class UserSession

class UserSession implements AccountInterface {

  /**
   * User ID.
   *
   * @var int
   */
  protected $uid = 0;

  /**
   * List of the roles this user has.
   *
   * Defaults to the anonymous role.
   *
   * @var array
   */
  protected $roles = [
    AccountInterface::ANONYMOUS_ROLE,
  ];

  /**
   * The Unix timestamp when the user last accessed the site.
   *
   * @var string
   */
  protected $access;

  /**
   * The name of this account.
   *
   * @var string
   */
  public $name = '';

  /**
   * The preferred language code of the account.
   *
   * @var string
   */
  protected $preferred_langcode;

  /**
   * The preferred administrative language code of the account.
   *
   * @var string
   */
  protected $preferred_admin_langcode;

  /**
   * The email address of this account.
   *
   * @var string
   */
  protected $mail;

  /**
   * The timezone of this account.
   *
   * @var string
   */
  protected $timezone;

  /**
   * Constructs a new user session.
   *
   * @param array $values
   *   Array of initial values for the user session.
   */
  public function __construct(array $values = []) {
    foreach ($values as $key => $value) {
      $this->{$key} = $value;
    }
  }

  /**
   * {@inheritdoc}
   */
  public function id() {
    return $this->uid;
  }

  /**
   * {@inheritdoc}
   */
  public function getRoles($exclude_locked_roles = FALSE) {
    $roles = $this->roles;
    if ($exclude_locked_roles) {
      $roles = array_values(array_diff($roles, [
        AccountInterface::ANONYMOUS_ROLE,
        AccountInterface::AUTHENTICATED_ROLE,
      ]));
    }
    return $roles;
  }

  /**
   * {@inheritdoc}
   */
  public function hasPermission($permission) {

    // User #1 has all privileges.
    if ((int) $this
      ->id() === 1) {
      return TRUE;
    }
    return $this
      ->getRoleStorage()
      ->isPermissionInRoles($permission, $this
      ->getRoles());
  }

  /**
   * {@inheritdoc}
   */
  public function isAuthenticated() {
    return $this->uid > 0;
  }

  /**
   * {@inheritdoc}
   */
  public function isAnonymous() {
    return $this->uid == 0;
  }

  /**
   * {@inheritdoc}
   */
  public function getPreferredLangcode($fallback_to_default = TRUE) {
    $language_list = \Drupal::languageManager()
      ->getLanguages();
    if (!empty($this->preferred_langcode) && isset($language_list[$this->preferred_langcode])) {
      return $language_list[$this->preferred_langcode]
        ->getId();
    }
    else {
      return $fallback_to_default ? \Drupal::languageManager()
        ->getDefaultLanguage()
        ->getId() : '';
    }
  }

  /**
   * {@inheritdoc}
   */
  public function getPreferredAdminLangcode($fallback_to_default = TRUE) {
    $language_list = \Drupal::languageManager()
      ->getLanguages();
    if (!empty($this->preferred_admin_langcode) && isset($language_list[$this->preferred_admin_langcode])) {
      return $language_list[$this->preferred_admin_langcode]
        ->getId();
    }
    else {
      return $fallback_to_default ? \Drupal::languageManager()
        ->getDefaultLanguage()
        ->getId() : '';
    }
  }

  /**
   * {@inheritdoc}
   */
  public function getUsername() {
    @trigger_error('\\Drupal\\Core\\Session\\AccountInterface::getUsername() is deprecated in Drupal 8.0.0, will be removed before Drupal 9.0.0. Use \\Drupal\\Core\\Session\\AccountInterface::getAccountName() or \\Drupal\\user\\UserInterface::getDisplayName() instead. See https://www.drupal.org/node/2572493', E_USER_DEPRECATED);
    return $this
      ->getAccountName();
  }

  /**
   * {@inheritdoc}
   */
  public function getAccountName() {
    return $this->name;
  }

  /**
   * {@inheritdoc}
   */
  public function getDisplayName() {
    $name = $this->name ?: \Drupal::config('user.settings')
      ->get('anonymous');
    \Drupal::moduleHandler()
      ->alter('user_format_name', $name, $this);
    return $name;
  }

  /**
   * {@inheritdoc}
   */
  public function getEmail() {
    return $this->mail;
  }

  /**
   * {@inheritdoc}
   */
  public function getTimeZone() {
    return $this->timezone;
  }

  /**
   * {@inheritdoc}
   */
  public function getLastAccessedTime() {
    return $this->access;
  }

  /**
   * Returns the role storage object.
   *
   * @return \Drupal\user\RoleStorageInterface
   *   The role storage object.
   */
  protected function getRoleStorage() {
    return \Drupal::entityTypeManager()
      ->getStorage('user_role');
  }

}