from collections.abc import Generator
from functools import lru_cache

from sqlalchemy import create_engine
from sqlalchemy.orm import DeclarativeBase, Session, sessionmaker

from app.config import get_settings


class AuthBase(DeclarativeBase):
    pass


def _build_connect_args(database_url: str) -> dict[str, object]:
    connect_args: dict[str, object] = {}
    if database_url.startswith("sqlite"):
        connect_args["check_same_thread"] = False
    return connect_args


@lru_cache
def _get_auth_engine(database_url: str):
    return create_engine(database_url, connect_args=_build_connect_args(database_url))


@lru_cache
def _get_auth_session_local(database_url: str):
    engine = _get_auth_engine(database_url)
    return sessionmaker(bind=engine, autoflush=False, autocommit=False, class_=Session)


def get_auth_engine():
    settings = get_settings()
    return _get_auth_engine(settings.app_database_url)


def get_auth_session_local():
    settings = get_settings()
    return _get_auth_session_local(settings.app_database_url)


def reset_auth_db_caches() -> None:
    _get_auth_session_local.cache_clear()
    _get_auth_engine.cache_clear()


def get_auth_db_session() -> Generator[Session, None, None]:
    session_local = get_auth_session_local()
    session = session_local()
    try:
        yield session
    finally:
        session.close()