WIP checkpoint: US-1: Asset Import Pipeline \u2014 glTF upload endpoint with metadata extraction

backend/app/routers/assets.py

@@ -37,6 +37,7 @@ class AssetResponse(BaseModel):
     file_path: str
     file_size: Optional[int]
     mime_type: Optional[str]
+    metadata_json: Optional[dict]
     world_id: Optional[int]
     owner_id: int
     is_public: bool
@@ -64,6 +65,75 @@ def _sanitize_filename(filename: str) -> str:
     return safe or "file"
 
 
+def _extract_gltf_metadata(content: bytes) -> Optional[dict]:
+    """Extract metadata from a glTF/GLB file.
+
+    Returns a dict with mesh_count, vertex_count, has_animation, texture_refs
+    if the file is a valid glTF/GLB, or None otherwise.
+    """
+    try:
+        import gltflib
+    except ImportError:
+        return None
+
+    try:
+        model = gltflib.GLFModel.from_json(content)
+    except Exception:
+        return None
+
+    # Count meshes
+    meshes = model.meshes or []
+    mesh_count = len(meshes)
+
+    # Count total vertices across all primitives
+    vertex_count = 0
+    for mesh in meshes:
+        primitives = mesh.primitives or []
+        for primitive in primitives:
+            indices = primitive.indices
+            if indices is not None:
+                # Use index count
+                accessor = model.accessors[indices] if indices < len(model.accessors or []) else None
+                if accessor and accessor.count is not None:
+                    vertex_count += accessor.count
+                else:
+                    vertex_count += 1  # fallback
+            else:
+                # No indices — count from POSITION attribute
+                if primitive.attributes and primitive.attributes.POSITION is not None:
+                    accessor = model.accessors[primitive.attributes.POSITION] if primitive.attributes.POSITION < len(model.accessors or []) else None
+                    if accessor and accessor.count is not None:
+                        vertex_count += accessor.count
+                    else:
+                        vertex_count += 1  # fallback
+
+    # Check for animations
+    animations = model.animations or []
+    has_animation = len(animations) > 0
+
+    # Collect texture references
+    texture_refs = []
+    textures = model.textures or []
+    for texture in textures:
+        if texture.source is not None and texture.source < len(model.images or []):
+            image = model.images[texture.source]
+            ref = {}
+            if image.name:
+                ref["name"] = image.name
+            if image.uri:
+                ref["uri"] = image.uri
+            if image.mimeType:
+                ref["mime_type"] = image.mimeType
+            texture_refs.append(ref)
+
+    return {
+        "mesh_count": mesh_count,
+        "vertex_count": vertex_count,
+        "has_animation": has_animation,
+        "texture_refs": texture_refs,
+    }
+
+
 # --- Endpoints ---
 
 @router.post("/", response_model=AssetResponse, status_code=201)
@@ -204,6 +274,13 @@ async def upload_asset_file(
     asset.mime_type = file.content_type
     asset.file_size = file_size
 
+    # Extract glTF metadata for glTF/GLB files.
+    filename_lower = (file.filename or "").lower()
+    if filename_lower.endswith(".glb") or filename_lower.endswith(".gltf"):
+        metadata = _extract_gltf_metadata(content)
+        if metadata is not None:
+            asset.metadata_json = str(metadata)
+
     await db.commit()
     await db.refresh(asset)
     return asset