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

from app.config import get_settings


class Base(DeclarativeBase):
    pass


_engine = None


def get_engine():
    global _engine
    if _engine is None:
        _engine = create_engine(get_settings().database_url)
    return _engine


def get_session():
    with Session(get_engine()) as session:
        yield session