import uuid
from collections.abc import AsyncGenerator

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

from .config import settings


class Base(DeclarativeBase):
    pass


def gen_uuid7() -> uuid.UUID:
    # Python 3.14+ has uuid.uuid7(); fall back on older interpreters.
    if hasattr(uuid, "uuid7"):
        return uuid.uuid7()
    return uuid.uuid4()


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

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


async def get_session() -> AsyncGenerator[AsyncSession, None]:
    async with session_factory() as session:
        yield session