MauMau-Server/Mau/Game.cs

using System.Net.WebSockets;
using System.Text.Json;

namespace MauMau_Server.Mau;

public class Game
{
    public readonly Deck Deck = new();
    public Card CurrentCard;
    public List<Player> Players = new();
    public Player CurrentPlayer;
    public int TurnDirection = 1;

    public Game()
    {
        CurrentCard = Deck.DrawCard();
        Deck.AddCardToUsedDeck(CurrentCard);
    }

    public void AddPlayerToGame(string playerId, WebSocket socket)
    {
        var player = new Player("Koetje " + playerId.Split('-')[0], playerId, socket)
        {
            Hand = Deck.DrawCards(8)
        };
        Players.Add(player);
        if (Players.Count == 1) CurrentPlayer = player;
    }
    
    public void RemovePlayer(string playerId)
    {
        var player = GetPlayer(playerId);
        Players.Remove(player);
    }

    public void HandleAction(string playerId, ActionDTO action)
    {
        var player = GetPlayer(playerId);
        if (CurrentPlayer != player) return;
        switch (action.Action)
        {
            case "PLAYCARD":
            {
                var card = JsonSerializer.Deserialize<CardDTO>(action.Data).ToCard();
                PlayCard(player, card);
                break;
            }
            case "DRAW":
                DrawCard(player);
                break;
        }
    }

    private void PlayCard(Player player, Card card)
    {
        var hand = player.Hand;
        if (!IsCardInHand(hand, card) || !IsCardPlayable(CurrentCard, card)) return;
        Deck.AddCardToUsedDeck(card);
        hand.Remove(GetSameCardFromHand(hand, card));
        CurrentCard = card;
        HandleNextPlayer(card);
    }

    private void HandleNextPlayer(Card card)
    {
        switch (card.CardValue)
        {
            case CardValue.TWO:
            {
                var nextPlayer = GetNextPlayer();
                var cardsToDraw = Deck.DrawCards(2);
                foreach (var drawnCard in cardsToDraw)
                {
                    nextPlayer.Hand.Add(drawnCard);
                }
                CurrentPlayer = GetNextPlayer(2);
                break;
            }
            case CardValue.SEVEN:
            case CardValue.KING:
                break;
            case CardValue.EIGHT:
                CurrentPlayer = GetNextPlayer(2);
                break;
            case CardValue.ACE:
                if (Players.Count > 2)
                {
                    TurnDirection *= -1;
                    CurrentPlayer = GetNextPlayer();
                }
                break;
            case CardValue.THREE:
            case CardValue.FOUR:
            case CardValue.FIVE:
            case CardValue.SIX:
            case CardValue.NINE:
            case CardValue.TEN:
            case CardValue.JACK:
            case CardValue.QUEEN:
            default:
                CurrentPlayer = GetNextPlayer();
                break;
        }
    }

    private void DrawCard(Player player)
    {
        player.Hand.Add(Deck.DrawCard());
        CurrentPlayer = GetNextPlayer();
    }

    private Player GetNextPlayer(int numberOfPlayers = 1)
    {
        var index = Players.IndexOf(CurrentPlayer);
        for (var i = 0; i < numberOfPlayers; i++)
        {
            index += TurnDirection;
            if (index >= Players.Count) index = 0;
            if (index < 0) index = Players.Count - 1;
        }

        return Players[index];
    }

    public Player GetPlayer(string playerId)
    {
        return Players.FirstOrDefault(p => p.IsMe(playerId));
    }

    private static Card GetSameCardFromHand(IEnumerable<Card> hand, Card card)
    {
        return hand.FirstOrDefault(handCard => IsSameCard(handCard, card));
    }

    private static bool IsCardPlayable(Card currentCard, Card playedCard)
    {
        return IsSameCardType(currentCard, playedCard) || IsSameCardValue(currentCard, playedCard);
    }

    private static bool IsCardInHand(IEnumerable<Card> hand, Card card)
    {
        return hand.Any(handCard => IsSameCard(handCard, card));
    }

    private static bool IsSameCard(Card card1, Card card2)
    {
        return IsSameCardType(card1, card2) && IsSameCardValue(card1, card2);
    }

    private static bool IsSameCardType(Card card1, Card card2)
    {
        return card1.CardType == card2.CardType;
    }

    private static bool IsSameCardValue(Card card1, Card card2)
    {
        return card1.CardValue == card2.CardValue;
    }
}