.menu

os.pullEvent = os.pullEventRaw

local w,h = term.getSize()

--Center print function
function printCentered(y,s)
  local x = math.floor((w - string.len(s)) /2)
  term.setCursorPos(x,y)
  term.clearLine()
  term.write(s)
end

--Menu draw function
local nOption = 1

local function drawMenu()
  term.clear()
  term.setCursorPos(1,2)
  term.write("Welcome to Worth OS")
  term.setCursorPos(1,3)

  shell.run("os/.version")
  term.write(stringVersion)

  term.setCursorPos(w-11,1)
  if nOption == 1 then
    term.write("Command")
  elseif nOption == 2 then
    term.write("Programs")
  elseif nOption == 3 then
    term.write("Shutdown")
  elseif nOption == 4 then
    term.write("Uninstall")
  else
  end
end

--GUI

term.clear()
local function drawFrontend()
  printCentered(math.floor(h/2) - 3, "")
  printCentered(math.floor(h/2) - 2, "Access Menu")
  printCentered(math.floor(h/2) - 1, "---------")
  printCentered(math.floor(h/2) + 0, ((nOption == 1 and "[ Commands ]") or "Commands"))
  printCentered(math.floor(h/2) + 1, ((nOption == 2 and "[ Programs ]") or "Programs"))
  printCentered(math.floor(h/2) + 2, ((nOption == 3 and "[ Shutdown ]") or "Shutdown"))
  printCentered(math.floor(h/2) + 3, ((nOption == 4 and "[ Uninstall ]") or "Uninstall"))
end

--Display

drawMenu()
drawFrontend()

while true do
  local e,p = os.pullEvent()
    if e == "key" then
      local key = p
      if key == 17 or key == 200 then
        if nOption > 1 then
          nOption = nOption - 1
          drawMenu()
          drawFrontend()
        end
      elseif key == 31 or key == 208 then
        if nOption < 4 then
          nOption = nOption + 1
          drawMenu()
          drawFrontend()
        end
      elseif key == 28 then
        break
      end
    end
end

term.clear()

if nOption == 1 then
  shell.run("os/.command")
elseif nOption == 2 then
  shell.run("os/.programs")
elseif nOption == 3 then
  os.shutdown()
else
  shell.run("os/.uninstall")
end