from django_filters import rest_framework as filters
from rest_framework.decorators import action
from rest_framework.exceptions import NotFound
from rest_framework.permissions import IsAuthenticated
from rest_framework.views import Response
from rest_framework.viewsets import ReadOnlyModelViewSet

from apps.api.permissions import LegacyAccessControlRole
from apps.auth_token.auth import ApiTokenAuthentication, UserScheduleExportAuthentication
from apps.public_api.custom_renderers import CalendarRenderer
from apps.public_api.serializers import FastUserSerializer, UserSerializer
from apps.public_api.tf_sync import is_request_from_terraform, sync_users_on_tf_request
from apps.public_api.throttlers.user_throttle import UserThrottle
from apps.schedules.ical_utils import user_ical_export
from apps.schedules.models import OnCallSchedule
from apps.user_management.models import User
from common.api_helpers.mixins import RateLimitHeadersMixin, ShortSerializerMixin
from common.api_helpers.paginators import HundredPageSizePaginator


class UserFilter(filters.FilterSet):
    """
    https://django-filter.readthedocs.io/en/master/guide/rest_framework.html
    """

    email = filters.CharFilter(field_name="email", lookup_expr="iexact")
    roles = filters.MultipleChoiceFilter(
        field_name="role", choices=LegacyAccessControlRole.choices()
    )  # LEGACY, should be removed eventually
    username = filters.CharFilter(field_name="username", lookup_expr="iexact")

    class Meta:
        model = User
        fields = ["email", "roles", "username"]


class UserView(RateLimitHeadersMixin, ShortSerializerMixin, ReadOnlyModelViewSet):
    authentication_classes = (ApiTokenAuthentication,)
    permission_classes = (IsAuthenticated,)

    model = User
    pagination_class = HundredPageSizePaginator

    serializer_class = UserSerializer
    short_serializer_class = FastUserSerializer
    filterset_class = UserFilter
    filter_backends = (filters.DjangoFilterBackend,)

    throttle_classes = [UserThrottle]

    # self.get_object() is not used in export action because UserScheduleExportAuthentication is used
    extra_actions_ignore_no_get_object = ["schedule_export"]

    def get_queryset(self):
        if is_request_from_terraform(self.request):
            sync_users_on_tf_request(self.request.auth.organization)
        is_short_request = self.request.query_params.get("short", "false") == "true"
        queryset = self.request.auth.organization.users.all()
        if not is_short_request:
            queryset = self.serializer_class.setup_eager_loading(queryset)
        queryset = self.filter_queryset(queryset)
        return queryset.order_by("id")

    def get_object(self):
        public_primary_key = self.kwargs["pk"]

        if public_primary_key == "current":
            return self.request.user

        organization = self.request.auth.organization

        try:
            user = User.objects.get(public_primary_key=public_primary_key, organization=organization)
        except User.DoesNotExist:
            raise NotFound

        return user

    @action(
        methods=["get"],
        detail=True,
        renderer_classes=(CalendarRenderer,),
        authentication_classes=(UserScheduleExportAuthentication,),
        permission_classes=(IsAuthenticated,),
    )
    def schedule_export(self, request, pk):
        schedules = OnCallSchedule.objects.filter(organization=self.request.auth.organization).related_to_user(
            self.request.user
        )
        export = user_ical_export(self.request.user, schedules)
        return Response(export)
