HewlettPackard / squest / 2455960912

from operator import xor

from rest_framework.exceptions import PermissionDenied

from rest_framework.generics import ListCreateAPIView, RetrieveUpdateDestroyAPIView, get_object_or_404, CreateAPIView

from rest_framework.permissions import IsAdminUser

from service_catalog.api.serializers.approval_step_serializer import ApprovalStepSerializer

from service_catalog.filters.approval_step_filter import ApprovalStepFilter

from service_catalog.models import ApprovalWorkflow

from service_catalog.models.approval_step import ApprovalStep

class ApprovalStepDetails(RetrieveUpdateDestroyAPIView):

    permission_classes = [IsAdminUser]

    queryset = ApprovalStep.objects.all()

    serializer_class = ApprovalStepSerializer

class ApprovalStepListCreate(ListCreateAPIView):

    permission_classes = [IsAdminUser]

    filterset_class = ApprovalStepFilter

    serializer_class = ApprovalStepSerializer

    def get_queryset(self):

        return ApprovalStep.objects.filter(approval_workflow_id=self.kwargs.get("approval_workflow_id"))

    def perform_create(self, serializer):

        approval_workflow = get_object_or_404(ApprovalWorkflow, id=self.kwargs.get("approval_workflow_id"))

        previous_id = serializer.validated_data.pop('previous_id', None)

        previous = get_object_or_404(ApprovalStep.objects.filter(approval_workflow=approval_workflow),

        if xor(bool(approval_workflow.entry_point), bool(previous_id)):

            if approval_workflow.entry_point:

                raise PermissionDenied(detail="An entry point already exist in this approval workflow please use the *"

        approval_step = serializer.save(approval_workflow=approval_workflow)

        next_approval_step_id = None

        if previous:

            next_approval_step_id = previous.next.id if previous.next else None

            previous.set_next(approval_step.id)

        approval_step.set_next(next_approval_step_id)