added fix to weighted edges

cognee/infrastructure/databases/graph/neo4j_driver/adapter.py

@@ -410,6 +410,38 @@ class Neo4jAdapter(GraphDBInterface):
 
         return await self.query(query, params)
 
+    def _flatten_edge_properties(self, properties: Dict[str, Any]) -> Dict[str, Any]:
+        """
+        Flatten edge properties to handle nested dictionaries like weights.
+
+        Neo4j doesn't support nested dictionaries as property values, so we need to
+        flatten the 'weights' dictionary into individual properties with prefixes.
+
+        Args:
+            properties: Dictionary of edge properties that may contain nested dicts
+
+        Returns:
+            Flattened properties dictionary suitable for Neo4j storage
+        """
+        flattened = {}
+
+        for key, value in properties.items():
+            if key == "weights" and isinstance(value, dict):
+                # Flatten weights dictionary into individual properties
+                for weight_name, weight_value in value.items():
+                    flattened[f"weight_{weight_name}"] = weight_value
+            elif isinstance(value, dict):
+                # For other nested dictionaries, serialize as JSON string
+                flattened[f"{key}_json"] = json.dumps(value, cls=JSONEncoder)
+            elif isinstance(value, list):
+                # For lists, serialize as JSON string
+                flattened[f"{key}_json"] = json.dumps(value, cls=JSONEncoder)
+            else:
+                # Keep primitive types as-is
+                flattened[key] = value
+
+        return flattened
+
     @record_graph_changes
     @override_distributed(queued_add_edges)
     async def add_edges(self, edges: list[tuple[str, str, str, dict[str, Any]]]) -> None:
@@ -448,11 +480,13 @@ class Neo4jAdapter(GraphDBInterface):
                 "from_node": str(edge[0]),
                 "to_node": str(edge[1]),
                 "relationship_name": edge[2],
-                "properties": {
+                "properties": self._flatten_edge_properties(
-                    **(edge[3] if edge[3] else {}),
+                    {
-                    "source_node_id": str(edge[0]),
+                        **(edge[3] if edge[3] else {}),
-                    "target_node_id": str(edge[1]),
+                        "source_node_id": str(edge[0]),
-                },
+                        "target_node_id": str(edge[1]),
+                    }
+                ),
             }
             for edge in edges
         ]