class MailHandler

class MailHandler implements MailHandlerInterface {
  use StringTranslationTrait;

  /**
   * Language manager service.
   *
   * @var \Drupal\Core\Language\LanguageManagerInterface
   */
  protected $languageManager;

  /**
   * Logger service.
   *
   * @var \Drupal\Core\Logger\LoggerChannelInterface
   */
  protected $logger;

  /**
   * Mail manager service.
   *
   * @var \Drupal\Core\Mail\MailManagerInterface
   */
  protected $mailManager;

  /**
   * The user entity storage handler.
   *
   * @var \Drupal\Core\Entity\EntityStorageInterface
   */
  protected $userStorage;

  /**
   * Constructs a new \Drupal\contact\MailHandler object.
   *
   * @param \Drupal\Core\Mail\MailManagerInterface $mail_manager
   *   Mail manager service.
   * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
   *   Language manager service.
   * @param \Psr\Log\LoggerInterface $logger
   *   A logger instance.
   * @param \Drupal\Core\StringTranslation\TranslationInterface $string_translation
   *   String translation service.
   * @param \Drupal\Core\Entity\EntityTypeManagerInterface $entity_type_manager
   *   The entity type manager.
   */
  public function __construct(MailManagerInterface $mail_manager, LanguageManagerInterface $language_manager, LoggerInterface $logger, TranslationInterface $string_translation, EntityTypeManagerInterface $entity_type_manager) {
    $this->languageManager = $language_manager;
    $this->mailManager = $mail_manager;
    $this->logger = $logger;
    $this->stringTranslation = $string_translation;
    $this->userStorage = $entity_type_manager
      ->getStorage('user');
  }

  /**
   * {@inheritdoc}
   */
  public function sendMailMessages(MessageInterface $message, AccountInterface $sender) {

    // Clone the sender, as we make changes to mail and name properties.
    $sender_cloned = clone $this->userStorage
      ->load($sender
      ->id());
    $params = [];
    $current_langcode = $this->languageManager
      ->getCurrentLanguage()
      ->getId();
    $recipient_langcode = $this->languageManager
      ->getDefaultLanguage()
      ->getId();
    $contact_form = $message
      ->getContactForm();
    if ($sender_cloned
      ->isAnonymous()) {

      // At this point, $sender contains an anonymous user, so we need to take
      // over the submitted form values.
      $sender_cloned->name = $message
        ->getSenderName();
      $sender_cloned->mail = $message
        ->getSenderMail();

      // For the email message, clarify that the sender name is not verified; it
      // could potentially clash with a username on this site.
      $sender_cloned->name = $this
        ->t('@name (not verified)', [
        '@name' => $message
          ->getSenderName(),
      ]);
    }

    // Build email parameters.
    $params['contact_message'] = $message;
    $params['sender'] = $sender_cloned;
    if (!$message
      ->isPersonal()) {

      // Send to the form recipient(s), using the site's default language.
      $params['contact_form'] = $contact_form;
      $to = implode(', ', $contact_form
        ->getRecipients());
    }
    elseif ($recipient = $message
      ->getPersonalRecipient()) {

      // Send to the user in the user's preferred language.
      $to = $recipient
        ->getEmail();
      $recipient_langcode = $recipient
        ->getPreferredLangcode();
      $params['recipient'] = $recipient;
    }
    else {
      throw new MailHandlerException('Unable to determine message recipient');
    }

    // Send email to the recipient(s).
    $key_prefix = $message
      ->isPersonal() ? 'user' : 'page';
    $this->mailManager
      ->mail('contact', $key_prefix . '_mail', $to, $recipient_langcode, $params, $sender_cloned
      ->getEmail());

    // If requested, send a copy to the user, using the current language.
    if ($message
      ->copySender()) {
      $this->mailManager
        ->mail('contact', $key_prefix . '_copy', $sender_cloned
        ->getEmail(), $current_langcode, $params, $sender_cloned
        ->getEmail());
    }

    // If configured, send an auto-reply, using the current language.
    if (!$message
      ->isPersonal() && $contact_form
      ->getReply()) {

      // User contact forms do not support an auto-reply message, so this
      // message always originates from the site.
      if (!$sender_cloned
        ->getEmail()) {
        $this->logger
          ->error('Error sending auto-reply, missing sender email address in %contact_form', [
          '%contact_form' => $contact_form
            ->label(),
        ]);
      }
      else {
        $this->mailManager
          ->mail('contact', 'page_autoreply', $sender_cloned
          ->getEmail(), $current_langcode, $params);
      }
    }
    if (!$message
      ->isPersonal()) {
      $this->logger
        ->info('%sender-name (@sender-from) sent an email regarding %contact_form.', [
        '%sender-name' => $sender_cloned
          ->getAccountName(),
        '@sender-from' => $sender_cloned
          ->getEmail() ?? '',
        '%contact_form' => $contact_form
          ->label(),
      ]);
    }
    else {
      $this->logger
        ->info('%sender-name (@sender-from) sent %recipient-name an email.', [
        '%sender-name' => $sender_cloned
          ->getAccountName(),
        '@sender-from' => $sender_cloned
          ->getEmail(),
        '%recipient-name' => $message
          ->getPersonalRecipient()
          ->getAccountName(),
      ]);
    }
  }

}