feat(objects): ExtractOpl — decode OPL buffer into cliloc/args/text lines

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Projects/UOContent.Tests/Tests/Commands/Objects/ObjectIntrospectionOplTests.cs

@@ -0,0 +1,17 @@
+using Server.Commands;
+using Server.Items;
+using Xunit;
+
+namespace UOContent.Tests.Commands.Objects;
+
+[Collection("Sequential UOContent Tests")]
+public class ObjectIntrospectionOplTests
+{
+    [Fact]
+    public void ExtractOpl_captures_the_runebook_name_cliloc()
+    {
+        // Runebook.LabelNumber is 1041267 ("runebook") — it appears as an OPL line.
+        var opl = ObjectIntrospection.ExtractOpl(typeof(Runebook));
+        Assert.Contains(opl, line => line.Cliloc == 1041267);
+    }
+}

Projects/UOContent/Commands/Object Creation/ObjectIntrospection.cs

@@ -1,6 +1,8 @@
 using System;
+using System.Buffers.Binary;
 using System.Collections.Generic;
 using System.Reflection;
+using System.Text;
 using Server.Items;
 
 namespace Server.Commands;
@@ -120,4 +122,66 @@ public static class ObjectIntrospection
 
         return docs;
     }
+
+    public static List<OplLine> ExtractOpl(Type type)
+    {
+        if (type.IsAssignableTo(typeof(Item)))
+        {
+            var item = type.CreateInstance<Item>();
+            try
+            {
+                var opl = new ObjectPropertyList(item);
+                item.GetProperties(opl);
+                return DecodeOpl(opl);
+            }
+            finally
+            {
+                item.Delete();
+            }
+        }
+
+        if (type.IsAssignableTo(typeof(Mobile)))
+        {
+            var m = type.CreateInstance<Mobile>();
+            try
+            {
+                var opl = new ObjectPropertyList(m);
+                m.GetProperties(opl);
+                return DecodeOpl(opl);
+            }
+            finally
+            {
+                m.Delete();
+            }
+        }
+
+        return [];
+    }
+
+    private static List<OplLine> DecodeOpl(ObjectPropertyList opl)
+    {
+        opl.Terminate();
+        var buffer = opl.Buffer;
+        var lines = new List<OplLine>();
+        var pos = 15; // fixed OPL header length
+
+        while (pos + 4 <= buffer.Length)
+        {
+            var cliloc = BinaryPrimitives.ReadInt32BigEndian(buffer.AsSpan(pos));
+            pos += 4;
+            if (cliloc == 0)
+            {
+                break;
+            }
+
+            var byteLen = BinaryPrimitives.ReadUInt16BigEndian(buffer.AsSpan(pos));
+            pos += 2;
+            var args = byteLen > 0 ? Encoding.Unicode.GetString(buffer, pos, byteLen) : null;
+            pos += byteLen;
+
+            lines.Add(new OplLine { Cliloc = cliloc, Args = args, Text = Localization.GetText(cliloc) });
+        }
+
+        return lines;
+    }
 }