class RevisionHtmlRouteProvider

class RevisionHtmlRouteProvider implements EntityRouteProviderInterface {
  
  /**
   * {@inheritdoc}
   */
  public function getRoutes(EntityTypeInterface $entity_type) {
    $collection = new RouteCollection();
    $entityTypeId = $entity_type->id();
    if ($version_history_route = $this->getVersionHistoryRoute($entity_type)) {
      $collection->add("entity.{$entityTypeId}.version_history", $version_history_route);
    }
    if ($revision_view_route = $this->getRevisionViewRoute($entity_type)) {
      $collection->add("entity.{$entityTypeId}.revision", $revision_view_route);
    }
    if ($revision_revert_route = $this->getRevisionRevertRoute($entity_type)) {
      $collection->add("entity.{$entityTypeId}.revision_revert_form", $revision_revert_route);
    }
    if ($revision_delete_route = $this->getRevisionDeleteRoute($entity_type)) {
      $collection->add("entity.{$entityTypeId}.revision_delete_form", $revision_delete_route);
    }
    return $collection;
  }
  
  /**
   * Gets the entity revision history route.
   *
   * @param \Drupal\Core\Entity\EntityTypeInterface $entityType
   *   The entity type.
   *
   * @return \Symfony\Component\Routing\Route|null
   *   The entity revision revert route, or NULL if the entity type does not
   *   support viewing version history.
   */
  protected function getVersionHistoryRoute(EntityTypeInterface $entityType) : ?Route {
    if (!$entityType->hasLinkTemplate('version-history')) {
      return NULL;
    }
    $entityTypeId = $entityType->id();
    return (new Route($entityType->getLinkTemplate('version-history')))
      ->addDefaults([
      '_controller' => VersionHistoryController::class,
      '_title' => 'Revisions',
    ])
      ->setRequirement('_entity_access', $entityTypeId . '.view all revisions')
      ->setOption('entity_type_id', $entityTypeId)
      ->setOption('_admin_route', TRUE)
      ->setOption('parameters', [
      $entityTypeId => [
        'type' => 'entity:' . $entityTypeId,
      ],
    ]);
  }
  
  /**
   * Gets the entity revision view route.
   *
   * @param \Drupal\Core\Entity\EntityTypeInterface $entityType
   *   The entity type.
   *
   * @return \Symfony\Component\Routing\Route|null
   *   The entity revision view route, or NULL if the entity type does not
   *   support viewing revisions.
   */
  protected function getRevisionViewRoute(EntityTypeInterface $entityType) : ?Route {
    if (!$entityType->hasLinkTemplate('revision')) {
      return NULL;
    }
    $entityTypeId = $entityType->id();
    $revisionParameterName = $entityTypeId . '_revision';
    return (new Route($entityType->getLinkTemplate('revision')))
      ->addDefaults([
      '_controller' => EntityRevisionViewController::class,
      '_title_callback' => EntityRevisionViewController::class . '::title',
    ])
      ->setRequirement('_entity_access', $revisionParameterName . '.view revision')
      ->setOption('parameters', [
      $entityTypeId => [
        'type' => 'entity:' . $entityTypeId,
      ],
      $revisionParameterName => [
        'type' => 'entity_revision:' . $entityTypeId,
      ],
    ]);
  }
  
  /**
   * Gets the entity revision revert route.
   *
   * @param \Drupal\Core\Entity\EntityTypeInterface $entityType
   *   The entity type.
   *
   * @return \Symfony\Component\Routing\Route|null
   *   The entity revision revert route, or NULL if the entity type does not
   *   support reverting revisions.
   */
  protected function getRevisionRevertRoute(EntityTypeInterface $entityType) : ?Route {
    if (!$entityType->hasLinkTemplate('revision-revert-form')) {
      return NULL;
    }
    $entityTypeId = $entityType->id();
    $revisionParameterName = $entityTypeId . '_revision';
    return (new Route($entityType->getLinkTemplate('revision-revert-form')))
      ->addDefaults([
      '_entity_form' => $entityTypeId . '.revision-revert',
      '_title' => 'Revert revision',
    ])
      ->setRequirement('_entity_access', $revisionParameterName . '.revert')
      ->setOption('_admin_route', TRUE)
      ->setOption('parameters', [
      $entityTypeId => [
        'type' => 'entity:' . $entityTypeId,
      ],
      $revisionParameterName => [
        'type' => 'entity_revision:' . $entityTypeId,
      ],
    ]);
  }
  
  /**
   * Gets the entity revision delete route.
   *
   * @param \Drupal\Core\Entity\EntityTypeInterface $entityType
   *   The entity type.
   *
   * @return \Symfony\Component\Routing\Route|null
   *   The entity revision delete route, or NULL if the entity type does not
   *   support deleting revisions.
   */
  protected function getRevisionDeleteRoute(EntityTypeInterface $entityType) : ?Route {
    if (!$entityType->hasLinkTemplate('revision-delete-form')) {
      return NULL;
    }
    $entityTypeId = $entityType->id();
    $revisionParameterName = $entityTypeId . '_revision';
    return (new Route($entityType->getLinkTemplate('revision-delete-form')))
      ->addDefaults([
      '_entity_form' => $entityTypeId . '.revision-delete',
      '_title' => 'Delete revision',
    ])
      ->setRequirement('_entity_access', $revisionParameterName . '.delete revision')
      ->setOption('_admin_route', TRUE)
      ->setOption('parameters', [
      $entityTypeId => [
        'type' => 'entity:' . $entityTypeId,
      ],
      $revisionParameterName => [
        'type' => 'entity_revision:' . $entityTypeId,
      ],
    ]);
  }

}