import os
import faiss

class UserIndexManager:
    def __init__(self, base_dir="index_data/"):
        self.base_dir = base_dir
        self.index_map = {}  # user_id -> faiss index
        self._load_all_indexes()

    def _load_all_indexes(self):
        for fname in os.listdir(self.base_dir):
            if fname.endswith(".index"):
                user_id = fname.replace(".index", "")
                path = os.path.join(self.base_dir, fname)
                self.index_map[user_id] = faiss.read_index(path)
                print(f"[INIT] Loaded index for user {user_id}")

    def get_index(self, user_id):
        if user_id not in self.index_map:
            raise ValueError(f"Index for user {user_id} not loaded.")
        return self.index_map[user_id]