import faiss
import json
import numpy as np


def build_faiss_index(vectors, metadata, output_dir):
dim = vectors.shape[1]
index = faiss.IndexFlatL2(dim)
index.add(vectors.astype("float32"))


faiss.write_index(index, f"{output_dir}/index.faiss")


with open(f"{output_dir}/metadata.json", "w", encoding="utf-8") as f:
json.dump(metadata, f, indent=2, ensure_ascii=False)