# A3XX Auxilliary Power Unit
# Jonathan Redpath (legoboyvdlp)

# Copyright (c) 2019 Jonathan Redpath (legoboyvdlp)

var APUNodes = {
	Controls: {
		master: props.globals.getNode("/controls/apu/master"),
		fire: props.globals.getNode("/controls/apu/fire-btn"),
		bleed: props.globals.getNode("/controls/pneumatics/switches/apu"),
	},
	Oil: {
		level: props.globals.getNode("/systems/apu/oil/level-l"),
		pressure: props.globals.getNode("/systems/apu/oil/oil-pressure-psi"),
		temperature: props.globals.getNode("/systems/apu/oil/oil-temperature-degC"),
	},
	masterElecThreeMin: props.globals.getNode("/systems/apu/dc-bat-three-minutes"),
};

var APU = {
	state: 0, # off, power up, watch, starting preparation, starting, run, cooldown, shutdown
	inletFlap: aircraft.door.new("/controls/apu/inlet-flap", 12),
	fuelValveCmd: props.globals.getNode("/systems/fuel/valves/apu-lp-valve-cmd"),
	fuelValvePos: props.globals.getNode("/systems/fuel/valves/apu-lp-valve"),
	inletFlapPos: props.globals.getNode("/controls/apu/inlet-flap/position-norm"),
	oilLevel: props.globals.getNode("/systems/apu/oil/level-l"),
	listenSignals: 0,
	listenStopSignal: 0,
	bleedTime: 0,
	cooldownEndTime: 0,
	fastStart: 0,
	inhibitEMERELEC: 0,
	_count: 0,
	warnings: {
		lowOilLevel: 0,
	},
	GenericControls: {
		starter: props.globals.getNode("/controls/engines/engine[2]/starter"),
		cutoff: props.globals.getNode("/controls/engines/engine[2]/cutoff"),
		throttle: props.globals.getNode("/controls/engines/engine[2]/throttle"),
	},
	signals: {
		startInProgress: props.globals.getNode("/systems/apu/start"),
		oilTestComplete: 0,
		available: props.globals.getNode("/systems/apu/available"),
		bleedWasUsed: 0,
		fault: props.globals.getNode("/systems/apu/fault"),
		autoshutdown: 0,
		emer: 0,
	},
	setState: func(num) {
		me.state = num;
	},
	resetStuff: func() {
		me.setState(0);
		me.warnings.lowOilLevel = 0;
		me.listenSignals = 0;
		me.listenStopSignal = 0;
		me.bleedTime = 0;
		me.cooldownEndTime = 0;
		me.signals.oilTestComplete = 0;
		me.signals.bleedWasUsed = 0;
		me.signals.fault.setValue(0);
		me.signals.autoshutdown = 0;
		me.signals.emer = 0;
		me.inhibitEMERELEC = 0;
		checkApuStartTimer.stop();
		apuStartTimer.stop();
		apuStartTimer2.stop();
		shutdownTimer.stop();
		cooldownTimer.stop();
	},
	new: func() {
		var a = { parents:[APU] };
		return a;
		me.GenericControls.throttle.setValue(1);
	},
	# Tests
	checkOil: func() {
		if (me.oilLevel.getValue() < 3.69) {
			me.warnings.lowOilLevel = 1;
		} else {
			me.warnings.lowOilLevel = 0;
		}
		me.signals.oilTestComplete = 1;
	},
	
	# Routines to do with state
	powerOn: func() {
		# just in case
		me.resetStuff();
		if (systems.ELEC.Bus.dcBat.getValue() < 25) { 
			settimer(func() {
				if (systems.ELEC.Bus.dcBat.getValue() < 25) {
					me.resetStuff();
					return;
				}
			}, 0.2);
		}
		# apu able to receive emergency stop or start signals
		me.setState(1);
		me.fuelValveCmd.setValue(1);
		me.inletFlap.open();
		me.listenSignals = 1;
		settimer(func() { 
			if (APUNodes.Controls.master.getValue() and !pts.Acconfig.running.getValue()) { 
				me.setState(2);
			}
		}, 3);
		settimer(func() { me.checkOil() }, 8);
	},
	startCommand: func(fast = 0) {
		if (me.listenSignals and (me.state == 1 or me.state == 2)) {
			me.signals.startInProgress.setBoolValue(1);
			me.setState(3);
			checkApuStartTimer.start();
			me.fastStart = fast;
		}
	},
	checkApuStart: func() {
		if (me.fastStart) {
			me.inletFlap.setpos(1);
		}
		if (pts.APU.rpm.getValue() < 7 and me.fuelValvePos.getValue() and me.inletFlapPos.getValue() == 1 and me.signals.oilTestComplete and !me.warnings.lowOilLevel and !me.inhibitEMERELEC) {
			me.setState(4);
			me.listenStopSignal = 1;
			checkApuStartTimer.stop();
			me.startSequence();
		}
	},
	startSequence: func() {
		me.GenericControls.starter.setValue(1);
		apuStartTimer.start();
	},
	waitStart: func() {
		if (pts.APU.rpm.getValue() >= 4.9 or me.fastStart) {
			me.GenericControls.cutoff.setValue(0);
			if (me.fastStart) {
				setprop("/fdm/jsbsim/propulsion/set-running", 2);
			}
			apuStartTimer.stop();
			apuStartTimer2.start();
		}
	},
	waitStart2: func() {
		if (pts.APU.rpm.getValue() >= 99.9) {
			me.GenericControls.starter.setValue(0);
			me.signals.startInProgress.setBoolValue(0);
			me.signals.available.setValue(1);
			me.setState(5);
			apuStartTimer2.stop();
		}
	},
	cooldown: func() {
		if (APUNodes.Controls.master.getValue()) {
			cooldownTimer.stop();
			me.setState(5);
			return;
		}
		if (pts.Sim.Time.elapsedSec.getValue() >= me.cooldownEndTime) {
			cooldownTimer.stop();
			me.stopAPU();
			me.setState(7);
			shutdownTimer.start();
		}
	},
	shutdown: func() {
		if (!me.signals.autoshutdown and APUNodes.Controls.master.getValue()) {
			me.powerOn();
			return;
		}
		
		me.GenericControls.cutoff.setValue(1);
		me.GenericControls.starter.setValue(0);
		
		if (!me.signals.autoshutdown and pts.APU.rpm.getValue() < 95 and me.signals.available.getValue()) {
			me.signals.available.setValue(0);
		}
		if (me.signals.autoshutdown and (me.signals.available.getValue() or !me.signals.fault.getValue())) {
			me.signals.available.setValue(0);
			me.signals.fault.setValue(1);
		}
		
		if (pts.APU.rpm.getValue() < 7 and !APUNodes.Controls.master.getValue()) {
			me.inletFlap.close();
			me.fuelValveCmd.setValue(0);
			if (!APUNodes.Controls.master.getValue()) {
				me.setState(0);
				me.resetStuff();
				shutdownTimer.stop();
			}
		}
	},
	
	# Signal generators / receivers
	stop: func() {
		if (me.listenStopSignal and me.state == 4) {
			me.signals.startInProgress.setBoolValue(0);
			me.stopAPU();
			me.setState(7);
			shutdownTimer.start();
		} else {
			if (me.signals.startInProgress.getBoolValue()) {
				me.signals.startInProgress.setBoolValue(0);
			}
			if (me.signals.bleedWasUsed) {
				if (me.bleedTime == 0) { me.shutBleed(); }
				if (120 - (pts.Sim.Time.elapsedSec.getValue() - me.bleedTime) > 0) {
					me.cooldownEndTime = me.bleedTime + 120;
					me.setState(6);
					cooldownTimer.start();
				} else {
					me.stopAPU();
					me.setState(7);
					shutdownTimer.start();
				}
			} else {
				me.stopAPU();
				me.setState(7);
				shutdownTimer.start();
			}
		}
	},
	autoStop: func() {
		if (me.state >= 4) {
			checkApuStartTimer.stop();
			apuStartTimer.stop();
			apuStartTimer2.stop();
			cooldownTimer.stop();
			me.stopAPU();
			me.setState(7);
			shutdownTimer.start();
			me.signals.autoshutdown = 1;
			me.signals.fault.setValue(1);
		} else {
			checkApuStartTimer.stop();
			me.inletFlap.close();
			me.fuelValveCmd.setValue(0);
			me.signals.autoshutdown = 1;
			me.signals.fault.setValue(1);
			me.setState(0);
		}
	},
	emergencyStop: func() {
		me.signals.emer = 1;
		if (me.listenSignals and (me.state < 4)) {
			checkApuStartTimer.stop();
			me.inletFlap.close();
			me.fuelValveCmd.setValue(0);
			me.signals.autoshutdown = 1;
			me.signals.fault.setValue(1);
			me.setState(0);
		} elsif (me.state >= 4) {
			me.fuelValveCmd.setValue(0);
			me.autoStop();
		}
	},
	
	# Functions
	stopAPU: func() {
		me.GenericControls.cutoff.setValue(1);
	},
	shutBleed: func() {
		APUNodes.Controls.bleed.setValue(0);
		me.bleedTime = pts.Sim.Time.elapsedSec.getValue();
	},
	_powerLost: 0,
	update: func() {
		me._count += 1;
		if (me._count == 5) {
			me._count = 0;
			if (me.state == 5 and APUNodes.Oil.pressure.getValue() < 35 or APUNodes.Oil.temperature.getValue() > 135) {
				me.autoStop();
			}
			
			if (systems.ELEC.Bus.dcBat.getValue() < 25) {	
				if (!me._powerLost) {
					me._powerLost = 1;
					settimer(func() {
						if (me._powerLost) {
							if (me.GenericControls.starter.getValue()) {
								me.GenericControls.starter.setValue(0);
							}
							if (me.state != 0) {
								me.autoStop();
							}
						}
					}, 0.2);
				}
			} else {
				me._powerLost = 0;
			}
			
			if (systems.ELEC.EmerElec.getValue() == 1 and (systems.ELEC.EmerElec45.getValue() != 1 and systems.ELEC.Source.EmerGen.voltsRelay.getValue() < 110)) {
				me.inhibitEMERELEC = 1;
			} else {
				me.inhibitEMERELEC = 0;
			}
		}
	},
};

var APUController = {
	_init: 0,
	APU: nil,
	init: func() {
		if (!me._init) {
			me.APU = APU.new();
			me._init = 1;
		}
	},
	loop: func() {
		if (me._init) {
			me.APU.update();
		}
	}
};

var _masterTime = 0;
setlistener("/controls/apu/master", func() {
	if (APUController.APU != nil) {
		if (APUNodes.Controls.master.getValue() and APUController.APU.state == 0) {
			shutdownTimer.stop();
			APUNodes.masterElecThreeMin.setValue(1);
			checkMasterThreeMinTimer.start();
			_masterTime = pts.Sim.Time.elapsedSec.getValue();
			APUController.APU.powerOn();
		} elsif (!APUNodes.Controls.master.getValue()) {
			APUController.APU.stop();
		}
	}
}, 0, 0);

setlistener("/controls/pneumatics/switches/apu", func() {
	if (APUController.APU != nil) {
		if (APUNodes.Controls.bleed.getValue()) {
			APUController.APU.signals.bleedWasUsed = 1;
		} else {
			APUController.APU.bleedTime = pts.Sim.Time.elapsedSec.getValue();
		}
	}
}, 0, 0);

var checkMasterThreeMinTimer = maketimer(0.1, func() {
	if (!APUNodes.Controls.master.getValue()) {
		APUNodes.masterElecThreeMin.setValue(0);
		checkMasterThreeMinTimer.stop();
		return;
	}
	
	if (pts.Sim.Time.elapsedSec.getValue() >= _masterTime + 180) {
		APUNodes.masterElecThreeMin.setValue(0);
		checkMasterThreeMinTimer.stop();
	}
});
var checkApuStartTimer = maketimer(0.1, func() {
	APUController.APU.checkApuStart();
});
var apuStartTimer = maketimer(0.1, func() {
	APUController.APU.waitStart();
});
var apuStartTimer2 = maketimer(0.1, func() {
	APUController.APU.waitStart2();
});
var cooldownTimer = maketimer(0.1, func() {
	APUController.APU.cooldown();
});
var shutdownTimer = maketimer(0.1, func() {
	APUController.APU.shutdown();
});