class UserPasswordForm

class UserPasswordForm extends FormBase {
    
    /**
     * The user storage.
     *
     * @var \Drupal\user\UserStorageInterface
     */
    protected $userStorage;
    
    /**
     * The language manager.
     *
     * @var \Drupal\Core\Language\LanguageManagerInterface
     */
    protected $languageManager;
    
    /**
     * The flood service.
     *
     * @var \Drupal\Core\Flood\FloodInterface
     */
    protected $flood;
    
    /**
     * The typed data manager.
     *
     * @var \Drupal\Core\TypedData\TypedDataManagerInterface
     */
    protected $typedDataManager;
    
    /**
     * The email validator service.
     *
     * @var \Drupal\Component\Utility\EmailValidatorInterface
     */
    protected $emailValidator;
    
    /**
     * Constructs a UserPasswordForm object.
     *
     * @param \Drupal\user\UserStorageInterface $user_storage
     *   The user storage.
     * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
     *   The language manager.
     * @param \Drupal\Core\Config\ConfigFactory $config_factory
     *   The config factory.
     * @param \Drupal\Core\Flood\FloodInterface $flood
     *   The flood service.
     * @param \Drupal\Core\TypedData\TypedDataManagerInterface $typed_data_manager
     *   The typed data manager.
     * @param \Drupal\Component\Utility\EmailValidatorInterface $email_validator
     *   The email validator service.
     */
    public function __construct(UserStorageInterface $user_storage, LanguageManagerInterface $language_manager, ConfigFactory $config_factory, FloodInterface $flood, TypedDataManagerInterface $typed_data_manager = NULL, EmailValidatorInterface $email_validator = NULL) {
        $this->userStorage = $user_storage;
        $this->languageManager = $language_manager;
        $this->configFactory = $config_factory;
        $this->flood = $flood;
        if (is_null($typed_data_manager)) {
            @trigger_error('Calling ' . __METHOD__ . ' without the $typed_data_manager argument is deprecated in drupal:9.2.0 and will be required in drupal:10.0.0. See https://www.drupal.org/node/3189310', E_USER_DEPRECATED);
            $typed_data_manager = \Drupal::typedDataManager();
        }
        $this->typedDataManager = $typed_data_manager;
        if (is_null($email_validator)) {
            @trigger_error('Calling ' . __METHOD__ . ' without the $email_validator argument is deprecated in drupal:9.2.0 and will be required in drupal:10.0.0. See https://www.drupal.org/node/3189310', E_USER_DEPRECATED);
            $email_validator = \Drupal::service('email.validator');
        }
        $this->emailValidator = $email_validator;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) {
        return new static($container->get('entity_type.manager')
            ->getStorage('user'), $container->get('language_manager'), $container->get('config.factory'), $container->get('flood'), $container->get('typed_data_manager'), $container->get('email.validator'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function getFormId() {
        return 'user_pass';
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildForm(array $form, FormStateInterface $form_state) {
        $form['name'] = [
            '#type' => 'textfield',
            '#title' => $this->t('Username or email address'),
            '#size' => 60,
            '#maxlength' => max(UserInterface::USERNAME_MAX_LENGTH, Email::EMAIL_MAX_LENGTH),
            '#required' => TRUE,
            '#attributes' => [
                'autocorrect' => 'off',
                'autocapitalize' => 'off',
                'spellcheck' => 'false',
                'autofocus' => 'autofocus',
            ],
        ];
        // Allow logged in users to request this also.
        $user = $this->currentUser();
        if ($user->isAuthenticated()) {
            $form['name']['#type'] = 'value';
            $form['name']['#value'] = $user->getEmail();
            $form['mail'] = [
                '#prefix' => '<p>',
                '#markup' => $this->t('Password reset instructions will be mailed to %email. You must log out to use the password reset link in the email.', [
                    '%email' => $user->getEmail(),
                ]),
                '#suffix' => '</p>',
            ];
        }
        else {
            $form['mail'] = [
                '#prefix' => '<p>',
                '#markup' => $this->t('Password reset instructions will be sent to your registered email address.'),
                '#suffix' => '</p>',
            ];
            $form['name']['#default_value'] = $this->getRequest()->query
                ->get('name');
        }
        $form['actions'] = [
            '#type' => 'actions',
        ];
        $form['actions']['submit'] = [
            '#type' => 'submit',
            '#value' => $this->t('Submit'),
        ];
        $form['#cache']['contexts'][] = 'url.query_args';
        return $form;
    }
    
    /**
     * {@inheritdoc}
     */
    public function validateForm(array &$form, FormStateInterface $form_state) {
        $flood_config = $this->configFactory
            ->get('user.flood');
        if (!$this->flood
            ->isAllowed('user.password_request_ip', $flood_config->get('ip_limit'), $flood_config->get('ip_window'))) {
            $form_state->setErrorByName('name', $this->t('Too many password recovery requests from your IP address. It is temporarily blocked. Try again later or contact the site administrator.'));
            return;
        }
        $this->flood
            ->register('user.password_request_ip', $flood_config->get('ip_window'));
        // First, see if the input is possibly valid as a username.
        $name = trim($form_state->getValue('name'));
        $definition = BaseFieldDefinition::create('string')->addConstraint('UserName', []);
        $data = $this->typedDataManager
            ->create($definition);
        $data->setValue($name);
        $violations = $data->validate();
        // Usernames have a maximum length shorter than email addresses. Only print
        // this error if the input is not valid as a username or email address.
        if ($violations->count() > 0 && !$this->emailValidator
            ->isValid($name)) {
            $form_state->setErrorByName('name', $this->t("The username or email address is invalid."));
            return;
        }
        // Try to load by email.
        $users = $this->userStorage
            ->loadByProperties([
            'mail' => $name,
        ]);
        if (empty($users)) {
            // No success, try to load by name.
            $users = $this->userStorage
                ->loadByProperties([
                'name' => $name,
            ]);
        }
        $account = reset($users);
        // Blocked accounts cannot request a new password.
        if ($account && $account->id() && $account->isActive()) {
            // Register flood events based on the uid only, so they apply for any
            // IP address. This allows them to be cleared on successful reset (from
            // any IP).
            $identifier = $account->id();
            if (!$this->flood
                ->isAllowed('user.password_request_user', $flood_config->get('user_limit'), $flood_config->get('user_window'), $identifier)) {
                return;
            }
            $this->flood
                ->register('user.password_request_user', $flood_config->get('user_window'), $identifier);
            $form_state->setValueForElement([
                '#parents' => [
                    'account',
                ],
            ], $account);
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitForm(array &$form, FormStateInterface $form_state) {
        $account = $form_state->getValue('account');
        if ($account) {
            // Mail one time login URL and instructions using current language.
            $mail = _user_mail_notify('password_reset', $account);
            if (!empty($mail)) {
                $this->logger('user')
                    ->notice('Password reset instructions mailed to %name at %email.', [
                    '%name' => $account->getAccountName(),
                    '%email' => $account->getEmail(),
                ]);
            }
        }
        else {
            $this->logger('user')
                ->notice('Password reset form was submitted with an unknown or inactive account: %name.', [
                '%name' => $form_state->getValue('name'),
            ]);
        }
        // Make sure the status text is displayed even if no email was sent. This
        // message is deliberately the same as the success message for privacy.
        $this->messenger()
            ->addStatus($this->t('If %identifier is a valid account, an email will be sent with instructions to reset your password.', [
            '%identifier' => $form_state->getValue('name'),
        ]));
        $form_state->setRedirect('<front>');
    }

}