class FieldBlockDeriver

class FieldBlockDeriver extends DeriverBase implements ContainerDeriverInterface {
    use StringTranslationTrait;
    use LoggerChannelTrait;
    
    /**
     * The entity type repository.
     *
     * @var \Drupal\Core\Entity\EntityTypeRepositoryInterface
     */
    protected $entityTypeRepository;
    
    /**
     * The entity field manager.
     *
     * @var \Drupal\Core\Entity\EntityFieldManagerInterface
     */
    protected $entityFieldManager;
    
    /**
     * The field type manager.
     *
     * @var \Drupal\Core\Field\FieldTypePluginManagerInterface
     */
    protected $fieldTypeManager;
    
    /**
     * The formatter manager.
     *
     * @var \Drupal\Core\Field\FormatterPluginManager
     */
    protected $formatterManager;
    
    /**
     * Constructs new FieldBlockDeriver.
     *
     * @param \Drupal\Core\Entity\EntityTypeRepositoryInterface $entity_type_repository
     *   The entity type repository.
     * @param \Drupal\Core\Entity\EntityFieldManagerInterface $entity_field_manager
     *   The entity field manager.
     * @param \Drupal\Core\Field\FieldTypePluginManagerInterface $field_type_manager
     *   The field type manager.
     * @param \Drupal\Core\Field\FormatterPluginManager $formatter_manager
     *   The formatter manager.
     * @param \Drupal\Core\Config\Entity\ConfigEntityStorageInterface $entityViewDisplayStorage
     *   The entity view display storage.
     * @param \Drupal\Core\Extension\ModuleHandlerInterface $moduleHandler
     *   The module handler.
     */
    public function __construct(EntityTypeRepositoryInterface $entity_type_repository, EntityFieldManagerInterface $entity_field_manager, FieldTypePluginManagerInterface $field_type_manager, FormatterPluginManager $formatter_manager, ConfigEntityStorageInterface $entityViewDisplayStorage, ModuleHandlerInterface $moduleHandler) {
        $this->entityTypeRepository = $entity_type_repository;
        $this->entityFieldManager = $entity_field_manager;
        $this->fieldTypeManager = $field_type_manager;
        $this->formatterManager = $formatter_manager;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container, $base_plugin_id) {
        return new static($container->get('entity_type.repository'), $container->get('entity_field.manager'), $container->get('plugin.manager.field.field_type'), $container->get('plugin.manager.field.formatter'), $container->get('entity_type.manager')
            ->getStorage('entity_view_display'), $container->get('module_handler'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDerivativeDefinitions($base_plugin_definition) {
        $entity_type_labels = $this->entityTypeRepository
            ->getEntityTypeLabels();
        foreach ($this->getFieldMap() as $entity_type_id => $entity_field_map) {
            foreach ($entity_field_map as $field_name => $field_info) {
                // Skip fields without any formatters.
                $options = $this->formatterManager
                    ->getOptions($field_info['type']);
                if (empty($options)) {
                    continue;
                }
                foreach ($field_info['bundles'] as $bundle) {
                    $derivative = $base_plugin_definition;
                    $field_definitions = $this->entityFieldManager
                        ->getFieldDefinitions($entity_type_id, $bundle);
                    if (empty($field_definitions[$field_name])) {
                        $this->getLogger('field')
                            ->error('Field %field_name exists but is missing a corresponding field definition and may be misconfigured.', [
                            '%field_name' => "{$entity_type_id}.{$bundle}.{$field_name}",
                        ]);
                        continue;
                    }
                    $field_definition = $field_definitions[$field_name];
                    // Store the default formatter on the definition.
                    $derivative['default_formatter'] = '';
                    $field_type_definition = $this->fieldTypeManager
                        ->getDefinition($field_info['type']);
                    if (isset($field_type_definition['default_formatter'])) {
                        $derivative['default_formatter'] = $field_type_definition['default_formatter'];
                    }
                    $derivative['category'] = $this->t('@entity fields', [
                        '@entity' => $entity_type_labels[$entity_type_id],
                    ]);
                    $derivative['admin_label'] = $field_definition->getLabel();
                    // Add a dependency on the field if it is configurable.
                    if ($field_definition instanceof FieldConfigInterface) {
                        $derivative['config_dependencies'][$field_definition->getConfigDependencyKey()][] = $field_definition->getConfigDependencyName();
                    }
                    // For any field that is not display configurable, mark it as
                    // unavailable to place in the block UI.
                    $derivative['_block_ui_hidden'] = !$field_definition->isDisplayConfigurable('view');
                    $context_definition = EntityContextDefinition::fromEntityTypeId($entity_type_id)->setLabel($entity_type_labels[$entity_type_id]);
                    $context_definition->addConstraint('Bundle', [
                        $bundle,
                    ]);
                    $derivative['context_definitions'] = [
                        'entity' => $context_definition,
                        'view_mode' => new ContextDefinition('string'),
                    ];
                    $derivative_id = $entity_type_id . PluginBase::DERIVATIVE_SEPARATOR . $bundle . PluginBase::DERIVATIVE_SEPARATOR . $field_name;
                    $this->derivatives[$derivative_id] = $derivative;
                }
            }
        }
        return $this->derivatives;
    }
    
    /**
     * Returns the entity field map for deriving block definitions.
     *
     * @return array
     *   The entity field map.
     *
     * @see \Drupal\Core\Entity\EntityFieldManagerInterface::getFieldMap()
     */
    protected function getFieldMap() : array {
        $field_map = $this->entityFieldManager
            ->getFieldMap();
        // If all fields are exposed as field blocks, just return the field map
        // without any further processing.
        if ($this->moduleHandler
            ->moduleExists('layout_builder_expose_all_field_blocks')) {
            return $field_map;
        }
        // Load all entity view displays which are using Layout Builder.
        
        /** @var \Drupal\layout_builder\Entity\LayoutEntityDisplayInterface[] $displays */
        $displays = $this->entityViewDisplayStorage
            ->loadByProperties([
            'third_party_settings.layout_builder.enabled' => TRUE,
        ]);
        $layout_bundles = [];
        foreach ($displays as $display) {
            $bundle = $display->getTargetBundle();
            $layout_bundles[$display->getTargetEntityTypeId()][$bundle] = $bundle;
        }
        // Process $field_map, removing any entity types which are not using Layout
        // Builder.
        $field_map = array_intersect_key($field_map, $layout_bundles);
        foreach ($field_map as $entity_type_id => $fields) {
            foreach ($fields as $field_name => $field_info) {
                $field_map[$entity_type_id][$field_name]['bundles'] = array_intersect($field_info['bundles'], $layout_bundles[$entity_type_id]);
                // If no bundles are using Layout Builder, remove this field from the
                // field map.
                if (empty($field_info['bundles'])) {
                    unset($field_map[$entity_type_id][$field_name]);
                }
            }
        }
        return $field_map;
    }

}