from typing import Generator, Type

from ..utils.projector import ProjectorElement
from .exceptions import ProjectorException
from .models import Countdown, ProjectorMessage


class Clock(ProjectorElement):
    """
    Clock on the projector.
    """

    name = "core/clock"


class CountdownElement(ProjectorElement):
    """
    Countdown slide for the projector.
    """

    name = "core/countdown"

    def check_data(self):
        if not Countdown.objects.filter(pk=self.config_entry.get("id")).exists():
            raise ProjectorException("Countdown does not exists.")


class ProjectorMessageElement(ProjectorElement):
    """
    Short message on the projector. Rendered as overlay.
    """

    name = "core/projector-message"

    def check_data(self):
        if not ProjectorMessage.objects.filter(pk=self.config_entry.get("id")).exists():
            raise ProjectorException("Message does not exists.")


def get_projector_elements() -> Generator[Type[ProjectorElement], None, None]:
    yield Clock
    yield CountdownElement
    yield ProjectorMessageElement