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

# 创建数据库引擎
engine = create_engine(
    settings.DATABASE_URL,
    echo=settings.DEBUG,
    pool_pre_ping=True,
    pool_size=5,
    max_overflow=10,
)

# 创建会话工厂
SessionLocal = sessionmaker(bind=engine)


def get_session() -> Session:
    """获取新的数据库会话

    使用示例:
        session = get_session()
        try:
            result = session.query(Model).all()
            session.commit()
            return result
        except Exception:
            session.rollback()
            raise
        finally:
            session.close()
    """
    return SessionLocal()