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;
    }

}