a

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

local k,r = component.os_keypad, component.redstone
local cc,c = "","1234"

customText = {"1","2","3","4","5","6","7","8","9","CL","0","OK"}
customColor = {15,15,15,15,15,15,15,15,15,15,15,15}
k.setKey(customText,customColor)

r.setOutput(sides.back, 0)

function checkCode()
  if (cc == c) then
    k.setDisplay("Granted", 2)
    cc = ""
    r.setOutput(sides.back, 15)
    os.sleep(5)
    r.setOutput(sides.back, 0)
  else
    k.setDisplay("Denied", 4)
    cc = ""
    os.sleep(2)
  end
  k.setDisplay("")
end

function updateDisplay()
  local display = ""
  for i=1, #cc do
    display = display .. "*"
  end
  k.setDisplay(display, 15)
end

function keyPressed(eventName, address, button, buttonLabel)
  if (buttonLabel == "CL") then
    cc = ""
  elseif (buttonLabel == "OK") then
    checkCode()
  else
    cc = cc..buttonLabel
  end

  updateDisplay()
end

event.listen("keypad",keyPressed)