NS_IMETHODIMP nsAlertsService::ShowPersistentNotification(const nsAString & aPersistentData,
                                                          nsIAlertNotification * aAlert,
                                                          nsIObserver * aAlertListener)
{
  NS_ENSURE_ARG(aAlert);

  nsAutoString cookie;
  nsresult rv = aAlert->GetCookie(cookie);
  NS_ENSURE_SUCCESS(rv, rv);

  if (XRE_IsContentProcess()) {
    ContentChild* cpc = ContentChild::GetSingleton();

    if (aAlertListener)
      cpc->AddRemoteAlertObserver(cookie, aAlertListener);

    cpc->SendShowAlert(aAlert);
    return NS_OK;
  }

  // Check if there is an optional service that handles system-level notifications
  if (mBackend) {
    rv = ShowWithBackend(mBackend, aAlert, aAlertListener, aPersistentData);
    if (NS_SUCCEEDED(rv)) {
      return rv;
    }
    // If the system backend failed to show the alert, clear the backend and
    // retry with XUL notifications. Future alerts will always use XUL.
    mBackend = nullptr;
  }

  if (!ShouldShowAlert()) {
    // Do not display the alert. Instead call alertfinished and get out.
    if (aAlertListener)
      aAlertListener->Observe(nullptr, "alertfinished", cookie.get());
    return NS_OK;
  }

  // Use XUL notifications as a fallback if above methods have failed.
  nsCOMPtr<nsIAlertsService> xulBackend(nsXULAlerts::GetInstance());
  NS_ENSURE_TRUE(xulBackend, NS_ERROR_FAILURE);
  return ShowWithBackend(xulBackend, aAlert, aAlertListener, aPersistentData);
}
NS_IMETHODIMP nsAlertsService::ShowAlert(nsIAlertNotification * aAlert,
                                         nsIObserver * aAlertListener)
{
  NS_ENSURE_ARG(aAlert);

  nsAutoString cookie;
  nsresult rv = aAlert->GetCookie(cookie);
  NS_ENSURE_SUCCESS(rv, rv);

  if (XRE_IsContentProcess()) {
    ContentChild* cpc = ContentChild::GetSingleton();

    if (aAlertListener)
      cpc->AddRemoteAlertObserver(cookie, aAlertListener);

    cpc->SendShowAlert(aAlert);
    return NS_OK;
  }

  nsAutoString imageUrl;
  rv = aAlert->GetImageURL(imageUrl);
  NS_ENSURE_SUCCESS(rv, rv);

  nsAutoString title;
  rv = aAlert->GetTitle(title);
  NS_ENSURE_SUCCESS(rv, rv);

  nsAutoString text;
  rv = aAlert->GetText(text);
  NS_ENSURE_SUCCESS(rv, rv);

  nsAutoString name;
  rv = aAlert->GetName(name);
  NS_ENSURE_SUCCESS(rv, rv);

  nsCOMPtr<nsIPrincipal> principal;
  rv = aAlert->GetPrincipal(getter_AddRefs(principal));
  NS_ENSURE_SUCCESS(rv, rv);

#ifdef MOZ_WIDGET_ANDROID
  mozilla::AndroidBridge::Bridge()->ShowAlertNotification(imageUrl, title, text, cookie,
                                                          aAlertListener, name, principal);
  return NS_OK;
#else
  // Check if there is an optional service that handles system-level notifications
  nsCOMPtr<nsIAlertsService> sysAlerts(do_GetService(NS_SYSTEMALERTSERVICE_CONTRACTID));
  if (sysAlerts) {
    rv = sysAlerts->ShowAlert(aAlert, aAlertListener);
    if (NS_SUCCEEDED(rv))
      return NS_OK;
  }

  if (!ShouldShowAlert()) {
    // Do not display the alert. Instead call alertfinished and get out.
    if (aAlertListener)
      aAlertListener->Observe(nullptr, "alertfinished", cookie.get());
    return NS_OK;
  }

  bool textClickable;
  rv = aAlert->GetTextClickable(&textClickable);
  NS_ENSURE_SUCCESS(rv, rv);

  nsAutoString bidi;
  rv = aAlert->GetDir(bidi);
  NS_ENSURE_SUCCESS(rv, rv);

  nsAutoString lang;
  rv = aAlert->GetLang(lang);
  NS_ENSURE_SUCCESS(rv, rv);

  bool inPrivateBrowsing;
  rv = aAlert->GetInPrivateBrowsing(&inPrivateBrowsing);
  NS_ENSURE_SUCCESS(rv, rv);

  // Use XUL notifications as a fallback if above methods have failed.
  rv = mXULAlerts.ShowAlertNotification(imageUrl, title, text, textClickable,
                                        cookie, aAlertListener, name,
                                        bidi, lang, principal, inPrivateBrowsing);
  return rv;
#endif // !MOZ_WIDGET_ANDROID
}