satnogs-network/network/users/admin.py

from django.contrib import admin
from django.contrib.auth.admin import UserAdmin as AuthUserAdmin
from django.contrib.auth.forms import UserChangeForm, UserCreationForm
from django.db.models import Count

from network.users.models import User


class HasStationListFilter(admin.SimpleListFilter):
    title = 'having station'
    parameter_name = 'has_station'

    def lookups(self, request, model_admin):
        return (
            (1, 'Yes'),
            (0, 'No'),
        )

    def queryset(self, request, queryset):
        if self.value() == '1':
            return queryset.annotate(count=Count('ground_stations')).filter(count__gt=0)
        if self.value() == '0':
            return queryset.annotate(count=Count('ground_stations')).filter(count__lt=1)


class UserAdmin(AuthUserAdmin):
    create_form_class = UserCreationForm
    update_form_class = UserChangeForm
    list_filter = AuthUserAdmin.list_filter + (HasStationListFilter, )


admin.site.register(User, UserAdmin)