from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
from app.config import settings

# SQLite 不支持某些连接池选项
if settings.USE_SQLITE:
    engine = create_engine(
        settings.DATABASE_URL,
        connect_args={"check_same_thread": False},
        echo=False
    )
else:
    engine = create_engine(
        settings.DATABASE_URL,
        pool_pre_ping=True,
        pool_recycle=3600,
        echo=False
    )

SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
Base = declarative_base()

def get_db():
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()