class WorkspacePublishForm

class WorkspacePublishForm extends ConfirmFormBase implements ContainerInjectionInterface, WorkspaceSafeFormInterface {

  /**
   * The workspace that will be published.
   *
   * @var \Drupal\workspaces\WorkspaceInterface
   */
  protected $workspace;

  /**
   * The workspace operation factory.
   *
   * @var \Drupal\workspaces\WorkspaceOperationFactory
   */
  protected $workspaceOperationFactory;

  /**
   * The entity type manager.
   *
   * @var \Drupal\Core\Entity\EntityTypeManagerInterface
   */
  protected $entityTypeManager;

  /**
   * Constructs a new WorkspacePublishForm.
   *
   * @param \Drupal\workspaces\WorkspaceOperationFactory $workspace_operation_factory
   *   The workspace operation factory service.
   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
   *   The entity type manager.
   */
  public function __construct(WorkspaceOperationFactory $workspace_operation_factory, EntityTypeManagerInterface $entity_type_manager) {
    $this->workspaceOperationFactory = $workspace_operation_factory;
    $this->entityTypeManager = $entity_type_manager;
  }

  /**
   * {@inheritdoc}
   */
  public static function create(ContainerInterface $container) {
    return new static($container
      ->get('workspaces.operation_factory'), $container
      ->get('entity_type.manager'));
  }

  /**
   * {@inheritdoc}
   */
  public function getFormId() {
    return 'workspace_publish_form';
  }

  /**
   * {@inheritdoc}
   */
  public function buildForm(array $form, FormStateInterface $form_state, WorkspaceInterface $workspace = NULL) {
    $this->workspace = $workspace;
    $form = parent::buildForm($form, $form_state);
    $workspace_publisher = $this->workspaceOperationFactory
      ->getPublisher($this->workspace);
    $args = [
      '%source_label' => $this->workspace
        ->label(),
      '%target_label' => $workspace_publisher
        ->getTargetLabel(),
    ];
    $form['#title'] = $this
      ->t('Publish %source_label workspace', $args);

    // List the changes that can be pushed.
    if ($source_rev_diff = $workspace_publisher
      ->getDifferringRevisionIdsOnSource()) {
      $total_count = $workspace_publisher
        ->getNumberOfChangesOnSource();
      $form['description'] = [
        '#theme' => 'item_list',
        '#title' => $this
          ->formatPlural($total_count, 'There is @count item that can be published from %source_label to %target_label', 'There are @count items that can be published from %source_label to %target_label', $args),
        '#items' => [],
        '#total_count' => $total_count,
      ];
      foreach ($source_rev_diff as $entity_type_id => $revision_difference) {
        $form['description']['#items'][$entity_type_id] = $this->entityTypeManager
          ->getDefinition($entity_type_id)
          ->getCountLabel(count($revision_difference));
      }
      $form['actions']['submit']['#value'] = $this
        ->formatPlural($total_count, 'Publish @count item to @target', 'Publish @count items to @target', [
        '@target' => $workspace_publisher
          ->getTargetLabel(),
      ]);
    }
    else {

      // If there are no changes to push or pull, show an informational message.
      $form['help'] = [
        '#markup' => $this
          ->t('There are no changes that can be published from %source_label to %target_label.', $args),
      ];

      // Do not allow the 'Publish' operation if there's nothing to publish.
      $form['actions']['submit']['#value'] = $this
        ->t('Publish');
      $form['actions']['submit']['#disabled'] = TRUE;
    }
    return $form;
  }

  /**
   * {@inheritdoc}
   */
  public function getQuestion() {
    return $this
      ->t('Would you like to publish the contents of the %label workspace?', [
      '%label' => $this->workspace
        ->label(),
    ]);
  }

  /**
   * {@inheritdoc}
   */
  public function getDescription() {
    return $this
      ->t('Publish workspace contents.');
  }

  /**
   * {@inheritdoc}
   */
  public function getCancelUrl() {
    return Url::fromRoute('entity.workspace.collection', [], [
      'query' => $this
        ->getDestinationArray(),
    ]);
  }

  /**
   * {@inheritdoc}
   */
  public function submitForm(array &$form, FormStateInterface $form_state) {
    $workspace = $this->workspace;
    try {
      $workspace
        ->publish();
      $this
        ->messenger()
        ->addMessage($this
        ->t('Successful publication.'));
    } catch (WorkspaceAccessException $e) {
      $this
        ->messenger()
        ->addMessage($e
        ->getMessage(), 'error');
    } catch (\Exception $e) {
      $this
        ->messenger()
        ->addMessage($this
        ->t('Publication failed. All errors have been logged.'), 'error');
      $this
        ->getLogger('workspaces')
        ->error($e
        ->getMessage());
    }
  }

}