from typing import AsyncGenerator
from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession
from sqlalchemy.orm import sessionmaker
from app.config import settings

engine = create_async_engine(settings.DATABASE_URL, echo=settings.DEBUG)
AsyncSessionLocal = sessionmaker(engine, class_=AsyncSession, expire_on_commit=False)

async def connect():
    pass  # engine initializes at module level

async def disconnect():
    await engine.dispose()

async def get_db() -> AsyncGenerator[AsyncSession, None]:
    async with AsyncSessionLocal() as session:
        try:
            yield session
            await session.commit()
        except Exception:
            await session.rollback()
            raise