feat(headless): share immutable gameplay content

src/AcDream.Content/RetailDataIdResolver.cs

@@ -0,0 +1,28 @@
+using DatReaderWriter;
+using DatReaderWriter.DBObjs;
+
+namespace AcDream.Content;
+
+/// <summary>
+/// Ports <c>DBCache::GetDIDFromEnumStatic @ 0x00413940</c>: the portal master map
+/// selects an enum category, then that category map resolves the client enum value.
+/// </summary>
+public static class RetailDataIdResolver
+{
+    public static uint Resolve(IDatReaderWriter dats, uint enumValue, uint enumCategory)
+    {
+        ArgumentNullException.ThrowIfNull(dats);
+
+        uint masterDid = (uint)dats.Portal.Db.Header.MasterMapId;
+        if (masterDid == 0
+            || !dats.Portal.TryGet<EnumIDMap>(masterDid, out var master)
+            || master is null
+            || !master.ClientEnumToID.TryGetValue(enumCategory, out uint subMapDid)
+            || !dats.Portal.TryGet<EnumIDMap>(subMapDid, out var subMap)
+            || subMap is null
+            || !subMap.ClientEnumToID.TryGetValue(enumValue, out uint did))
+            return 0u;
+
+        return did;
+    }
+}