<?php

namespace Drupal\layout_builder\Plugin\Derivative;

use Drupal\Component\Plugin\Derivative\DeriverBase;
use Drupal\Component\Plugin\PluginBase;
use Drupal\Core\Entity\EntityFieldManagerInterface;
use Drupal\Core\Entity\EntityTypeBundleInfoInterface;
use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\Core\Entity\FieldableEntityInterface;
use Drupal\Core\Plugin\Context\EntityContextDefinition;
use Drupal\Core\Plugin\Discovery\ContainerDeriverInterface;
use Drupal\Core\StringTranslation\StringTranslationTrait;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Provides entity field block definitions for every field.
 *
 * @internal
 *   Layout Builder is currently experimental and should only be leveraged by
 *   experimental modules and development releases of contributed modules.
 *   See https://www.drupal.org/core/experimental for more information.
 */
class ExtraFieldBlockDeriver extends DeriverBase implements ContainerDeriverInterface {

  use StringTranslationTrait;

  /**
   * The entity field manager.
   *
   * @var \Drupal\Core\Entity\EntityFieldManagerInterface
   */
  protected $entityFieldManager;

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

  /**
   * The entity type bundle info.
   *
   * @var \Drupal\Core\Entity\EntityTypeBundleInfoInterface
   */
  protected $entityTypeBundleInfo;

  /**
   * Constructs new FieldBlockDeriver.
   *
   * @param \Drupal\Core\Entity\EntityFieldManagerInterface $entity_field_manager
   *   The entity field manager.
   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
   *   The entity type manager.
   * @param \Drupal\Core\Entity\EntityTypeBundleInfoInterface $entity_type_bundle_info
   *   The entity type bundle info.
   */
  public function __construct(EntityFieldManagerInterface $entity_field_manager, EntityTypeManagerInterface $entity_type_manager, EntityTypeBundleInfoInterface $entity_type_bundle_info) {
    $this->entityFieldManager = $entity_field_manager;
    $this->entityTypeManager = $entity_type_manager;
    $this->entityTypeBundleInfo = $entity_type_bundle_info;
  }

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

  /**
   * {@inheritdoc}
   */
  public function getDerivativeDefinitions($base_plugin_definition) {
    foreach ($this->entityTypeManager->getDefinitions() as $entity_type_id => $entity_type) {
      // Only process fieldable entity types.
      if (!$entity_type->entityClassImplements(FieldableEntityInterface::class)) {
        continue;
      }

      $bundles = $this->entityTypeBundleInfo->getBundleInfo($entity_type_id);
      foreach ($bundles as $bundle_id => $bundle) {
        $extra_fields = $this->entityFieldManager->getExtraFields($entity_type_id, $bundle_id);
        // Skip bundles without any extra fields.
        if (empty($extra_fields['display'])) {
          continue;
        }

        foreach ($extra_fields['display'] as $extra_field_id => $extra_field) {
          $derivative = $base_plugin_definition;

          $derivative['category'] = $entity_type->getLabel();

          $derivative['admin_label'] = $extra_field['label'];

          $context_definition = EntityContextDefinition::fromEntityType($entity_type)
            ->addConstraint('Bundle', [$bundle_id]);
          $derivative['context'] = [
            'entity' => $context_definition,
          ];

          $derivative_id = $entity_type_id . PluginBase::DERIVATIVE_SEPARATOR . $bundle_id . PluginBase::DERIVATIVE_SEPARATOR . $extra_field_id;
          $this->derivatives[$derivative_id] = $derivative;
        }
      }
    }
    return $this->derivatives;
  }

}