class EntityDenormalizerBase

abstract class EntityDenormalizerBase extends NormalizerBase implements DenormalizerInterface {
  
  /**
   * The JSON:API resource type repository.
   *
   * @var \Drupal\jsonapi\ResourceType\ResourceTypeRepositoryInterface
   */
  protected $resourceTypeRepository;
  
  /**
   * The entity type manager.
   *
   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
   */
  protected $entityTypeManager;
  
  /**
   * The entity field manager.
   *
   * @var \Drupal\Core\Entity\EntityFieldManagerInterface
   */
  protected $fieldManager;
  
  /**
   * The field plugin manager.
   *
   * @var \Drupal\Core\Field\FieldTypePluginManagerInterface
   */
  protected $pluginManager;
  
  /**
   * Constructs an EntityDenormalizerBase object.
   *
   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
   *   The entity type manager.
   * @param \Drupal\Core\Entity\EntityFieldManagerInterface $field_manager
   *   The entity field manager.
   * @param \Drupal\Core\Field\FieldTypePluginManagerInterface $plugin_manager
   *   The plugin manager for fields.
   */
  public function __construct(EntityTypeManagerInterface $entity_type_manager, EntityFieldManagerInterface $field_manager, FieldTypePluginManagerInterface $plugin_manager) {
    $this->entityTypeManager = $entity_type_manager;
    $this->fieldManager = $field_manager;
    $this->pluginManager = $plugin_manager;
  }
  
  /**
   * {@inheritdoc}
   */
  public function supportsNormalization($data, $format = NULL) {
    return FALSE;
  }
  
  /**
   * {@inheritdoc}
   */
  public function normalize($object, $format = NULL, array $context = []) {
    throw new \LogicException('This method should never be called.');
  }
  
  /**
   * {@inheritdoc}
   */
  public function denormalize($data, $class, $format = NULL, array $context = []) {
    if (empty($context['resource_type']) || !$context['resource_type'] instanceof ResourceType) {
      throw new PreconditionFailedHttpException('Missing context during denormalization.');
    }
    /** @var \Drupal\jsonapi\ResourceType\ResourceType $resource_type */
    $resource_type = $context['resource_type'];
    $entity_type_id = $resource_type->getEntityTypeId();
    $bundle = $resource_type->getBundle();
    $bundle_key = $this->entityTypeManager
      ->getDefinition($entity_type_id)
      ->getKey('bundle');
    if ($bundle_key && $bundle) {
      $data[$bundle_key] = $bundle;
    }
    return $this->entityTypeManager
      ->getStorage($entity_type_id)
      ->create($this->prepareInput($data, $resource_type, $format, $context));
  }
  
  /**
   * Prepares the input data to create the entity.
   *
   * @param array $data
   *   The input data to modify.
   * @param \Drupal\jsonapi\ResourceType\ResourceType $resource_type
   *   Contains the info about the resource type.
   * @param string $format
   *   Format the given data was extracted from.
   * @param array $context
   *   Options available to the denormalizer.
   *
   * @return array
   *   The modified input data.
   */
  abstract protected function prepareInput(array $data, ResourceType $resource_type, $format, array $context);

}