"""
AIFlow 数据库连接与Session管理
"""
from sqlalchemy import create_engine, event
from sqlalchemy.orm import sessionmaker, declarative_base
from sqlalchemy.pool import QueuePool
from .config import DATABASE_URL

engine = create_engine(
    DATABASE_URL,
    poolclass=QueuePool,
    pool_size=20,
    max_overflow=40,
    pool_pre_ping=True,
    pool_recycle=3600,
    echo=False,
)

# 为日志表禁止DELETE操作添加触发器检查
# 通过数据库层确保operation_logs, audit_logs, token_usage_logs不可删除

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

Base = declarative_base()


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