"""
A custom AdminSite for AdminViewPermissionsTest.test_login_has_permission().
"""
from django.contrib import admin
from django.contrib.auth import get_permission_codename
from django.contrib.auth.forms import AuthenticationForm
from django.core.exceptions import ValidationError

from . import admin as base_admin, models

PERMISSION_NAME = 'admin_views.%s' % get_permission_codename('change', models.Article._meta)


class PermissionAdminAuthenticationForm(AuthenticationForm):
    def confirm_login_allowed(self, user):
        if not user.is_active or not (user.is_staff or user.has_perm(PERMISSION_NAME)):
            raise ValidationError('permission denied')


class HasPermissionAdmin(admin.AdminSite):
    login_form = PermissionAdminAuthenticationForm

    def has_permission(self, request):
        return (
            request.user.is_active and
            (request.user.is_staff or request.user.has_perm(PERMISSION_NAME))
        )


site = HasPermissionAdmin(name="has_permission_admin")
site.register(models.Article, base_admin.ArticleAdmin)