Open Computers redstone signal toggle latch

local component = require("component")
local event = require("event")
local sides = require("sides")
local term = require("term")

local gpu = term.gpu()
local rs = component.redstone

-- SETUP
-- Place the computer down and configure it with a redstone card and an Internet card (to download this program)
-- Place a "Player Detector" down on the left side of the computer (can be hard wired using a lever if all you want is pulse toggling)
-- Place a redstone pulse device on the right side of the computer (The signal to toggle the setup). Pulse duration should be less than one second but longer than a few ticks (5 ticks is usually good)
-- Download and run this program

-- Interrupt state. Changed when the program is closed using Ctrl+C
interrupted = false

-- Global state
state = false
online = false

-- Screen size
initialWidth, initialHeight = gpu.getViewport()

-- Write to the centre of the screen
function writeScreen(text)
    if term.isAvailable() then
        local width, height = gpu.getResolution()
        term.clear()
        gpu.set(width / 2 - #text / 2, height / 2, text)
    else
        print(text)
    end
end

-- Initializes the screen
function initializeScreen()
    print("Initializing screen...")
    -- Act like we are doing something :P
    os.sleep(1)
    if term.isAvailable() then
        term.clear()
        gpu.setResolution(16, 8)
        writeScreen("Standby")
    end
end

function interruptRecieved()
    print("Interrupt recieved... Exiting...")
    -- Change the interrupted state value to close the program
    interrupted = true
    return false
end

function getState()
    if online == false then
        return false
    end
    if state == false then
        return true
    elseif state == true then
        return false
    end
end

-- Listen for interruption event
event.listen("interrupted", interruptRecieved)

-- Initialize the screen
initializeScreen()

-- Main loop
while interrupted == false do
    local pulseValue = rs.getInput(sides.east)
    local onlineValue = rs.getInput(sides.west)
    local backValue = rs.getInput(sides.back)
    if onlineValue == 15 then
        online = true
    else
        online = false
    end
    state = getState()
    -- Player is not online and setup is active so we disable it.
    if online == false and backValue > 0 then
        rs.setOutput(sides.back, 0)
        writeScreen("Disabled")
        os.sleep(1)
    else
        if pulseValue == 15 then
            if state == true then
                if backValue < 15 then
                    rs.setOutput(sides.back, 15)
                end
                    writeScreen("Enabled")
                    os.sleep(1)
            elseif state == false then
                if backValue > 0 then
                    rs.setOutput(sides.back, 0)
                end
                writeScreen("Disabled")
                os.sleep(1)
            -- If anything funny happened, we want to fail safe and set the output to disabled.
            else
                rs.setOutput(sides.back, 0)
                writeScreen("What happened.")
                os.sleep(1)
            end
        end
    end
    os.sleep(0.1)
end

-- Cleanup tasks
rs.setOutput(sides.back, 0)
gpu.setResolution(initialWidth, initialHeight)
term.clear()
os.exit()