class NodeAccessControlHandler

class NodeAccessControlHandler extends EntityAccessControlHandler implements NodeAccessControlHandlerInterface, EntityHandlerInterface {
    
    /**
     * The node grant storage.
     *
     * @var \Drupal\node\NodeGrantDatabaseStorageInterface
     */
    protected $grantStorage;
    
    /**
     * The entity type manager.
     *
     * @var \Drupal\Core\Entity\EntityTypeManagerInterface
     */
    protected $entityTypeManager;
    
    /**
     * Map of revision operations.
     *
     * Keys contain revision operations, where values are an array containing the
     * permission operation and entity operation.
     *
     * Permission operation is used to build the required permission, e.g.
     * 'permissionOperation all revisions', 'permissionOperation type revisions'.
     *
     * Entity operation is used to determine access, e.g for 'delete revision'
     * operation, an account must also have access to 'delete' operation on an
     * entity.
     */
    protected const REVISION_OPERATION_MAP = [
        'view all revisions' => [
            'view',
            'view',
        ],
        'view revision' => [
            'view',
            'view',
        ],
        'revert revision' => [
            'revert',
            'update',
        ],
        'delete revision' => [
            'delete',
            'delete',
        ],
    ];
    
    /**
     * Constructs a NodeAccessControlHandler object.
     *
     * @param \Drupal\Core\Entity\EntityTypeInterface $entity_type
     *   The entity type definition.
     * @param \Drupal\node\NodeGrantDatabaseStorageInterface $grant_storage
     *   The node grant storage.
     * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
     *   The entity type manager.
     */
    public function __construct(EntityTypeInterface $entity_type, NodeGrantDatabaseStorageInterface $grant_storage, EntityTypeManagerInterface $entity_type_manager) {
        parent::__construct($entity_type);
        $this->grantStorage = $grant_storage;
        $this->entityTypeManager = $entity_type_manager;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function createInstance(ContainerInterface $container, EntityTypeInterface $entity_type) {
        return new static($entity_type, $container->get('node.grant_storage'), $container->get('entity_type.manager'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function access(EntityInterface $entity, $operation, ?AccountInterface $account = NULL, $return_as_object = FALSE) {
        $account = $this->prepareUser($account);
        // Only bypass if not a revision operation, to retain compatibility.
        if ($account->hasPermission('bypass node access') && !isset(static::REVISION_OPERATION_MAP[$operation])) {
            $result = AccessResult::allowed()->cachePerPermissions();
            return $return_as_object ? $result : $result->isAllowed();
        }
        if (!$account->hasPermission('access content')) {
            $result = AccessResult::forbidden("The 'access content' permission is required.")->cachePerPermissions();
            return $return_as_object ? $result : $result->isAllowed();
        }
        $result = parent::access($entity, $operation, $account, TRUE)->cachePerPermissions();
        return $return_as_object ? $result : $result->isAllowed();
    }
    
    /**
     * {@inheritdoc}
     */
    public function createAccess($entity_bundle = NULL, ?AccountInterface $account = NULL, array $context = [], $return_as_object = FALSE) {
        $account = $this->prepareUser($account);
        if ($account->hasPermission('bypass node access')) {
            $result = AccessResult::allowed()->cachePerPermissions();
            return $return_as_object ? $result : $result->isAllowed();
        }
        if (!$account->hasPermission('access content')) {
            $result = AccessResult::forbidden("The 'access content' permission is required.")->cachePerPermissions();
            return $return_as_object ? $result : $result->isAllowed();
        }
        $result = parent::createAccess($entity_bundle, $account, $context, TRUE)->cachePerPermissions();
        return $return_as_object ? $result : $result->isAllowed();
    }
    
    /**
     * {@inheritdoc}
     */
    protected function checkAccess(EntityInterface $node, $operation, AccountInterface $account) {
        
        /** @var \Drupal\node\NodeInterface $node */
        // Fetch information from the node object if possible.
        $status = $node->isPublished();
        $uid = $node->getOwnerId();
        // Check if authors can view their own unpublished nodes.
        if ($operation === 'view' && !$status && $account->hasPermission('view own unpublished content') && $account->isAuthenticated() && $account->id() == $uid) {
            return AccessResult::allowed()->cachePerPermissions()
                ->cachePerUser()
                ->addCacheableDependency($node);
        }
        [
            $revision_permission_operation,
            $entity_operation,
        ] = static::REVISION_OPERATION_MAP[$operation] ?? [
            NULL,
            NULL,
        ];
        // Revision operations.
        if ($revision_permission_operation) {
            $bundle = $node->bundle();
            // If user doesn't have any of these then quit.
            if (!$account->hasPermission("{$revision_permission_operation} all revisions") && !$account->hasPermission("{$revision_permission_operation} {$bundle} revisions") && !$account->hasPermission('administer nodes')) {
                return AccessResult::neutral()->cachePerPermissions();
            }
            // If the user has the view all revisions permission and this is the view
            // all revisions operation then we can allow access.
            if ($operation === 'view all revisions') {
                return AccessResult::allowed()->cachePerPermissions();
            }
            // If this is the default revision, return access denied for revert or
            // delete operations.
            if ($node->isDefaultRevision() && ($operation === 'revert revision' || $operation === 'delete revision')) {
                return AccessResult::forbidden()->addCacheableDependency($node);
            }
            elseif ($account->hasPermission('administer nodes')) {
                return AccessResult::allowed()->cachePerPermissions();
            }
            // First check the access to the default revision and finally, if the
            // node passed in is not the default revision then check access to
            // that, too.
            $node_storage = $this->entityTypeManager
                ->getStorage($node->getEntityTypeId());
            $access = $this->access($node_storage->load($node->id()), $entity_operation, $account, TRUE);
            if (!$node->isDefaultRevision()) {
                $access = $access->andIf($this->access($node, $entity_operation, $account, TRUE));
            }
            return $access->cachePerPermissions()
                ->addCacheableDependency($node);
        }
        // Evaluate node grants.
        $access_result = $this->grantStorage
            ->access($node, $operation, $account);
        if ($operation === 'view' && $access_result instanceof RefinableCacheableDependencyInterface) {
            // Node variations can affect the access to the node. For instance, the
            // access result cache varies on the node's published status. Only the
            // 'view' node grant can currently be cached. The 'update' and 'delete'
            // grants are already marked as uncacheable in the node grant storage.
            // @see \Drupal\node\NodeGrantDatabaseStorage::access()
            $access_result->addCacheableDependency($node);
        }
        return $access_result;
    }
    
    /**
     * {@inheritdoc}
     */
    protected function checkCreateAccess(AccountInterface $account, array $context, $entity_bundle = NULL) {
        return AccessResult::allowedIf($account->hasPermission('create ' . $entity_bundle . ' content'))
            ->cachePerPermissions();
    }
    
    /**
     * {@inheritdoc}
     */
    protected function checkFieldAccess($operation, FieldDefinitionInterface $field_definition, AccountInterface $account, ?FieldItemListInterface $items = NULL) {
        // Only users with the administer nodes permission can edit administrative
        // fields.
        $administrative_fields = [
            'uid',
            'status',
            'created',
            'promote',
            'sticky',
        ];
        if ($operation == 'edit' && in_array($field_definition->getName(), $administrative_fields, TRUE)) {
            return AccessResult::allowedIfHasPermission($account, 'administer nodes');
        }
        // No user can change read only fields.
        $read_only_fields = [
            'revision_timestamp',
            'revision_uid',
        ];
        if ($operation == 'edit' && in_array($field_definition->getName(), $read_only_fields, TRUE)) {
            return AccessResult::forbidden();
        }
        // Users have access to the revision_log field either if they have
        // administrative permissions or if the new revision option is enabled.
        if ($operation == 'edit' && $field_definition->getName() == 'revision_log') {
            if ($account->hasPermission('administer nodes')) {
                return AccessResult::allowed()->cachePerPermissions();
            }
            return AccessResult::allowedIf($items->getEntity()->type->entity
                ->shouldCreateNewRevision())
                ->cachePerPermissions();
        }
        return parent::checkFieldAccess($operation, $field_definition, $account, $items);
    }
    
    /**
     * {@inheritdoc}
     */
    public function acquireGrants(NodeInterface $node) {
        $grants = $this->moduleHandler
            ->invokeAll('node_access_records', [
            $node,
        ]);
        // Let modules alter the grants.
        $this->moduleHandler
            ->alter('node_access_records', $grants, $node);
        // If no grants are set and the node is published, then use the default grant.
        if (empty($grants) && $node->isPublished()) {
            $grants[] = [
                'realm' => 'all',
                'gid' => 0,
                'grant_view' => 1,
                'grant_update' => 0,
                'grant_delete' => 0,
            ];
        }
        return $grants;
    }
    
    /**
     * {@inheritdoc}
     */
    public function writeDefaultGrant() {
        $this->grantStorage
            ->writeDefault();
    }
    
    /**
     * {@inheritdoc}
     */
    public function deleteGrants() {
        $this->grantStorage
            ->delete();
    }
    
    /**
     * {@inheritdoc}
     */
    public function countGrants() {
        return $this->grantStorage
            ->count();
    }
    
    /**
     * {@inheritdoc}
     */
    public function checkAllGrants(AccountInterface $account) {
        return $this->grantStorage
            ->checkAll($account);
    }

}