# Properties under /consumables/fuel/tank[n]:
# + level-gal_us    - Current fuel load.  Can be set by user code.
# + level-lbs       - OUTPUT ONLY property, do not try to set
# + selected        - boolean indicating tank selection.
# + density-ppg     - Fuel density, in lbs/gallon.
# + capacity-gal_us - Tank capacity 
#
# Properties under /engines/engine[n]:
# + fuel-consumed-lbs - Output from the FDM, zeroed by this script
# + out-of-fuel       - boolean, set by this code.

# ==================================== timer stuff ===========================================

# set the update period

UPDATE_PERIOD = 0.3;

# set the timer for the selected function

registerTimer = func {
	
    settimer(arg[0], UPDATE_PERIOD);

} # end function 

# =============================== end timer stuff ===========================================



initialized = 0;
enabled = 0;

#print ("running aar");
#print (" enabled " , enabled,  " initialized ", initialized);  

updateTanker = func {
#print ("tanker update running ");
				#if (!initialized ) {
				#print("calling initialize");
				#initialize();}
    
        Refueling = props.globals.getNode("/systems/refuel/contact");
        AllAircraft = props.globals.getNode("ai/models").getChildren("aircraft");
				AllMultiplayer = props.globals.getNode("ai/models").getChildren("multiplayer");
        Aircraft = props.globals.getNode("ai/models/aircraft");
        
#   select all tankers which are in contact. For now we assume that it must be in 
#		contact	with us.
                
        selectedTankers = [];
				
				if ( enabled ) { # check that AI Models are enabled, otherwise don't bother
            foreach(a; AllAircraft) {
                contact_node = a.getNode("refuel/contact");
                id_node = a.getNode("id");
                tanker_node = a.getNode("tanker");
                
                contact = contact_node.getValue();
                id = id_node.getValue();
                tanker = tanker_node.getValue();
                
				#print ("contact ", contact , " tanker " , tanker );
                            
                if (tanker and contact) {
                    append(selectedTankers, a);
                }
            }
						
						foreach(m; AllMultiplayer) {
                contact_node = m.getNode("refuel/contact");
                id_node = m.getNode("id");
                tanker_node = m.getNode("tanker");
                
                contact = contact_node.getValue();
                id = id_node.getValue();
                tanker = tanker_node.getValue();
                
#				print (" mp contact ", contact , " tanker " , tanker );
                            
                if (tanker and contact) {
                    append(selectedTankers, m);
                }
            }
        }
         
		#print ("tankers ", size(selectedTankers) );

        if ( size(selectedTankers) >= 1 ){
            Refueling.setBoolValue(1);
        } else {
            Refueling.setBoolValue(0);
        }
		registerTimer(updateTanker);
}

# Initalize: Make sure all needed properties are present and accounted
# for, and that they have sane default values.

initialize = func {
   
    AI_Enabled = props.globals.getNode("sim/ai/enabled");
    Refueling = props.globals.getNode("/systems/refuel/contact",1);
            
    Refueling.setBoolValue(0);
    enabled = AI_Enabled.getValue();
        
    initialized = 1;
}

initDoubleProp = func {
    node = arg[0]; prop = arg[1]; val = arg[2];
    if(node.getNode(prop) != nil) {
        val = num(node.getNode(prop).getValue());
    }
    node.getNode(prop, 1).setDoubleValue(val);
}

# Fire it up
if (!initialized) {initialize();}
registerTimer(updateTanker);