CustomSmeltingScript

local smelt = false
local runProg = true

local lastOutput = false

function cls()
    term.clear()
    term.setCursorPos(1,1)
end

function writeX (monitor, x, y)
    monitor.setCursorPos(x,y)
    monitor.write("x")
end

while runProg do

    if peripheral.isPresent("left") then
        local leftMonitor = peripheral.wrap("left")
        leftMonitor.clear()
        leftMonitor.setCursorPos(1,1)
        leftMonitor.write("Smelt:")
        leftMonitor.setCursorPos(1,2)
        leftMonitor.write((smelt and "YES" or "NO"))

        if (not smelt) then
            writeX(leftMonitor,3,3)
            writeX(leftMonitor,5,3)
            writeX(leftMonitor,4,4)
            writeX(leftMonitor,3,5)
            writeX(leftMonitor,5,5)
        else
            writeX(leftMonitor,2,4)
            writeX(leftMonitor,3,5)
            writeX(leftMonitor,4,5)
            writeX(leftMonitor,5,4)
            writeX(leftMonitor,6,3)
        end
    end

    cls()
    print("Smelting: " .. (smelt and "ENABLED" or "DISABLED"))
    print("")
    print("Type \"help\" for more options...")
    local input = read()
    cls()

    if input == "help" then

        print ("\"enable\" - enables smelting.")
        print ("\"disable\" - disables smelting.")
        print ("\"help\" - prints this page.")
        print ("\"exit\" - exits to terminal.")
        print ("")
        print ("Press any key to continue...")
        os.pullEvent ('key')

    elseif input == "exit" then

        runProg = false
        print ("Goodbye!")
        os.sleep(3)
        cls()

    elseif input == "enable" then

        if smelt ~= true then
            print("Enabling...")
            smelt = true
            redstone.setOutput("back", not lastOutput)
            os.sleep (0.1)
            redstone.setOutput("back", lastOutput)
            os.sleep (0.1)
            lastOutput = lastOutput --Just in here for documentation purposes
        else
            print ("Smelting is already enabled!")
            os.sleep(3)
        end

    elseif input == "disable" then

        if smelt ~= false then
            print("Disabling...")
            smelt = false
            redstone.setOutput("back", not lastOutput)
            os.sleep (0.1)
            lastOutput = not lastOutput
        else
            print("Smelting is already disabled!")
            os.sleep(3)
        end

    else

        print("Invalid command \"" .. input .. "\"")
        os.sleep(3)

    end
end