nadekobot/src/NadekoBot/Modules/Gambling/Common/Blackjack/Player.cs

namespace NadekoBot.Modules.Gambling.Common.Blackjack;

public abstract class Player
{
    public List<Deck.Card> Cards { get; } = new List<Deck.Card>();

    public int GetHandValue()
    {
        var val = GetRawHandValue();

        // while the hand value is greater than 21, for each ace you have in the deck
        // reduce the value by 10 until it drops below 22
        // (emulating the fact that ace is either a 1 or a 11)
        var i = Cards.Count(x => x.Number == 1);
        while (val > 21 && i-- > 0)
        {
            val -= 10;
        }
        return val;
    }

    public int GetRawHandValue()
    {
        return Cards.Sum(x => x.Number == 1 ? 11 : x.Number >= 10 ? 10 : x.Number);
    }
}

public class Dealer : Player
{

}

public class User : Player
{
    public enum UserState
    {
        Waiting,
        Stand,
        Bust,
        Blackjack,
        Won,
        Lost
    }

    public User(IUser user, long bet)
    {
        if (bet <= 0)
            throw new ArgumentOutOfRangeException(nameof(bet));

        this.Bet = bet;
        this.DiscordUser = user;
    }

    public UserState State { get; set; } = UserState.Waiting;
    public long Bet { get; set; }
    public IUser DiscordUser { get; }
    public bool Done => State != UserState.Waiting;
}