class UserCancelForm

class UserCancelForm extends ContentEntityConfirmFormBase {
    
    /**
     * Available account cancellation methods.
     *
     * @var array
     */
    protected $cancelMethods;
    
    /**
     * Whether allowed to select cancellation method.
     *
     * @var bool
     */
    protected $selectCancel;
    
    /**
     * The user 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() {
        $description = '';
        $default_method = $this->config('user.settings')
            ->get('cancel_method');
        $own_account = $this->entity
            ->id() == $this->currentUser()
            ->id();
        if ($this->selectCancel) {
            $description = $this->t('Select the method to cancel the account above.');
        }
        elseif ($own_account && isset($this->cancelMethods[$default_method]['#confirm_description'])) {
            $description = $this->cancelMethods[$default_method]['#confirm_description'];
        }
        else {
            $description = $this->cancelMethods['#options'][$default_method];
        }
        return $description . ' ' . $this->t('This action cannot be undone.');
    }
    
    /**
     * {@inheritdoc}
     */
    public function getConfirmText() {
        return $this->t('Cancel account');
    }
    
    /**
     * {@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('When cancelling the account'),
            '#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' => $this->t('Require email confirmation to cancel account'),
            '#default_value' => !$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')
                ->notice('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(),
            ]);
        }
    }

}