Fixed some bugs and added new features that came up while testing:

- Check for allowed card type was before the check for the mau cards, which caused incorrect cards to be played and mau cards to be passed to wrong players
- Ending with a special card is now a faulty move, which grants the player 5 fault cards now
- Grabbed cards could be registered as playable as it didnt include next allowed card type
- If the first card is a joker, set the next allowed card type to a random other card type to prevent an instant softlock
- Other cleanup :)

Mau/Card.cs

@@ -31,22 +31,37 @@ public static class CardExtensions
     {
         return card1.IsSameCardType(card2) && card1.IsSameCardValue(card2);
     }
-    
+
     public static bool IsSameCardType(this Card card1, Card card2)
     {
         return card1.CardType == card2.CardType;
     }
-    
+
     public static bool IsSameCardValue(this Card card1, Card card2)
     {
         return card1.CardValue == card2.CardValue;
     }
-    
+
     public static bool CanBePlayedOn(this Card playedCard, Card currentCard)
     {
         return playedCard.IsSameCardType(currentCard)
-            || playedCard.IsSameCardValue(currentCard)
+               || playedCard.IsSameCardValue(currentCard)
-            || playedCard.CardType == CardType.JOKER;
+               || playedCard.CardType == CardType.JOKER;
+    }
+
+    public static bool IsSpecialCard(this Card card)
+    {
+        return card.IsMauCard() || card.CardValue is
+            CardValue.SEVEN or
+            CardValue.EIGHT or
+            CardValue.JACK or
+            CardValue.KING or
+            CardValue.ACE;
+    }
+
+    public static bool IsMauCard(this Card card)
+    {
+        return card.CardType == CardType.JOKER || card.CardValue is CardValue.TWO;
     }
 }
 

Mau/Deck.cs

@@ -2,9 +2,9 @@
 
 public class Deck
 {
-    private List<Card> _unusedDeck = new();
+    private readonly List<Card> _unusedDeck = new();
-    private List<Card> _usedDeck = new();
+    private readonly List<Card> _usedDeck = new();
-    public Card CurrentCard;
+    public Card CurrentCard { get; private set; }
 
     /**
      * <summary>
@@ -15,23 +15,20 @@ public class Deck
     {
         CreateSet();
         ShuffleDeck();
-        CurrentCard = DrawCard();
+        var initialCard = DrawCard();
-        _usedDeck.Add(CurrentCard);
+        CurrentCard = initialCard;
-
-        if (CurrentCard.CardType != CardType.JOKER) return;
-        CurrentCard = DrawCard();
-        _usedDeck.Add(CurrentCard);
     }
     
     /**
      * <summary>
-     * Adds the given card to the used cards deck.
+     * Adds the given card to the used cards deck and sets the current card to the given card.
      * </summary>
      * <param name="card">The card to add to the used cards deck.</param>
      */
     public void AddCardToUsedDeck(Card card)
     {
         _usedDeck.Add(card);
+        CurrentCard = card;
     }
 
     /**
@@ -44,29 +41,6 @@ public class Deck
     {
         _usedDeck.AddRange(cards);
     }
-
-    /**
-     * <summary>
-     * Creates a new deck of cards and adds them to the unused deck.
-     * </summary>
-     */
-    private void CreateSet()
-    {
-        foreach (CardType cardType in Enum.GetValues(typeof(CardType)))
-        {
-            if (cardType == CardType.JOKER)
-            {
-                _unusedDeck.Add(new Card(cardType, CardValue.RED));
-                _unusedDeck.Add(new Card(cardType, CardValue.BLACK));
-                continue;
-            }
-            foreach (CardValue cardValue in Enum.GetValues(typeof(CardValue)))
-            {
-                if (cardValue is CardValue.RED or CardValue.BLACK) continue;
-                _unusedDeck.Add(new Card(cardType, cardValue));
-            }
-        }
-    }
     
     /**
      * <summary>
@@ -97,6 +71,29 @@ public class Deck
         }
         return cards;
     }
+    
+    /**
+     * <summary>
+     * Creates a new deck of cards and adds them to the unused deck.
+     * </summary>
+     */
+    private void CreateSet()
+    {
+        foreach (CardType cardType in Enum.GetValues(typeof(CardType)))
+        {
+            if (cardType == CardType.JOKER)
+            {
+                _unusedDeck.Add(new Card(cardType, CardValue.RED));
+                _unusedDeck.Add(new Card(cardType, CardValue.BLACK));
+                continue;
+            }
+            foreach (CardValue cardValue in Enum.GetValues(typeof(CardValue)))
+            {
+                if (cardValue is CardValue.RED or CardValue.BLACK) continue;
+                _unusedDeck.Add(new Card(cardType, cardValue));
+            }
+        }
+    }
 
     /**
      * <summary>
@@ -124,6 +121,9 @@ public class Deck
      */
     private void ShuffleDeck()
     {
-        _unusedDeck = _unusedDeck.OrderBy(x => Guid.NewGuid()).ToList();
+        var unusedDeckCopy = new List<Card>(_unusedDeck);
+        _unusedDeck.Clear();
+        unusedDeckCopy = unusedDeckCopy.OrderBy(x => Guid.NewGuid()).ToList();
+        _unusedDeck.AddRange(unusedDeckCopy);
     }
 }

Mau/Game.cs

@@ -9,19 +9,38 @@ namespace MauMau_Server.Mau;
 
 public class Game : RoomType
 {
+    // Helpers
     private readonly Deck _deck = new();
     private readonly TurnManager _turnManager = new();
-    public readonly List<Card> MauCardBuffer = new();
+    
-    public CardType? NextAllowedCardType { get; set; }
+    // Game state
+    private readonly List<Card> _mauCardBuffer = new();
+    private CardType? NextAllowedCardType { get; set; }
+    
+    // Variables
+    private const int NumberOfFaultcards = 5;
+    private const int NumberOfStartCards = 8;
 
     public Game(Room.Room room, IEnumerable<ConnectionInstance> connections) : base(room)
     {
+        // If the current card is a joker, set the next allowed card type to a random card type
+        if (_deck.CurrentCard.CardType == CardType.JOKER)
+        {
+            // In the case the random card type is a joker, try again until it is not
+            do
+            {
+                var cardTypes = Enum.GetValues(typeof(CardType));
+                var randomIndex = new Random().Next(cardTypes.Length);
+                NextAllowedCardType = (CardType?)cardTypes.GetValue(randomIndex) ?? CardType.SPADES;
+            } while (NextAllowedCardType == CardType.JOKER);
+        }
+        
         // Convert all the connections to players
         List<Player> players = new();
         foreach (var player in connections.Select(connection => new Player(connection)))
         {
             // Give the new player a hand of cards
-            var initialHand = _deck.DrawCards(8);
+            var initialHand = _deck.DrawCards(NumberOfStartCards);
             player.GiveCards(initialHand);
             players.Add(player);
         }
@@ -155,7 +174,7 @@ public class Game : RoomType
     {
         // If there are cards in the MauCardBuffer, this means there are multiple cards that need to be drawn
         // Otherwise, just draw a single card
-        if (MauCardBuffer.Count > 0)
+        if (_mauCardBuffer.Count > 0)
         {
             // Count the amount of cards that need to be drawn
             var totalCards = CountMauCardBuffer();
@@ -178,7 +197,7 @@ public class Game : RoomType
             player.GiveCard(drawnCard);
 
             // Change the player if the drawn card cannot be played
-            if (!drawnCard.CanBePlayedOn(_deck.CurrentCard))
+            if (!CardCanBePlayed(drawnCard))
             {
                 _turnManager.ChangeTurnTo();
             }
@@ -217,43 +236,26 @@ public class Game : RoomType
         {
             return;
         }
-        
+
-        // Check if there is a specific card type that is allowed to be played
+        if (!CardCanBePlayed(playerCard)) return;
-        if (NextAllowedCardType != null)
-        {
-            // If the card is not the allowed card type, not the same value or a joker, ignore the message
-            if (playerCard.CardType != NextAllowedCardType && playerCard.CardType != CardType.JOKER && playerCard.CardValue != _deck.CurrentCard.CardValue)
-            {
-                return;
-            }
-            // Reset the allowed card type, so the next player has the normal same type and same value rules
-            NextAllowedCardType = null;
-        } else if (MauCardBuffer.Count > 0)
-        {
-            // If there are queued mau cards, the player can only another mau card (or draw)
-            if (playerCard.CardType != CardType.JOKER && playerCard.CardValue != CardValue.TWO)
-            {
-                return;
-            }
-        }
-        else
-        {
-            // Check if the card can be played on the current card, if not, ignore the message
-            if (!playerCard.CanBePlayedOn(_deck.CurrentCard))
-            {
-                return;
-            }
-        }
         
         // Remove the card from the player's hand
         player.Hand.Remove(playerCard);
 
+        // If the player's last played card is a special card, give the player 5 fault cards
+        if (player.Hand.Count < 1 && playerCard.IsSpecialCard())
+        {
+            var faultCards = _deck.DrawCards(NumberOfFaultcards);
+            player.GiveCards(faultCards);
+        }
+
         // Add the card to the used deck
         _deck.AddCardToUsedDeck(playerCard);
+        
+        // Reset the allowed card type, so the next player has the normal same type and same value rules
+        NextAllowedCardType = null;
 
-        // Set the new current card
+        // If the player has no cards left, end the game with player as winner
-        _deck.CurrentCard = playerCard;
-
         if (player.Hand.Count == 0)
         {
             EndGame(player);
@@ -280,13 +282,13 @@ public class Game : RoomType
             case CardValue.RED:
             case CardValue.BLACK:
             {
-                MauCardBuffer.Add(card);
+                _mauCardBuffer.Add(card);
                 _turnManager.CurrentPlayer.State = PlayerState.CHOOSE;
                 break;
             }
             case CardValue.TWO:
             {
-                MauCardBuffer.Add(card);
+                _mauCardBuffer.Add(card);
                 _turnManager.ChangeTurnTo();
                 break;
             }
@@ -319,6 +321,37 @@ public class Game : RoomType
         }
     }
 
+    /**
+     * <summary>
+     * Check if the card can be played with the current game state.
+     * <list type="bullet">
+     * <item>The player can only play a mau card if there are pending mau cards (or draw)</item>
+     * <item>If there is a next allowed card type, the player can only play that card type, a joker or a card with the same value as the current card</item>
+     * <item>Otherwise, the player can play a card that has the same type, same value or is a joker</item>
+     * </list>
+     * </summary>
+     * <returns>True if the given card could be played</returns>
+     */
+    private bool CardCanBePlayed(Card card)
+    {
+        // Check if there are pending mau cards played
+        if (_mauCardBuffer.Count > 0)
+        {
+            // If so, the card must be a mau card
+            return card.IsMauCard();
+        }
+
+        // Check if there is a next allowed card type
+        if (NextAllowedCardType != null)
+        {
+            // If so, the card must be the allowed card type, a joker or the same value as the current card
+            return card.CardType == NextAllowedCardType || card.CardType == CardType.JOKER || card.CardValue == _deck.CurrentCard.CardValue;
+        }
+        
+        // Otherwise, use the normal rules
+        return card.CanBePlayedOn(_deck.CurrentCard);
+    }
+
     /**
      * <summary>
      * Count the amount of cards that need to be drawn from the MauCardBuffer. This method also clears the buffer.
@@ -328,7 +361,7 @@ public class Game : RoomType
     private int CountMauCardBuffer()
     {
         var totalCards = 0;
-        foreach (var card in MauCardBuffer)
+        foreach (var card in _mauCardBuffer)
         {
             if (card.CardType == CardType.JOKER)
             {
@@ -342,7 +375,7 @@ public class Game : RoomType
                 continue;
             }
         }
-        MauCardBuffer.Clear();
+        _mauCardBuffer.Clear();
         return totalCards;
     }