class ToolbarItemConditionsMetConstraintValidator

class ToolbarItemConditionsMetConstraintValidator extends ConstraintValidator implements ContainerInjectionInterface {
    use PluginManagerDependentValidatorTrait;
    use TextEditorObjectDependentValidatorTrait;
    
    /**
     * {@inheritdoc}
     *
     * @throws \Symfony\Component\Validator\Exception\UnexpectedTypeException
     *   Thrown when the given constraint is not supported by this validator.
     */
    public function validate($toolbar_item, Constraint $constraint) {
        if (!$constraint instanceof ToolbarItemConditionsMetConstraint) {
            throw new UnexpectedTypeException($constraint, __NAMESPACE__ . '\\ToolbarItemConditionsMetConstraint');
        }
        try {
            $definition = $this->findDefinitionForToolbarItem($toolbar_item);
        } catch (\OutOfBoundsException $e) {
            // No plugin definition found for this toolbar item. It's the
            // responsibility of another validation constraint to raise this problem.
            // @see \Drupal\ckeditor5\Plugin\Validation\Constraint\ToolbarItemConstraint
            return;
        }
        // If there are no conditions, there is nothing to validate.
        if (!$definition->hasConditions()) {
            return;
        }
        $toolbar_item_label = $definition->getToolbarItems()[$toolbar_item]['label'];
        $text_editor = $this->createTextEditorObjectFromContext();
        $conditions = $definition->getConditions();
        foreach ($conditions as $condition_type => $required_value) {
            switch ($condition_type) {
                case 'toolbarItem':
                    // Nothing to validate.
                    break;
                case 'imageUploadStatus':
                    $image_upload_settings = $text_editor->getImageUploadSettings();
                    if (!isset($image_upload_settings['status']) || (bool) $image_upload_settings['status'] !== TRUE) {
                        $this->context
                            ->buildViolation($constraint->imageUploadStatusRequiredMessage)
                            ->setParameter('%toolbar_item', (string) $toolbar_item_label)
                            ->setInvalidValue($toolbar_item)
                            ->addViolation();
                    }
                    break;
                case 'filter':
                    $filters = $text_editor->getFilterFormat()
                        ->filters();
                    if (!$filters->has($required_value) || !$filters->get($required_value)->status) {
                        $filter_label = $filters->has($required_value) ? $filters->get($required_value)
                            ->getLabel() : $required_value;
                        $this->context
                            ->buildViolation($constraint->filterRequiredMessage)
                            ->setParameter('%toolbar_item', (string) $toolbar_item_label)
                            ->setParameter('%filter', (string) $filter_label)
                            ->setInvalidValue($toolbar_item)
                            ->addViolation();
                    }
                    break;
                case 'plugins':
                    $enabled_definitions = $this->pluginManager
                        ->getEnabledDefinitions($text_editor);
                    if (!array_key_exists($definition->id(), $enabled_definitions)) {
                        $required_plugin_ids = $definition->getConditions()['plugins'];
                        $missing_plugin_ids = array_diff($required_plugin_ids, array_keys($enabled_definitions));
                        $all_plugins = $this->pluginManager
                            ->getDefinitions();
                        $missing_plugin_labels = array_map(function (string $plugin_id) use ($all_plugins) : TranslatableMarkup {
                            return !array_key_exists($plugin_id, $all_plugins) ? $plugin_id : $all_plugins[$plugin_id]->label();
                        }, $missing_plugin_ids);
                        if (count($missing_plugin_ids) === 1) {
                            $message = $constraint->singleMissingRequiredPluginMessage;
                            $parameter = '%plugin';
                        }
                        else {
                            $message = $constraint->multipleMissingRequiredPluginMessage;
                            $parameter = '%plugins';
                        }
                        $this->context
                            ->buildViolation($message)
                            ->setParameter('%toolbar_item', (string) $toolbar_item_label)
                            ->setParameter($parameter, implode(', ', $missing_plugin_labels))
                            ->setInvalidValue($toolbar_item)
                            ->addViolation();
                    }
                    break;
            }
        }
    }
    
    /**
     * Searches for CKEditor 5 plugin that provides a given toolbar item.
     *
     * @param string $toolbar_item
     *   The toolbar item to be searched for within plugin definitions.
     *
     * @return \Drupal\ckeditor5\Plugin\CKEditor5PluginDefinition
     *   The corresponding plugin definition.
     *
     * @throws \OutOfBoundsException
     */
    protected function findDefinitionForToolbarItem(string $toolbar_item) : CKEditor5PluginDefinition {
        $definitions = $this->pluginManager
            ->getDefinitions();
        foreach ($definitions as $definition) {
            if (array_key_exists($toolbar_item, $definition->getToolbarItems())) {
                return $definition;
            }
        }
        // @see \Drupal\ckeditor5\Plugin\Validation\Constraint\ToolbarItemConstraint
        throw new \OutOfBoundsException("Toolbar item '{$toolbar_item}' not found.");
    }

}