from typing import TypeVar, Type

T = TypeVar("T")


class BaseClientFactory:
    """External API clients factory."""

    def _get_client(self, client_cls: Type[T]) -> T:
        """Get client or create new if does not exist."""

        client_prop_name = f"_{client_cls.__name__.lower()}"
        instance = getattr(self, client_prop_name, None)
        if not instance:
            instance = client_cls()
            setattr(self, client_prop_name, instance)
        return instance