Blackjack (#18)

* Blackjack

* idk

KfChatDotNetBot/Models/BlackjackGameMetaModel.cs

@@ -0,0 +1,149 @@
+namespace KfChatDotNetBot.Models;
+
+public class BlackjackGameMetaModel
+{
+    /// <summary>
+    /// The wager ID associated with this game
+    /// </summary>
+    public required int WagerId { get; set; }
+    
+    /// <summary>
+    /// Player's hand
+    /// </summary>
+    public required List<Card> PlayerHand { get; set; }
+    
+    /// <summary>
+    /// Dealer's hand
+    /// </summary>
+    public required List<Card> DealerHand { get; set; }
+    
+    /// <summary>
+    /// Remaining cards in the deck
+    /// </summary>
+    public required List<Card> Deck { get; set; }
+    
+    /// <summary>
+    /// When the game was started
+    /// </summary>
+    public required DateTimeOffset GameStarted { get; set; }
+    
+    /// <summary>
+    /// Whether player has doubled down (can only hit once more)
+    /// </summary>
+    public bool HasDoubledDown { get; set; } = false;
+}
+
+public class Card
+{
+    /// <summary>
+    /// Card rank (2-10, J, Q, K, A)
+    /// </summary>
+    public required string Rank { get; set; }
+    
+    /// <summary>
+    /// Card suit (♠, ♥, ♦, ♣)
+    /// </summary>
+    public required string Suit { get; set; }
+    
+    /// <summary>
+    /// Get the blackjack value of this card
+    /// </summary>
+    public int GetValue()
+    {
+        return Rank switch
+        {
+            "A" => 11, // Aces are handled specially in hand calculation
+            "K" or "Q" or "J" => 10,
+            _ => int.Parse(Rank)
+        };
+    }
+    
+    /// <summary>
+    /// Display card as string
+    /// </summary>
+    public override string ToString()
+    {
+        return $"{Rank}{Suit}";
+    }
+}
+
+public static class BlackjackHelper
+{
+    private static readonly string[] Ranks = { "2", "3", "4", "5", "6", "7", "8", "9", "10", "J", "Q", "K", "A" };
+    private static readonly string[] Suits = { "♠", "♥", "♦", "♣" };
+    
+    /// <summary>
+    /// Create a new shuffled deck
+    /// </summary>
+    public static List<Card> CreateDeck(Random random)
+    {
+        var deck = new List<Card>();
+        foreach (var suit in Suits)
+        {
+            foreach (var rank in Ranks)
+            {
+                deck.Add(new Card { Rank = rank, Suit = suit });
+            }
+        }
+        
+        // Shuffle using Fisher-Yates
+        for (int i = deck.Count - 1; i > 0; i--)
+        {
+            int j = random.Next(0, i + 1);
+            (deck[i], deck[j]) = (deck[j], deck[i]);
+        }
+        
+        return deck;
+    }
+    
+    /// <summary>
+    /// Calculate hand value with proper Ace handling
+    /// </summary>
+    public static int CalculateHandValue(List<Card> hand)
+    {
+        int value = 0;
+        int aces = 0;
+        
+        foreach (var card in hand)
+        {
+            if (card.Rank == "A")
+            {
+                aces++;
+                value += 11;
+            }
+            else
+            {
+                value += card.GetValue();
+            }
+        }
+        
+        // Convert Aces from 11 to 1 if needed to avoid bust
+        while (value > 21 && aces > 0)
+        {
+            value -= 10;
+            aces--;
+        }
+        
+        return value;
+    }
+    
+    /// <summary>
+    /// Check if hand is blackjack (21 with 2 cards)
+    /// </summary>
+    public static bool IsBlackjack(List<Card> hand)
+    {
+        return hand.Count == 2 && CalculateHandValue(hand) == 21;
+    }
+    
+    /// <summary>
+    /// Format hand for display
+    /// </summary>
+    public static string FormatHand(List<Card> hand, bool hideFirstCard = false)
+    {
+        if (hideFirstCard && hand.Count > 0)
+        {
+            return $"[HIDDEN] {string.Join(" ", hand.Skip(1).Select(c => c.ToString()))}";
+        }
+        return string.Join(" ", hand.Select(c => c.ToString()));
+    }
+}

KfChatDotNetBot/Models/DbModels/MoneyDbModels.cs

@@ -291,7 +291,8 @@ public enum WagerGame
     [Description("Guess what number I'm thinking of")]
     GuessWhatNumber,
     Wheel,
-    Slots
+    Slots,
+    Blackjack
 }
 
 public enum GamblerState