class ContentEntityCloneBase

class ContentEntityCloneBase implements EntityHandlerInterface, EntityCloneInterface {
    
    /**
     * The entity type manager.
     *
     * @var \Drupal\Core\Entity\EntityTypeManagerInterface
     */
    protected $entityTypeManager;
    
    /**
     * The entity type ID.
     *
     * @var string
     */
    protected $entityTypeId;
    
    /**
     * A service for obtaining the system's time.
     *
     * @var \Drupal\Component\Datetime\TimeInterface
     */
    protected $timeService;
    
    /**
     * The current user.
     *
     * @var \Drupal\Core\Session\AccountProxyInterface
     */
    protected $currentUser;
    
    /**
     * Constructs a new ContentEntityCloneBase.
     *
     * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
     *   The entity type manager.
     * @param string $entity_type_id
     *   The entity type ID.
     * @param \Drupal\Component\Datetime\TimeInterface $time_service
     *   A service for obtaining the system's time.
     * @param \Drupal\Core\Session\AccountProxyInterface $current_user
     *   The current user.
     */
    public function __construct(EntityTypeManagerInterface $entity_type_manager, $entity_type_id, TimeInterface $time_service, AccountProxyInterface $current_user) {
        $this->entityTypeManager = $entity_type_manager;
        $this->entityTypeId = $entity_type_id;
        $this->timeService = $time_service;
        $this->currentUser = $current_user;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function createInstance(ContainerInterface $container, EntityTypeInterface $entity_type) {
        return new static($container->get('entity_type.manager'), $entity_type->id(), $container->get('datetime.time'), $container->get('current_user'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function cloneEntity(EntityInterface $entity, EntityInterface $cloned_entity, array $properties = [], array &$already_cloned = []) {
        // Clone referenced entities.
        $already_cloned[$entity->getEntityTypeId()][$entity->id()] = $cloned_entity;
        if ($cloned_entity instanceof FieldableEntityInterface && $entity instanceof FieldableEntityInterface) {
            foreach ($cloned_entity->getFieldDefinitions() as $field_id => $field_definition) {
                if ($this->fieldIsClonable($field_definition)) {
                    $field = $entity->get($field_id);
                    
                    /** @var \Drupal\Core\Field\Plugin\Field\FieldType\EntityReferenceItem $value */
                    if ($field->count() > 0) {
                        $cloned_entity->set($field_id, $this->cloneReferencedEntities($field, $field_definition, $properties, $already_cloned));
                    }
                }
            }
        }
        if (isset($properties['take_ownership']) && $properties['take_ownership'] === 1) {
            // Set owner on cloned entity:
            $cloned_entity->setOwnerId($this->currentUser
                ->id());
            // Set owner on translations:
            $languages = $cloned_entity->getTranslationLanguages();
            foreach ($languages as $langcode => $language) {
                $translation = $cloned_entity->getTranslation($langcode);
                $translation->setOwnerId($this->currentUser
                    ->id());
            }
        }
        $this->setClonedEntityLabel($entity, $cloned_entity, $properties);
        $this->setCreatedAndChangedDates($cloned_entity);
        if ($this->hasTranslatableModerationState($cloned_entity)) {
            // If we are using moderation state, ensure that each translation gets
            // the same moderation state BEFORE we save so that upon save, each
            // translation gets its publishing status updated according to the
            // moderation state. After the entity is saved, we kick in the creation
            // of translations of created moderation state entity.
            foreach ($cloned_entity->getTranslationLanguages(TRUE) as $language) {
                $translation = $cloned_entity->getTranslation($language->getId());
                $translation->set('moderation_state', $cloned_entity->get('moderation_state')->value);
            }
        }
        $cloned_entity->save();
        // If we are using content moderation, make sure the moderation state
        // entity gets translated to reflect the available translations on the
        // source entity. Thus, we call this after the save because we need the
        // original moderation state entity to have been created.
        if ($this->hasTranslatableModerationState($cloned_entity)) {
            $this->setTranslationModerationState($entity, $cloned_entity);
        }
        return $cloned_entity;
    }
    
    /**
     * Determines if a field is clonable.
     *
     * @param \Drupal\Core\Field\FieldDefinitionInterface $field_definition
     *   The field definition.
     *
     * @return bool
     *   TRUE if the field is clonable; FALSE otherwise.
     */
    protected function fieldIsClonable(FieldDefinitionInterface $field_definition) {
        $clonable_field_types = [
            'entity_reference',
            'entity_reference_revisions',
        ];
        $type_is_clonable = in_array($field_definition->getType(), $clonable_field_types, TRUE);
        if ($field_definition instanceof FieldConfigInterface && $type_is_clonable) {
            return TRUE;
        }
        return FALSE;
    }
    
    /**
     * Sets the cloned entity's label.
     *
     * @param \Drupal\Core\Entity\EntityInterface $original_entity
     *   The original entity.
     * @param \Drupal\Core\Entity\EntityInterface $cloned_entity
     *   The entity cloned from the original.
     * @param array $properties
     *   The properties array.
     */
    protected function setClonedEntityLabel(EntityInterface $original_entity, EntityInterface $cloned_entity, array $properties) {
        $label_key = $this->entityTypeManager
            ->getDefinition($this->entityTypeId)
            ->getKey('label');
        if ($label_key && $cloned_entity->hasField($label_key)) {
            if (isset($properties['no_suffix']) && $properties['no_suffix'] === 1) {
                $cloned_entity->set($label_key, $original_entity->label());
            }
            else {
                $languages = $cloned_entity->getTranslationLanguages();
                foreach ($languages as $langcode => $language) {
                    $translation = $cloned_entity->getTranslation($langcode);
                    $translation->set($label_key, $translation->label() . ' - Cloned');
                }
            }
        }
    }
    
    /**
     * Clones referenced entities.
     *
     * @param \Drupal\Core\Field\FieldItemListInterface $field
     *   The field item.
     * @param \Drupal\Core\Field\FieldConfigInterface $field_definition
     *   The field definition.
     * @param array $properties
     *   All new properties to replace old.
     * @param array $already_cloned
     *   List of all already cloned entities, used for circular references.
     *
     * @return array
     *   Referenced entities.
     */
    protected function cloneReferencedEntities(FieldItemListInterface $field, FieldConfigInterface $field_definition, array $properties, array &$already_cloned) {
        $referenced_entities = [];
        foreach ($field as $value) {
            // Check if we're not dealing with an entity
            // that has been deleted in the meantime.
            if (!($referenced_entity = $value->get('entity')
                ->getTarget())) {
                continue;
            }
            
            /** @var \Drupal\Core\Entity\ContentEntityInterface $referenced_entity */
            $referenced_entity = $value->get('entity')
                ->getTarget()
                ->getValue();
            $child_properties = $this->getChildProperties($properties, $field_definition, $referenced_entity);
            if (!empty($child_properties['clone'])) {
                $cloned_reference = $referenced_entity->createDuplicate();
                
                /** @var \Drupal\entity_clone\EntityClone\EntityCloneInterface $entity_clone_handler */
                $entity_clone_handler = $this->entityTypeManager
                    ->getHandler($referenced_entity->getEntityTypeId(), 'entity_clone');
                $entity_clone_handler->cloneEntity($referenced_entity, $cloned_reference, $child_properties['children'], $already_cloned);
                $referenced_entities[] = $cloned_reference;
            }
            elseif (!empty($child_properties['is_circular'])) {
                if (!empty($already_cloned[$referenced_entity->getEntityTypeId()][$referenced_entity->id()])) {
                    $referenced_entities[] = $already_cloned[$referenced_entity->getEntityTypeId()][$referenced_entity->id()];
                }
                else {
                    $referenced_entities[] = $referenced_entity;
                }
            }
            else {
                $referenced_entities[] = $referenced_entity;
            }
        }
        return $referenced_entities;
    }
    
    /**
     * Fetches the properties of a child entity.
     *
     * @param array $properties
     *   Properties of the clone operation.
     * @param \Drupal\Core\Field\FieldConfigInterface $field_definition
     *   The field definition.
     * @param \Drupal\Core\Entity\EntityInterface $referenced_entity
     *   The field's target entity.
     *
     * @return array
     *   Child properties.
     */
    protected function getChildProperties(array $properties, FieldConfigInterface $field_definition, EntityInterface $referenced_entity) {
        $child_properties = [];
        if (isset($properties['recursive'][$field_definition->id()]['references'][$referenced_entity->id()])) {
            $child_properties = $properties['recursive'][$field_definition->id()]['references'][$referenced_entity->id()];
        }
        if (!isset($child_properties['children'])) {
            $child_properties['children'] = [];
        }
        return $child_properties;
    }
    
    /**
     * Create moderation_state translations for the cloned entities.
     *
     * When a new translation is saved, content moderation creates a corresponding
     * translation to the moderation_state entity as well. However, for this to
     * happen, the translation itself needs to be saved. When we clone, this
     * doesn't happen as the original entity gets cloned together with the
     * translations and a save is called on the original language being cloned. So
     * we have to do this manually.
     *
     * This is doing essentially what
     * Drupal\content_moderation\EntityOperations::updateOrCreateFromEntity but
     * we had to replicate it because if a user clones a node translation
     * directly, updateOrCreateFromEntity() would not create a translation for
     * the original language but would override the language when passing the
     * original entity translation.
     */
    protected function setTranslationModerationState(ContentEntityInterface $entity, ContentEntityInterface $cloned_entity) {
        $languages = $cloned_entity->getTranslationLanguages();
        // Load the existing moderation state entity for the cloned entity. This
        // should exist and have only 1 translation.
        $needs_save = FALSE;
        $moderation_state = ContentModerationState::loadFromModeratedEntity($cloned_entity);
        $original_translation = $cloned_entity->getUntranslated();
        if ($moderation_state && $moderation_state->language()
            ->getId() !== $original_translation->language()
            ->getId()) {
            // If we are cloning a node while not being in the original translation
            // language, Drupal core will set the default language of the moderation
            // state to that language whereas the node is simply duplicated and will
            // keep the original default language. So we need to change it to that
            // also in the moderation state to keep things consistent.
            $moderation_state->set($moderation_state->getEntityType()
                ->getKey('langcode'), $original_translation->language()
                ->getId());
            $needs_save = TRUE;
        }
        foreach ($languages as $language) {
            $translation = $cloned_entity->getTranslation($language->getId());
            if ($moderation_state && !$moderation_state->hasTranslation($translation->language()
                ->getId())) {
                // We make a 1 to 1 copy of the moderation state entity from the
                // original created already by the content_moderation module. This is ok
                // because even if translations can be in different moderation states,
                // when cloning, the moderation state is reset to whatever the workflow
                // default is configured to be. So we anyway should end up with the
                // same state across all languages.
                $moderation_state->addTranslation($translation->language()
                    ->getId(), $moderation_state->toArray());
                $needs_save = TRUE;
            }
        }
        if ($needs_save) {
            ContentModerationState::updateOrCreateFromEntity($moderation_state);
        }
    }
    
    /**
     * Checks if the entity has the moderation state field and can be moderated.
     *
     * @param \Drupal\Core\Entity\ContentEntityInterface $entity
     *   The entity.
     *
     * @return bool
     *   Whether it can be moderated.
     */
    protected function hasTranslatableModerationState(ContentEntityInterface $entity) : bool {
        if (!$entity->hasField('moderation_state') || !$entity->get('moderation_state') instanceof ModerationStateFieldItemList) {
            return FALSE;
        }
        return !empty($entity->getTranslationLanguages(FALSE));
    }
    
    /**
     * Resets the created and changed dates on the cloned entity.
     *
     * Since we don't want the cloned entity to have the old dates (as a new
     * entity is being created), we need to reset the created and changed dates
     * for those entities that support it.
     *
     * @param \Drupal\Core\Entity\EntityInterface $entity
     *   The cloned entity.
     * @param bool $is_translation
     *   Whether we are recursing over a translation.
     */
    protected function setCreatedAndChangedDates(EntityInterface $entity, bool $is_translation = FALSE) {
        $created_time = $this->timeService
            ->getRequestTime();
        // For now, check that the cloned entity has a 'setCreatedTime' method, and
        // if so, try to call it. This condition can be replaced with a more-robust
        // check whether $cloned_entity is an instance of
        // Drupal\Core\Entity\EntityCreatedInterface once
        // https://www.drupal.org/project/drupal/issues/2833378 lands.
        if (method_exists($entity, 'setCreatedTime')) {
            $entity->setCreatedTime($created_time);
        }
        // If the entity has a changed time field, we should update it to the
        // created time we set above as it cannot possibly be before.
        if ($entity instanceof EntityChangedInterface) {
            $entity->setChangedTime($created_time);
        }
        if ($is_translation) {
            return;
        }
        if ($entity instanceof TranslatableInterface) {
            foreach ($entity->getTranslationLanguages(FALSE) as $language) {
                $translation = $entity->getTranslation($language->getId());
                $this->setCreatedAndChangedDates($translation, TRUE);
            }
        }
    }

}