/* -*- Mode: C++; tab-width: 2; indent-tabs-mode:nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "mozilla/dom/ContentChild.h"
#include "mozilla/dom/PermissionMessageUtils.h"
#include "mozilla/Preferences.h"
#include "mozilla/StaticPrefs_alerts.h"
#include "mozilla/Telemetry.h"
#include "nsXULAppAPI.h"

#include "nsAlertsService.h"

#include "nsXPCOM.h"
#include "nsPromiseFlatString.h"
#include "nsToolkitCompsCID.h"
#include "nsComponentManagerUtils.h"

#ifdef MOZ_PLACES
#  include "nsIFaviconService.h"
#endif  // MOZ_PLACES

#ifdef XP_WIN
#  include <shellapi.h>
#endif

using namespace mozilla;

using mozilla::dom::ContentChild;

namespace {

#ifdef MOZ_PLACES

class IconCallback final : public nsIFaviconDataCallback {
 public:
  NS_DECL_ISUPPORTS

  IconCallback(nsIAlertsService* aBackend, nsIAlertNotification* aAlert,
               nsIObserver* aAlertListener)
      : mBackend(aBackend), mAlert(aAlert), mAlertListener(aAlertListener) {}

  NS_IMETHOD
  OnComplete(nsIURI* aIconURI, uint32_t aIconSize, const uint8_t* aIconData,
             const nsACString& aMimeType, uint16_t aWidth) override {
    nsresult rv = NS_ERROR_FAILURE;
    if (aIconSize > 0) {
      nsCOMPtr<nsIAlertsIconData> alertsIconData(do_QueryInterface(mBackend));
      if (alertsIconData) {
        rv = alertsIconData->ShowAlertWithIconData(mAlert, mAlertListener,
                                                   aIconSize, aIconData);
      }
    } else if (aIconURI) {
      nsCOMPtr<nsIAlertsIconURI> alertsIconURI(do_QueryInterface(mBackend));
      if (alertsIconURI) {
        rv = alertsIconURI->ShowAlertWithIconURI(mAlert, mAlertListener,
                                                 aIconURI);
      }
    }
    if (NS_FAILED(rv)) {
      rv = mBackend->ShowAlert(mAlert, mAlertListener);
    }
    return rv;
  }

 private:
  virtual ~IconCallback() = default;

  nsCOMPtr<nsIAlertsService> mBackend;
  nsCOMPtr<nsIAlertNotification> mAlert;
  nsCOMPtr<nsIObserver> mAlertListener;
};

NS_IMPL_ISUPPORTS(IconCallback, nsIFaviconDataCallback)

#endif  // MOZ_PLACES

nsresult ShowWithIconBackend(nsIAlertsService* aBackend,
                             nsIAlertNotification* aAlert,
                             nsIObserver* aAlertListener) {
#ifdef MOZ_PLACES
  nsCOMPtr<nsIURI> uri;
  nsresult rv = aAlert->GetURI(getter_AddRefs(uri));
  if (NS_FAILED(rv) || !uri) {
    return NS_ERROR_FAILURE;
  }

  // Ensure the backend supports favicons.
  nsCOMPtr<nsIAlertsIconData> alertsIconData(do_QueryInterface(aBackend));
  nsCOMPtr<nsIAlertsIconURI> alertsIconURI;
  if (!alertsIconData) {
    alertsIconURI = do_QueryInterface(aBackend);
  }
  if (!alertsIconData && !alertsIconURI) {
    return NS_ERROR_NOT_IMPLEMENTED;
  }

  nsCOMPtr<nsIFaviconService> favicons(
      do_GetService("@mozilla.org/browser/favicon-service;1"));
  NS_ENSURE_TRUE(favicons, NS_ERROR_FAILURE);

  nsCOMPtr<nsIFaviconDataCallback> callback =
      new IconCallback(aBackend, aAlert, aAlertListener);
  if (alertsIconData) {
    return favicons->GetFaviconDataForPage(uri, callback, 0);
  }
  return favicons->GetFaviconURLForPage(uri, callback, 0);
#else
  return NS_ERROR_NOT_IMPLEMENTED;
#endif  // !MOZ_PLACES
}

nsresult ShowWithBackend(nsIAlertsService* aBackend,
                         nsIAlertNotification* aAlert,
                         nsIObserver* aAlertListener,
                         const nsAString& aPersistentData) {
  if (!aPersistentData.IsEmpty()) {
    return aBackend->ShowPersistentNotification(aPersistentData, aAlert,
                                                aAlertListener);
  }

  if (Preferences::GetBool("alerts.showFavicons")) {
    nsresult rv = ShowWithIconBackend(aBackend, aAlert, aAlertListener);
    if (NS_SUCCEEDED(rv)) {
      return rv;
    }
  }

  // If favicons are disabled, or the backend doesn't support them, show the
  // alert without one.
  return aBackend->ShowAlert(aAlert, aAlertListener);
}

}  // anonymous namespace

NS_IMPL_ISUPPORTS(nsAlertsService, nsIAlertsService, nsIAlertsDoNotDisturb)

nsAlertsService::nsAlertsService() : mBackend(nullptr) {
  mBackend = do_GetService(NS_SYSTEMALERTSERVICE_CONTRACTID);
}

nsAlertsService::~nsAlertsService() = default;

bool nsAlertsService::ShouldShowAlert() {
  bool result = true;

#ifdef XP_WIN
  if (!xpc::IsInAutomation()) {
    QUERY_USER_NOTIFICATION_STATE qstate;
    if (SUCCEEDED(SHQueryUserNotificationState(&qstate))) {
      if (qstate != QUNS_ACCEPTS_NOTIFICATIONS) {
        result = false;
      }
    }
  }
#endif

  nsCOMPtr<nsIAlertsDoNotDisturb> alertsDND(GetDNDBackend());
  if (alertsDND) {
    bool suppressForScreenSharing = false;
    nsresult rv =
        alertsDND->GetSuppressForScreenSharing(&suppressForScreenSharing);
    if (NS_SUCCEEDED(rv)) {
      result &= !suppressForScreenSharing;
    }
  }

  return result;
}

bool nsAlertsService::ShouldUseSystemBackend() {
  if (!mBackend) {
    return false;
  }
  return StaticPrefs::alerts_useSystemBackend();
}

NS_IMETHODIMP nsAlertsService::ShowAlertNotification(
    const nsAString& aImageUrl, const nsAString& aAlertTitle,
    const nsAString& aAlertText, bool aAlertTextClickable,
    const nsAString& aAlertCookie, nsIObserver* aAlertListener,
    const nsAString& aAlertName, const nsAString& aBidi, const nsAString& aLang,
    const nsAString& aData, nsIPrincipal* aPrincipal, bool aInPrivateBrowsing,
    bool aRequireInteraction) {
  nsCOMPtr<nsIAlertNotification> alert =
      do_CreateInstance(ALERT_NOTIFICATION_CONTRACTID);
  NS_ENSURE_TRUE(alert, NS_ERROR_FAILURE);
  // vibrate is unused
  nsTArray<uint32_t> vibrate;
  nsresult rv = alert->Init(aAlertName, aImageUrl, aAlertTitle, aAlertText,
                            aAlertTextClickable, aAlertCookie, aBidi, aLang,
                            aData, aPrincipal, aInPrivateBrowsing,
                            aRequireInteraction, false, vibrate);
  NS_ENSURE_SUCCESS(rv, rv);
  return ShowAlert(alert, aAlertListener);
}

NS_IMETHODIMP nsAlertsService::ShowAlert(nsIAlertNotification* aAlert,
                                         nsIObserver* aAlertListener) {
  return ShowPersistentNotification(u""_ns, aAlert, aAlertListener);
}

static bool ShouldFallBackToXUL() {
#if defined(XP_WIN) || defined(XP_MACOSX)
  // We know we always have system backend on Windows and macOS. Let's not
  // permanently fall back to XUL just because of temporary failure.
  return false;
#else
  // The system may not have the notification library, we should fall back to
  // XUL.
  return true;
#endif
}

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 (ShouldUseSystemBackend()) {
    rv = ShowWithBackend(mBackend, aAlert, aAlertListener, aPersistentData);
    if (NS_SUCCEEDED(rv) || !ShouldFallBackToXUL()) {
      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::CloseAlert(const nsAString& aAlertName,
                                          bool aContextClosed) {
  if (XRE_IsContentProcess()) {
    ContentChild* cpc = ContentChild::GetSingleton();
    cpc->SendCloseAlert(nsAutoString(aAlertName), aContextClosed);
    return NS_OK;
  }

  nsresult rv;
  // Try the system notification service.
  if (ShouldUseSystemBackend()) {
    rv = mBackend->CloseAlert(aAlertName, aContextClosed);
    if (NS_WARN_IF(NS_FAILED(rv)) && ShouldFallBackToXUL()) {
      // If the system backend failed to close the alert, fall back to XUL for
      // future alerts.
      mBackend = nullptr;
    }
  } else {
    nsCOMPtr<nsIAlertsService> xulBackend(nsXULAlerts::GetInstance());
    NS_ENSURE_TRUE(xulBackend, NS_ERROR_FAILURE);
    rv = xulBackend->CloseAlert(aAlertName, aContextClosed);
  }
  return rv;
}

// nsIAlertsDoNotDisturb
NS_IMETHODIMP nsAlertsService::GetManualDoNotDisturb(bool* aRetVal) {
#ifdef MOZ_WIDGET_ANDROID
  return NS_ERROR_NOT_IMPLEMENTED;
#else
  nsCOMPtr<nsIAlertsDoNotDisturb> alertsDND(GetDNDBackend());
  NS_ENSURE_TRUE(alertsDND, NS_ERROR_NOT_IMPLEMENTED);
  return alertsDND->GetManualDoNotDisturb(aRetVal);
#endif
}

NS_IMETHODIMP nsAlertsService::SetManualDoNotDisturb(bool aDoNotDisturb) {
#ifdef MOZ_WIDGET_ANDROID
  return NS_ERROR_NOT_IMPLEMENTED;
#else
  nsCOMPtr<nsIAlertsDoNotDisturb> alertsDND(GetDNDBackend());
  NS_ENSURE_TRUE(alertsDND, NS_ERROR_NOT_IMPLEMENTED);

  nsresult rv = alertsDND->SetManualDoNotDisturb(aDoNotDisturb);
  if (NS_SUCCEEDED(rv)) {
    Telemetry::Accumulate(Telemetry::ALERTS_SERVICE_DND_ENABLED, 1);
  }
  return rv;
#endif
}

NS_IMETHODIMP nsAlertsService::GetSuppressForScreenSharing(bool* aRetVal) {
#ifdef MOZ_WIDGET_ANDROID
  return NS_ERROR_NOT_IMPLEMENTED;
#else
  nsCOMPtr<nsIAlertsDoNotDisturb> alertsDND(GetDNDBackend());
  NS_ENSURE_TRUE(alertsDND, NS_ERROR_NOT_IMPLEMENTED);
  return alertsDND->GetSuppressForScreenSharing(aRetVal);
#endif
}

NS_IMETHODIMP nsAlertsService::SetSuppressForScreenSharing(bool aSuppress) {
#ifdef MOZ_WIDGET_ANDROID
  return NS_ERROR_NOT_IMPLEMENTED;
#else
  nsCOMPtr<nsIAlertsDoNotDisturb> alertsDND(GetDNDBackend());
  NS_ENSURE_TRUE(alertsDND, NS_ERROR_NOT_IMPLEMENTED);
  return alertsDND->SetSuppressForScreenSharing(aSuppress);
#endif
}

already_AddRefed<nsIAlertsDoNotDisturb> nsAlertsService::GetDNDBackend() {
  nsCOMPtr<nsIAlertsService> backend;
  // Try the system notification service.
  if (ShouldUseSystemBackend()) {
    backend = mBackend;
  }
  if (!backend) {
    backend = nsXULAlerts::GetInstance();
  }

  nsCOMPtr<nsIAlertsDoNotDisturb> alertsDND(do_QueryInterface(backend));
  return alertsDND.forget();
}