from __future__ import annotations

from functools import lru_cache

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

from app.config import DATA_DIR, get_settings
from app.db_models import Base


def _sqlite_connect_args(database_url: str) -> dict[str, bool]:
    if database_url.startswith("sqlite"):
        return {"check_same_thread": False}
    return {}


@lru_cache(maxsize=1)
def get_engine():
    settings = get_settings()
    DATA_DIR.mkdir(parents=True, exist_ok=True)
    return create_engine(
        settings.database_url,
        echo=settings.database_echo,
        future=True,
        connect_args=_sqlite_connect_args(settings.database_url),
    )


@lru_cache(maxsize=1)
def get_session_factory():
    return sessionmaker(bind=get_engine(), autoflush=False, autocommit=False, future=True)


def init_db() -> None:
    Base.metadata.create_all(bind=get_engine())


def get_session() -> Session:
    return get_session_factory()()