Aperture Science OS System - Shutdown Prompt

os.pullEvent = os.pullEventRaw
--SHUTDOWN PROMPT
--this program is called before a OS Shutsdown, and asks if the user really wants to shutdown, cancel shutdown, or instead reboot the OS
--this program is for Minecraft 1.16.5, CC Tweaked
local i = 15

term.clear()
term.setCursorPos(1,1)
print("SHUTTING DOWN")
print("press e to cancel, or r to instead reboot the OS")
term.setCursorPos(2,5)
os.startTimer(15)
while true do
  sleep(3)
  term.write(i.." seconds until system shutsdown")
  if i > 1 then
    i = i - 1
  end
  local event, item = os.pullEvent()
  term.clearLine()
  if event == "timer" then
    break
  elseif event == "key" and item == keys.e then
    sleep(2)
    print("Canceling Shutdown, sending back to Menu")
    sleep(5)
    i = -1
  elseif event == "key" and item == keys.r then
    sleep(5)
    print("Rebooting in 5...")
    os.reboot()
  end
end
if i == -1 then
  shell.run(".ApertureOS_Base")
elseif i >= 0 then
  print("Shutting Down Now...")
  sleep(5)
  os.shutdown()
end