Reactor Watchdog

RSide = "back"

RLamp = colors.yellow
RAlarm = colors.magenta
RReactor = colors.green
RTemp = colors.red
RReset = colors.black
RAck = colors.cyan
REnergy = colors.lime

monitor = peripheral.wrap("top")
monitor.setTextScale(5)

currOut = 0

function onOut(color)
    currOut = colors.combine(currOut, color)
    redstone.setBundledOutput(RSide, currOut)
end

function offOut(color)
    currOut = colors.subtract(currOut, color)
    redstone.setBundledOutput(RSide, currOut)
end

function testIn(color)
    local curr = redstone.getBundledInput(RSide)
    return colors.test(curr, color)
end

function tst()
    monitor.setCursorPos(1,2)
    monitor.write(currOut)
end

function standbyState()
    offOut(RReactor)
    offOut(RLamp)
    offOut(RAlarm)

    while true do
        tst()
        if testIn(REnergy) then
            state = "running"
            break
        end
        os.pullEvent("redstone")
    end
end

function runningState()
    onOut(RReactor)
    offOut(RLamp)
    offOut(RAlarm)

    while true do
        tst()
        if not testIn(REnergy) then
            state = "standby"
            break
        elseif testIn(RTemp) then
            state = "error"
            break
        end
        os.pullEvent("redstone")
    end
end

function errorState()
    offOut(RReactor)
    onOut(RLamp)
    onOut(RAlarm)

    while true do
        tst()
        os.pullEvent("redstone")
        if testIn(RReset) then
            state = "standby"
            break
        elseif testIn(RAck) then
            state = "ack"
            break
        end
    end
end

function ackState()
    offOut(RReactor)
    onOut(RLamp)
    offOut(RAlarm)
    while true do
        tst()
        if testIn(RReset) then
            state = "standby"
            break
        end
        os.pullEvent("redstone")
    end
end

state = ""

if testIn(RTemp) then
    state = "alarm"
else
    if testIn(REnergy) then
        state = "running"
    else
        state = "standby"
    end
end

while true do
    monitor.clear()
    monitor.setCursorPos(1,1)
    monitor.write(state)
    if state == "standby" then
        standbyState()
    elseif state == "running" then
        runningState()
    elseif state == "error" then
        errorState()
    elseif state == "ack" then
        ackState()
    end
end