from sqlalchemy import create_engine
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
from sqlalchemy.pool import QueuePool

from app.config.settings import settings

# 创建数据库引擎
engine = create_engine(
    settings.DATABASE_URL,
    poolclass=QueuePool,
    pool_pre_ping=True,
    pool_size=10,
    max_overflow=20,
    pool_recycle=3600,  # 连接回收时间
    pool_timeout=30,    # 连接超时时间
    echo=False          # 关闭SQL日志
)

# 创建会话工厂
SessionLocal = sessionmaker(
    autocommit=False, 
    autoflush=False, 
    bind=engine,
    expire_on_commit=False  # 提交后不自动过期对象
)

# 创建基类
Base = declarative_base()


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