from django.db.models import CharField
from django.db.models.functions import Cast
from django_filters import rest_framework as filters
from rest_framework import mixins
from rest_framework.permissions import IsAuthenticated
from rest_framework.viewsets import GenericViewSet

from apps.alerts.models import Alert
from apps.api.permissions import RBACPermission
from apps.auth_token.auth import ApiTokenAuthentication, GrafanaServiceAccountAuthentication
from apps.public_api.serializers.alerts import AlertSerializer
from apps.public_api.throttlers.user_throttle import UserThrottle
from common.api_helpers.mixins import RateLimitHeadersMixin
from common.api_helpers.paginators import FiftyPageSizePaginator


class AlertFilter(filters.FilterSet):
    id = filters.CharFilter(field_name="public_primary_key")


class AlertView(RateLimitHeadersMixin, mixins.ListModelMixin, GenericViewSet):
    authentication_classes = (GrafanaServiceAccountAuthentication, ApiTokenAuthentication)
    permission_classes = (IsAuthenticated, RBACPermission)

    rbac_permissions = {
        "list": [RBACPermission.Permissions.ALERT_GROUPS_READ],
    }

    throttle_classes = [UserThrottle]

    model = Alert
    serializer_class = AlertSerializer
    pagination_class = FiftyPageSizePaginator

    filter_backends = (filters.DjangoFilterBackend,)
    filterset_class = AlertFilter

    def get_queryset(self):
        alert_group_id = self.request.query_params.get("alert_group_id", None)
        search = self.request.query_params.get("search", None)

        queryset = Alert.objects.filter(group__channel__organization=self.request.auth.organization)

        if alert_group_id:
            queryset = queryset.filter(group__public_primary_key=alert_group_id)

        if search:
            queryset = queryset.annotate(
                raw_request_data_str=Cast("raw_request_data", output_field=CharField())
            ).filter(raw_request_data_str__icontains=search)

        queryset = self.serializer_class.setup_eager_loading(queryset)

        return queryset.order_by("-id")