menu

local termWidth, termHeight = term.getSize()
local selectedItem = 1
local running = true


function Login()

end

function Register()

end

function Exit()
    running = false
end

mainMenu = {
[1] = { text = "Login", handler = Login},
[2] = { text = "Register", handler = Register},
[3] = { text = "Exit", handler = Exit}

}

function printMenu( menu )
    for i=1,#menu do
        if i == selectedItem then
            print(">> "..menu[i].text.." <<")
        else
            print("   "..menu[i].text.."   ")
    end
end
end
end

function onKeyPressed( key, menu)
    if key == keys.enter then
        onItemSelected(menu)
    elseif key == keys.up then
        if selectedItem > 1 then
            selectedItem = selectedItem - 1
        end
    elseif key == keys.down then
        if selectedItem < #menu then
            selectedItem = selectedItem + 1
    end
end
function onItemSelected( menu)
    menu[selectedItem].handler()
end

function main()
    while running do
        term.clear()
        term.setCursorPos(1,1)
        printMenu(mainMenu)

        event, key = os.pullEvent("key")
        onKeyPressed(key,mainMenu)
    end
end

main()