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

from .config import settings


class Base(DeclarativeBase):
    pass


engine = create_async_engine(
    settings.database_url,
    echo=False,
    pool_pre_ping=True,
)

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


async def get_db() -> AsyncSession:
    """Dependency for getting 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)