using System;

public class Program

​

{

    public static void Commands()

    {

        string inp, inpUp;

        bool valInp = false;

        while(valInp == false) {

        Console.WriteLine("Welcome to Command Search. Type your command.");

        inp = Console.ReadLine();

        inpUp = inp.ToUpper();

        if(inpUp == "/MAINMENU")

        {

            valInp = true;

            MainMenu();

        }else if (inpUp == "/COMMANDS")

        {

            valInp = true;

            CommandsMenu();

        }else if(inpUp == "/CMD") 

        {

            valInp = true;

            Commands();

        }//

        }//

    }

    public static void CommandsMenu()

    {

        bool check = false;

        string inp, inpUp;

        Console.WriteLine("Commands: ");

        Console.WriteLine("/MainMenu - returns to the main menu");

        Console.WriteLine("/Calculator - Calculator Application");

        Console.WriteLine("/Settings - Settings Menu");

        Console.WriteLine("/ShutDown - Restarts the program");

        Console.WriteLine("================================================");

        while(check == false) 

        {

            Console.WriteLine("Type /exit to exit the Commands Menu. You will then be allowed to enter one of the above commands. You can't use commands in this menu.");

                inp = Console.ReadLine();

            inpUp = inp.ToUpper();

            if(inpUp == "/EXIT")

            {

                check = true;

                Commands();

            }//

        }//

    }

    public static void MainMenu()

    {

    string mainI, mainUp;

        bool checkS = true;

        Console.WriteLine("================================================");

        Console.WriteLine("Welcome to the OS. Type /commands to check commands.");

        Console.WriteLine("================================================");

        while(checkS = true)

        {mainI = Console.ReadLine();

        mainUp = mainI.ToUpper();

        if(mainUp == "/COMMANDS")

        {

            CommandsMenu();

        } else

        {

            Console.WriteLine("Invalid Command. Try Again.");

        }

        }

    }

    public static void Main()

    {

        string usr, passI;

        string pass = "Pass1";

        bool login = false;

        int attempt = 0;

        Console.Write("Welcome. Please enter your name: ");

        usr = Console.ReadLine();

        while (login == false){

            Console.WriteLine("Now please enter your password: ");

        passI = Console.ReadLine();

            if(passI == pass)

        {

            login = true;

                Console.WriteLine("Welcome, " + usr + ".");

                break;

        }else

        {

                attempt = attempt+ 1;

            Console.WriteLine("Attempt " + attempt + ". Incorrect password. Please try again.");

        }//

        }//

        MainMenu();

    }

}