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

# Create async engine
engine = create_async_engine(
    settings.DATABASE_URL,
    echo=settings.DEBUG,
    future=True
)

# Create async session factory
async_session_maker = async_sessionmaker(
    engine,
    class_=AsyncSession,
    expire_on_commit=False
)


class Base(DeclarativeBase):
    """Base class for all database models."""
    pass


async def get_db() -> AsyncSession:
    """Dependency to get database session."""
    async with async_session_maker() as session:
        try:
            yield session
        finally:
            await session.close()


async def init_db():
    """Initialize database tables."""
    async with engine.begin() as conn:
        await conn.run_sync(Base.metadata.create_all)