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

backend/app/models/asset.py

@@ -3,6 +3,8 @@ from sqlalchemy.dialects.postgresql import ENUM
 from sqlalchemy.orm import relationship
 from sqlalchemy.sql import func
 import enum
+import json
+from typing import Optional, List
 
 from app.database import Base
 
@@ -38,3 +40,31 @@ class Asset(Base):
 
     owner = relationship("User", back_populates="assets")
     world = relationship("World", back_populates="assets")
+
+
+class GLTFMetadata(BaseModel):
+    """Pydantic schema for glTF asset metadata."""
+    mesh_count: Optional[int] = None
+    vertex_count: Optional[int] = None
+    has_animation: bool = False
+    texture_refs: Optional[List[str]] = None
+    tags: Optional[List[str]] = None
+
+    model_config = {"from_attributes": True}
+
+
+def parse_metadata_json(metadata_text: Optional[str]) -> dict:
+    """Parse the metadata_json text field into a dict, handling None gracefully."""
+    if not metadata_text:
+        return {}
+    try:
+        return json.loads(metadata_text)
+    except (json.JSONDecodeError, TypeError):
+        return {}
+
+
+def serialize_metadata(metadata: dict) -> Optional[str]:
+    """Serialize metadata dict to JSON string for storage."""
+    if not metadata:
+        return None
+    return json.dumps(metadata)