class AccountForm

abstract class AccountForm extends ContentEntityForm implements TrustedCallbackInterface {
    
    /**
     * The language manager.
     *
     * @var \Drupal\Core\Language\LanguageManagerInterface
     */
    protected $languageManager;
    
    /**
     * Constructs a new EntityForm object.
     *
     * @param \Drupal\Core\Entity\EntityRepositoryInterface $entity_repository
     *   The entity repository.
     * @param \Drupal\Core\Language\LanguageManagerInterface $language_manager
     *   The language manager.
     * @param \Drupal\Core\Entity\EntityTypeBundleInfoInterface $entity_type_bundle_info
     *   The entity type bundle service.
     * @param \Drupal\Component\Datetime\TimeInterface $time
     *   The time service.
     */
    public function __construct(EntityRepositoryInterface $entity_repository, LanguageManagerInterface $language_manager, ?EntityTypeBundleInfoInterface $entity_type_bundle_info = NULL, ?TimeInterface $time = NULL) {
        parent::__construct($entity_repository, $entity_type_bundle_info, $time);
        $this->languageManager = $language_manager;
    }
    
    /**
     * {@inheritdoc}
     */
    public static function create(ContainerInterface $container) {
        return new static($container->get('entity.repository'), $container->get('language_manager'), $container->get('entity_type.bundle.info'), $container->get('datetime.time'));
    }
    
    /**
     * {@inheritdoc}
     */
    public function form(array $form, FormStateInterface $form_state) {
        
        /** @var \Drupal\user\UserInterface $account */
        $account = $this->entity;
        $user = $this->currentUser();
        $config = \Drupal::config('user.settings');
        $form['#cache']['tags'] = $config->getCacheTags();
        $language_interface = \Drupal::languageManager()->getCurrentLanguage();
        // Check for new account.
        $register = $account->isNew();
        // For a new account, there are 2 sub-cases:
        // $self_register: A user creates their own, new, account
        // (path '/user/register')
        // $admin_create: An administrator creates a new account for another user
        // (path '/admin/people/create')
        // If the current user is logged in and has permission to create users
        // then it must be the second case.
        $admin_create = $register && $account->access('create');
        $self_register = $register && !$admin_create;
        // Account information.
        $form['account'] = [
            '#type' => 'container',
            '#weight' => -10,
        ];
        // The mail field is NOT required if account originally had no mail set
        // and the user performing the edit has 'administer users' permission.
        // This allows users without email address to be edited and deleted.
        // Also see \Drupal\user\Plugin\Validation\Constraint\UserMailRequired.
        $form['account']['mail'] = [
            '#type' => 'email',
            '#title' => $this->t('Email address'),
            '#description' => $this->t('The email address is not made public. It will only be used if you need to be contacted about your account or for opted-in notifications.'),
            '#required' => !(!$account->getEmail() && $user->hasPermission('administer users')),
            '#default_value' => !$register ? $account->getEmail() : '',
            '#access' => $account->mail
                ->access('edit'),
        ];
        // Only show name field on registration form or user can change own username.
        $form['account']['name'] = [
            '#type' => 'textfield',
            '#title' => $this->t('Username'),
            '#maxlength' => UserInterface::USERNAME_MAX_LENGTH,
            '#description' => $this->t("Several special characters are allowed, including space, period (.), hyphen (-), apostrophe ('), underscore (_), and the @ sign."),
            '#required' => TRUE,
            '#attributes' => [
                'class' => [
                    'username',
                ],
                'autocorrect' => 'off',
                'autocapitalize' => 'off',
                'spellcheck' => 'false',
            ],
            '#default_value' => !$register ? $account->getAccountName() : '',
            '#access' => $account->name
                ->access('edit'),
        ];
        // Display password field only for existing users or when user is allowed to
        // assign a password during registration.
        if (!$register) {
            $form['account']['pass'] = [
                '#type' => 'password_confirm',
                '#size' => 25,
                '#description' => $this->t('To change the current user password, enter the new password in both fields.'),
            ];
            // To skip the current password field, the user must have logged in via a
            // one-time link and have the token in the URL. Store this in $form_state
            // so it persists even on subsequent Ajax requests.
            $request = $this->getRequest();
            if (!$form_state->get('user_pass_reset') && ($token = $request->query
                ->get('pass-reset-token'))) {
                $session_key = 'pass_reset_' . $account->id();
                $session_value = $request->getSession()
                    ->get($session_key);
                $user_pass_reset = isset($session_value) && hash_equals($session_value, $token);
                $form_state->set('user_pass_reset', $user_pass_reset);
            }
            // The user must enter their current password to change to a new one.
            if ($user->id() == $account->id()) {
                $form['account']['current_pass'] = [
                    '#type' => 'password',
                    '#title' => $this->t('Current password'),
                    '#size' => 25,
                    '#access' => !$form_state->get('user_pass_reset'),
                    '#weight' => -5,
                    // Do not let web browsers remember this password, since we are
                    // trying to confirm that the person submitting the form actually
                    // knows the current one.
'#attributes' => [
                        'autocomplete' => 'off',
                    ],
                ];
                $form_state->set('user', $account);
                // The user may only change their own password without their current
                // password if they logged in via a one-time login link.
                if (!$form_state->get('user_pass_reset')) {
                    $form['account']['current_pass']['#description'] = $this->t('Required if you want to change the %mail or %pass below. <a href=":request_new_url" title="Send password reset instructions via email.">Reset your password</a>.', [
                        '%mail' => $form['account']['mail']['#title'],
                        '%pass' => $this->t('Password'),
                        ':request_new_url' => Url::fromRoute('user.pass')->toString(),
                    ]);
                }
            }
        }
        elseif (!$config->get('verify_mail') || $admin_create) {
            $form['account']['pass'] = [
                '#type' => 'password_confirm',
                '#size' => 25,
                '#description' => $this->t('Provide a password for the new account in both fields.'),
                '#required' => TRUE,
            ];
        }
        // When not building the user registration form, prevent web browsers from
        // auto-filling/prefilling the email, username, and password fields.
        if (!$register) {
            foreach ([
                'mail',
                'name',
                'pass',
            ] as $key) {
                if (isset($form['account'][$key])) {
                    $form['account'][$key]['#attributes']['autocomplete'] = 'off';
                }
            }
        }
        if (!$self_register) {
            $status = $account->get('status')->value;
        }
        else {
            $status = $config->get('register') == UserInterface::REGISTER_VISITORS ? 1 : 0;
        }
        $form['account']['status'] = [
            '#type' => 'radios',
            '#title' => $this->t('Status'),
            '#default_value' => $status,
            '#options' => [
                $this->t('Blocked'),
                $this->t('Active'),
            ],
            '#access' => $account->status
                ->access('edit'),
        ];
        $roles = Role::loadMultiple();
        unset($roles[RoleInterface::ANONYMOUS_ID]);
        $roles = array_map(fn(RoleInterface $role) => Html::escape($role->label()), $roles);
        $form['account']['roles'] = [
            '#type' => 'checkboxes',
            '#title' => $this->t('Roles'),
            '#default_value' => !$register ? $account->getRoles() : [],
            '#options' => $roles,
            '#access' => $roles && $user->hasPermission('administer permissions'),
        ];
        // Special handling for the inevitable "Authenticated user" role.
        $form['account']['roles'][RoleInterface::AUTHENTICATED_ID] = [
            '#default_value' => TRUE,
            '#disabled' => TRUE,
        ];
        $form['account']['notify'] = [
            '#type' => 'checkbox',
            '#title' => $this->t('Notify user of new account'),
            '#access' => $admin_create,
        ];
        $user_preferred_langcode = $register ? $language_interface->getId() : $account->getPreferredLangcode();
        $user_preferred_admin_langcode = $register ? $language_interface->getId() : $account->getPreferredAdminLangcode(FALSE);
        // Is the user preferred language added?
        $user_language_added = FALSE;
        if ($this->languageManager instanceof ConfigurableLanguageManagerInterface) {
            $negotiator = $this->languageManager
                ->getNegotiator();
            $user_language_added = $negotiator && $negotiator->isNegotiationMethodEnabled(LanguageNegotiationUser::METHOD_ID, LanguageInterface::TYPE_INTERFACE);
        }
        $form['language'] = [
            '#type' => $this->languageManager
                ->isMultilingual() ? 'details' : 'container',
            '#title' => $this->t('Language settings'),
            '#open' => TRUE,
            // Display language selector when either creating a user on the admin
            // interface or editing a user account.
'#access' => !$self_register,
        ];
        $form['language']['preferred_langcode'] = [
            '#type' => 'language_select',
            '#title' => $this->t('Site language'),
            '#languages' => LanguageInterface::STATE_CONFIGURABLE,
            '#default_value' => $user_preferred_langcode,
            '#description' => $user_language_added ? $this->t("This account's preferred language for emails and site presentation.") : $this->t("This account's preferred language for emails."),
            // This is used to explain that user preferred language and entity
            // language are synchronized. It can be removed if a different behavior is
            // desired.
'#pre_render' => [
                'user_langcode' => [
                    $this,
                    'alterPreferredLangcodeDescription',
                ],
            ],
        ];
        // Only show the account setting for Administration pages language to users
        // if one of the detection and selection methods uses it.
        $show_admin_language = FALSE;
        if (($account->hasPermission('access administration pages') || $account->hasPermission('view the administration theme')) && $this->languageManager instanceof ConfigurableLanguageManagerInterface) {
            $negotiator = $this->languageManager
                ->getNegotiator();
            $show_admin_language = $negotiator && $negotiator->isNegotiationMethodEnabled(LanguageNegotiationUserAdmin::METHOD_ID);
        }
        $form['language']['preferred_admin_langcode'] = [
            '#type' => 'language_select',
            '#title' => $this->t('Administration pages language'),
            '#languages' => LanguageInterface::STATE_CONFIGURABLE,
            '#default_value' => $user_preferred_admin_langcode,
            '#access' => $show_admin_language,
            '#empty_option' => $this->t('- No preference -'),
            '#empty_value' => '',
        ];
        // User entities contain both a langcode property (for identifying the
        // language of the entity data) and a preferred_langcode property (see
        // above). Rather than provide a UI forcing the user to choose both
        // separately, assume that the user profile data is in the user's preferred
        // language. This entity builder provides that synchronization. For
        // use-cases where this synchronization is not desired, a module can alter
        // or remove this item. Sync user langcode only when a user registers and
        // not when a user is updated or translated.
        if ($register) {
            $form['#entity_builders']['sync_user_langcode'] = '::syncUserLangcode';
        }
        $system_date_config = \Drupal::config('system.date');
        $form['timezone'] = [
            '#type' => 'details',
            '#title' => $this->t('Locale settings'),
            '#open' => TRUE,
            '#weight' => 6,
            '#access' => $system_date_config->get('timezone.user.configurable'),
        ];
        if ($self_register && $system_date_config->get('timezone.user.default') != UserInterface::TIMEZONE_SELECT) {
            $form['timezone']['#access'] = FALSE;
        }
        $form['timezone']['timezone'] = [
            '#type' => 'select',
            '#title' => $this->t('Time zone'),
            '#default_value' => $account->getTimezone() ?: $system_date_config->get('timezone.default'),
            '#options' => TimeZoneFormHelper::getOptionsListByRegion($account->id() != $user->id()),
            '#description' => $this->t('Select the desired local time and time zone. Dates and times throughout this site will be displayed using this time zone.'),
        ];
        // If not set or selected yet, detect timezone for the current user only.
        $user_input = $form_state->getUserInput();
        if (!$account->getTimezone() && $account->id() == $user->id() && empty($user_input['timezone'])) {
            $form['timezone']['#attached']['library'][] = 'core/drupal.timezone';
            $form['timezone']['timezone']['#attributes'] = [
                'class' => [
                    'timezone-detect',
                ],
            ];
        }
        return parent::form($form, $form_state);
    }
    
    /**
     * {@inheritdoc}
     */
    public static function trustedCallbacks() {
        return [
            'alterPreferredLangcodeDescription',
        ];
    }
    
    /**
     * Alters the preferred language widget description.
     *
     * @param array $element
     *   The preferred language form element.
     *
     * @return array
     *   The preferred language form element.
     */
    public function alterPreferredLangcodeDescription(array $element) {
        // Only add to the description if the form element has a description.
        if (isset($element['#description'])) {
            $element['#description'] .= ' ' . $this->t("This is also assumed to be the primary language of this account's profile information.");
        }
        return $element;
    }
    
    /**
     * Synchronizes preferred language and entity language.
     *
     * @param string $entity_type_id
     *   The entity type identifier.
     * @param \Drupal\user\UserInterface $user
     *   The entity updated with the submitted values.
     * @param array $form
     *   The complete form array.
     * @param \Drupal\Core\Form\FormStateInterface $form_state
     *   The current state of the form.
     */
    public function syncUserLangcode($entity_type_id, UserInterface $user, array &$form, FormStateInterface &$form_state) {
        $user->getUntranslated()->langcode = $user->preferred_langcode;
    }
    
    /**
     * {@inheritdoc}
     */
    public function buildEntity(array $form, FormStateInterface $form_state) {
        // Change the roles array to a list of enabled roles.
        // @todo Alter the form state as the form values are directly extracted and
        //   set on the field, which throws an exception as the list requires
        //   numeric keys. Allow to override this per field. As this function is
        //   called twice, we have to prevent it from getting the array keys twice.
        if (is_string(key($form_state->getValue('roles')))) {
            $form_state->setValue('roles', array_keys(array_filter($form_state->getValue('roles'))));
        }
        
        /** @var \Drupal\user\UserInterface $account */
        $account = parent::buildEntity($form, $form_state);
        // Translate the empty value '' of language selects to an unset field.
        foreach ([
            'preferred_langcode',
            'preferred_admin_langcode',
        ] as $field_name) {
            if ($form_state->getValue($field_name) === '') {
                $account->{$field_name} = NULL;
            }
        }
        // Set existing password if set in the form state.
        $current_pass = trim($form_state->getValue('current_pass', ''));
        if (strlen($current_pass) > 0) {
            $account->setExistingPassword($current_pass);
        }
        // Skip the protected user field constraint if the user came from the
        // password recovery page.
        $account->_skipProtectedUserFieldConstraint = $form_state->get('user_pass_reset');
        return $account;
    }
    
    /**
     * {@inheritdoc}
     */
    protected function getEditedFieldNames(FormStateInterface $form_state) {
        return array_merge([
            'name',
            'pass',
            'mail',
            'timezone',
            'langcode',
            'preferred_langcode',
            'preferred_admin_langcode',
        ], parent::getEditedFieldNames($form_state));
    }
    
    /**
     * {@inheritdoc}
     */
    protected function flagViolations(EntityConstraintViolationListInterface $violations, array $form, FormStateInterface $form_state) {
        // Manually flag violations of fields not handled by the form display. This
        // is necessary as entity form displays only flag violations for fields
        // contained in the display.
        $field_names = [
            'name',
            'pass',
            'mail',
            'timezone',
            'langcode',
            'preferred_langcode',
            'preferred_admin_langcode',
        ];
        foreach ($violations->getByFields($field_names) as $violation) {
            [
                $field_name,
            ] = explode('.', $violation->getPropertyPath(), 2);
            $form_state->setErrorByName($field_name, $violation->getMessage());
        }
        parent::flagViolations($violations, $form, $form_state);
    }
    
    /**
     * {@inheritdoc}
     */
    public function submitForm(array &$form, FormStateInterface $form_state) {
        parent::submitForm($form, $form_state);
        $user = $this->getEntity();
        // If there's a session set to the users id, remove the password reset tag
        // since a new password was saved.
        $this->getRequest()
            ->getSession()
            ->remove('pass_reset_' . $user->id());
    }

}