From d45fc0601db457fa0f4c4ba82459f363ca59ccd0 Mon Sep 17 00:00:00 2001
From: Ryan Schultz <ryan@openingdesign.com>
Date: Mon, 16 Mar 2026 11:39:59 -0500
Subject: [PATCH] copy_representation: preserve MappedRepresentation structure
 for IfcTypeProduct

Incorporates the per-map copy logic from build-0.8.5 that preserves nested
MappedRepresentation structure instead of blindly using copy_deep, while
retaining HasShapeAspects and StyledByItem handling from this branch.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 src/bonsai/bonsai/tool/root.py | 42 +++++++++++++++++++++++-----------
 1 file changed, 29 insertions(+), 13 deletions(-)

diff --git a/src/bonsai/bonsai/tool/root.py b/src/bonsai/bonsai/tool/root.py
index e7d612ba73..ccc76b9526 100644
--- a/src/bonsai/bonsai/tool/root.py
+++ b/src/bonsai/bonsai/tool/root.py
@@ -124,17 +124,33 @@ class Root(bonsai.core.tool.Root):
             if not source.RepresentationMaps:
                 return copied_entities
 
-            new_representation_maps = []
-            for map in source.RepresentationMaps:
-                new_map = ifcopenshell.util.element.copy_deep(
-                    tool.Ifc.get(),
-                    map,
-                    exclude=["IfcGeometricRepresentationContext"],
-                    exclude_callback=exclude_callback,
-                    copied_entities=copied_entities,
-                )
+            # Copy representation maps while preserving mapped representation structures
+            new_maps = []
+            for rep_map in source.RepresentationMaps:
+                source_rep = rep_map.MappedRepresentation
 
-                for aspect in map.HasShapeAspects:
+                # Copy the map itself
+                new_map = ifcopenshell.util.element.copy(tool.Ifc.get(), rep_map)
+
+                # Handle the mapped representation - preserve mapping structure if present
+                if (source_rep.RepresentationType == 'MappedRepresentation' and
+                    len(source_rep.Items) == 1 and
+                    source_rep.Items[0].is_a("IfcMappedItem")):
+                    # This is a mapped representation - preserve the structure
+                    new_rep = ifcopenshell.util.element.copy(tool.Ifc.get(), source_rep)
+                    new_rep.Items = [ifcopenshell.util.element.copy(tool.Ifc.get(), item) for item in source_rep.Items]
+                    new_map.MappedRepresentation = new_rep
+                else:
+                    # Not a mapped representation - use copy_deep as before
+                    new_map.MappedRepresentation = ifcopenshell.util.element.copy_deep(
+                        tool.Ifc.get(),
+                        source_rep,
+                        exclude=["IfcGeometricRepresentationContext"],
+                        exclude_callback=exclude_callback,
+                        copied_entities=copied_entities,
+                    )
+
+                for aspect in rep_map.HasShapeAspects:
                     ifcopenshell.util.element.copy_deep(
                         tool.Ifc.get(),
                         aspect,
@@ -143,15 +159,15 @@ class Root(bonsai.core.tool.Root):
                         copied_entities=copied_entities,
                     )
 
-                for item in map.MappedRepresentation.Items:
+                for item in rep_map.MappedRepresentation.Items:
                     if item.StyledByItem:
                         for styled_by in item.StyledByItem:
                             new_styled_by = ifcopenshell.util.element.copy(tool.Ifc.get(), styled_by)
                             new_styled_by.Item = copied_entities[styled_by.Item.id()]
                             copied_entities[styled_by.id()] = new_styled_by
 
-                new_representation_maps.append(new_map)
-            dest.RepresentationMaps = new_representation_maps
+                new_maps.append(new_map)
+            dest.RepresentationMaps = new_maps
         return copied_entities
 
     @classmethod