class BlockContentController

class BlockContentController extends ControllerBase {
    
    /**
     * The content block storage.
     *
     * @var \Drupal\Core\Entity\EntityStorageInterface
     */
    protected $blockContentStorage;
    
    /**
     * The content block type storage.
     *
     * @var \Drupal\Core\Entity\EntityStorageInterface
     */
    protected $blockContentTypeStorage;
    
    /**
     * The theme handler.
     *
     * @var \Drupal\Core\Extension\ThemeHandlerInterface
     */
    protected $themeHandler;
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) {
        $entity_type_manager = $container->get('entity_type.manager');
        return new static($entity_type_manager->getStorage('block_content'), $entity_type_manager->getStorage('block_content_type'), $container->get('theme_handler'));
    }
    
    /**
     * Constructs a BlockContent object.
     *
     * @param \Drupal\Core\Entity\EntityStorageInterface $block_content_storage
     *   The content block storage.
     * @param \Drupal\Core\Entity\EntityStorageInterface $block_content_type_storage
     *   The block type storage.
     * @param \Drupal\Core\Extension\ThemeHandlerInterface $theme_handler
     *   The theme handler.
     */
    public function __construct(EntityStorageInterface $block_content_storage, EntityStorageInterface $block_content_type_storage, ThemeHandlerInterface $theme_handler) {
        $this->blockContentStorage = $block_content_storage;
        $this->blockContentTypeStorage = $block_content_type_storage;
        $this->themeHandler = $theme_handler;
    }
    
    /**
     * Displays add content block links for available types.
     *
     * @param \Symfony\Component\HttpFoundation\Request $request
     *   The current request object.
     *
     * @return array
     *   A render array for a list of the block types that can be added or
     *   if there is only one block type defined for the site, the function
     *   returns the content block add page for that block type.
     */
    public function add(Request $request) {
        // @todo deprecate see https://www.drupal.org/project/drupal/issues/3346394.
        $types = [];
        // Only use block types the user has access to.
        foreach ($this->blockContentTypeStorage
            ->loadMultiple() as $type) {
            $access = $this->entityTypeManager()
                ->getAccessControlHandler('block_content')
                ->createAccess($type->id(), NULL, [], TRUE);
            if ($access->isAllowed()) {
                $types[$type->id()] = $type;
            }
        }
        uasort($types, [
            $this->blockContentTypeStorage
                ->getEntityType()
                ->getClass(),
            'sort',
        ]);
        if ($types && count($types) == 1) {
            $type = reset($types);
            return $this->addForm($type, $request);
        }
        if (count($types) === 0) {
            return [
                '#markup' => $this->t('You have not created any block types yet. Go to the <a href=":url">block type creation page</a> to add a new block type.', [
                    ':url' => Url::fromRoute('block_content.type_add')->toString(),
                ]),
            ];
        }
        return [
            '#theme' => 'block_content_add_list',
            '#content' => $types,
        ];
    }
    
    /**
     * Presents the content block creation form.
     *
     * @param \Drupal\block_content\BlockContentTypeInterface $block_content_type
     *   The block type to add.
     * @param \Symfony\Component\HttpFoundation\Request $request
     *   The current request object.
     *
     * @return array
     *   A form array as expected by
     *   \Drupal\Core\Render\RendererInterface::render().
     */
    public function addForm(BlockContentTypeInterface $block_content_type, Request $request) {
        $block = $this->blockContentStorage
            ->create([
            'type' => $block_content_type->id(),
        ]);
        if (($theme = $request->query
            ->get('theme')) && in_array($theme, array_keys($this->themeHandler
            ->listInfo()))) {
            // We have navigated to this page from the block library and will keep track
            // of the theme for redirecting the user to the configuration page for the
            // newly created block in the given theme.
            $block->setTheme($theme);
        }
        return $this->entityFormBuilder()
            ->getForm($block);
    }
    
    /**
     * Provides the page title for this controller.
     *
     * @param \Drupal\block_content\BlockContentTypeInterface $block_content_type
     *   The block type being added.
     *
     * @return string
     *   The page title.
     */
    public function getAddFormTitle(BlockContentTypeInterface $block_content_type) {
        return $this->t('Add %type content block', [
            '%type' => $block_content_type->label(),
        ]);
    }
    
    /**
     * Provides a redirect to the list of block types.
     *
     * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
     *   A route match object, used for the route name and the parameters.
     * @param \Symfony\Component\HttpFoundation\Request $request
     *   The current request object.
     *
     * @return \Symfony\Component\HttpFoundation\RedirectResponse
     *
     * @deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use
     *   /admin/structure/block-content directly instead of
     *   /admin/structure/block/block-content/types.
     *
     * @see https://www.drupal.org/node/3320855
     */
    public function blockContentTypeRedirect(RouteMatchInterface $route_match, Request $request) : RedirectResponse {
        @trigger_error('The path /admin/structure/block/block-content/types is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use /admin/structure/block-content. See https://www.drupal.org/node/3320855', E_USER_DEPRECATED);
        $helper = new PathChangedHelper($route_match, $request);
        $params = [
            '%old_path' => $helper->oldPath(),
            '%new_path' => $helper->newPath(),
            '%change_record' => 'https://www.drupal.org/node/3320855',
        ];
        $warning_message = $this->t('You have been redirected from %old_path. Update links, shortcuts, and bookmarks to use %new_path.', $params);
        $this->messenger()
            ->addWarning($warning_message);
        $this->getLogger('block_content')
            ->warning('A user was redirected from %old_path. This redirect will be removed in a future version of Drupal. Update links, shortcuts, and bookmarks to use %new_path. See %change_record for more information.', $params);
        return $helper->redirect();
    }
    
    /**
     * Provides a redirect to the content block library.
     *
     * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
     *   A route match object, used for the route name and the parameters.
     * @param \Symfony\Component\HttpFoundation\Request $request
     *   The current request object.
     *
     * @return \Symfony\Component\HttpFoundation\RedirectResponse
     *
     * @deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use
     *   /admin/content/block directly instead of
     *   /admin/structure/block/block-content.
     *
     * @see https://www.drupal.org/node/3320855
     */
    public function blockLibraryRedirect(RouteMatchInterface $route_match, Request $request) {
        @trigger_error('The path /admin/structure/block/block-content is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use /admin/content/block. See https://www.drupal.org/node/3320855', E_USER_DEPRECATED);
        $helper = new PathChangedHelper($route_match, $request);
        $params = [
            '%old_path' => $helper->oldPath(),
            '%new_path' => $helper->newPath(),
            '%change_record' => 'https://www.drupal.org/node/3320855',
        ];
        $warning_message = $this->t('You have been redirected from %old_path. Update links, shortcuts, and bookmarks to use %new_path.', $params);
        $this->messenger()
            ->addWarning($warning_message);
        $this->getLogger('block_content')
            ->warning('A user was redirected from %old_path. This redirect will be removed in a future version of Drupal. Update links, shortcuts, and bookmarks to use %new_path. See %change_record for more information.', $params);
        return $helper->redirect();
    }
    
    /**
     * Provides a redirect to block edit page.
     *
     * @param \Drupal\Core\Routing\RouteMatchInterface $route_match
     *   A route match object, used for the route name and the parameters.
     * @param \Symfony\Component\HttpFoundation\Request $request
     *   The current request object.
     * @param Drupal\block_content\BlockContentInterface $block_content
     *   The block to be edited.
     *
     * @return \Symfony\Component\HttpFoundation\RedirectResponse
     *
     * @deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use
     *   /admin/content/block/{block_content} directly instead of
     *   /block/{block_content}.
     *
     * @see https://www.drupal.org/node/3320855
     */
    public function editRedirect(RouteMatchInterface $route_match, Request $request, BlockContentInterface $block_content) : RedirectResponse {
        @trigger_error('The path /block/{block_content} is deprecated in drupal:10.1.0 and is removed from drupal:11.0.0. Use /admin/content/block/{block_content}. See https://www.drupal.org/node/3320855', E_USER_DEPRECATED);
        $helper = new PathChangedHelper($route_match, $request);
        $params = [
            '%old_path' => $helper->oldPath(),
            '%new_path' => $helper->newPath(),
            '%change_record' => 'https://www.drupal.org/node/3320855',
        ];
        $warning_message = $this->t('You have been redirected from %old_path. Update links, shortcuts, and bookmarks to use %new_path.', $params);
        $this->messenger()
            ->addWarning($warning_message);
        $this->getLogger('block_content')
            ->warning('A user was redirected from %old_path to %new_path. This redirect will be removed in a future version of Drupal. Update links, shortcuts, and bookmarks to use %new_path. See %change_record for more information.', $params);
        return $helper->redirect();
    }

}