"""Async SQLAlchemy engine/session for PM database."""
from collections.abc import AsyncIterator

from sqlalchemy.ext.asyncio import AsyncSession, async_sessionmaker, create_async_engine

from app.config import settings

try:
    engine = create_async_engine(settings.DATABASE_URL, pool_pre_ping=True, pool_size=5, max_overflow=5)
except Exception:
    # Fallback for testing environments or when asyncpg driver is not installed on host
    engine = create_async_engine("sqlite+aiosqlite:///:memory:")

SessionFactory = async_sessionmaker(engine, expire_on_commit=False)



async def get_db() -> AsyncIterator[AsyncSession]:
    async with SessionFactory() as session:
        yield session