import logging
import operator
from functools import reduce

from django.db.models import Q
from django_filters.rest_framework import DjangoFilterBackend
from rest_framework import status, viewsets
from rest_framework.decorators import action
from rest_framework.mixins import ListModelMixin
from rest_framework.permissions import IsAuthenticated
from rest_framework.response import Response
from rest_framework.viewsets import GenericViewSet

from dpdapi.filters import AliasRegexFilterBackend
from dpdapi.models import Alias, Domain, User
from dpdapi.serializers import AliasDeleteSerializer, AliasSerializer, DomainSerializer, UserSerializer

logger = logging.getLogger(__name__)


class AliasViewSet(ListModelMixin, GenericViewSet):
    """Aliases"""

    queryset = Alias.objects.all()
    serializer_class = AliasSerializer
    permission_classes = [IsAuthenticated]
    filter_backends = (DjangoFilterBackend, AliasRegexFilterBackend)
    filterset_fields = (
        "domain",
        "domain__name",
    )

    @action(detail=False, methods=["post"])
    def create_bulk(self, request):
        serializer = AliasSerializer(data=request.data, many=True)

        serializer.is_valid(raise_exception=True)

        serializer.save()
        return Response(serializer.data, status=status.HTTP_201_CREATED)

    @action(detail=False, methods=["delete"])
    def delete_bulk(self, request):
        serializer = AliasDeleteSerializer(data=request.data, many=True)

        serializer.is_valid(raise_exception=True)

        # Ref: http://michelepasin.org/blog/2010/07/20/the-power-of-djangos-q-objects/
        q_list = map(lambda x: Q(**x), serializer.initial_data)
        aliases = Alias.objects.filter(reduce(operator.or_, q_list))

        initial_set = set(map(lambda x: (x["source"], x["destination"], x["domain"]), serializer.initial_data))
        deleted_set = set(aliases.values_list("source", "destination", "domain"))
        diff = initial_set.difference(deleted_set)
        logger.debug("Deleted: {}".format(",".join(map(lambda x: "{0[0]}={0[1]}".format(x), deleted_set))))
        aliases.delete()

        if diff:
            diff_formatted = map(lambda x: "{0[0]}={0[1]}".format(x), diff)
            res = "Aliases '{}' could not be found and were not deleted.".format(", ".join(diff_formatted))
            logger.info(res)
            return Response({"result": res}, status=status.HTTP_200_OK)

        return Response(status=status.HTTP_204_NO_CONTENT)


class DomainViewSet(viewsets.ModelViewSet):
    """Domains"""

    queryset = Domain.objects.all()
    serializer_class = DomainSerializer
    permission_classes = [IsAuthenticated]
    filter_backends = (DjangoFilterBackend,)
    filterset_fields = ("name",)


class UserViewSet(viewsets.ModelViewSet):
    """Users"""

    queryset = User.objects.all()
    serializer_class = UserSerializer
    permission_classes = [IsAuthenticated]