using System;
using System.Threading;

namespace ConsoleMenu
{
    enum MenuOptions { Play = 0, Credits, Exit }

    class Menu
    {
        public MenuOptions SelectedItem { get; set; }
        public const string menuText = "{0,-3}Play\n{1,-3}Credits\n{2,-3}Exit";

        public Menu()
        {
            SelectedItem = MenuOptions.Play;
        }

        public MenuOptions ShowMenu()
        {
            Console.CursorVisible = false;
            ConsoleKeyInfo key;
            SelectedItem = MenuOptions.Play;
            do
            {
                Console.Clear();
                Console.WriteLine(menuText,
                    GetPrefix(SelectedItem == MenuOptions.Play),
                    GetPrefix(SelectedItem == MenuOptions.Credits),
                    GetPrefix(SelectedItem == MenuOptions.Exit));
                key = Console.ReadKey();
                if (key.Key == ConsoleKey.UpArrow)
                    SelectedItem = MenuUp(SelectedItem);
                else if (key.Key == ConsoleKey.DownArrow)
                    SelectedItem = MenuDown(SelectedItem);
            } while (key.Key != ConsoleKey.Enter);
            Console.CursorVisible = true;
            return SelectedItem;
        }

        public string GetPrefix(bool selected)
        {
            return selected ? ">" : "";
        }

        public MenuOptions MenuUp(MenuOptions current)
        {
            if (current == MenuOptions.Play)
                return MenuOptions.Exit;
            else return current - 1;
        }

        public MenuOptions MenuDown(MenuOptions current)
        {
            if (current == MenuOptions.Exit)
                return MenuOptions.Play;
            else return current + 1;
        }
    }
}