class EventViewSet(viewsets.ModelViewSet):
    queryset = models.Event.objects.all()
    serializer_class = serializers.EventSerializer
    permission_classes = (permissions.AllowAny,)
    filter_backends = (django_filters.rest_framework.DjangoFilterBackend,)
    filterset_fields = ('patient', 'type')
    pagination_class = None

    def create(self, request, *args, **kwargs):
        patient_id = request.data['patient']
        patient = models.Patient.objects.filter(pk=patient_id)

        if not patient.exists():
            raise Http404
        else:
            patient = patient.get()

        keys = request.data.keys()
        if 'doctor' not in keys:
            request.data['doctor'] = models.Patient.objects.get(pk=patient_id).doctor_id
        if 'card' not in keys:
            request.data['card'] = models.Card.objects.get(patient_id=patient_id).pk

        if request.data['type'] == models.Event.MENSTRUATION:
            models.Event.objects.filter(
                (Q(type=models.Event.MENSTRUATION) | Q(type=models.Event.OVULATION)) & Q(patient_id=patient_id)
            ).delete()

            start_date = parse_datetime(request.data['start_date'])
            cycle = request.data['duration']

            serializer = self.get_serializer(data=request.data)
            serializer.is_valid(raise_exception=True)
            self.perform_create(serializer)
            headers = self.get_success_headers(serializer.data)

            if cycle % 2 == 0:
                ovulation_delta_days = cycle / 2 - 2
            else:
                ovulation_delta_days = cycle // 2 - 2

            year_offset = start_date + timedelta(days=365)
            while start_date < year_offset:
                models.Event.objects.create(
                    type=models.Event.OVULATION,
                    doctor_id=request.data['doctor'],
                    card_id=request.data['card'],
                    start_date=start_date + timedelta(days=ovulation_delta_days),
                    duration=5,
                    patient_id=patient_id
                )

                start_date += timedelta(days=cycle)
                request.data['start_date'] = start_date

                serializer = self.get_serializer(data=request.data)
                serializer.is_valid(raise_exception=True)
                self.perform_create(serializer)
            return Response(serializer.data, status=status.HTTP_201_CREATED, headers=headers)

        elif request.data['type'] == models.Event.PREGNANCY:
            patient.state = models.Patient.PREGNANT
            patient.save()

        elif request.data['type'] == models.Event.ABORTION:
            patient.state = models.Patient.DEFAULT
            patient.save()

        elif request.data['type'] == models.Event.INTAKE:
            start_date = parse_datetime(request.data['start_date'])
            request.data['start_date'] = start_date + timedelta(days=4)
            models.Event.objects.create(
                type=models.Event.TREATMENT_ASSIGNMENT,
                doctor_id=request.data['doctor'],
                card_id=request.data['card'],
                start_date=start_date,
                patient_id=patient_id
            )

        elif request.data['type'] == models.Event.ANALYSIS:
            #details = request.data['analysisType']
            #details = models.Analyzes.FRAGMENTATION
            details = 'FRAGMENTATION'


        return super().create(request, *args, **kwargs)

    def get_serializer(self, *args, **kwargs):
        """ if an array is passed, set serializer to many """
        if isinstance(kwargs.get('data', {}), list):
            kwargs['many'] = True
        return super().get_serializer(*args, **kwargs)