"""Database utilities for async SQLAlchemy engine and sessions."""

from __future__ import annotations

from collections.abc import AsyncGenerator

from app.core.config import settings
from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine

engine = create_async_engine(settings.database_url, echo=settings.sqlalchemy_echo)
AsyncSessionMaker = async_sessionmaker(bind=engine, expire_on_commit=False)


async def get_session() -> AsyncGenerator[AsyncSession, None]:
    """Yield an async database session for request scope."""
    async with AsyncSessionMaker() as session:
        try:
            yield session
            await session.commit()
        except Exception:  # pragma: no cover - defensive cleanup
            await session.rollback()
            raise