class FieldConfigStorage

class FieldConfigStorage extends FieldConfigStorageBase {
  
  /**
   * The entity type manager.
   *
   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
   */
  protected $entityTypeManager;
  
  /**
   * The field type plugin manager.
   *
   * @var \Drupal\Core\Field\FieldTypePluginManagerInterface
   */
  protected $fieldTypeManager;
  
  /**
   * The deleted fields repository.
   *
   * @var \Drupal\Core\Field\DeletedFieldsRepositoryInterface
   */
  protected $deletedFieldsRepository;
  
  /**
   * Constructs a FieldConfigStorage object.
   *
   * @param \Drupal\Core\Entity\EntityTypeInterface $entity_type
   *   The entity type definition.
   * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
   *   The config factory service.
   * @param \Drupal\Component\Uuid\UuidInterface $uuid_service
   *   The UUID service.
   * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
   *   The language manager.
   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
   *   The entity type manager.
   * @param \Drupal\Core\Field\FieldTypePluginManagerInterface $field_type_manager
   *   The field type plugin manager.
   * @param \Drupal\Core\Field\DeletedFieldsRepositoryInterface $deleted_fields_repository
   *   The deleted fields repository.
   * @param \Drupal\Core\Cache\MemoryCache\MemoryCacheInterface $memory_cache
   *   The memory cache.
   */
  public function __construct(EntityTypeInterface $entity_type, ConfigFactoryInterface $config_factory, UuidInterface $uuid_service, LanguageManagerInterface $language_manager, EntityTypeManagerInterface $entity_type_manager, FieldTypePluginManagerInterface $field_type_manager, DeletedFieldsRepositoryInterface $deleted_fields_repository, MemoryCacheInterface $memory_cache) {
    parent::__construct($entity_type, $config_factory, $uuid_service, $language_manager, $memory_cache);
    $this->entityTypeManager = $entity_type_manager;
    $this->fieldTypeManager = $field_type_manager;
    $this->deletedFieldsRepository = $deleted_fields_repository;
  }
  
  /**
   * {@inheritdoc}
   */
  public static function createInstance(ContainerInterface $container, EntityTypeInterface $entity_type) {
    return new static($entity_type, $container->get('config.factory'), $container->get('uuid'), $container->get('language_manager'), $container->get('entity_type.manager'), $container->get('plugin.manager.field.field_type'), $container->get('entity_field.deleted_fields_repository'), $container->get('entity.memory_cache'));
  }
  
  /**
   * {@inheritdoc}
   */
  public function importDelete($name, Config $new_config, Config $old_config) {
    // If the field storage has been deleted in the same import, the field will
    // be deleted by then, and there is nothing left to do. Just return TRUE so
    // that the file does not get written to active store.
    if (!$old_config->get()) {
      return TRUE;
    }
    return parent::importDelete($name, $new_config, $old_config);
  }
  
  /**
   * {@inheritdoc}
   */
  public function loadByProperties(array $conditions = []) {
    // Include deleted fields if specified in the $conditions parameters.
    $include_deleted = $conditions['include_deleted'] ?? FALSE;
    unset($conditions['include_deleted']);
    $fields = [];
    // Get fields stored in configuration. If we are explicitly looking for
    // deleted fields only, this can be skipped, because they will be
    // retrieved from the deleted fields repository below.
    if (empty($conditions['deleted'])) {
      if (isset($conditions['entity_type']) && isset($conditions['bundle']) && isset($conditions['field_name'])) {
        // Optimize for the most frequent case where we do have a specific ID.
        $id = $conditions['entity_type'] . '.' . $conditions['bundle'] . '.' . $conditions['field_name'];
        $fields = $this->loadMultiple([
          $id,
        ]);
      }
      else {
        // No specific ID, we need to examine all existing fields.
        $fields = $this->loadMultiple();
      }
    }
    // Merge deleted fields from the deleted fields repository if needed.
    if ($include_deleted || !empty($conditions['deleted'])) {
      $deleted_field_definitions = $this->deletedFieldsRepository
        ->getFieldDefinitions();
      foreach ($deleted_field_definitions as $id => $field_definition) {
        if ($field_definition instanceof FieldConfigInterface) {
          $fields[$id] = $field_definition;
        }
      }
    }
    // Collect matching fields.
    $matching_fields = [];
    foreach ($fields as $field) {
      // Some conditions are checked against the field storage.
      $field_storage = $field->getFieldStorageDefinition();
      // Only keep the field if it matches all conditions.
      foreach ($conditions as $key => $value) {
        // Extract the actual value against which the condition is checked.
        switch ($key) {
          case 'field_name':
            $checked_value = $field_storage->getName();
            break;

          case 'field_id':
          case 'field_storage_uuid':
            $checked_value = $field_storage->uuid();
            break;

          case 'uuid':
            $checked_value = $field->uuid();
            break;

          case 'deleted':
            $checked_value = $field->isDeleted();
            break;

          default:
            $checked_value = $field->get($key);
            break;

        }
        // Skip to the next field as soon as one condition does not match.
        if ($checked_value != $value) {
          continue 2;
        }
      }
      // When returning deleted fields, key the results by UUID since they
      // can include several fields with the same ID.
      $key = $include_deleted ? $field->uuid() : $field->id();
      $matching_fields[$key] = $field;
    }
    return $matching_fields;
  }

}