def get_navigation_object_from_page(page: Page, current_page_id: int) -> dict:
    page_object = {
        "text": str(page.title),
        "nodes": [],
        "href": page.get_url(),
        "state": {}
    }
    if isinstance(page.specific, PageWithSidebar) or isinstance(page.specific, LessonPage) or isinstance(page.specific,
                                                                                                         ArticlePage):
        menu_title = page.specific.menu_title
        if not isinstance(menu_title, str):
            menu_title = menu_title.decode()
        if menu_title != '':
            page_object["text"] = menu_title
        if not page.specific.is_selectable:
            page_object["selectable"] = False
    if page.id == current_page_id:
        page_object["state"] = {
            "selected": True
        }
        page_object["selectable"] = False
    for child in page.get_children():
        if child.show_in_menus:
            page_object["nodes"].append(get_navigation_object_from_page(child, current_page_id))
    if len(page_object["nodes"]) == 0:
        page_object.pop('nodes', None)
    return page_object

    def test_construct_queryset_hook(self):
        page = SimplePage(title="Test shown", content="hello")
        Page.get_first_root_node().add_child(instance=page)

        page_not_shown = SimplePage(title="Test not shown", content="hello")
        Page.get_first_root_node().add_child(instance=page_not_shown)

        def filter_pages(pages, request):
            return pages.filter(id=page.id)

        with self.register_hook('construct_page_chooser_queryset', filter_pages):
            response = self.get()
        self.assertEqual(len(response.context['pages']), 1)
        self.assertEqual(response.context['pages'][0].specific, page)

def move_choose_destination(request, page_to_move_id, viewed_page_id=None):
    page_to_move = get_object_or_404(Page, id=page_to_move_id)
    page_perms = page_to_move.permissions_for_user(request.user)
    if not page_perms.can_move():
        raise PermissionDenied

    if viewed_page_id:
        viewed_page = get_object_or_404(Page, id=viewed_page_id)
    else:
        viewed_page = Page.get_first_root_node()

    viewed_page.can_choose = page_perms.can_move_to(viewed_page)

    child_pages = []
    for target in viewed_page.get_children():
        # can't move the page into itself or its descendants
        target.can_choose = page_perms.can_move_to(target)

        target.can_descend = (
            not(target == page_to_move or
                target.is_child_of(page_to_move)) and
            target.get_children_count()
        )

        child_pages.append(target)

    # Pagination
    paginator, child_pages = paginate(request, child_pages, per_page=50)

    return render(request, 'wagtailadmin/pages/move_choose_destination.html', {
        'page_to_move': page_to_move,
        'viewed_page': viewed_page,
        'child_pages': child_pages,
    })

    def clean(self):

        cleaned_data = super().clean()
        if 'slug' in self.cleaned_data:
            if not Page._slug_is_available(
                cleaned_data['slug'], self.parent_page, self.instance
            ):
                self.add_error('slug', forms.ValidationError(_("This slug is already in use")))

        # Check scheduled publishing fields
        go_live_at = cleaned_data.get('go_live_at')
        expire_at = cleaned_data.get('expire_at')

        # Go live must be before expire
        if go_live_at and expire_at:
            if go_live_at > expire_at:
                msg = _('Go live date/time must be before expiry date/time')
                self.add_error('go_live_at', forms.ValidationError(msg))
                self.add_error('expire_at', forms.ValidationError(msg))

        # Expire at must be in the future
        if expire_at and expire_at < timezone.now():
            self.add_error('expire_at', forms.ValidationError(_('Expiry date/time must be in the future')))

        # Don't allow an existing first_published_at to be unset by clearing the field
        if 'first_published_at' in cleaned_data and not cleaned_data['first_published_at']:
            del cleaned_data['first_published_at']

        return cleaned_data

def test_rendering(root_page, example_svg_upload, dummy_wagtail_doc):
    page = Page(title="nnep", slug="nnep")
    page.set_url_path(root_page)
    root_page.add_child(instance=page)
    page.save()
    assert page.url

    map = ImageMap.objects.create(svg=example_svg_upload)
    map.regions.create(element_id='green', link_external='/foobar', target='_blank')
    map.regions.create(element_id='blue', link_page=page, target='_top')
    map.regions.create(element_id='red', link_document=dummy_wagtail_doc)

    svg = map.rendered_svg
    assert '/foobar' in svg
    assert '_blank' in svg
    assert 'nnep' in svg
    assert '_top' in svg
    assert ('documents/%s' % dummy_wagtail_doc.pk) in svg

    def setUp(self):
        self.site_2_page = SimplePage(
            title="Site 2 page",
            slug="site_2_page",
            content="Hello",
        )
        Page.get_first_root_node().add_child(instance=self.site_2_page)
        self.site_2_subpage = SimplePage(
            title="Site 2 subpage",
            slug="site_2_subpage",
            content="Hello again",
        )
        self.site_2_page.add_child(instance=self.site_2_subpage)

        self.site_2 = Site.objects.create(
            hostname='example.com',
            port=8080,
            root_page=Page.objects.get(pk=self.site_2_page.pk),
            is_default_site=False
        )
        self.about_us_page = SimplePage.objects.get(url_path='/home/about-us/')

def test_auto_recache(root_page, example_svg_upload):
    page = Page(title="nnep", slug="nnep")
    page.set_url_path(root_page)
    root_page.add_child(instance=page)
    page.save()
    assert page.url

    map = ImageMap.objects.create(svg=example_svg_upload)
    map.regions.create(element_id='blue', link_page=page)
    map.recache_svg(save=True)
    assert 'nnep' in map.rendered_svg
    page.slug = 'ffflop'
    page.save()  # The `post_save` triggers will get called...
    assert 'ffflop' in ImageMap.objects.get(pk=map.pk).rendered_svg

    def setUpClass(cls):
        super().setUpClass()

        cls.test_page = SimplePage(title="test", slug='test', content="test")
        cls.wagtail_root = Page.get_first_root_node()
        cls.wagtail_root.add_child(instance=cls.test_page)

        cls.test_page_group = Group.objects.create(name="Test page")
        GroupPagePermission.objects.create(
            group=cls.test_page_group,
            page=cls.test_page,
            permission_type='edit'
        )

def move_confirm(request, page_to_move_id, destination_id):
    page_to_move = get_object_or_404(Page, id=page_to_move_id).specific
    destination = get_object_or_404(Page, id=destination_id)
    if not page_to_move.permissions_for_user(request.user).can_move_to(destination):
        raise PermissionDenied

    if not Page._slug_is_available(page_to_move.slug, destination, page=page_to_move):
        messages.error(
            request,
            _("The slug '{0}' is already in use at the selected parent page. Make sure the slug is unique and try again".format(page_to_move.slug))
        )
        return redirect('wagtailadmin_pages:move_choose_destination', page_to_move.id, destination.id)

    for fn in hooks.get_hooks('before_move_page'):
        result = fn(request, page_to_move, destination)
        if hasattr(result, 'status_code'):
            return result

    if request.method == 'POST':
        # any invalid moves *should* be caught by the permission check above,
        # so don't bother to catch InvalidMoveToDescendant
        page_to_move.move(destination, pos='last-child')

        messages.success(request, _("Page '{0}' moved.").format(page_to_move.get_admin_display_title()), buttons=[
            messages.button(reverse('wagtailadmin_pages:edit', args=(page_to_move.id,)), _('Edit'))
        ])

        for fn in hooks.get_hooks('after_move_page'):
            result = fn(request, page_to_move)
            if hasattr(result, 'status_code'):
                return result

        return redirect('wagtailadmin_explore', destination.id)

    return render(request, 'wagtailadmin/pages/confirm_move.html', {
        'page_to_move': page_to_move,
        'destination': destination,
    })

    def get_page(self):
        (content_type_app_name, content_type_model_name,
         parent_page_id) = self.args
        try:
            content_type = ContentType.objects.get_by_natural_key(
                content_type_app_name, content_type_model_name)
        except ContentType.DoesNotExist:
            raise Http404

        page = content_type.model_class()()
        parent_page = get_object_or_404(Page, id=parent_page_id).specific
        # We need to populate treebeard's path / depth fields in order to
        # pass validation. We can't make these 100% consistent with the rest
        # of the tree without making actual database changes (such as
        # incrementing the parent's numchild field), but by calling treebeard's
        # internal _get_path method, we can set a 'realistic' value that will
        # hopefully enable tree traversal operations
        # to at least partially work.
        page.depth = parent_page.depth + 1
        # Puts the page at the maximum possible path
        # for a child of `parent_page`.
        page.path = Page._get_children_path_interval(parent_page.path)[1]
        return page

 def get_root_page(self, request):
     return Page.get_first_root_node()

 def handle(self, *args, **options):
     for node in Page.get_root_nodes():
         self.set_subtree(node)

def index(request, parent_page_id=None):
    if parent_page_id:
        parent_page = get_object_or_404(Page, id=parent_page_id)
    else:
        parent_page = Page.get_first_root_node()

    # This will always succeed because of the @user_passes_test above.
    root_page = get_explorable_root_page(request.user)

    # If this page isn't a descendant of the user's explorable root page,
    # then redirect to that explorable root page instead.
    if not (
        parent_page.pk == root_page.pk or
        parent_page.is_descendant_of(root_page)
    ):
        return redirect('wagtailadmin_explore', root_page.pk)

    parent_page = parent_page.specific

    pages = parent_page.get_children().prefetch_related('content_type', 'sites_rooted_here')

    # Get page ordering
    ordering = request.GET.get('ordering', '-latest_revision_created_at')
    if ordering not in [
        'title',
        '-title',
        'content_type',
        '-content_type',
        'live', '-live',
        'latest_revision_created_at',
        '-latest_revision_created_at',
        'ord'
    ]:
        ordering = '-latest_revision_created_at'

    if ordering == 'ord':
        # preserve the native ordering from get_children()
        pass
    elif ordering == 'latest_revision_created_at':
        # order by oldest revision first.
        # Special case NULL entries - these should go at the top of the list.
        # Do this by annotating with Count('latest_revision_created_at'),
        # which returns 0 for these
        pages = pages.annotate(
            null_position=Count('latest_revision_created_at')
        ).order_by('null_position', 'latest_revision_created_at')
    elif ordering == '-latest_revision_created_at':
        # order by oldest revision first.
        # Special case NULL entries - these should go at the end of the list.
        pages = pages.annotate(
            null_position=Count('latest_revision_created_at')
        ).order_by('-null_position', '-latest_revision_created_at')
    else:
        pages = pages.order_by(ordering)

    # Don't paginate if sorting by page order - all pages must be shown to
    # allow drag-and-drop reordering
    do_paginate = ordering != 'ord'

    if do_paginate or pages.count() < 100:
        # Retrieve pages in their most specific form, so that custom
        # get_admin_display_title and get_url_parts methods on subclasses are respected.
        # However, skip this on unpaginated listings with >100 child pages as this could
        # be a significant performance hit. (This should only happen on the reorder view,
        # and hopefully no-one is having to do manual reordering on listings that large...)
        pages = pages.specific(defer=True)

    # allow hooks to modify the queryset
    for hook in hooks.get_hooks('construct_explorer_page_queryset'):
        pages = hook(parent_page, pages, request)

    # Pagination
    if do_paginate:
        paginator, pages = paginate(request, pages, per_page=50)

    return render(request, 'wagtailadmin/pages/index.html', {
        'parent_page': parent_page.specific,
        'ordering': ordering,
        'pagination_query_params': "ordering=%s" % ordering,
        'pages': pages,
        'do_paginate': do_paginate,
    })

 def test_empty_queryset(self):
     self.assertEqual(
         Page.get_first_root_node(),
         Page.objects.none().first_common_ancestor())

 def test_all_pages_include_self_strict(self):
     self.assertEqual(
         Page.get_first_root_node(),
         Page.objects.first_common_ancestor(include_self=True, strict=True))

 def test_all_pages(self):
     self.assertEqual(
         Page.get_first_root_node(),
         Page.objects.first_common_ancestor())

    def handle(self, **options):
        any_problems_fixed = False

        for page in Page.objects.all():
            try:
                page.specific
            except page.specific_class.DoesNotExist:
                self.stdout.write("Page %d (%s) is missing a subclass record; deleting." % (page.id, page.title))
                any_problems_fixed = True
                page.delete()

        (bad_alpha, bad_path, orphans, bad_depth, bad_numchild) = Page.find_problems()

        if bad_depth:
            self.stdout.write("Incorrect depth value found for pages: %s" % self.numberlist_to_string(bad_depth))
        if bad_numchild:
            self.stdout.write("Incorrect numchild value found for pages: %s" % self.numberlist_to_string(bad_numchild))

        if bad_depth or bad_numchild:
            Page.fix_tree(destructive=False)
            any_problems_fixed = True

        if orphans:
            # The 'orphans' list as returned by treebeard only includes pages that are
            # missing an immediate parent; descendants of orphans are not included.
            # Deleting only the *actual* orphans is a bit silly (since it'll just create
            # more orphans), so generate a queryset that contains descendants as well.
            orphan_paths = Page.objects.filter(id__in=orphans).values_list('path', flat=True)
            filter_conditions = []
            for path in orphan_paths:
                filter_conditions.append(Q(path__startswith=path))

            # combine filter_conditions into a single ORed condition
            final_filter = functools.reduce(operator.or_, filter_conditions)

            # build a queryset of all pages to be removed; this must be a vanilla Django
            # queryset rather than a treebeard MP_NodeQuerySet, so that we bypass treebeard's
            # custom delete() logic that would trip up on the very same corruption that we're
            # trying to fix here.
            pages_to_delete = models.query.QuerySet(Page).filter(final_filter)

            self.stdout.write("Orphaned pages found:")
            for page in pages_to_delete:
                self.stdout.write("ID %d: %s" % (page.id, page.title))
            self.stdout.write('')

            if options.get('interactive', True):
                yes_or_no = input("Delete these pages? [y/N] ")
                delete_orphans = yes_or_no.lower().startswith('y')
                self.stdout.write('')
            else:
                # Running tests, check for the "delete_orphans" option
                delete_orphans = options.get('delete_orphans', False)

            if delete_orphans:
                deletion_count = len(pages_to_delete)
                pages_to_delete.delete()
                self.stdout.write(
                    "%d orphaned page%s deleted." % (deletion_count, "s" if deletion_count != 1 else "")
                )
                any_problems_fixed = True

        if any_problems_fixed:
            # re-run find_problems to see if any new ones have surfaced
            (bad_alpha, bad_path, orphans, bad_depth, bad_numchild) = Page.find_problems()

        if any((bad_alpha, bad_path, orphans, bad_depth, bad_numchild)):
            self.stdout.write("Remaining problems (cannot fix automatically):")
            if bad_alpha:
                self.stdout.write(
                    "Invalid characters found in path for pages: %s" % self.numberlist_to_string(bad_alpha)
                )
            if bad_path:
                self.stdout.write("Invalid path length found for pages: %s" % self.numberlist_to_string(bad_path))
            if orphans:
                self.stdout.write("Orphaned pages found: %s" % self.numberlist_to_string(orphans))
            if bad_depth:
                self.stdout.write("Incorrect depth value found for pages: %s" % self.numberlist_to_string(bad_depth))
            if bad_numchild:
                self.stdout.write(
                    "Incorrect numchild value found for pages: %s" % self.numberlist_to_string(bad_numchild)
                )

        elif any_problems_fixed:
            self.stdout.write("All problems fixed.")
        else:
            self.stdout.write("No problems found.")

def browse(request, parent_page_id=None):
    # A missing or empty page_type parameter indicates 'all page types'
    # (i.e. descendants of wagtailcore.page)
    page_type_string = request.GET.get('page_type') or 'wagtailcore.page'
    user_perm = request.GET.get('user_perms', False)

    try:
        desired_classes = page_models_from_string(page_type_string)
    except (ValueError, LookupError):
        raise Http404

    # Find parent page
    if parent_page_id:
        parent_page = get_object_or_404(Page, id=parent_page_id)
    elif desired_classes == (Page,):
        # Just use the root page
        parent_page = Page.get_first_root_node()
    else:
        # Find the highest common ancestor for the specific classes passed in
        # In many cases, such as selecting an EventPage under an EventIndex,
        # this will help the administrator find their page quicker.
        all_desired_pages = filter_page_type(Page.objects.all(), desired_classes)
        parent_page = all_desired_pages.first_common_ancestor()

    # Get children of parent page
    pages = parent_page.get_children().specific()

    # allow hooks to modify the queryset
    for hook in hooks.get_hooks('construct_page_chooser_queryset'):
        pages = hook(pages, request)

    # Filter them by page type
    if desired_classes != (Page,):
        # restrict the page listing to just those pages that:
        # - are of the given content type (taking into account class inheritance)
        # - or can be navigated into (i.e. have children)
        choosable_pages = filter_page_type(pages, desired_classes)
        descendable_pages = pages.filter(numchild__gt=0)
        pages = choosable_pages | descendable_pages

    can_choose_root = request.GET.get('can_choose_root', False)

    # Do permission lookups for this user now, instead of for every page.
    permission_proxy = UserPagePermissionsProxy(request.user)

    # Parent page can be chosen if it is a instance of desired_classes
    parent_page.can_choose = can_choose_page(
        parent_page, permission_proxy, desired_classes, can_choose_root, user_perm)

    # Pagination
    # We apply pagination first so we don't need to walk the entire list
    # in the block below
    paginator, pages = paginate(request, pages, per_page=25)

    # Annotate each page with can_choose/can_decend flags
    for page in pages:
        page.can_choose = can_choose_page(page, permission_proxy, desired_classes, can_choose_root, user_perm)
        page.can_descend = page.get_children_count()

    # Render
    context = shared_context(request, {
        'parent_page': parent_page,
        'parent_page_id': parent_page.pk,
        'pages': pages,
        'search_form': SearchForm(),
        'page_type_string': page_type_string,
        'page_type_names': [desired_class.get_verbose_name() for desired_class in desired_classes],
        'page_types_restricted': (page_type_string != 'wagtailcore.page')
    })

    return render_modal_workflow(
        request,
        'wagtailadmin/chooser/browse.html', None,
        context,
        json_data={'step': 'browse', 'parent_page_id': context['parent_page_id']},
    )

 def normal_page(self, request):
     return Page.serve(self, request)

def index(request, parent_page_id=None):
    if parent_page_id:
        parent_page = get_object_or_404(Page, id=parent_page_id).specific
    else:
        parent_page = Page.get_first_root_node().specific

    pages = parent_page.get_children().prefetch_related('content_type', 'sites_rooted_here')

    # Get page ordering
    ordering = request.GET.get('ordering', '-latest_revision_created_at')
    if ordering not in [
        'title',
        '-title',
        'content_type',
        '-content_type',
        'live', '-live',
        'latest_revision_created_at',
        '-latest_revision_created_at',
        'ord'
    ]:
        ordering = '-latest_revision_created_at'

    if ordering == 'ord':
        # preserve the native ordering from get_children()
        pass
    elif ordering == 'latest_revision_created_at':
        # order by oldest revision first.
        # Special case NULL entries - these should go at the top of the list.
        # Do this by annotating with Count('latest_revision_created_at'),
        # which returns 0 for these
        pages = pages.annotate(
            null_position=Count('latest_revision_created_at')
        ).order_by('null_position', 'latest_revision_created_at')
    elif ordering == '-latest_revision_created_at':
        # order by oldest revision first.
        # Special case NULL entries - these should go at the end of the list.
        pages = pages.annotate(
            null_position=Count('latest_revision_created_at')
        ).order_by('-null_position', '-latest_revision_created_at')
    else:
        pages = pages.order_by(ordering)

    # Don't paginate if sorting by page order - all pages must be shown to
    # allow drag-and-drop reordering
    do_paginate = ordering != 'ord'

    if do_paginate:
        # Retrieve pages in their most specific form.
        # Only do this for paginated listings, as this could potentially be a
        # very expensive operation when performed on a large queryset.
        pages = pages.specific()

    # allow hooks to modify the queryset
    for hook in hooks.get_hooks('construct_explorer_page_queryset'):
        pages = hook(parent_page, pages, request)

    # Pagination
    if do_paginate:
        paginator, pages = paginate(request, pages, per_page=50)

    return render(request, 'wagtailadmin/pages/index.html', {
        'parent_page': parent_page.specific,
        'ordering': ordering,
        'pagination_query_params': "ordering=%s" % ordering,
        'pages': pages,
        'do_paginate': do_paginate,
    })