DMENOFFLNDISABMONITOR

MonitorSide = "bottom"
DMGenerationColour = colours.orange
DMGenDisabledColour = colours.magenta
RedstoneInputSide = "top"
Monitor = peripheral.wrap(MonitorSide)

function ClearMonitor()
    Monitor.setTextColor(colours.black)
    Monitor.setBackgroundColor(colours.black)
    Monitor.clear()
    Monitor.setCursorPos(1,1)
end

function DrawText(xPos, yPos, text, textColour, backgroundColour)
    Monitor.setBackgroundColor(backgroundColour)
    Monitor.setTextColor(textColour)
    Monitor.setCursorPos(xPos,yPos)
    Monitor.write(text)
end

function DrawCenteredHorizontal(xPos, yPos, width, text, textColour, backgroundColour)
    local textLength = string.len(text)
    local centerX = (width / 2) - (textLength / 2)
    DrawText(xPos + centerX, yPos, text, textColour, backgroundColour)
end

function DMGeneratorIsOnline()
    local inColours = redstone.getBundledInput(RedstoneInputSide)
    return colours.test(inColours, DMGenerationColour)
end

function IsDisabled()
    local inColours = redstone.getBundledInput(RedstoneInputSide)
    return colours.test(inColours, DMGenDisabledColour) == false
end

function Main()
    while true do
        Monitor.setTextScale(3)
        local w, h = Monitor.getSize()
        if (DMGeneratorIsOnline()) then
            Monitor.setBackgroundColor(colours.green)
            Monitor.setTextColor(colours.green)
            Monitor.clear()
            DrawCenteredHorizontal(2, 2, w - 2, "DM Generator", colours.white, colours.green)
            DrawCenteredHorizontal(2, 5, w - 2, "ONLINE", colours.white, colours.green)
        else
            if (IsDisabled()) then
                Monitor.setBackgroundColor(colours.red)
                Monitor.setTextColor(colours.red)
                Monitor.clear()
                DrawCenteredHorizontal(2, 2, w - 2, "DM Generator", colours.white, colours.red)
                DrawCenteredHorizontal(2, 4, w - 2, "-- EMERGENCY --", colours.white, colours.red)
                DrawCenteredHorizontal(2, 5, w - 2, "-- DISABLED  --", colours.white, colours.red)
            else
                Monitor.setBackgroundColor(colours.orange)
                Monitor.setTextColor(colours.orange)
                Monitor.clear()
                DrawCenteredHorizontal(2, 2, w - 2, "DM Generator", colours.white, colours.orange)
                DrawCenteredHorizontal(2, 5, w - 2, "OFFLINE", colours.white, colours.orange)
            end
        end

        os.sleep(1)
    end
end

Main()