fgdata/Nasal/canvas/map/WXR_live.symbol

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

var element_type = "group";

var getWXRImageFilePath = func(){
	var home = getprop('sim/fg-home');
	var aircraft = getprop('sim/aircraft');
	var idx = me.layer.getCanvas()._node.getIndex();
	return home ~ '/Export/' ~ aircraft ~ '-wxr-'~idx~'.png';
};

var processRequest = func(r) {
	var splitVector = split(",", r.response);
	var timeStamp = split("]",splitVector[size(splitVector) - 1]);
	return timeStamp[0];
};

var getWXRAPIUrl = func(lat, lon){
	if (me.timeStamp == nil) { return nil; }
	return "https://tilecache.rainviewer.com/v2/radar/" ~ sprintf("%s",me.timeStamp) ~ "/512/5/" ~ lat ~ "/" ~ lon ~ "/7/0_0.png";
};

var fetchWXRMap = func(size){
	if(me.fetching) return;
	var pos = geo.aircraft_position();
	var lat = pos.lat();
	var lon = pos.lon();
	var url = me.getWXRAPIUrl(lat, lon);
	var filePath = me.getWXRImageFilePath();
	if(url == nil) {
		logprint(LOG_INFO,me.name,": No URL!");
		return;
	}
	me.fetching = 1;
	http.save(url, filePath)
		.fail(func(){
			logprint(LOG_INFO,me.name,":Download failed!");}
		)
		.done(func(){
			var sz = size * 2;
			var transl = -size;
			me.wxlayer.hide();
			me.wxlayer.setFile(filePath)
					  .setSize(sz, sz)
					  .setTranslation(transl, transl);
			me.wxlayer.show();
			me.last_request = getprop("/sim/time/elapsed-sec");
		})
		.always(func(){
			setprop("/instrumentation/wxr/center/latitude-deg", lat);
			setprop("/instrumentation/wxr/center/longitude-deg", lon);
			me.fetching = 0;
			logprint(LOG_DEBUG,me.name,": Layer Request: ",url);
		});
};

var init = func {
	#print('WXR init');
	me.fetching = 0;
	me.timeStamp = nil;
	me.fetchRad = me.model.fetchRad; # Radius of radar layer to fetch
	me.range = me.model.rangeNm; # Range of Navigation Display
	me.viewport_radius = me.getOption('viewport_radius', 670);
	
	me.wxlayer = me.element.createChild("image").set("z-index", -100).hide();
	
	me.last_request = -600;
	me.update_interval = 600;
	
	var r_scaled = (me.fetchRad*me.viewport_radius)/me.range;
	me.fetchWXRMap(r_scaled);
	
	me.timeStamp = nil;
	http.load("https://api.rainviewer.com/public/maps.json").done(func(r) me.timeStamp = processRequest(r));
};

var draw = func {
	var range = me.layer.map.getRange(); # Range of Navigation Display
	var update_size = (range != me.range);
	me.range = range;
	me.fetchRad = me.model.fetchRad; # Radius of radar layer to fetch
	var r_scaled = (me.fetchRad*me.viewport_radius)/me.range;
	var hdg = me.layer.map.getHdg();
	var rot = 0 - hdg;
	if(rot < 0) rot = 360 + rot + -getprop("/environment/magnetic-variation-deg"); 
	me.element.setRotation(rot*D2R);
	if(update_size){
		me.wxlayer.hide();
		me.wxlayer.setSize(2*r_scaled, 2*r_scaled)
				  .setTranslation(-r_scaled, -r_scaled);
		me.wxlayer.show();
	}

	if(getprop("/sim/time/elapsed-sec") - me.last_request > me.update_interval) {
		me.fetchWXRMap(r_scaled);
	}
};