from __future__ import annotations

from typing import TYPE_CHECKING, List

from .slot import Slot

if TYPE_CHECKING:
    from .client import Client


def get_slot_stack() -> List[Slot]:
    """Return the slot stack of the current asyncio task."""
    return Slot.get_stack()


def get_slot() -> Slot:
    """Return the current slot."""
    slot_stack = get_slot_stack()
    if not slot_stack:
        raise RuntimeError('The current slot cannot be determined because the slot stack for this task is empty.\n'
                           'This may happen if you try to create UI from a background task.\n'
                           'To fix this, enter the target slot explicitly using `with container_element:`.')
    return slot_stack[-1]


def get_client() -> Client:
    """Return the current client."""
    return get_slot().parent.client