from typing import Callable, Type


def prepare_list_arg(name: str, required: bool = True, make_unique: bool = True, result_type: Type = list):
    """Decorator to make list argument items unique and not none.
        If the list is empty and required then return empty list without calling the function.

    Args:
        name: List kwarg name.
        required: If the list is required (to be not empty).
        make_unique: Remove list arg duplicates.
        result_type: Result type (list or dict).

    """

    def wrapper(f: Callable):
        async def wrapped(*args, **kwargs):
            if name in kwargs and isinstance(kwargs[name], list):
                if make_unique:
                    kwargs[name] = [i for i in set(kwargs[name]) if i]
                if required and not kwargs[name]:
                    return result_type()
            return await f(*args, **kwargs)

        return wrapped

    return wrapper