fix: rebuild BM25 index from Qdrant if pkl not found

Dockerfile

@@ -16,9 +16,6 @@ COPY src/ ./src/
 COPY static/ ./static/
 COPY api.py .
 
-# Download bm25_index.pkl từ HF Spaces repo
-RUN python -c "from huggingface_hub import hf_hub_download; hf_hub_download(repo_id='thaidinhz1/rag-vietnamese', repo_type='space', filename='bm25_index.pkl', local_dir='.')"
-
 # Model sẽ được download tự động lần đầu chạy
 
 # Qdrant storage và BM25 index mount từ volume

src/vector_store.py

@@ -75,7 +75,36 @@ def add_chunks(chunks: list[dict]):
     print(f"Đã lưu {len(chunks)} chunks vào Qdrant + BM25")
 
 
+def _build_bm25_from_qdrant() -> dict:
+    """Rebuild BM25 index từ Qdrant nếu file pkl không tồn tại."""
+    print("BM25 index không tìm thấy, đang rebuild từ Qdrant...")
+    client = get_client()
+    texts, metadatas = [], []
+    offset = None
+    while True:
+        result, next_offset = client.scroll(
+            collection_name=COLLECTION_NAME,
+            limit=100, offset=offset,
+            with_payload=True, with_vectors=False,
+        )
+        for p in result:
+            texts.append(p.payload.get("text", ""))
+            metadatas.append({k: v for k, v in p.payload.items() if k != "text"})
+        if next_offset is None:
+            break
+        offset = next_offset
+    tokenized = [_tokenize_vi(t) for t in texts]
+    bm25 = BM25Okapi(tokenized)
+    data = {"bm25": bm25, "texts": texts, "metadatas": metadatas}
+    with open(BM25_PATH, "wb") as f:
+        pickle.dump(data, f)
+    print(f"Rebuild xong: {len(texts)} chunks.")
+    return data
+
+
 def _load_bm25():
+    if not Path(BM25_PATH).exists():
+        return _build_bm25_from_qdrant()
     with open(BM25_PATH, "rb") as f:
         return pickle.load(f)