myNode marker at closest point from mouseLatLng to polylines contained in gpolys array

	var zoom, point;

	if (routeNodes.length == 0) { // cache is empty
	// convert to pixels and cache coordinates of displayed polylines for better performance
		var dist = 0;
		zoom = map.getZoom();

		for (var i = 0; i < gpolys.length; i++) {
			dist += gpolys[i].getLength();

			var last_point;

			for (var j = ((i == 0) ? 0 : 1); j < gpolys[i].getVertexCount(); j++) {
				var point = normalProj.fromLatLngToPixel(gpolys[i].getVertex(j), zoom)

				if (j==0 || last_point.x != point.x || last_point.y != point.y) {
					routeNodes.push(point.x);
					routeNodes.push(point.y);
					routeNodes.push(i); // store the index of polyline containing this node
					last_point = point;
				}
			}
		}

		var panel;

		if (routeNodes.length > 0 && (panel = document.getElementById('distance'))) {
			panel.innerHTML = (dist/1000).toFixed(1) + " km";
		}
	}

	var l = routeNodes.length;

	if (!mouseLatLng || l <= 1 || isDragged > 0) // no route is displayed or route is already being dragged
		return;

	zoom = map.getZoom();
	var mousePx = normalProj.fromLatLngToPixel(mouseLatLng, zoom);
	var mouseX = mousePx.x;
	var mouseY = mousePx.y;

	var x = routeNodes[0];
	var y = routeNodes[1];
	var minX = x; // we will search closest point on the line to mouse position for displaying marker there available for dragging
	var minY = y;
	var minDist = 99999;

	for (var n = 3; n < l; n +=3) {
		var x0 = x;
		var y0 = y;
		x = routeNodes[n];
		y = routeNodes[n+1];

		if ((x < mouseX-50 && x0 < mouseX-50) || (x > mouseX+50 && x0 > mouseX+50)) {
			continue;
		}
		if ((y < mouseY-50 && y0 < mouseY-50) || (y > mouseY+50 && y0 > mouseY+50)) {
			continue;
		}

		var dx = x - x0;
		var dy = y - y0;
		var d = dx*dx + dy*dy; // lenght^2 of segment n

		var u = ((mouseX - x) * dx + (mouseY - y) * dy) / d; // a bit of vector algebra :)
		var x2 = x + (u*dx); // x,y coordinates in pixels of closest point to mouse in segment n
		var y2 = y + (u*dy);

		var dist = (mouseX - x2)*(mouseX - x2) + (mouseY - y2)*(mouseY - y2); // distance^2 from mouse to closest point in segment n

		if (minDist > dist) { // closest point in segment n is closest point overall so far
			var d1 = (mouseX - x0)*(mouseX - x0) + (mouseY - y0)*(mouseY - y0); // distance^2 from mouse to end of segment n in pixels
			var d2 = (mouseX - x)*(mouseX - x) + (mouseY - y)*(mouseY - y)

			if ((d1 - dist) + (d2 - dist) > d) { // closest point is outside the segment, so the real closest point is either start or end of segment
				if (d1 < d2) {
					dist = d1;
					x2 = x0;
					y2 = y0;
				}
				else {
					dist = d2;
					x2 = x;
					y2 = y;
				}
			}
		}

		if (minDist > dist) { // closest point in segment n is closest point overall so far
			minDist = dist;
			minX = x2;
			minY = y2;
			myNode.MyIndex = routeNodes[n+2]; // remember index of segment closest to mouse
		}
	}

	if (minDist > 2500) { // mouse is not close enough to the displayed line
		myNode.hide(); // do not display marker for dragging the polyline
	}
	else {
		for (n = waypoints.length; --n >= 0;) { // check if mouse is not too close to existing waypoints markers
			var markerPx = normalProj.fromLatLngToPixel(waypoints[n].getPoint(), zoom);

			dx = markerPx.x - minX;
			dy = markerPx.y - minY;

			if (dx*dx + dy*dy < 25) { // mouse is too close to existing marker
				myNode.hide(); // do not show additional marker for dragging the line - the user is about to drag existing waypoint
				return;
			}
		}

		myNode.setPoint(normalProj.fromPixelToLatLng(new GPoint(minX, minY), zoom));
		myNode.show(); // display marker for dragging the polyline
	}

	//document.getElementById('panel').innerHTML = '<br>Mouse distance to line ' + n + ': ' + minDist.toFixed(2);
}