"""
数据库连接
"""
from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
from app.config import settings

# 创建数据库引擎
engine = create_engine(
    settings.DATABASE_URL,
    pool_pre_ping=True,  # 在使用连接前检查连接是否可用
    pool_recycle=1800,   # 30分钟后回收连接
    pool_size=10,        # 连接池大小
    max_overflow=20,     # 最大溢出连接数
    pool_timeout=30,     # 获取连接的超时时间
    echo=settings.DEBUG,
)

# 创建会话工厂
SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)

# 创建基类
Base = declarative_base()

def get_db():
    """获取数据库会话"""
    db = SessionLocal()
    try:
        yield db
    finally:
        db.close()