--StationmasterCG by Communeguy
--Purpose-rolled Train-Sorting Application
--Depends on Railcraft for hardware.
--Code documentation in comments.
--Hardware documentation at pastebin: ##Code##
--DevNotes commented at end.

--Begin Config Block. These are the only variables the user should manipulate!
local sSide = "left" -- side with the Sensor Line attached.
local rSide = "right" -- side with the Railcraft Line attached.
local mSide = "monitor_0" -- side with the monitor attached, or address of the monitor if networked.
local tSide = "bottom" -- Trigger sensor side
local cSide = "top" -- side with the check receiver.
local train1 = "Kobold Delver" -- name of first train.
local train2 = "Eshu's Bounty"
local train3 = "Hardscrabble Shuttle"
local train4 = "Sidhe Heighliner"

--Additional Variable Defaults. Don't touch.
local v = "Alpha 2"
local a = 1
local p1 = "Unknown"
local p2 = "Unknown"
local p3 = "Unknown"
local p4 = "Unknown"
local bypass = false
local incoming = "string"

--Functions redefined for brevity and utility.
local function set1() --Set functions trigger the switch tracks they are assigned to.
rs.setBundledOutput(rSide, colors.combine(rs.getBundledOutput(rSide), colors.orange)) end
local function set2() 
rs.setBundledOutput(rSide, colors.combine(rs.getBundledOutput(rSide), colors.lightBlue)) end
local function set3() 
rs.setBundledOutput(rSide, colors.combine(rs.getBundledOutput(rSide), colors.lime)) end
local function set4() 
rs.setBundledOutput(rSide, colors.combine(rs.getBundledOutput(rSide), colors.gray)) end
local function sig1() --Sig functions check to see if there is something on the platform.
return rs.testBundledInput(rSide, colors.white)
end
local function sig2()
return rs.testBundledInput(rSide, colors.magenta)
end
local function sig3()
return rs.testBundledInput(rSide, colors.yellow)
end
local function sig4()
return rs.testBundledInput(rSide, colors.pink)
end
local function det1() -- Det functions are checking to see if any of the Routing Detectors tripped on the train, as part of IDing it.
return rs.testBundledInput(sSide, colors.white)
end
local function det2()
return rs.testBundledInput(sSide, colors.orange)
end
local function det3()
return rs.testBundledInput(sSide, colors.magenta)
end
local function det4()
return rs.testBundledInput(sSide, colors.lightBlue)
end
local function release() --releases the holding track
rs.setBundledOutput(sSide, colors.yellow)
end
local function hold() -- holds the train to the holding track.
rs.setBundledOutput(sSide,0)
end
local function check() -- checks that the signal blocks are correctly assigned.
return rs.getInput(cSide)
end
local function switch() -- Tests the state of the signal blocks and handles their switches accordingly
	rs.setBundledOutput(rSide, colors.black)
	if sig1() == true then
	set1()
	end
	if sig2() == true then
	set2()
	end
	if sig3() == true then
	set3()
	end
	if sig4() == true then
	set4()
	end
end
local function park() -- where's the train going?
	if sig1() == true then
		p1 = incoming
		bypass = false
	elseif sig2() == true then
		p2 = incoming
		bypass = false
	elseif sig3() == true then
		p3 = incoming
		bypass = false
	elseif sig4() == true then
		p4 = incoming
		bypass = false
	else
		bypass = true
	end
end
local function checkDepartures() -- has anyone left?
	if sig1() == true then p1 = "Vacant" end
	if sig2() == true then p2 = "Vacant" end
	if sig3() == true then p3 = "Vacant" end
	if sig4() == true then p4 = "Vacant" end
end

--Initialization
local m = peripheral.wrap(mSide) -- wraps the monitor and pushes the outputs to it.
term.redirect(m)
sleep (45) --Allows time for the world to load if that is why the program is loading.

--Actual program execution
while true do
	if check() == true then --throws an error if the signal is faulty.
		print("Welcome to Stationmaster CG" .. v)
		print("Signal Assignment Error. Please verify and relaunch")
		sleep(45)
		os.reboot()
	else
		hold()
		switch() -- initialises the state of the platform switches
		sleep(2) -- Prevents those redstone changes from triggering the system
		checkDepartures() -- makes sure trains that have left are noted before printing.
		term.clear()
		term.setCursorPos(1,1)
		print("Welcome to Stationmaster CG " .. v)
		print("Platform #1: " .. p1)
		print("Platform #2: " .. p2)
		print("Platform #3: " .. p3)
		print("Platform #4: " .. p4)
		if bypass == true then
		print(incoming .. "has bypassed the station due to unavailable space. Sorry about that.")
		end
		os.pullEvent("redstone")
			if det1() == true then --IEI determining which train just arrived.
			incoming = train1			
			elseif det2() == true then
			incoming = train2			
			elseif det3() == true then
			incoming = train3			
			elseif det4() == true then
			incoming = train4		
			else
			incoming = "Unknown"
		end
		park() -- where will this train go? Works because it will always go in ascending order of available sets.
		release() -- lets the train go where it needs to.
		sleep(10) -- lets it get there.
end
end