app/database.py

from sqlalchemy.ext.asyncio import create_async_engine, AsyncSession, async_sessionmaker
from sqlalchemy.orm import DeclarativeBase
from app.config import get_settings

settings = get_settings()

# SQLite doesn't support connection pooling
is_sqlite = "sqlite" in settings.DATABASE_URL.lower()

if is_sqlite:
    engine = create_async_engine(
        settings.DATABASE_URL,
        echo=settings.DEBUG,
    )
else:
    engine = create_async_engine(
        settings.DATABASE_URL,
        echo=settings.DEBUG,
        pool_pre_ping=True,
        pool_size=10,
        max_overflow=20,
    )

async_session_factory = async_sessionmaker(
    engine,
    class_=AsyncSession,
    expire_on_commit=False,
)


class Base(DeclarativeBase):
    pass


async def get_db() -> AsyncSession:
    async with async_session_factory() as session:
        try:
            yield session
            await session.commit()
        except Exception:
            await session.rollback()
            raise