class UserCancelForm

class UserCancelForm extends ContentEntityConfirmFormBase {

  /**
   * Available account cancellation methods.
   *
   * @var array
   */
  protected $cancelMethods;

  /**
   * Whether it is allowed to select cancellation method.
   *
   * @var bool
   */
  protected $selectCancel;

  /**
   * The account being cancelled.
   *
   * @var \Drupal\user\UserInterface
   */
  protected $entity;

  /**
   * {@inheritdoc}
   */
  public function getQuestion() {
    if ($this->entity
      ->id() == $this
      ->currentUser()
      ->id()) {
      return $this
        ->t('Are you sure you want to cancel your account?');
    }
    return $this
      ->t('Are you sure you want to cancel the account %name?', [
      '%name' => $this->entity
        ->label(),
    ]);
  }

  /**
   * {@inheritdoc}
   */
  public function getCancelUrl() {
    return $this->entity
      ->toUrl();
  }

  /**
   * {@inheritdoc}
   */
  public function getDescription() {
    if ($this->selectCancel) {
      return '';
    }
    $default_method = $this
      ->config('user.settings')
      ->get('cancel_method');
    $own_account = $this->entity
      ->id() == $this
      ->currentUser()
      ->id();

    // Options supplied via user_cancel_methods() can have a custom
    // #confirm_description property for the confirmation form description.
    // This text refers to "Your account" so only user it if cancelling own account.
    if ($own_account && isset($this->cancelMethods[$default_method]['#confirm_description'])) {
      return $this->cancelMethods[$default_method]['#confirm_description'];
    }
    return $this->cancelMethods['#options'][$default_method];
  }

  /**
   * {@inheritdoc}
   */
  public function getConfirmText() {
    return $this
      ->t('Confirm');
  }

  /**
   * {@inheritdoc}
   */
  public function buildForm(array $form, FormStateInterface $form_state) {
    $user = $this
      ->currentUser();
    $this->cancelMethods = user_cancel_methods();

    // Display account cancellation method selection, if allowed.
    $own_account = $this->entity
      ->id() == $user
      ->id();
    $this->selectCancel = $user
      ->hasPermission('administer users') || $user
      ->hasPermission('select account cancellation method');
    $form['user_cancel_method'] = [
      '#type' => 'radios',
      '#title' => $own_account ? $this
        ->t('When cancelling your account') : $this
        ->t('Cancellation method'),
      '#access' => $this->selectCancel,
    ];
    $form['user_cancel_method'] += $this->cancelMethods;

    // When managing another user, can skip the account cancellation
    // confirmation mail (by default).
    $override_access = !$own_account;
    $form['user_cancel_confirm'] = [
      '#type' => 'checkbox',
      '#title' => $this
        ->t('Require email confirmation'),
      '#default_value' => !$override_access,
      '#access' => $override_access,
      '#description' => $this
        ->t('When enabled, the user must confirm the account cancellation via email.'),
    ];

    // Also allow to send account canceled notification mail, if enabled.
    $default_notify = $this
      ->config('user.settings')
      ->get('notify.status_canceled');
    $form['user_cancel_notify'] = [
      '#type' => 'checkbox',
      '#title' => $this
        ->t('Notify user when account is canceled'),
      '#default_value' => $override_access ? FALSE : $default_notify,
      '#access' => $override_access && $default_notify,
      '#description' => $this
        ->t('When enabled, the user will receive an email notification after the account has been canceled.'),
    ];

    // Always provide entity id in the same form key as in the entity edit form.
    $form['uid'] = [
      '#type' => 'value',
      '#value' => $this->entity
        ->id(),
    ];

    // Store the user permissions so that it can be altered in hook_form_alter()
    // if desired.
    $form['access'] = [
      '#type' => 'value',
      '#value' => !$own_account,
    ];
    $form = parent::buildForm($form, $form_state);
    return $form;
  }

  /**
   * {@inheritdoc}
   */
  public function submitForm(array &$form, FormStateInterface $form_state) {

    // Cancel account immediately, if the current user has administrative
    // privileges, no confirmation mail shall be sent, and the user does not
    // attempt to cancel the own account.
    if (!$form_state
      ->isValueEmpty('access') && $form_state
      ->isValueEmpty('user_cancel_confirm') && $this->entity
      ->id() != $this
      ->currentUser()
      ->id()) {
      user_cancel($form_state
        ->getValues(), $this->entity
        ->id(), $form_state
        ->getValue('user_cancel_method'));
      $form_state
        ->setRedirectUrl($this->entity
        ->toUrl('collection'));
    }
    else {

      // Store cancelling method and whether to notify the user in
      // $this->entity for
      // \Drupal\user\Controller\UserController::confirmCancel().
      $this->entity->user_cancel_method = $form_state
        ->getValue('user_cancel_method');
      $this->entity->user_cancel_notify = $form_state
        ->getValue('user_cancel_notify');
      $this->entity
        ->save();
      _user_mail_notify('cancel_confirm', $this->entity);
      $this
        ->messenger()
        ->addStatus($this
        ->t('A confirmation request to cancel your account has been sent to your email address.'));
      $this
        ->logger('user')
        ->info('Sent account cancellation request to %name %email.', [
        '%name' => $this->entity
          ->label(),
        '%email' => '<' . $this->entity
          ->getEmail() . '>',
      ]);
      $form_state
        ->setRedirect('entity.user.canonical', [
        'user' => $this->entity
          ->id(),
      ]);
    }
  }

}