# Django imports
from django.db import IntegrityError

# Third party imports
from rest_framework import status
from rest_framework.response import Response

from plane.api.serializers import StateSerializer
from plane.app.permissions import ProjectEntityPermission
from plane.db.models import Issue, State

# Module imports
from .base import BaseAPIView


class StateAPIEndpoint(BaseAPIView):
    serializer_class = StateSerializer
    model = State
    permission_classes = [
        ProjectEntityPermission,
    ]

    def get_queryset(self):
        return (
            State.objects.filter(workspace__slug=self.kwargs.get("slug"))
            .filter(project_id=self.kwargs.get("project_id"))
            .filter(
                project__project_projectmember__member=self.request.user,
                project__project_projectmember__is_active=True,
            )
            .filter(is_triage=False)
            .filter(project__archived_at__isnull=True)
            .select_related("project")
            .select_related("workspace")
            .distinct()
        )

    def post(self, request, slug, project_id):
        try:
            serializer = StateSerializer(
                data=request.data, context={"project_id": project_id}
            )
            if serializer.is_valid():
                if (
                    request.data.get("external_id")
                    and request.data.get("external_source")
                    and State.objects.filter(
                        project_id=project_id,
                        workspace__slug=slug,
                        external_source=request.data.get("external_source"),
                        external_id=request.data.get("external_id"),
                    ).exists()
                ):
                    state = State.objects.filter(
                        workspace__slug=slug,
                        project_id=project_id,
                        external_id=request.data.get("external_id"),
                        external_source=request.data.get("external_source"),
                    ).first()
                    return Response(
                        {
                            "error": "State with the same external id and external source already exists",
                            "id": str(state.id),
                        },
                        status=status.HTTP_409_CONFLICT,
                    )

                serializer.save(project_id=project_id)
                return Response(serializer.data, status=status.HTTP_200_OK)
            return Response(
                serializer.errors, status=status.HTTP_400_BAD_REQUEST
            )
        except IntegrityError:
            state = State.objects.filter(
                workspace__slug=slug,
                project_id=project_id,
                name=request.data.get("name"),
            ).first()
            return Response(
                {
                    "error": "State with the same name already exists in the project",
                    "id": str(state.id),
                },
                status=status.HTTP_409_CONFLICT,
            )

    def get(self, request, slug, project_id, state_id=None):
        if state_id:
            serializer = StateSerializer(
                self.get_queryset().get(pk=state_id),
                fields=self.fields,
                expand=self.expand,
            )
            return Response(serializer.data, status=status.HTTP_200_OK)
        return self.paginate(
            request=request,
            queryset=(self.get_queryset()),
            on_results=lambda states: StateSerializer(
                states,
                many=True,
                fields=self.fields,
                expand=self.expand,
            ).data,
        )

    def delete(self, request, slug, project_id, state_id):
        state = State.objects.get(
            is_triage=False,
            pk=state_id,
            project_id=project_id,
            workspace__slug=slug,
        )

        if state.default:
            return Response(
                {"error": "Default state cannot be deleted"},
                status=status.HTTP_400_BAD_REQUEST,
            )

        # Check for any issues in the state
        issue_exist = Issue.issue_objects.filter(state=state_id).exists()

        if issue_exist:
            return Response(
                {
                    "error": "The state is not empty, only empty states can be deleted"
                },
                status=status.HTTP_400_BAD_REQUEST,
            )

        state.delete()
        return Response(status=status.HTTP_204_NO_CONTENT)

    def patch(self, request, slug, project_id, state_id=None):
        state = State.objects.get(
            workspace__slug=slug, project_id=project_id, pk=state_id
        )
        serializer = StateSerializer(state, data=request.data, partial=True)
        if serializer.is_valid():
            if (
                request.data.get("external_id")
                and (state.external_id != str(request.data.get("external_id")))
                and State.objects.filter(
                    project_id=project_id,
                    workspace__slug=slug,
                    external_source=request.data.get(
                        "external_source", state.external_source
                    ),
                    external_id=request.data.get("external_id"),
                ).exists()
            ):
                return Response(
                    {
                        "error": "State with the same external id and external source already exists",
                        "id": str(state.id),
                    },
                    status=status.HTTP_409_CONFLICT,
                )
            serializer.save()
            return Response(serializer.data, status=status.HTTP_200_OK)
        return Response(serializer.errors, status=status.HTTP_400_BAD_REQUEST)