from collections.abc import AsyncGenerator

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

from app.core.config import settings

# Engine setup
engine = create_async_engine(
    settings.database_url,
    echo=False,
    future=True,
    connect_args={"check_same_thread": False} if settings.database_url.startswith("sqlite") else {}
)

# Session factory
async_session_maker = async_sessionmaker(
    engine, class_=AsyncSession, expire_on_commit=False, autoflush=False
)

Base = declarative_base()


async def get_db() -> AsyncGenerator[AsyncSession, None]:
    """Dependency for getting async database sessions."""
    async with async_session_maker() as session:
        yield session