from src.vector_store import FAISSVectorStore
from typing import Dict

def patch_metadata_for_store(store: FAISSVectorStore, metadata_fixes: Dict[str, Dict]):
    """
    Patch metadata in an in-memory FAISSVectorStore and save it.

    store: existing FAISSVectorStore instance (will be modified in place).
    metadata_fixes: mapping filename -> metadata dict (e.g. {"a.pdf": {"authors":"X","year":"2021"}})
    """
    for doc in store.documents:
        fname = doc.get("metadata", {}).get("filename")
        if fname in metadata_fixes:
            doc.setdefault("metadata", {}).update(metadata_fixes[fname])

    store.save_index()