<?php

namespace Drupal\migrate_drupal\Plugin\migrate\source;

use Drupal\Component\Plugin\Derivative\DeriverBase;
use Drupal\Core\Entity\ContentEntityTypeInterface;
use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\Core\Plugin\Discovery\ContainerDeriverInterface;
use Symfony\Component\DependencyInjection\ContainerInterface;

/**
 * Deriver for content entity source plugins.
 */
class ContentEntityDeriver extends DeriverBase implements ContainerDeriverInterface {

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

  /**
   * Constructs a new ContentEntityDeriver.
   *
   * @param string $base_plugin_id
   *   The base plugin ID.
   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entityTypeManager
   *   The entity type manager.
   */
  public function __construct($base_plugin_id, EntityTypeManagerInterface $entityTypeManager) {
    $this->entityTypeManager = $entityTypeManager;
  }

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

  /**
   * {@inheritdoc}
   */
  public function getDerivativeDefinitions($base_plugin_definition) {
    $this->derivatives = [];
    foreach ($this->entityTypeManager->getDefinitions() as $id => $definition) {
      if ($definition instanceof ContentEntityTypeInterface) {
        $this->derivatives[$id] = $base_plugin_definition;
        // Provide entity_type so the source can be used apart from a deriver.
        $this->derivatives[$id]['entity_type'] = $id;
      }
    }
    return parent::getDerivativeDefinitions($base_plugin_definition);
  }

}