oliverdavies.uk/modules/opd_daily_emails/src/AddRandomCtaToDailyEmail.php

<?php

declare(strict_types=1);

namespace Drupal\opd_daily_emails;

use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\node\NodeInterface;
use Drupal\opd_daily_emails\Ctas;

readonly final class AddRandomCtaToDailyEmail {

  public function __construct(private EntityTypeManagerInterface $entityTypeManager) {
  }

  public function __invoke(DailyEmail $email): void {
    if (!$email->isNew()) {
      return;
    }

    if ($email->get('field_daily_email_cta')->getValue() !== []) {
      return;
    }

    if (str_contains(haystack: $email->get('body')->value, needle: 'P.S.')) {
      return;
    }

    $nodeStorage = $this->entityTypeManager->getStorage('node');
    $query = $nodeStorage->getQuery();
    $query->condition('status', NodeInterface::PUBLISHED);
    $query->condition('type', 'daily_email_cta');
    $query->accessCheck();
    $ctaNodes = $nodeStorage->loadMultiple($query->execute());

    $ctas = Ctas::fromNodes($ctaNodes);

    if ($ctas->isEmpty()) {
      return;
    }

    $email->set('field_daily_email_cta', $ctas->getRandomCta());
  }

}