from collections.abc import Generator

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

from app.config import get_settings

settings = get_settings()
_engine_kwargs: dict = {"pool_pre_ping": True}
if settings.database_url.startswith("postgresql"):
    _engine_kwargs["pool_size"] = max(1, int(settings.sac_db_pool_size))
    _engine_kwargs["max_overflow"] = max(0, int(settings.sac_db_max_overflow))
engine = create_engine(settings.database_url, **_engine_kwargs)
SessionLocal = sessionmaker(bind=engine, autocommit=False, autoflush=False)


class Base(DeclarativeBase):
    pass


def get_db() -> Generator[Session, None, None]:
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()