refactor: As neo4j can't support dictionaries, add foreign metadata as string

cognee/modules/data/processing/document_types/Document.py

@@ -7,6 +7,7 @@ from cognee.infrastructure.engine import DataPoint
 class Document(DataPoint):
     name: str
     raw_data_location: str
+    foreign_metadata: Optional[str]
     mime_type: str
     _metadata: dict = {"index_fields": ["name"], "type": "Document"}
 

cognee/tasks/documents/classify_documents.py

@@ -1,4 +1,5 @@
 from cognee.modules.data.models import Data
+import json
 from cognee.modules.data.processing.document_types import (
     Document,
     PdfDocument,
@@ -57,6 +58,7 @@ async def classify_documents(data_documents: list[Data]) -> list[Document]:
             raw_data_location=data_item.raw_data_location,
             name=data_item.name,
             mime_type=data_item.mime_type,
+            foreign_metadata=json.dumps(data_item.foreign_metadata, indent=4),
         )
         documents.append(document)