local accessCode = "1111"

local isOpened = false

local component = require("component")
local gpu = component.gpu
local event = require("event")
local ser = require("serialization")
local computer = component.computer
local door = component.os_door
keypad = component.os_keypad

customButtons = {"1", "2", "3", "4", "5", "6", "7", "8", "9", "<-", "0", "OK"}
customButtonColor = {"1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1"}
keypad.setKey(customButtons, customButtonColor)

if door.isOpen()
then
    door.toggle()
end

local inputStr = ""
while true do
    ev, address, button, button_label = event.pull("keypad")
    if ev then
        if (button_label == "OK")
        then
            if inputStr == accessCode
            then
                inputStr = "OK!"
                keypad.setDisplay(inputStr)
                computer.beep()
                door.toggle()
                isOpened = true
            else
                inputStr = "Invalid!"
                keypad.setDisplay(inputStr)
                os.sleep(2)
            end
            inputStr = ""
        elseif (button_label == "<-")
        then
            if (isOpened == false)
            then
                if string.len(inputStr) > 0
                then
                    tmpStr = string.sub(inputStr, 1 , string.len(inputStr) -1)
                    inputStr = tmpStr
                end
            else
                door.toggle()
                isOpened = false
                keypad.setDisplay("Locked!")
                inputStr = ""
                os.sleep(2)
                keypad.setDisplay(inputStr)
            end
        else
            inputStr = inputStr .. button_label
        end
        a = inputStr.len(inputStr)
        b = ""
        for i = a,1,-1
        do
            b = b .. "*"
        end
        keypad.setDisplay(b)
    end
    os.sleep(0)
end