class ConfigController

class ConfigController implements ContainerInjectionInterface {
    
    /**
     * The target storage.
     *
     * @var \Drupal\Core\Config\StorageInterface
     */
    protected $targetStorage;
    
    /**
     * The sync storage.
     *
     * @var \Drupal\Core\Config\StorageInterface
     */
    protected $syncStorage;
    
    /**
     * The import transformer service.
     *
     * @var \Drupal\Core\Config\ImportStorageTransformer
     */
    protected $importTransformer;
    
    /**
     * The configuration manager.
     *
     * @var \Drupal\Core\Config\ConfigManagerInterface
     */
    protected $configManager;
    
    /**
     * The export storage.
     *
     * @var \Drupal\Core\Config\StorageInterface
     */
    protected $exportStorage;
    
    /**
     * The file download controller.
     *
     * @var \Drupal\system\FileDownloadController
     */
    protected $fileDownloadController;
    
    /**
     * The diff formatter.
     *
     * @var \Drupal\Core\Diff\DiffFormatter
     */
    protected $diffFormatter;
    
    /**
     * The file system.
     *
     * @var \Drupal\Core\File\FileSystemInterface
     */
    protected $fileSystem;
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) {
        return new static($container->get('config.storage'), $container->get('config.storage.sync'), $container->get('config.manager'), FileDownloadController::create($container), $container->get('diff.formatter'), $container->get('file_system'), $container->get('config.storage.export'), $container->get('config.import_transformer'));
    }
    
    /**
     * Constructs a ConfigController object.
     *
     * @param \Drupal\Core\Config\StorageInterface $target_storage
     *   The target storage.
     * @param \Drupal\Core\Config\StorageInterface $sync_storage
     *   The sync storage.
     * @param \Drupal\Core\Config\ConfigManagerInterface $config_manager
     *   The config manager.
     * @param \Drupal\system\FileDownloadController $file_download_controller
     *   The file download controller.
     * @param \Drupal\Core\Diff\DiffFormatter $diff_formatter
     *   The diff formatter.
     * @param \Drupal\Core\File\FileSystemInterface $file_system
     *   The file system.
     * @param \Drupal\Core\Config\StorageInterface $export_storage
     *   The export storage.
     * @param \Drupal\Core\Config\ImportStorageTransformer $import_transformer
     *   The import transformer service.
     */
    public function __construct(StorageInterface $target_storage, StorageInterface $sync_storage, ConfigManagerInterface $config_manager, FileDownloadController $file_download_controller, DiffFormatter $diff_formatter, FileSystemInterface $file_system, StorageInterface $export_storage, ImportStorageTransformer $import_transformer) {
        $this->targetStorage = $target_storage;
        $this->syncStorage = $sync_storage;
        $this->configManager = $config_manager;
        $this->fileDownloadController = $file_download_controller;
        $this->diffFormatter = $diff_formatter;
        $this->fileSystem = $file_system;
        $this->exportStorage = $export_storage;
        $this->importTransformer = $import_transformer;
    }
    
    /**
     * Downloads a tarball of the site configuration.
     */
    public function downloadExport() {
        try {
            $this->fileSystem
                ->delete($this->fileSystem
                ->getTempDirectory() . '/config.tar.gz');
        } catch (FileException $e) {
            // Ignore failed deletes.
        }
        $archiver = new ArchiveTar($this->fileSystem
            ->getTempDirectory() . '/config.tar.gz', 'gz');
        // Add all contents of the export storage to the archive.
        foreach ($this->exportStorage
            ->listAll() as $name) {
            $archiver->addString("{$name}.yml", Yaml::encode($this->exportStorage
                ->read($name)));
        }
        // Get all  data from the remaining collections.
        foreach ($this->exportStorage
            ->getAllCollectionNames() as $collection) {
            $collection_storage = $this->exportStorage
                ->createCollection($collection);
            foreach ($collection_storage->listAll() as $name) {
                $archiver->addString(str_replace('.', '/', $collection) . "/{$name}.yml", Yaml::encode($collection_storage->read($name)));
            }
        }
        $request = new Request([
            'file' => 'config.tar.gz',
        ]);
        return $this->fileDownloadController
            ->download($request, 'temporary');
    }
    
    /**
     * Shows diff of specified configuration file.
     *
     * @param string $source_name
     *   The name of the configuration file.
     * @param string $target_name
     *   (optional) The name of the target configuration file if different from
     *   the $source_name.
     * @param string $collection
     *   (optional) The configuration collection name. Defaults to the default
     *   collection.
     *
     * @return array
     *   Table showing a two-way diff between the active and staged configuration.
     */
    public function diff($source_name, $target_name = NULL, $collection = NULL) {
        if (!isset($collection)) {
            $collection = StorageInterface::DEFAULT_COLLECTION;
        }
        $syncStorage = $this->importTransformer
            ->transform($this->syncStorage);
        $diff = $this->configManager
            ->diff($this->targetStorage, $syncStorage, $source_name, $target_name, $collection);
        $this->diffFormatter->show_header = FALSE;
        $build = [];
        $build['#title'] = t('View changes of @config_file', [
            '@config_file' => $source_name,
        ]);
        // Add the CSS for the inline diff.
        $build['#attached']['library'][] = 'system/diff';
        $build['diff'] = [
            '#type' => 'table',
            '#attributes' => [
                'class' => [
                    'diff',
                ],
            ],
            '#header' => [
                [
                    'data' => t('Active'),
                    'colspan' => '2',
                ],
                [
                    'data' => t('Staged'),
                    'colspan' => '2',
                ],
            ],
            '#rows' => $this->diffFormatter
                ->format($diff),
        ];
        $build['back'] = [
            '#type' => 'link',
            '#attributes' => [
                'class' => [
                    'dialog-cancel',
                ],
            ],
            '#title' => "Back to 'Synchronize configuration' page.",
            '#url' => Url::fromRoute('config.sync'),
        ];
        return $build;
    }

}