trait BasicAuthTrait in Search API Solr 8.2

trait BasicAuthTrait {

  /**
   * {@inheritdoc}
   */
  public function defaultConfiguration() {
    return parent::defaultConfiguration() + [
      'username' => '',
      'password' => '',
    ];
  }

  /**
   * {@inheritdoc}
   */
  public function buildConfigurationForm(array $form, FormStateInterface $form_state) {
    $form = parent::buildConfigurationForm($form, $form_state);
    $form['auth'] = [
      '#type' => 'fieldset',
      '#title' => $this
        ->t('HTTP Basic Authentication'),
      '#description' => $this
        ->t('If your Solr server is protected by basic HTTP authentication, enter the login data here.'),
      '#collapsible' => TRUE,
      '#collapsed' => empty($this->configuration['username']),
    ];
    $form['auth']['username'] = [
      '#type' => 'textfield',
      '#title' => $this
        ->t('Username'),
      '#default_value' => $this->configuration['username'],
      '#required' => TRUE,
    ];
    $form['auth']['password'] = [
      '#type' => 'password',
      '#title' => $this
        ->t('Password'),
      '#description' => $this
        ->t('If this field is left blank and the HTTP username is filled out, the current password will not be changed.'),
    ];
    return $form;
  }

  /**
   * {@inheritdoc}
   */
  public function submitConfigurationForm(array &$form, FormStateInterface $form_state) {
    $values = $form_state
      ->getValues();

    // Since the form is nested into another, we can't simply use #parents for
    // doing this array restructuring magic. (At least not without creating an
    // unnecessary dependency on internal implementation.)
    $values += $values['auth'];

    // For password fields, there is no default value, they're empty by default.
    // Therefore we ignore empty submissions if the user didn't change either.
    if ($values['password'] === '' && isset($this->configuration['username']) && $values['username'] === $this->configuration['username']) {
      $values['password'] = $this->configuration['password'];
    }
    foreach ($values['auth'] as $key => $value) {
      $form_state
        ->setValue($key, $value);
    }

    // Clean-up the form to avoid redundant entries in the stored configuration.
    $form_state
      ->unsetValue('auth');
    parent::submitConfigurationForm($form, $form_state);
  }

  /**
   * {@inheritdoc}
   */
  public function search(Query $query, Endpoint $endpoint = NULL) {
    $this
      ->connect();
    if (!$endpoint) {
      $endpoint = $this->solr
        ->getEndpoint('core');
    }

    // Use the 'postbigrequest' plugin if no specific http method is
    // configured. The plugin needs to be loaded before the request is
    // created.
    if ($this->configuration['http_method'] == 'AUTO') {
      $this->solr
        ->getPlugin('postbigrequest');
    }

    // Use the manual method of creating a Solarium request so we can control
    // the HTTP method.
    $request = $this->solr
      ->createRequest($query);

    // Set the configured HTTP method.
    if ($this->configuration['http_method'] == 'POST') {
      $request
        ->setMethod(Request::METHOD_POST);
    }
    elseif ($this->configuration['http_method'] == 'GET') {
      $request
        ->setMethod(Request::METHOD_GET);
    }

    // Set HTTP Basic Authentication parameter, if login data was set.
    if (strlen($this->configuration['username']) && strlen($this->configuration['password'])) {
      $request
        ->setAuthentication($this->configuration['username'], $this->configuration['password']);
    }
    return $this->solr
      ->executeRequest($request, $endpoint);
  }

  /**
   * {@inheritdoc}
   */
  public function viewSettings() {
    $vars = [
      '%user' => $this->configuration['username'],
      '%pass' => str_repeat('*', strlen($this->configuration['password'])),
    ];
    $info[] = [
      'label' => $this
        ->t('Basic HTTP authentication'),
      'info' => $this
        ->t('Username: %user | Password: %pass', $vars),
    ];
    return $info;
  }

}