class EntityConfigBase

class EntityConfigBase extends Entity {
    
    /**
     * The language manager.
     *
     * @var \Drupal\Core\Language\LanguageManagerInterface
     */
    protected $languageManager;
    
    /**
     * The configuration factory.
     *
     * @var \Drupal\Core\Config\ConfigFactoryInterface
     */
    protected $configFactory;
    
    /**
     * Construct a new entity.
     *
     * @param array $configuration
     *   A configuration array containing information about the plugin instance.
     * @param string $plugin_id
     *   The plugin_id for the plugin instance.
     * @param mixed $plugin_definition
     *   The plugin implementation definition.
     * @param \Drupal\migrate\Plugin\MigrationInterface $migration
     *   The migration.
     * @param \Drupal\Core\Entity\EntityStorageInterface $storage
     *   The storage for this entity type.
     * @param array $bundles
     *   The list of bundles this entity type has.
     * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
     *   The language manager.
     * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
     *   The configuration factory.
     */
    public function __construct(array $configuration, $plugin_id, $plugin_definition, MigrationInterface $migration, EntityStorageInterface $storage, array $bundles, LanguageManagerInterface $language_manager, ConfigFactoryInterface $config_factory) {
        parent::__construct($configuration, $plugin_id, $plugin_definition, $migration, $storage, $bundles);
        $this->languageManager = $language_manager;
        $this->configFactory = $config_factory;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition, MigrationInterface $migration = NULL) {
        $entity_type_id = static::getEntityTypeId($plugin_id);
        return new static($configuration, $plugin_id, $plugin_definition, $migration, $container->get('entity_type.manager')
            ->getStorage($entity_type_id), array_keys($container->get('entity_type.bundle.info')
            ->getBundleInfo($entity_type_id)), $container->get('language_manager'), $container->get('config.factory'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function import(Row $row, array $old_destination_id_values = []) {
        if ($row->isStub()) {
            throw new MigrateException('Config entities can not be stubbed.');
        }
        $this->rollbackAction = MigrateIdMapInterface::ROLLBACK_DELETE;
        $ids = $this->getIds();
        $id_key = $this->getKey('id');
        if (count($ids) > 1) {
            // Ids is keyed by the key name so grab the keys.
            $id_keys = array_keys($ids);
            if (!$row->getDestinationProperty($id_key)) {
                // Set the ID into the destination in for form "val1.val2.val3".
                $row->setDestinationProperty($id_key, $this->generateId($row, $id_keys));
            }
        }
        $entity = $this->getEntity($row, $old_destination_id_values);
        // Translations are already saved in updateEntity by configuration override.
        if (!$this->isTranslationDestination()) {
            $entity->save();
        }
        if (count($ids) > 1) {
            // This can only be a config entity, content entities have their ID key
            // and that's it.
            $return = [];
            foreach ($id_keys as $id_key) {
                if ($this->isTranslationDestination() && $id_key == 'langcode') {
                    // Config entities do not have a language property, get the language
                    // code from the destination.
                    $return[] = $row->getDestinationProperty($id_key);
                }
                else {
                    $return[] = $entity->get($id_key);
                }
            }
            return $return;
        }
        return [
            $entity->id(),
        ];
    }
    
    /**
     * Get whether this destination is for translations.
     *
     * @return bool
     *   Whether this destination is for translations.
     */
    protected function isTranslationDestination() {
        return !empty($this->configuration['translations']);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getIds() {
        $id_key = $this->getKey('id');
        $ids[$id_key]['type'] = 'string';
        if ($this->isTranslationDestination()) {
            $ids['langcode']['type'] = 'string';
        }
        return $ids;
    }
    
    /**
     * Updates an entity with the contents of a row.
     *
     * @param \Drupal\Core\Entity\EntityInterface $entity
     *   The entity to update.
     * @param \Drupal\migrate\Row $row
     *   The row object to update from.
     */
    protected function updateEntity(EntityInterface $entity, Row $row) {
        // This is a translation if the language in the active config does not
        // match the language of this row.
        $translation = FALSE;
        if ($row->hasDestinationProperty('langcode') && $this->languageManager instanceof ConfigurableLanguageManager) {
            $config = $entity->getConfigDependencyName();
            $langcode = $this->configFactory
                ->get('langcode');
            if ($langcode != $row->getDestinationProperty('langcode')) {
                $translation = TRUE;
            }
        }
        if ($translation) {
            $config_override = $this->languageManager
                ->getLanguageConfigOverride($row->getDestinationProperty('langcode'), $config);
            $config_override->set(str_replace(Row::PROPERTY_SEPARATOR, '.', $row->getDestinationProperty('property')), $row->getDestinationProperty('translation'));
            $config_override->save();
        }
        else {
            foreach ($row->getRawDestination() as $property => $value) {
                $this->updateEntityProperty($entity, explode(Row::PROPERTY_SEPARATOR, $property), $value);
            }
            $this->setRollbackAction($row->getIdMap());
        }
    }
    
    /**
     * Updates a (possible nested) entity property with a value.
     *
     * @param \Drupal\Core\Entity\EntityInterface $entity
     *   The config entity.
     * @param array $parents
     *   The array of parents.
     * @param string|object $value
     *   The value to update to.
     */
    protected function updateEntityProperty(EntityInterface $entity, array $parents, $value) {
        $top_key = array_shift($parents);
        $entity_value = $entity->get($top_key);
        if (is_array($entity_value)) {
            NestedArray::setValue($entity_value, $parents, $value);
        }
        else {
            $entity_value = $value;
        }
        $entity->set($top_key, $entity_value);
    }
    
    /**
     * Generates an entity ID.
     *
     * @param \Drupal\migrate\Row $row
     *   The current row.
     * @param array $ids
     *   The destination IDs.
     *
     * @return string
     *   The generated entity ID.
     */
    protected function generateId(Row $row, array $ids) {
        $id_values = [];
        foreach ($ids as $id) {
            if ($this->isTranslationDestination() && $id == 'langcode') {
                continue;
            }
            $id_values[] = $row->getDestinationProperty($id);
        }
        return implode('.', $id_values);
    }
    
    /**
     * {@inheritdoc}
     */
    public function rollback(array $destination_identifier) {
        if ($this->isTranslationDestination()) {
            // The entity id does not include the langcode.
            $id_values = [];
            foreach ($destination_identifier as $key => $value) {
                if ($this->isTranslationDestination() && $key === 'langcode') {
                    continue;
                }
                $id_values[] = $value;
            }
            $entity_id = implode('.', $id_values);
            $language = $destination_identifier['langcode'];
            $config = $this->storage
                ->load($entity_id)
                ->getConfigDependencyName();
            $config_override = $this->languageManager
                ->getLanguageConfigOverride($language, $config);
            // Rollback the translation.
            $config_override->delete();
        }
        else {
            $destination_identifier = implode('.', $destination_identifier);
            parent::rollback([
                $destination_identifier,
            ]);
        }
    }

}