// guess Wally's password game

#include <iostream>
#include <string>
#include <algorithm>
#include <limits>
#include <cstddef>
#include <cstdlib>
#include <ctime>

char random_letter()
{
    const std::string alphanum =
        "abcdefghijklmnopqrstuvwxyz"
        "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
        "0123456789";

    return alphanum[rand() % alphanum.length()];
}

int main()
{
    srand(time(NULL));

    size_t difficulty = 6;
    bool   playing    = true;

    std::cout << "Guess Wally's Password!\n\n";

    while (playing)
    {
        std::cout << "Enter difficulty (input 0 to quit): ";
        std::cout.flush(); // just in case
        std::cin >> difficulty;
        std::cin.ignore();

        if (difficulty == 0)
            break;

        std::string real_password;
        real_password.resize(difficulty);
        std::generate(real_password.begin(), real_password.end(), random_letter);
        std::string fake_password = real_password;
        std::random_shuffle(fake_password.begin(), fake_password.end());

        bool guessed = false;

        while (!guessed)
        {
            std::cout << "\n\nWally's password uses these letters but"
                " in a different order:\n\t" << fake_password;
            std::cout << "\nWhat could it be? (Type !EXIT to quit): " << std::endl;
            std::string user_password;
            getline(std::cin, user_password);

            if (user_password.compare("!EXIT") == 0)
            {
                playing = false;
                break;
            }

            if (user_password.compare(real_password) == 0)
            {
                std::cout << "Correct. Well done Mr. Password Cracker!\n\n" << std::endl;
                guessed = true;
            }
            else
                std::cout << "You suck." << std::endl;
        }
    }

    return EXIT_SUCCESS;
}