class BlockPluginId

class BlockPluginId extends ProcessPluginBase implements ContainerFactoryPluginInterface {
    
    /**
     * The migration process plugin.
     *
     * The plugin is configured for lookups in d6_custom_block and
     * d7_custom_block.
     *
     * @var \Drupal\migrate\Plugin\MigrateProcessInterface
     *
     * @deprecated in drupal:8.8.x and is removed from drupal:9.0.0. Use
     *   the migrate.lookup service instead.
     *
     * @see https://www.drupal.org/node/3047268
     */
    protected $migrationPlugin;
    
    /**
     * The migrate lookup service.
     *
     * @var \Drupal\migrate\MigrateLookupInterface
     */
    protected $migrateLookup;
    
    /**
     * The block_content entity storage handler.
     *
     * @var \Drupal\Core\Entity\EntityStorageInterface
     */
    protected $blockContentStorage;
    
    /**
     * Constructs a BlockPluginId object.
     *
     * @param array $configuration
     *   The plugin configuration.
     * @param string $plugin_id
     *   The plugin ID.
     * @param mixed $plugin_definition
     *   The plugin definition.
     * @param \Drupal\Core\Entity\EntityStorageInterface $storage
     *   The block content storage object.
     * @param \Drupal\migrate\MigrateLookupInterface $migrate_lookup
     *   The migrate lookup service.
     */
    // @codingStandardsIgnoreLine
    public function __construct(array $configuration, $plugin_id, array $plugin_definition, EntityStorageInterface $storage, $migrate_lookup) {
        parent::__construct($configuration, $plugin_id, $plugin_definition);
        if ($migrate_lookup instanceof MigrateProcessInterface) {
            @trigger_error('Passing a migration process plugin as the fifth argument to ' . __METHOD__ . ' is deprecated in drupal:8.8.0 and will throw an error in drupal:9.0.0. Pass the migrate.lookup service instead. See https://www.drupal.org/node/3047268', E_USER_DEPRECATED);
            $this->migrationPlugin = $migrate_lookup;
            $migrate_lookup = \Drupal::service('migrate.lookup');
        }
        elseif (!$migrate_lookup instanceof MigrateLookupInterface) {
            throw new \InvalidArgumentException("The fifth argument to " . __METHOD__ . " must be an instance of MigrateLookupInterface.");
        }
        $this->blockContentStorage = $storage;
        $this->migrateLookup = $migrate_lookup;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition, MigrationInterface $migration = NULL) {
        $entity_type_manager = $container->get('entity_type.manager');
        return new static($configuration, $plugin_id, $plugin_definition, $entity_type_manager->getDefinition('block_content') ? $entity_type_manager->getStorage('block_content') : NULL, $container->get('migrate.lookup'));
    }
    
    /**
     * {@inheritdoc}
     *
     * Set the block plugin id.
     */
    public function transform($value, MigrateExecutableInterface $migrate_executable, Row $row, $destination_property) {
        if (is_array($value)) {
            list($module, $delta) = $value;
            switch ($module) {
                case 'aggregator':
                    list($type, $id) = explode('-', $delta);
                    if ($type == 'feed') {
                        return 'aggregator_feed_block';
                    }
                    break;
                case 'menu':
                    return "system_menu_block:{$delta}";
                case 'block':
                    if ($this->blockContentStorage) {
                        // This BC layer is included because if the plugin constructor was
                        // called in the legacy way with a migration_lookup process plugin,
                        // it  may have been preconfigured with a different migration to
                        // look up against. While this is unlikely, for maximum BC we will
                        // continue to use the plugin to do the lookup if it is provided,
                        // and support for this will be removed in Drupal 9.
                        if ($this->migrationPlugin) {
                            $block_id = $this->migrationPlugin
                                ->transform($delta, $migrate_executable, $row, $destination_property);
                        }
                        else {
                            $lookup_result = $this->migrateLookup
                                ->lookup([
                                'd6_custom_block',
                                'd7_custom_block',
                            ], [
                                $delta,
                            ]);
                            if ($lookup_result) {
                                $block_id = $lookup_result[0]['id'];
                            }
                        }
                        if (!empty($block_id)) {
                            return 'block_content:' . $this->blockContentStorage
                                ->load($block_id)
                                ->uuid();
                        }
                    }
                    break;
                default:
                    break;
            }
        }
        else {
            return $value;
        }
    }

}