ATMS Train System - Tablet OS

--this program for CC: Tweaked is a Travel manager for a Tablet to overlook the operations of a Create Train system
--HIGHLY WIP
Settings_TrainID = 0
Settings_TrainState = "Standby"
Settings_TabletState = "Ready"
Settings_CurrentStation = "unknown"
Settings_TargetDestination[0,0]
--Temp
Train_X = 0
Train_Y = 0
Train_Z = 0
Point_X = []
Point_Y = []

start()

function start()
	TabletBootManager()
	GPSManager()
	if Settings_TrainState == "Standby" then
		Point_X[0] = Train_X
		Point_Z[0] = Train_Z
	end
	Menu()
end

function Menu()
	term.clear()
	term.setCursorPos(1,1)
	print("MAIN MENU")
	print("PLEASE CHOOSE AN OPTION")
	print("1 = Travel Map")
	print("2 = Train Logs")
	print("3 = Train Manager")
	print("4 = Resync Train")
	local event, key = os.pullEvent("key")
	while true do
		TrainManager()
        if key == keys.1 then
			TravelMenu()
        else if key == keys.2 then
			TrainLogsMenu()
        else if key == keys.3 then

        else if key == keys.4 then

		end
    end
end

function TravelMenu()
	term.clear()
	term.setCursorPos(1,1)
	print("To return to menu, press M")
	print("Travel Map")
	MapDrawer()
	local event, key = os.pullEvent("key")
	while true do
        if key == keys.m then
			Menu()
		end
	end
end

function TrainLogsMenu()

end

function TravelManager()
	local I = #Point_X
	GPSManager()
	Point_X[I] = Train_X
	Point_Z[I] = Train_Z
end

function TrainManager()
	sleep(10)
	if Settings_TrainState == "Moving" then
		TravelManager()
		PathCorrector()
	end
end

function PathCorrector()

end

function MapDrawer()
	for i = 1, #Point_X do
		paintutils.drawPoint(Point_X[i],Point_Z[i],colors.blue)
	end
	paintutils.drawPoint(Train_X,Train_Z,Colors.red)
end

function GPSManager()
	locate([timeout=2 [,debug=false]])
	Train_X = x
	Train_Y = y
	Train_Z = z
end

function NetworkManager(Action,Target,Signal)

end

function TabletBootManager()
	local h = fs.open(".TrainSettings","r")
	Settings_TrainState = h.readline(1)
	Settings_CurrentStation = h.readline(2)
	Settings_TrainID = h.readline(3)
	Settings_NextStation = h.readline(4)
	h.close()
end