class DeletedFieldsRepository

class DeletedFieldsRepository implements DeletedFieldsRepositoryInterface {
    
    /**
     * The state key/value store.
     *
     * @var \Drupal\Core\State\StateInterface
     */
    protected $state;
    
    /**
     * Constructs a new deleted fields repository.
     *
     * @param \Drupal\Core\State\StateInterface $state
     *   The state key/value store.
     */
    public function __construct(StateInterface $state) {
        $this->state = $state;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getFieldDefinitions($field_storage_unique_id = NULL) {
        $deleted_field_definitions = $this->state
            ->get('field.field.deleted', []);
        if ($field_storage_unique_id) {
            $deleted_field_definitions = array_filter($deleted_field_definitions, function (FieldDefinitionInterface $field_definition) use ($field_storage_unique_id) {
                return $field_definition->getFieldStorageDefinition()
                    ->getUniqueStorageIdentifier() === $field_storage_unique_id;
            });
        }
        return $deleted_field_definitions;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getFieldStorageDefinitions() {
        return $this->state
            ->get('field.storage.deleted', []);
    }
    
    /**
     * {@inheritdoc}
     */
    public function addFieldDefinition(FieldDefinitionInterface $field_definition) {
        $deleted_field_definitions = $this->state
            ->get('field.field.deleted', []);
        $deleted_field_definitions[$field_definition->getUniqueIdentifier()] = $field_definition;
        $this->state
            ->set('field.field.deleted', $deleted_field_definitions);
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function addFieldStorageDefinition(FieldStorageDefinitionInterface $field_storage_definition) {
        $deleted_storage_definitions = $this->state
            ->get('field.storage.deleted', []);
        $deleted_storage_definitions[$field_storage_definition->getUniqueStorageIdentifier()] = $field_storage_definition;
        $this->state
            ->set('field.storage.deleted', $deleted_storage_definitions);
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function removeFieldDefinition(FieldDefinitionInterface $field_definition) {
        $deleted_field_definitions = $this->state
            ->get('field.field.deleted', []);
        unset($deleted_field_definitions[$field_definition->getUniqueIdentifier()]);
        $this->state
            ->set('field.field.deleted', $deleted_field_definitions);
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function removeFieldStorageDefinition(FieldStorageDefinitionInterface $field_storage_definition) {
        $deleted_storage_definitions = $this->state
            ->get('field.storage.deleted', []);
        unset($deleted_storage_definitions[$field_storage_definition->getUniqueStorageIdentifier()]);
        $this->state
            ->set('field.storage.deleted', $deleted_storage_definitions);
        return $this;
    }

}