from fcm_django.models import FCMDevice
from rest_framework import generics, status
from rest_framework import permissions
from rest_framework.response import Response

from account import models
from account import serializers


class UserView(generics.RetrieveUpdateAPIView):
    """### User update view."""
    permission_classes = (permissions.IsAuthenticated,)
    serializer_class = serializers.UserSerializer
    queryset = models.User.objects.active()

    def get_object(self):
        return self.request.user


class FCMDeviceViewSet(generics.GenericAPIView):
    """FCMDevice registration view.

    * Pair of fields **registration_id** and **type** should be unique.
    * In case of requested device existance, existing device will be returned
      instead of creating new one.
    """

    serializer_class = serializers.FCMDeviceSerializer
    lookup_fields = ('registration_id', 'type',)
    queryset = FCMDevice.objects.all()
    permission_classes = (permissions.AllowAny, )

    def post(self, request, *args, **kwargs):
        """Override post method."""
        instance = self.get_object_or_none()
        serializer = self.get_serializer(instance, data=request.data)
        serializer.is_valid(raise_exception=True)
        serializer.save()
        return Response(
            serializer.data, status=status.HTTP_200_OK if instance else status.HTTP_201_CREATED)

    def get_object_or_none(self):
        """Object as resylt and the view is displaying or None."""
        queryset = self.get_queryset()  # get the base queryset
        queryset = self.filter_queryset(queryset)  # apply any filter backends
        # generate filter
        filter = {f: self.request.data.get(f) for f in self.lookup_fields
                  if self.request.data.get(f)}

        # get object and check permissions or return None
        obj = queryset.filter(**filter).first()
        obj and self.check_object_permissions(self.request, obj)
        return obj