class RevisionRevertForm

class RevisionRevertForm extends ConfirmFormBase implements EntityFormInterface {
    
    /**
     * The entity operation.
     *
     * @var string
     */
    protected string $operation;
    
    /**
     * The entity revision.
     *
     * @var \Drupal\Core\Entity\RevisionableInterface
     */
    protected RevisionableInterface $revision;
    
    /**
     * The module handler.
     *
     * @var \Drupal\Core\Extension\ModuleHandlerInterface
     */
    protected ModuleHandlerInterface $moduleHandler;
    
    /**
     * The entity type manager.
     *
     * @var \Drupal\Core\Entity\EntityTypeManagerInterface
     */
    protected EntityTypeManagerInterface $entityTypeManager;
    
    /**
     * Creates a new RevisionRevertForm instance.
     *
     * @param \Drupal\Core\Datetime\DateFormatterInterface $dateFormatter
     *   The date formatter.
     * @param \Drupal\Core\Entity\EntityTypeBundleInfoInterface $bundleInformation
     *   The bundle information.
     * @param \Drupal\Core\Messenger\MessengerInterface $messenger
     *   The messenger service.
     * @param \Drupal\Component\Datetime\TimeInterface $time
     *   The time service.
     * @param \Drupal\Core\Session\AccountInterface $currentUser
     *   The current user.
     */
    public function __construct(DateFormatterInterface $dateFormatter, EntityTypeBundleInfoInterface $bundleInformation, MessengerInterface $messenger, TimeInterface $time, AccountInterface $currentUser) {
        $this->messenger = $messenger;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) {
        return new static($container->get('date.formatter'), $container->get('entity_type.bundle.info'), $container->get('messenger'), $container->get('datetime.time'), $container->get('current_user'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function getBaseFormId() {
        return $this->revision
            ->getEntityTypeId() . '_revision_revert';
    }
    
    /**
     * {@inheritdoc}
     */
    public function getFormId() {
        return $this->revision
            ->getEntityTypeId() . '_revision_revert';
    }
    
    /**
     * {@inheritdoc}
     */
    public function getQuestion() {
        return $this->getEntity() instanceof RevisionLogInterface ? $this->t('Are you sure you want to revert to the revision from %revision-date?', [
            '%revision-date' => $this->dateFormatter
                ->format($this->getEntity()
                ->getRevisionCreationTime()),
        ]) : $this->t('Are you sure you want to revert the revision?');
    }
    
    /**
     * {@inheritdoc}
     */
    public function getCancelUrl() {
        return $this->getEntity()
            ->getEntityType()
            ->hasLinkTemplate('version-history') && $this->getEntity()
            ->toUrl('version-history')
            ->access($this->currentUser) ? $this->getEntity()
            ->toUrl('version-history') : $this->getEntity()
            ->toUrl();
    }
    
    /**
     * {@inheritdoc}
     */
    public function getConfirmText() {
        return $this->t('Revert');
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDescription() {
        return '';
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildForm(array $form, FormStateInterface $form_state) {
        $form = parent::buildForm($form, $form_state);
        $form['actions']['submit']['#submit'] = [
            '::submitForm',
            '::save',
        ];
        return $form;
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitForm(array &$form, FormStateInterface $form_state) {
        $revisionId = $this->revision
            ->getRevisionId();
        $revisionLabel = $this->revision
            ->label();
        $bundleLabel = $this->getBundleLabel($this->revision);
        if ($this->revision instanceof RevisionLogInterface) {
            $originalRevisionTimestamp = $this->revision
                ->getRevisionCreationTime();
        }
        $this->revision = $this->prepareRevision($this->revision, $form_state);
        if (isset($originalRevisionTimestamp)) {
            $date = $this->dateFormatter
                ->format($originalRevisionTimestamp);
            $this->messenger
                ->addMessage($this->t('@type %title has been reverted to the revision from %revision-date.', [
                '@type' => $bundleLabel,
                '%title' => $revisionLabel,
                '%revision-date' => $date,
            ]));
        }
        else {
            $this->messenger
                ->addMessage($this->t('@type %title has been reverted.', [
                '@type' => $bundleLabel,
                '%title' => $revisionLabel,
            ]));
        }
        $this->logger($this->revision
            ->getEntityType()
            ->getProvider())
            ->info('@type: reverted %title revision %revision.', [
            '@type' => $this->revision
                ->bundle(),
            '%title' => $revisionLabel,
            '%revision' => $revisionId,
        ]);
        $versionHistoryUrl = $this->revision
            ->toUrl('version-history');
        if ($versionHistoryUrl->access($this->currentUser())) {
            $form_state->setRedirectUrl($versionHistoryUrl);
        }
        if (!$form_state->getRedirect()) {
            $canonicalUrl = $this->revision
                ->toUrl();
            if ($canonicalUrl->access($this->currentUser())) {
                $form_state->setRedirectUrl($canonicalUrl);
            }
        }
    }
    
    /**
     * Prepares a revision to be reverted.
     *
     * @param \Drupal\Core\Entity\RevisionableInterface $revision
     *   The revision to be reverted.
     * @param \Drupal\Core\Form\FormStateInterface $formState
     *   The current state of the form.
     *
     * @return \Drupal\Core\Entity\RevisionableInterface
     *   The new revision, the same type as passed to $revision.
     */
    protected function prepareRevision(RevisionableInterface $revision, FormStateInterface $formState) : RevisionableInterface {
        $storage = $this->entityTypeManager
            ->getStorage($revision->getEntityTypeId());
        if (!$storage instanceof RevisionableStorageInterface) {
            throw new \LogicException('Revisionable entities are expected to implement RevisionableStorageInterface');
        }
        $revision = $storage->createRevision($revision);
        $time = $this->time
            ->getRequestTime();
        if ($revision instanceof EntityChangedInterface) {
            $revision->setChangedTime($time);
        }
        if ($revision instanceof RevisionLogInterface) {
            $originalRevisionTimestamp = $revision->getRevisionCreationTime();
            $date = $this->dateFormatter
                ->format($originalRevisionTimestamp);
            $revision->setRevisionLogMessage($this->t('Copy of the revision from %date.', [
                '%date' => $date,
            ]))
                ->setRevisionCreationTime($time)
                ->setRevisionUserId($this->currentUser()
                ->id());
        }
        return $revision;
    }
    
    /**
     * Returns the bundle label of an entity.
     *
     * @param \Drupal\Core\Entity\RevisionableInterface $entity
     *   The entity.
     *
     * @return string|null
     *   The bundle label.
     */
    protected function getBundleLabel(RevisionableInterface $entity) : ?string {
        $bundleInfo = $this->bundleInformation
            ->getBundleInfo($entity->getEntityTypeId());
        return isset($bundleInfo[$entity->bundle()]['label']) ? (string) $bundleInfo[$entity->bundle()]['label'] : NULL;
    }
    
    /**
     * {@inheritdoc}
     */
    public function setOperation($operation) {
        $this->operation = $operation;
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getOperation() {
        return $this->operation;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getEntity() {
        return $this->revision;
    }
    
    /**
     * {@inheritdoc}
     */
    public function setEntity(EntityInterface $entity) {
        assert($entity instanceof RevisionableInterface);
        $this->revision = $entity;
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getEntityFromRouteMatch(RouteMatchInterface $route_match, $entity_type_id) {
        return $route_match->getParameter($entity_type_id . '_revision');
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildEntity(array $form, FormStateInterface $form_state) {
        return $this->revision;
    }
    
    /**
     * {@inheritdoc}
     */
    public function save(array $form, FormStateInterface $form_state) {
        return $this->revision
            ->save();
    }
    
    /**
     * {@inheritdoc}
     */
    public function setModuleHandler(ModuleHandlerInterface $module_handler) {
        $this->moduleHandler = $module_handler;
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    public function setEntityTypeManager(EntityTypeManagerInterface $entity_type_manager) {
        $this->entityTypeManager = $entity_type_manager;
        return $this;
    }
    
    /**
     * {@inheritdoc}
     */
    protected function currentUser() {
        return $this->currentUser;
    }

}