class BlockVisibility

class BlockVisibility extends ProcessPluginBase implements ContainerFactoryPluginInterface {
  
  /**
   * The module handler.
   *
   * @var \Drupal\Core\Extension\ModuleHandlerInterface
   */
  protected $moduleHandler;
  
  /**
   * The migrate lookup service.
   *
   * @var \Drupal\migrate\MigrateLookupInterface
   */
  protected $migrateLookup;
  
  /**
   * Whether or not to skip blocks that use PHP for visibility.
   *
   * Only applies if the PHP module is not enabled.
   *
   * @var bool
   */
  protected $skipPHP = FALSE;
  
  /**
   * Constructs a BlockVisibility object.
   *
   * @param array $configuration
   *   The plugin configuration.
   * @param string $plugin_id
   *   The plugin ID.
   * @param mixed $plugin_definition
   *   The plugin definition.
   * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
   *   The module handler service.
   * @param \Drupal\migrate\MigrateLookupInterface $migrate_lookup
   *   The migrate lookup service.
   */
  public function __construct(array $configuration, $plugin_id, $plugin_definition, ModuleHandlerInterface $module_handler, MigrateLookupInterface $migrate_lookup) {
    parent::__construct($configuration, $plugin_id, $plugin_definition);
    $this->moduleHandler = $module_handler;
    $this->migrateLookup = $migrate_lookup;
    if (isset($configuration['skip_php'])) {
      $this->skipPHP = $configuration['skip_php'];
    }
  }
  
  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container, array $configuration, $plugin_id, $plugin_definition, MigrationInterface $migration = NULL) {
    return new static($configuration, $plugin_id, $plugin_definition, $container->get('module_handler'), $container->get('migrate.lookup'));
  }
  
  /**
   * {@inheritdoc}
   */
  public function transform($value, MigrateExecutableInterface $migrate_executable, Row $row, $destination_property) {
    [$old_visibility, $pages, $roles] = $value;
    $visibility = [];
    // If the block is assigned to specific roles, add the user_role condition.
    if ($roles) {
      $visibility['user_role'] = [
        'id' => 'user_role',
        'roles' => [],
        'context_mapping' => [
          'user' => '@user.current_user_context:current_user',
        ],
        'negate' => FALSE,
      ];
      foreach ($roles as $key => $role_id) {
        $lookup_result = $this->migrateLookup
          ->lookup([
          'd6_user_role',
          'd7_user_role',
        ], [
          $role_id,
        ]);
        if ($lookup_result) {
          $roles[$key] = $lookup_result[0]['id'];
        }
      }
      $visibility['user_role']['roles'] = array_combine($roles, $roles);
    }
    if ($pages) {
      // 2 == BLOCK_VISIBILITY_PHP in Drupal 6 and 7.
      if ($old_visibility == 2) {
        // If the PHP module is present, migrate the visibility code unaltered.
        if ($this->moduleHandler
          ->moduleExists('php')) {
          $visibility['php'] = [
            'id' => 'php',
            // PHP code visibility could not be negated in Drupal 6 or 7.
'negate' => FALSE,
            'php' => $pages,
          ];
        }
        elseif ($this->skipPHP) {
          throw new MigrateSkipRowException(sprintf("The block with bid '%d' from module '%s' will have no PHP or request_path visibility configuration.", $row->getSourceProperty('bid'), $row->getSourceProperty('module')));
        }
      }
      else {
        $paths = preg_split("(\r\n?|\n)", $pages);
        foreach ($paths as $key => $path) {
          $paths[$key] = $path === '<front>' ? $path : '/' . ltrim($path, '/');
        }
        $visibility['request_path'] = [
          'id' => 'request_path',
          'negate' => !$old_visibility,
          'pages' => implode("\n", $paths),
        ];
      }
    }
    return $visibility;
  }

}