Pack opening

SVSim.EmulatedEntrypoint/Services/DbCardPoolProvider.cs

@@ -0,0 +1,42 @@
+using Microsoft.EntityFrameworkCore;
+using SVSim.Database;
+using SVSim.Database.Enums;
+using SVSim.Database.Models;
+
+namespace SVSim.EmulatedEntrypoint.Services;
+
+public class DbCardPoolProvider : ICardPoolProvider
+{
+    private readonly SVSimDbContext _db;
+    public DbCardPoolProvider(SVSimDbContext db) { _db = db; }
+
+    public IReadOnlyList<ShadowverseCardEntry> GetPool(PackConfigEntry pack)
+    {
+        switch (pack.PackCategory)
+        {
+            case PackCategory.None:
+            case PackCategory.LegendCardPack:
+                // Standard pack — pool comes from the card set whose id equals base_pack_id.
+                return _db.CardSets
+                    .Include(s => s.Cards)
+                    .Where(s => s.Id == pack.BasePackId)
+                    .SelectMany(s => s.Cards)
+                    .ToList();
+
+            case PackCategory.SpecialCardPack:
+            case PackCategory.LimitedSpecialCardPack:
+                // Legendary-special packs pull from all rotation sets. The slot-8 forced-Legendary
+                // rule in PackOpenService delivers the "at least one legendary" promise.
+                return _db.CardSets
+                    .Where(s => s.IsInRotation)
+                    .Include(s => s.Cards)
+                    .SelectMany(s => s.Cards)
+                    .Distinct()
+                    .ToList();
+
+            default:
+                // Skin / starter / leader-skin packs aren't drawn in v1 — controller rejects earlier.
+                return Array.Empty<ShadowverseCardEntry>();
+        }
+    }
+}