from rest_framework import decorators, mixins, response, status, viewsets

from apps.core.errors import ApiError, error_response
from apps.processing.models import StepExecution
from apps.processing.serializers import StepExecutionSerializer
from apps.processing.services import ProcessingService
from apps.rbac.permissions import ActionPermission


class StepExecutionViewSet(
    mixins.ListModelMixin, mixins.RetrieveModelMixin, viewsets.GenericViewSet
):
    serializer_class = StepExecutionSerializer
    permission_classes = [ActionPermission]
    code_map = {
        "list": "processing.view",
        "retrieve": "processing.view",
        "start": "processing.start",
        "pause": "processing.pause",
        "resume": "processing.start",
        "complete": "processing.complete",
        "reject": "processing.complete",
        "rework": "processing.complete",
    }
    service = ProcessingService()

    def get_queryset(self):
        user = self.request.user
        qs = StepExecution.objects.select_related("order", "step", "assigned_to").all()
        if user.is_superuser:
            return qs
        return qs.filter(order__customer__user=user)

    def _run(self, request, pk, method, **kwargs):
        execution = self.get_object()
        try:
            if method == "start":
                execution = self.service.start(execution, request.user)
            elif method == "rework":
                from apps.workflows.models import WorkflowStep

                target = WorkflowStep.objects.get(pk=kwargs["target_step"])
                execution = self.service.rework(execution, target)
            else:
                execution = getattr(self.service, method)(execution)
        except ApiError as exc:
            return response.Response(error_response(exc.code, exc.message, exc.details), status=exc.status)
        return response.Response(StepExecutionSerializer(execution).data)

    @decorators.action(detail=True, methods=["post"])
    def start(self, request, pk=None):
        return self._run(request, pk, "start")

    @decorators.action(detail=True, methods=["post"])
    def pause(self, request, pk=None):
        return self._run(request, pk, "pause")

    @decorators.action(detail=True, methods=["post"])
    def resume(self, request, pk=None):
        return self._run(request, pk, "resume")

    @decorators.action(detail=True, methods=["post"])
    def complete(self, request, pk=None):
        return self._run(request, pk, "complete")

    @decorators.action(detail=True, methods=["post"])
    def reject(self, request, pk=None):
        return self._run(request, pk, "reject")

    @decorators.action(detail=True, methods=["post"])
    def rework(self, request, pk=None):
        target_step = request.data.get("target_step")
        if not target_step:
            return response.Response(
                error_response("TARGET_STEP_REQUIRED", "A target_step id is required."),
                status=status.HTTP_400_BAD_REQUEST,
            )
        return self._run(request, pk, "rework", target_step=target_step)