"""Shared SentenceTransformer singleton — loaded once, used everywhere."""

from __future__ import annotations

import logging

from sentence_transformers import SentenceTransformer

logger = logging.getLogger(__name__)

_model: SentenceTransformer | None = None


def get_embedding_model() -> SentenceTransformer:
    global _model
    if _model is None:
        logger.info("Loading SentenceTransformer (all-MiniLM-L6-v2)…")
        _model = SentenceTransformer("all-MiniLM-L6-v2")
        logger.info("SentenceTransformer ready.")
    return _model