####    Bendix-King KFC-200 Flight Director    ####

# off - Off: v-bars hidden
# hdg - Heading: v-bars command a turn to the heading bug
# appr - Approach: bank and pitch commands capture and track LOC and GS
# bc - Reverse Localizer: bank command to caputre and track a reverse LOC
#      course.  GS is locked out.
# arm - Standby mode to compute capture point for nav, appr, or bc.
# cpld - Coupled: Active mode for nav, appr, or bc.
# ga - Go Around: commands wings level and missed approach attitude.
# alt - Altitude hold: commands pitch to hold altitude
# vertical trim - pitch command to adjust altitude at 500 fpm while in alt hold
#                 or pitch attitude at rate of 1 deg/sec when not in alt hold
# yd - Yaw Damper: system senses motion around ayw axis and moves rudder to
#                  oppose yaw.

fdprop = props.globals.getNode("/instrumentation/kfc200",1);
fdmode = "off";
fdmodeV = "off";
fdmode_last = "off";
current_alt=0.0;
alt_select = 0.0;
alt_offset = 0.0;
DH = 0;
NAVGS = props.globals.getNode("/instrumentation/nav/has-gs",1); 
NAVGS_RANGE = props.globals.getNode("/instrumentation/nav/gs-distance",1); 
NAVBC = props.globals.getNode("/instrumentation/nav/back-course-btn",1); 
NAV_IN_RANGE = props.globals.getNode("/instrumentation/nav/in-range",1); 
HDG_DEFLECTION = props.globals.getNode("/instrumentation/nav/heading-needle-deflection",1); 
GS_DEFLECTION = props.globals.getNode("/instrumentation/nav/gs-needle-deflection",1); 
HDG = props.globals.getNode("/autopilot/locks/heading",1);
ALT = props.globals.getNode("/autopilot/locks/altitude",1);
SPD = props.globals.getNode("/autopilot/locks/speed",1);

setlistener("/sim/signals/fdm-initialized", func {
	fdprop.getNode("fd_on",1).setBoolValue(0);
	fdprop.getNode("fdmode",1).setValue("off");
	fdprop.getNode("fdmodeV",1).setValue("off");
	fdprop.getNode("alt-offset",1).setValue(0.0);
	fdprop.getNode("alt-alert",1).setBoolValue(0);
    DH = props.globals.getNode("/autopilot/route-manager/min-lock-altitude-agl-ft").getValue();
	alt_select = 0;	
    print("KFC-200 ... OK");
    });

setlistener("/instrumentation/kfc200/fd_on", func {
	var fdON = cmdarg().getValue();
    clear_ap();
    });

setlistener("/autopilot/settings/target-altitude-ft",func {
	alt_select = cmdarg().getValue();
    });

setlistener("/autopilot/route-manager/min-lock-altitude-agl-ft", func {
	DH = cmdarg().getValue();
    });


setlistener("/instrumentation/kfc200/fdmode", func {
	fdmode = cmdarg().getValue();
	NAVBC.setBoolValue(0);
    if(fdmode == "off"){HDG.setValue("wing-leveler");return;}
    if(fdmode == "hdg"){
    	HDG.setValue("dg-heading-hold");
    	return;}
    if(fdmode == "appr"){
    	HDG.setValue("nav1-hold");
		if(NAVGS.getBoolValue()){
			fdprop.getNode("fdmodeV").setValue("gs-arm");
			}
		return;}

    if(fdmode == "nav-arm"){
    	HDG.setValue("dg-heading-hold");
    	return;}
    if(fdmode == "nav-cpld"){
    	HDG.setValue("nav1-hold");
    	return;}
    if(fdmode == "bc"){
    	HDG.setValue("nav1-hold");
		NAVBC.setBoolValue(1);
		return;}
	    });

setlistener("/instrumentation/kfc200/fdmodeV", func {
	altmode = cmdarg().getValue();
	if(altmode == "off"){
	setprop("/autopilot/settings/target-pitch-deg",getprop("/orientation/pitch-deg"));    
    ALT.setValue("pitch-hold");
	return;}
    if(altmode == "alt-arm"){
    	ALT.setValue("pitch-hold");
    	return;}
    if(altmode == "alt"){
    	ALT.setValue("altitude-hold");
    	return;}
    if(altmode == "gs-arm"){
		ALT.setValue("pitch-hold");
		return;}
	if(altmode == "gs"){
		ALT.setValue("gs1-hold");
		return;}
    });

clear_ap = func {
	setprop("/autopilot/settings/target-pitch-deg",getprop("/orientation/pitch-deg"));	
	HDG.setValue("wing-leveler");
	ALT.setValue("pitch-hold");
	}

update_nav = func {
   var APmode = fdprop.getNode("fdmode").getValue();
   var VNAV = fdprop.getNode("fdmodeV").getValue();
    if(APmode == "nav-arm"){
    	if(NAV_IN_RANGE.getBoolValue()){
    		var offset = HDG_DEFLECTION.getValue();
			if(offset < 5 or offset > -5){
				fdprop.getChild("fdmode").setValue("nav-cpld");		    	
    			}else{
    			fdprop.getChild("fdmode").setValue("nav-arm");
    			}
    		}
		}
	if(VNAV == "gs-arm"){
		if(NAVGS_RANGE.getValue()< 30000){
		test = GS_DEFLECTION.getValue();
		if(test < 10 or test > -10){fdprop.getNode("fdmodeV").setValue("gs");}
		}
	}
	
	if(VNAV == "alt-arm"){
		var offset = fdprop.getNode("alt-offset").getValue();		
		if(offset > -990 and offset < 990){
		fdprop.getNode("fdmodeV").setValue("alt");}
		}				
}

get_altoffset = func{
	current_alt = props.globals.getNode("/instrumentation/altimeter/indicated-altitude-ft").getValue();
	var offset = (current_alt - alt_select);
	var alert =0;
	fdprop.getNode("alt-offset").setValue(offset);
	if(offset > -1000 and offset < -300){alert = 1;}
	if(offset < 1000 and offset > 300){alert = 1;}	
	fdprop.getNode("alt-alert").setBoolValue(alert);
	if(getprop("/position/altitude-agl-ft") < DH){props.globals.getNode("/autopilot/locks/passive-mode").setBoolValue(1);}
	}

update = func {
	get_altoffset();
    update_nav();
    settimer(update, 0);
}

settimer(update, 0);