from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession
from sqlalchemy.ext.declarative import declarative_base
from sqlalchemy.orm import sessionmaker
from app.core.config import settings
import asyncio

# 创建异步数据库URL - 使用异步驱动
SQLALCHEMY_DATABASE_URL = f"mysql+aiomysql://{settings.DB_USER}:{settings.DB_PASSWORD}@{settings.DB_HOST}:{settings.DB_PORT}/{settings.DB_NAME}"

# 创建异步数据库引擎
engine = create_async_engine(
    SQLALCHEMY_DATABASE_URL,
    echo=settings.DB_ECHO,
    pool_pre_ping=True
)

# 创建异步会话工厂
AsyncSessionLocal = sessionmaker(
    engine, 
    class_=AsyncSession, 
    expire_on_commit=False,
    autocommit=False, 
    autoflush=False
)

# 创建基本模型类
Base = declarative_base()

# 异步数据库会话依赖项
async def get_db():
    async with AsyncSessionLocal() as session:
        try:
            yield session
        finally:
            await session.close()