class OverridesSectionStorage

class OverridesSectionStorage extends SectionStorageBase implements ContainerFactoryPluginInterface, OverridesSectionStorageInterface, SectionStorageLocalTaskProviderInterface {
    
    /**
     * The field name used by this storage.
     *
     * @var string
     */
    const FIELD_NAME = 'layout_builder__layout';
    
    /**
     * The entity type manager.
     *
     * @var \Drupal\Core\Entity\EntityTypeManagerInterface
     */
    protected $entityTypeManager;
    
    /**
     * The entity field manager.
     *
     * @var \Drupal\Core\Entity\EntityFieldManagerInterface
     */
    protected $entityFieldManager;
    
    /**
     * The section storage manager.
     *
     * @var \Drupal\layout_builder\SectionStorage\SectionStorageManagerInterface
     */
    protected $sectionStorageManager;
    
    /**
     * The entity repository.
     *
     * @var \Drupal\Core\Entity\EntityRepositoryInterface
     */
    protected $entityRepository;
    
    /**
     * The current user.
     *
     * @var \Drupal\Core\Session\AccountInterface
     */
    protected $currentUser;
    
    /**
     * {@inheritdoc}
     */
    public function __construct(array $configuration, $plugin_id, $plugin_definition, EntityTypeManagerInterface $entity_type_manager, EntityFieldManagerInterface $entity_field_manager, SectionStorageManagerInterface $section_storage_manager, EntityRepositoryInterface $entity_repository, AccountInterface $current_user) {
        parent::__construct($configuration, $plugin_id, $plugin_definition);
        $this->entityTypeManager = $entity_type_manager;
        $this->entityFieldManager = $entity_field_manager;
        $this->sectionStorageManager = $section_storage_manager;
        $this->entityRepository = $entity_repository;
        $this->currentUser = $current_user;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition) {
        return new static($configuration, $plugin_id, $plugin_definition, $container->get('entity_type.manager'), $container->get('entity_field.manager'), $container->get('plugin.manager.layout_builder.section_storage'), $container->get('entity.repository'), $container->get('current_user'));
    }
    
    /**
     * {@inheritdoc}
     */
    protected function getSectionList() {
        return $this->getEntity()
            ->get(static::FIELD_NAME);
    }
    
    /**
     * Gets the entity storing the overrides.
     *
     * @return \Drupal\Core\Entity\FieldableEntityInterface
     *   The entity storing the overrides.
     */
    protected function getEntity() {
        return $this->getContextValue('entity');
    }
    
    /**
     * {@inheritdoc}
     */
    public function getStorageId() {
        $entity = $this->getEntity();
        return $entity->getEntityTypeId() . '.' . $entity->id();
    }
    
    /**
     * {@inheritdoc}
     */
    public function getTempstoreKey() {
        $key = parent::getTempstoreKey();
        $key .= '.' . $this->getContextValue('view_mode');
        $entity = $this->getEntity();
        // @todo Allow entities to provide this contextual information in
        //   https://www.drupal.org/project/drupal/issues/3026957.
        if ($entity instanceof TranslatableInterface) {
            $key .= '.' . $entity->language()
                ->getId();
        }
        return $key;
    }
    
    /**
     * {@inheritdoc}
     */
    public function deriveContextsFromRoute($value, $definition, $name, array $defaults) {
        $contexts = [];
        if ($entity = $this->extractEntityFromRoute($value, $defaults)) {
            $contexts['entity'] = EntityContext::fromEntity($entity);
            // @todo Expand to work for all view modes in
            //   https://www.drupal.org/node/2907413.
            $view_mode = 'full';
            // Retrieve the actual view mode from the returned view display as the
            // requested view mode may not exist and a fallback will be used.
            $view_mode = LayoutBuilderEntityViewDisplay::collectRenderDisplay($entity, $view_mode)->getMode();
            $contexts['view_mode'] = new Context(new ContextDefinition('string'), $view_mode);
        }
        return $contexts;
    }
    
    /**
     * Extracts an entity from the route values.
     *
     * @param mixed $value
     *   The raw value from the route.
     * @param array $defaults
     *   The route defaults array.
     *
     * @return \Drupal\Core\Entity\EntityInterface|null
     *   The entity for the route, or NULL if none exist.
     *
     * @see \Drupal\layout_builder\SectionStorageInterface::deriveContextsFromRoute()
     * @see \Drupal\Core\ParamConverter\ParamConverterInterface::convert()
     */
    private function extractEntityFromRoute($value, array $defaults) {
        if (strpos($value, '.') !== FALSE) {
            [
                $entity_type_id,
                $entity_id,
            ] = explode('.', $value, 2);
        }
        elseif (isset($defaults['entity_type_id']) && !empty($defaults[$defaults['entity_type_id']])) {
            $entity_type_id = $defaults['entity_type_id'];
            $entity_id = $defaults[$entity_type_id];
        }
        else {
            return NULL;
        }
        $entity = $this->entityRepository
            ->getActive($entity_type_id, $entity_id);
        if ($entity instanceof FieldableEntityInterface && $entity->hasField(static::FIELD_NAME)) {
            return $entity;
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildRoutes(RouteCollection $collection) {
        foreach ($this->getEntityTypes() as $entity_type_id => $entity_type) {
            // If the canonical route does not exist, do not provide any Layout
            // Builder UI routes for this entity type.
            if (!$collection->get("entity.{$entity_type_id}.canonical")) {
                continue;
            }
            $defaults = [];
            $defaults['entity_type_id'] = $entity_type_id;
            // Retrieve the requirements from the canonical route.
            $requirements = $collection->get("entity.{$entity_type_id}.canonical")
                ->getRequirements();
            $options = [];
            // Ensure that upcasting is run in the correct order.
            $options['parameters']['section_storage'] = [];
            $options['parameters'][$entity_type_id]['type'] = 'entity:' . $entity_type_id;
            $template = $entity_type->getLinkTemplate('canonical') . '/layout';
            $this->buildLayoutRoutes($collection, $this->getPluginDefinition(), $template, $defaults, $requirements, $options, $entity_type_id, $entity_type_id);
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildLocalTasks($base_plugin_definition) {
        $local_tasks = [];
        foreach ($this->getEntityTypes() as $entity_type_id => $entity_type) {
            $local_tasks["layout_builder.overrides.{$entity_type_id}.view"] = $base_plugin_definition + [
                'route_name' => "layout_builder.overrides.{$entity_type_id}.view",
                'weight' => 15,
                'title' => $this->t('Layout'),
                'base_route' => "entity.{$entity_type_id}.canonical",
                'cache_contexts' => [
                    'layout_builder_is_active:' . $entity_type_id,
                ],
            ];
        }
        return $local_tasks;
    }
    
    /**
     * Determines if this entity type's ID is stored as an integer.
     *
     * @param \Drupal\Core\Entity\EntityTypeInterface $entity_type
     *   An entity type.
     *
     * @return bool
     *   TRUE if this entity type's ID key is always an integer, FALSE otherwise.
     */
    protected function hasIntegerId(EntityTypeInterface $entity_type) {
        $field_storage_definitions = $this->entityFieldManager
            ->getFieldStorageDefinitions($entity_type->id());
        return $field_storage_definitions[$entity_type->getKey('id')]
            ->getType() === 'integer';
    }
    
    /**
     * Returns an array of relevant entity types.
     *
     * @return \Drupal\Core\Entity\EntityTypeInterface[]
     *   An array of entity types.
     */
    protected function getEntityTypes() {
        return array_filter($this->entityTypeManager
            ->getDefinitions(), function (EntityTypeInterface $entity_type) {
            return $entity_type->entityClassImplements(FieldableEntityInterface::class) && $entity_type->hasHandlerClass('form', 'layout_builder') && $entity_type->hasViewBuilderClass() && $entity_type->hasLinkTemplate('canonical');
        });
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDefaultSectionStorage() {
        $display = LayoutBuilderEntityViewDisplay::collectRenderDisplay($this->getEntity(), $this->getContextValue('view_mode'));
        return $this->sectionStorageManager
            ->load('defaults', [
            'display' => EntityContext::fromEntity($display),
        ]);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getRedirectUrl() {
        return $this->getEntity()
            ->toUrl('canonical');
    }
    
    /**
     * {@inheritdoc}
     */
    public function getLayoutBuilderUrl($rel = 'view') {
        $entity = $this->getEntity();
        $route_parameters[$entity->getEntityTypeId()] = $entity->id();
        return Url::fromRoute("layout_builder.{$this->getStorageType()}.{$this->getEntity()->getEntityTypeId()}.{$rel}", $route_parameters);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getContextsDuringPreview() {
        $contexts = parent::getContextsDuringPreview();
        // @todo Remove this in https://www.drupal.org/node/3018782.
        if (isset($contexts['entity'])) {
            $contexts['layout_builder.entity'] = $contexts['entity'];
            unset($contexts['entity']);
        }
        return $contexts;
    }
    
    /**
     * {@inheritdoc}
     */
    public function label() {
        return $this->getEntity()
            ->label();
    }
    
    /**
     * {@inheritdoc}
     */
    public function save() {
        return $this->getEntity()
            ->save();
    }
    
    /**
     * {@inheritdoc}
     */
    public function access($operation, AccountInterface $account = NULL, $return_as_object = FALSE) {
        if ($account === NULL) {
            $account = $this->currentUser;
        }
        $entity = $this->getEntity();
        // Create an access result that will allow access to the layout if one of
        // these conditions applies:
        // 1. The user can configure any layouts.
        $any_access = AccessResult::allowedIfHasPermission($account, 'configure any layout');
        // 2. The user can configure layouts on all items of the bundle type.
        $bundle_access = AccessResult::allowedIfHasPermission($account, "configure all {$entity->bundle()} {$entity->getEntityTypeId()} layout overrides");
        // 3. The user can configure layouts items of this bundle type they can edit
        //    AND the user has access to edit this entity.
        $edit_only_bundle_access = AccessResult::allowedIfHasPermission($account, "configure editable {$entity->bundle()} {$entity->getEntityTypeId()} layout overrides");
        $edit_only_bundle_access = $edit_only_bundle_access->andIf($entity->access('update', $account, TRUE));
        $result = $any_access->orIf($bundle_access)
            ->orIf($edit_only_bundle_access);
        // Access also depends on the default being enabled.
        $result = $result->andIf($this->getDefaultSectionStorage()
            ->access($operation, $account, TRUE));
        $result = $this->handleTranslationAccess($result, $operation, $account);
        return $return_as_object ? $result : $result->isAllowed();
    }
    
    /**
     * Handles access checks related to translations.
     *
     * @param \Drupal\Core\Access\AccessResult $result
     *   The access result.
     * @param string $operation
     *   The operation to be performed.
     * @param \Drupal\Core\Session\AccountInterface $account
     *   The user for which to check access.
     *
     * @return \Drupal\Core\Access\AccessResultInterface
     *   The access result.
     */
    protected function handleTranslationAccess(AccessResult $result, $operation, AccountInterface $account) {
        $entity = $this->getEntity();
        // Access is always denied on non-default translations.
        return $result->andIf(AccessResult::allowedIf(!($entity instanceof TranslatableInterface && !$entity->isDefaultTranslation())))
            ->addCacheableDependency($entity);
    }
    
    /**
     * {@inheritdoc}
     */
    public function isApplicable(RefinableCacheableDependencyInterface $cacheability) {
        $default_section_storage = $this->getDefaultSectionStorage();
        $cacheability->addCacheableDependency($default_section_storage)
            ->addCacheableDependency($this);
        // Check that overrides are enabled and have at least one section.
        return $default_section_storage->isOverridable() && $this->isOverridden();
    }
    
    /**
     * {@inheritdoc}
     */
    public function isOverridden() {
        // If there are any sections at all, including a blank one, this section
        // storage has been overridden. Do not use count() as it does not include
        // blank sections.
        return !empty($this->getSections());
    }

}