from django.contrib.auth import get_user_model
from django.db.models import Q

from rest_framework.viewsets import ModelViewSet

from api.event.serializers import EventSerializer, PlaceSerializer,\
    ActivityTagSerializer, ActivityTemplateSerializer
from event.models import Event, Place, ActivityTag, ActivityTemplate

User = get_user_model()


# classes utilitaires
class EventSpecificViewSet(ModelViewSet):
    """
    ViewSet that returns :
    * rootlevel objects if no Event is specified
    * OR objects related to the specidied event
         AND root level objects
    if an event is specified it passes the event_pk
    to the save method. Works fine with serializers.EventSpecificSerializer
    Useful for models that exetends EventSpecificMixin
    """
    def get_queryset(self):
        """
        Warning : You may want to override this method
        and not call with super
        """
        event_pk = self.kwargs.get('event_pk')
        queryset = super().get_queryset()
        if event_pk:
            return queryset.filter(Q(event=event_pk) | Q(event=None))
        return queryset.filter(event=None)

    def perform_create(self, serializer):
        event_pk = self.kwargs.get('event_pk')
        serializer.save(event_pk=event_pk)


# ViewSets
class EventViewSet(ModelViewSet):
    """
    This viewset automatically provides `list`, `create`, `retrieve`,
    `update` and `destroy` actions.

    """
    queryset = Event.objects.all()
    serializer_class = EventSerializer

    def perform_create(self, serializer):
        serializer.save(created_by=self.request.user)


class PlaceViewSet(EventSpecificViewSet):
    queryset = Place.objects.all()
    serializer_class = PlaceSerializer


class ActivityTagViewSet(ModelViewSet):
    """
    This viewset automatically provides `list`, `create`, `retrieve`,
    `update` and `destroy` actions.

    """
    queryset = ActivityTag.objects.all()
    serializer_class = ActivityTagSerializer


class ActivityTemplateViewSet(ModelViewSet):
    """
    This viewset automatically provides `list`, `create`, `retrieve`,
    `update` and `destroy` actions.

    """
    queryset = ActivityTemplate.objects.all()
    serializer_class = ActivityTemplateSerializer