from typing import Any, Dict, Set

from django.apps import AppConfig
from django.db.models.signals import post_migrate

from ..utils.projector import register_projector_elements


class MotionsAppConfig(AppConfig):
    name = 'openslides.motions'
    verbose_name = 'OpenSlides Motion'
    angular_site_module = True
    angular_projector_module = True

    def ready(self):
        # Import all required stuff.
        from openslides.core.signals import permission_change
        from openslides.utils.rest_api import router
        from .projector import get_projector_elements
        from .signals import (
            create_builtin_workflows,
            get_permission_change_data,
        )
        from .views import (
            CategoryViewSet,
            StatuteParagraphViewSet,
            MotionViewSet,
            MotionCommentSectionViewSet,
            MotionBlockViewSet,
            MotionPollViewSet,
            MotionChangeRecommendationViewSet,
            StateViewSet,
            WorkflowViewSet,
        )
        from ..utils.access_permissions import required_user

        # Define projector elements.
        register_projector_elements(get_projector_elements())

        # Connect signals.
        post_migrate.connect(
            create_builtin_workflows,
            dispatch_uid='motion_create_builtin_workflows')
        permission_change.connect(
            get_permission_change_data,
            dispatch_uid='motions_get_permission_change_data')

        # Register viewsets.
        router.register(self.get_model('Category').get_collection_string(), CategoryViewSet)
        router.register(self.get_model('StatuteParagraph').get_collection_string(), StatuteParagraphViewSet)
        router.register(self.get_model('Motion').get_collection_string(), MotionViewSet)
        router.register(self.get_model('MotionBlock').get_collection_string(), MotionBlockViewSet)
        router.register(self.get_model('MotionCommentSection').get_collection_string(), MotionCommentSectionViewSet)
        router.register(self.get_model('Workflow').get_collection_string(), WorkflowViewSet)
        router.register(self.get_model('MotionChangeRecommendation').get_collection_string(),
                        MotionChangeRecommendationViewSet)
        router.register(self.get_model('MotionPoll').get_collection_string(), MotionPollViewSet)
        router.register(self.get_model('State').get_collection_string(), StateViewSet)

        # Register required_users
        required_user.add_collection_string(self.get_model('Motion').get_collection_string(), required_users)

    def get_config_variables(self):
        from .config_variables import get_config_variables
        return get_config_variables()

    def get_startup_elements(self):
        """
        Yields all Cachables required on startup i. e. opening the websocket
        connection.
        """
        for model_name in ('Category', 'StatuteParagraph', 'Motion', 'MotionBlock',
                           'Workflow', 'MotionChangeRecommendation', 'MotionCommentSection'):
            yield self.get_model(model_name)


def required_users(element: Dict[str, Any]) -> Set[int]:
    """
    Returns all user ids that are displayed as as submitter or supporter in
    any motion if request_user can see motions. This function may return an
    empty set.
    """
    submitters_supporters = set([submitter['user_id'] for submitter in element['submitters']])
    submitters_supporters.update(element['supporters_id'])
    return submitters_supporters