Added MultipleDeck which can be used in place of the old QuadDeck, converted cards from classes to records as it is useful to have default equality checks.

src/Nadeko.Econ/Deck/NewCard.cs

@@ -1,15 +1,5 @@
 namespace Nadeko.Econ;
 
-public abstract class NewCard<TSuit, TValue>
+public abstract record class NewCard<TSuit, TValue>(TSuit Suit, TValue Value)
     where TSuit : struct, Enum
-    where TValue : struct, Enum
-{
-    public TSuit Suit { get; }
-    public TValue Value { get; }
-
-    public NewCard(TSuit suit, TValue value)
-    {
-        Suit = suit;
-        Value = value;
-    }
-}
+    where TValue : struct, Enum;

src/Nadeko.Econ/Deck/NewDeck.cs

@@ -5,26 +5,18 @@ public abstract class NewDeck<TCard, TSuit, TValue>
     where TSuit : struct, Enum
     where TValue : struct, Enum
 {
+    protected static readonly TSuit[] _suits = Enum.GetValues<TSuit>();
+    protected static readonly TValue[] _values = Enum.GetValues<TValue>();
+    
     public virtual int CurrentCount
         => _cards.Count;
     
     public virtual int TotalCount { get; }
 
-    private readonly LinkedList<TCard> _cards = new();
+    protected readonly LinkedList<TCard> _cards = new();
     public NewDeck()
     {
-        var suits = Enum.GetValues<TSuit>();
-        var values = Enum.GetValues<TValue>();
-
-        TotalCount =  suits.Length * values.Length;
-        
-        foreach (var suit in suits)
-        {
-            foreach (var val in values)
-            {
-                _cards.AddLast((TCard)Activator.CreateInstance(typeof(TCard), suit, val)!);
-            }
-        }
+        TotalCount = _suits.Length * _values.Length;
     }
 
     public virtual TCard? Draw()

src/Nadeko.Econ/Deck/Regular/MultipleRegularDeck/MultipleRegularDeck.cs

@@ -0,0 +1,28 @@
+namespace Nadeko.Econ;
+
+public class MultipleRegularDeck : NewDeck<RegularCard, RegularSuit, RegularValue>
+{
+    private int Decks { get; }
+
+    public override int TotalCount { get; }
+
+    public MultipleRegularDeck(int decks = 1)
+    {
+        if (decks < 1)
+            throw new ArgumentOutOfRangeException(nameof(decks), "Has to be more than 0");
+
+        Decks = decks;
+        TotalCount = base.TotalCount * decks;
+        
+        for (var i = 0; i < Decks; i++)
+        {
+            foreach (var suit in _suits)
+            {
+                foreach (var val in _values)
+                {
+                    _cards.AddLast((RegularCard)Activator.CreateInstance(typeof(RegularCard), suit, val)!);
+                }
+            }
+        }
+    }
+}

src/Nadeko.Econ/Deck/Regular/RegularCard.cs

@@ -1,20 +1,4 @@
 namespace Nadeko.Econ;
 
-public sealed class RegularCard : NewCard<RegularSuit, RegularValue>
-{
-    public RegularCard(RegularSuit suit, RegularValue value) : base(suit, value)
-    {
-    }
-
-    private bool Equals(RegularCard other)
-        => other.Suit == this.Suit && other.Value == this.Value;
-
-    public override bool Equals(object? obj)
-        => ReferenceEquals(this, obj) || obj is RegularCard other && Equals(other);
-
-    public override int GetHashCode()
-        => Suit.GetHashCode() * 17 + Value.GetHashCode();
-
-    public override string ToString()
-        => $"{Value.ToString()}-{Suit.ToString()}";
-}
+public sealed record class RegularCard(RegularSuit Suit, RegularValue Value) 
+    : NewCard<RegularSuit, RegularValue>(Suit, Value);

src/Nadeko.Econ/Deck/Regular/RegularDeck.cs

@@ -2,4 +2,14 @@
 
 public sealed class RegularDeck : NewDeck<RegularCard, RegularSuit, RegularValue>
 {
+    public RegularDeck()
+    {
+        foreach (var suit in _suits)
+        {
+            foreach (var val in _values)
+            {
+                _cards.AddLast((RegularCard)Activator.CreateInstance(typeof(RegularCard), suit, val)!);
+            }
+        }
+    }
 }

src/NadekoBot.Tests/NewDeckTests.cs

@@ -42,7 +42,7 @@ public class NewDeckTests
         var lastCard = _deck.Draw();
         
         Assert.IsNotNull(lastCard);
-        Assert.AreEqual(lastCard, new RegularCard(RegularSuit.Spades, RegularValue.King));
+        Assert.AreEqual(new RegularCard(RegularSuit.Spades, RegularValue.King), lastCard);
 
         var noCard = _deck.Draw();
         
@@ -65,7 +65,19 @@ public class NewDeckTests
         var ace = _deck.Peek()!;
 
         var tenOfSpades = _deck.Peek(48);
-        Assert.AreEqual(ace, new RegularCard(RegularSuit.Hearts, RegularValue.Ace));
-        Assert.AreEqual(tenOfSpades, new RegularCard(RegularSuit.Spades, RegularValue.Ten));
+        Assert.AreEqual(new RegularCard(RegularSuit.Hearts, RegularValue.Ace), ace);
+        Assert.AreEqual(new RegularCard(RegularSuit.Spades, RegularValue.Ten), tenOfSpades);
+    }
+
+    [Test]
+    public void TestMultipleDeck()
+    {
+        var quadDeck = new MultipleRegularDeck(4);
+        var count = quadDeck.TotalCount;
+        
+        Assert.AreEqual(52 * 4, count);
+
+        var card = quadDeck.Peek(54);
+        Assert.AreEqual(new RegularCard(RegularSuit.Hearts, RegularValue.Three), card);
     }
 }