# See: http://wiki.flightgear.org/MapStructure
# Class things:
var name = 'TFC';
var parents = [DotSym];
var __self__ = caller(0)[0];
DotSym.makeinstance( name, __self__ );

SymbolLayer.get(name).df_style = { # style to use by default
	line_width: 3,
	scale_factor: 1,
	color_by_lvl: {
		3: [1,0,0], # resolution advisory
		2: [1,0.5,0], # traffic advisory
		1: [1,1,1], # proximate traffic
	},
	color_default: [1,1,1]
};

var element_type = "group"; # we want a group, becomes "me.element"
var text_tcas = nil;
var icon_tcas = nil;
var arrow_tcas = [nil,nil];
var arrow_type = nil;

var draw_tcas_arrow = nil;
var color = nil;
var threatLvl = 0e-0; # NaN to update even when threatLvl == nil

# TODO: how to integrate both styling and caching?
var draw = func {
	# TODO: get rid of draw_tcas_arrow hacks
	if (draw_tcas_arrow == nil)
		draw_tcas_arrow = [
			draw_tcas_arrow_above_500,
			draw_tcas_arrow_below_500
		];
	#var callsign = me.model.getNode("callsign").getValue();
	# print("Drawing traffic for:", callsign );
	var threatLvl = me.model.get_threat_lvl();
	var vspeed = me.model.get_vspd();
	var altDiff = me.layer.controller.get_alt_diff(me.model);
	# Init
	if (me.text_tcas == nil) {
		me.text_tcas = me.element.createChild("text")
			.setDrawMode( canvas.Text.TEXT )
			.setText(sprintf("%+02.0f",altDiff/100))
			.setFont("LiberationFonts/LiberationSans-Regular.ttf")
			.setColor(1,1,1)
			.setFontSize(28)
			.setAlignment("center-center");
		me.icon_tcas = me.element.createChild("path")
			.setStrokeLineWidth(3);
	}
	# Update
	if (altDiff > 0)
		me.text_tcas.setTranslation(0,-40);
	else
		me.text_tcas.setTranslation(0,40);
	var arrow_type = (vspeed >= 500);
	if (arrow_type != me.arrow_type) {
		(old_type, me.arrow_type) = (me.arrow_type, arrow_type);
		if (old_type != nil and me.arrow_tcas[old_type] != nil) me.arrow_tcas[old_type].hide();
		if (me.arrow_tcas[arrow_type] == nil)
			me.arrow_tcas[arrow_type] = me.draw_tcas_arrow[arrow_type](me.element);
		me.arrow_tcas[arrow_type].show();
	}
	if (threatLvl != me.threatLvl) {
		me.threatLvl = threatLvl;
		## TODO: should threat level symbols also be moved to *.draw files?
		if (threatLvl == 3) {
			# resolution advisory
			me.icon_tcas.moveTo(-17,-17)
				.horiz(34)
				.vert(34)
				.horiz(-34)
				.close();
		} elsif (threatLvl == 2) {
			# traffic advisory
			me.icon_tcas.moveTo(-17,0)
				.arcSmallCW(17,17,0,34,0)
				.arcSmallCW(17,17,0,-34,0);
		} elsif (threatLvl == 1) {
			# proximate traffic
			me.icon_tcas.moveTo(-10,0)
				.lineTo(0,-17)
				.lineTo(10,0)
				.lineTo(0,17)
				.close();
		} else {
			# other traffic
			me.icon_tcas.moveTo(-10,0)
				.lineTo(0,-17)
				.lineTo(10,0)
				.lineTo(0,17)
				.close();
		}
	}
	var color = nil;
	if (threatLvl != nil)
		if ((var c = me.style.color_by_lvl[threatLvl]) != nil)
			var color = canvas._getColor(c);
	if (color == nil)
		color = canvas._getColor(me.style.color_default);
	if (me.color != color) {
		me.color = color;
		me.icon_tcas.setColor(color);
		me.text_tcas.setColor(color);
		me.arrow_tcas[me.arrow_type].setColor(color);
		if (num(threatLvl) == nil or (threatLvl < 1 or threatLvl > 3)) {
			color = [0,0,0,0];
		}
		me.icon_tcas.setColorFill(color);
	}
	if (me.style.scale_factor != me.element.getScale())
		me.element.setScale(me.style.scale_factor);
};