"""Select the active SearchBackend from config (SPEC §8.1, env SEARCH_BACKEND)."""

from __future__ import annotations

from app.config import get_settings
from app.search.base import SearchBackend
from app.search.pg import PgSearchBackend

_backend: SearchBackend | None = None


def get_search_backend() -> SearchBackend:
    """Return the process-wide SearchBackend (``pg`` or ``meili`` per SEARCH_BACKEND)."""
    global _backend
    if _backend is None:
        which = get_settings().search_backend
        if which == "meili":
            from app.search.meili import MeiliSearchBackend

            _backend = MeiliSearchBackend()
        else:
            _backend = PgSearchBackend()
    return _backend