/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set sw=2 ts=8 et ft=cpp : */
/* 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 "Hal.h"

#include "HalImpl.h"
#include "HalLog.h"
#include "HalSandbox.h"
#include "nsIDOMDocument.h"
#include "nsIDOMWindow.h"
#include "nsIDocument.h"
#include "nsIDocShell.h"
#include "nsITabChild.h"
#include "nsIWebNavigation.h"
#include "nsThreadUtils.h"
#include "nsXULAppAPI.h"
#include "nsPIDOMWindow.h"
#include "nsJSUtils.h"
#include "mozilla/ClearOnShutdown.h"
#include "mozilla/Observer.h"
#include "mozilla/dom/ContentChild.h"
#include "mozilla/dom/ScreenOrientation.h"
#include "WindowIdentifier.h"

#ifdef XP_WIN
#include <process.h>
#define getpid _getpid
#endif

using namespace mozilla::services;
using namespace mozilla::dom;

#define PROXY_IF_SANDBOXED(_call)              \
  do {                                         \
    if (InSandbox()) {                         \
      if (!hal_sandbox::HalChildDestroyed()) { \
        hal_sandbox::_call;                    \
      }                                        \
    } else {                                   \
      hal_impl::_call;                         \
    }                                          \
  } while (0)

#define RETURN_PROXY_IF_SANDBOXED(_call, defValue) \
  do {                                             \
    if (InSandbox()) {                             \
      if (hal_sandbox::HalChildDestroyed()) {      \
        return defValue;                           \
      }                                            \
      return hal_sandbox::_call;                   \
    } else {                                       \
      return hal_impl::_call;                      \
    }                                              \
  } while (0)

namespace mozilla {
namespace hal {

mozilla::LogModule* GetHalLog() {
  static mozilla::LazyLogModule sHalLog("hal");
  return sHalLog;
}

namespace {

void AssertMainThread() { MOZ_ASSERT(NS_IsMainThread()); }

bool InSandbox() { return GeckoProcessType_Content == XRE_GetProcessType(); }

void AssertMainProcess() {
  MOZ_ASSERT(GeckoProcessType_Default == XRE_GetProcessType());
}

bool WindowIsActive(nsPIDOMWindowInner* aWindow) {
  nsIDocument* document = aWindow->GetDoc();
  NS_ENSURE_TRUE(document, false);

  return !document->Hidden();
}

StaticAutoPtr<WindowIdentifier::IDArrayType> gLastIDToVibrate;

void InitLastIDToVibrate() {
  gLastIDToVibrate = new WindowIdentifier::IDArrayType();
  ClearOnShutdown(&gLastIDToVibrate);
}

}  // namespace

void Vibrate(const nsTArray<uint32_t>& pattern, nsPIDOMWindowInner* window) {
  Vibrate(pattern, WindowIdentifier(window));
}

void Vibrate(const nsTArray<uint32_t>& pattern, const WindowIdentifier& id) {
  AssertMainThread();

  // Only active windows may start vibrations.  If |id| hasn't gone
  // through the IPC layer -- that is, if our caller is the outside
  // world, not hal_proxy -- check whether the window is active.  If
  // |id| has gone through IPC, don't check the window's visibility;
  // only the window corresponding to the bottommost process has its
  // visibility state set correctly.
  if (!id.HasTraveledThroughIPC() && !WindowIsActive(id.GetWindow())) {
    HAL_LOG("Vibrate: Window is inactive, dropping vibrate.");
    return;
  }

  if (!InSandbox()) {
    if (!gLastIDToVibrate) {
      InitLastIDToVibrate();
    }
    *gLastIDToVibrate = id.AsArray();
  }

  // Don't forward our ID if we are not in the sandbox, because hal_impl
  // doesn't need it, and we don't want it to be tempted to read it.  The
  // empty identifier will assert if it's used.
  PROXY_IF_SANDBOXED(Vibrate(pattern, InSandbox() ? id : WindowIdentifier()));
}

void CancelVibrate(nsPIDOMWindowInner* window) {
  CancelVibrate(WindowIdentifier(window));
}

void CancelVibrate(const WindowIdentifier& id) {
  AssertMainThread();

  // Although only active windows may start vibrations, a window may
  // cancel its own vibration even if it's no longer active.
  //
  // After a window is marked as inactive, it sends a CancelVibrate
  // request.  We want this request to cancel a playing vibration
  // started by that window, so we certainly don't want to reject the
  // cancellation request because the window is now inactive.
  //
  // But it could be the case that, after this window became inactive,
  // some other window came along and started a vibration.  We don't
  // want this window's cancellation request to cancel that window's
  // actively-playing vibration!
  //
  // To solve this problem, we keep track of the id of the last window
  // to start a vibration, and only accepts cancellation requests from
  // the same window.  All other cancellation requests are ignored.

  if (InSandbox() || (gLastIDToVibrate && *gLastIDToVibrate == id.AsArray())) {
    // Don't forward our ID if we are not in the sandbox, because hal_impl
    // doesn't need it, and we don't want it to be tempted to read it.  The
    // empty identifier will assert if it's used.
    PROXY_IF_SANDBOXED(CancelVibrate(InSandbox() ? id : WindowIdentifier()));
  }
}

template <class InfoType>
class ObserversManager {
 public:
  void AddObserver(Observer<InfoType>* aObserver) {
    if (!mObservers) {
      mObservers = new mozilla::ObserverList<InfoType>();
    }

    mObservers->AddObserver(aObserver);

    if (mObservers->Length() == 1) {
      EnableNotifications();
    }
  }

  void RemoveObserver(Observer<InfoType>* aObserver) {
    bool removed = mObservers && mObservers->RemoveObserver(aObserver);
    if (!removed) {
      return;
    }

    if (mObservers->Length() == 0) {
      DisableNotifications();

      OnNotificationsDisabled();

      delete mObservers;
      mObservers = nullptr;
    }
  }

  void BroadcastInformation(const InfoType& aInfo) {
    // It is possible for mObservers to be nullptr here on some platforms,
    // because a call to BroadcastInformation gets queued up asynchronously
    // while RemoveObserver is running (and before the notifications are
    // disabled). The queued call can then get run after mObservers has
    // been nulled out. See bug 757025.
    if (!mObservers) {
      return;
    }
    mObservers->Broadcast(aInfo);
  }

 protected:
  virtual void EnableNotifications() = 0;
  virtual void DisableNotifications() = 0;
  virtual void OnNotificationsDisabled() {}

 private:
  mozilla::ObserverList<InfoType>* mObservers;
};

template <class InfoType>
class CachingObserversManager : public ObserversManager<InfoType> {
 public:
  InfoType GetCurrentInformation() {
    if (mHasValidCache) {
      return mInfo;
    }

    GetCurrentInformationInternal(&mInfo);
    mHasValidCache = true;
    return mInfo;
  }

  void CacheInformation(const InfoType& aInfo) {
    mHasValidCache = true;
    mInfo = aInfo;
  }

  void BroadcastCachedInformation() { this->BroadcastInformation(mInfo); }

 protected:
  virtual void GetCurrentInformationInternal(InfoType*) = 0;

  void OnNotificationsDisabled() override { mHasValidCache = false; }

 private:
  InfoType mInfo;
  bool mHasValidCache;
};

class BatteryObserversManager
    : public CachingObserversManager<BatteryInformation> {
 protected:
  void EnableNotifications() override {
    PROXY_IF_SANDBOXED(EnableBatteryNotifications());
  }

  void DisableNotifications() override {
    PROXY_IF_SANDBOXED(DisableBatteryNotifications());
  }

  void GetCurrentInformationInternal(BatteryInformation* aInfo) override {
    PROXY_IF_SANDBOXED(GetCurrentBatteryInformation(aInfo));
  }
};

static BatteryObserversManager& BatteryObservers() {
  static BatteryObserversManager sBatteryObservers;
  AssertMainThread();
  return sBatteryObservers;
}

class NetworkObserversManager
    : public CachingObserversManager<NetworkInformation> {
 protected:
  void EnableNotifications() override {
    PROXY_IF_SANDBOXED(EnableNetworkNotifications());
  }

  void DisableNotifications() override {
    PROXY_IF_SANDBOXED(DisableNetworkNotifications());
  }

  void GetCurrentInformationInternal(NetworkInformation* aInfo) override {
    PROXY_IF_SANDBOXED(GetCurrentNetworkInformation(aInfo));
  }
};

static NetworkObserversManager& NetworkObservers() {
  static NetworkObserversManager sNetworkObservers;
  AssertMainThread();
  return sNetworkObservers;
}

class WakeLockObserversManager : public ObserversManager<WakeLockInformation> {
 protected:
  void EnableNotifications() override {
    PROXY_IF_SANDBOXED(EnableWakeLockNotifications());
  }

  void DisableNotifications() override {
    PROXY_IF_SANDBOXED(DisableWakeLockNotifications());
  }
};

static WakeLockObserversManager& WakeLockObservers() {
  static WakeLockObserversManager sWakeLockObservers;
  AssertMainThread();
  return sWakeLockObservers;
}

class ScreenConfigurationObserversManager
    : public CachingObserversManager<ScreenConfiguration> {
 protected:
  void EnableNotifications() override {
    PROXY_IF_SANDBOXED(EnableScreenConfigurationNotifications());
  }

  void DisableNotifications() override {
    PROXY_IF_SANDBOXED(DisableScreenConfigurationNotifications());
  }

  void GetCurrentInformationInternal(ScreenConfiguration* aInfo) override {
    PROXY_IF_SANDBOXED(GetCurrentScreenConfiguration(aInfo));
  }
};

static ScreenConfigurationObserversManager& ScreenConfigurationObservers() {
  AssertMainThread();
  static ScreenConfigurationObserversManager sScreenConfigurationObservers;
  return sScreenConfigurationObservers;
}

void RegisterBatteryObserver(BatteryObserver* aObserver) {
  AssertMainThread();
  BatteryObservers().AddObserver(aObserver);
}

void UnregisterBatteryObserver(BatteryObserver* aObserver) {
  AssertMainThread();
  BatteryObservers().RemoveObserver(aObserver);
}

void GetCurrentBatteryInformation(BatteryInformation* aInfo) {
  AssertMainThread();
  *aInfo = BatteryObservers().GetCurrentInformation();
}

void NotifyBatteryChange(const BatteryInformation& aInfo) {
  AssertMainThread();
  BatteryObservers().CacheInformation(aInfo);
  BatteryObservers().BroadcastCachedInformation();
}

class SystemClockChangeObserversManager : public ObserversManager<int64_t> {
 protected:
  void EnableNotifications() override {
    PROXY_IF_SANDBOXED(EnableSystemClockChangeNotifications());
  }

  void DisableNotifications() override {
    PROXY_IF_SANDBOXED(DisableSystemClockChangeNotifications());
  }
};

static SystemClockChangeObserversManager& SystemClockChangeObservers() {
  static SystemClockChangeObserversManager sSystemClockChangeObservers;
  AssertMainThread();
  return sSystemClockChangeObservers;
}

void RegisterSystemClockChangeObserver(SystemClockChangeObserver* aObserver) {
  AssertMainThread();
  SystemClockChangeObservers().AddObserver(aObserver);
}

void UnregisterSystemClockChangeObserver(SystemClockChangeObserver* aObserver) {
  AssertMainThread();
  SystemClockChangeObservers().RemoveObserver(aObserver);
}

void NotifySystemClockChange(const int64_t& aClockDeltaMS) {
  SystemClockChangeObservers().BroadcastInformation(aClockDeltaMS);
}

class SystemTimezoneChangeObserversManager
    : public ObserversManager<SystemTimezoneChangeInformation> {
 protected:
  void EnableNotifications() override {
    PROXY_IF_SANDBOXED(EnableSystemTimezoneChangeNotifications());
  }

  void DisableNotifications() override {
    PROXY_IF_SANDBOXED(DisableSystemTimezoneChangeNotifications());
  }
};

static SystemTimezoneChangeObserversManager& SystemTimezoneChangeObservers() {
  static SystemTimezoneChangeObserversManager sSystemTimezoneChangeObservers;
  return sSystemTimezoneChangeObservers;
}

void RegisterSystemTimezoneChangeObserver(
    SystemTimezoneChangeObserver* aObserver) {
  AssertMainThread();
  SystemTimezoneChangeObservers().AddObserver(aObserver);
}

void UnregisterSystemTimezoneChangeObserver(
    SystemTimezoneChangeObserver* aObserver) {
  AssertMainThread();
  SystemTimezoneChangeObservers().RemoveObserver(aObserver);
}

void NotifySystemTimezoneChange(
    const SystemTimezoneChangeInformation& aSystemTimezoneChangeInfo) {
  nsJSUtils::ResetTimeZone();
  SystemTimezoneChangeObservers().BroadcastInformation(
      aSystemTimezoneChangeInfo);
}

void AdjustSystemClock(int64_t aDeltaMilliseconds) {
  AssertMainThread();
  PROXY_IF_SANDBOXED(AdjustSystemClock(aDeltaMilliseconds));
}

void EnableSensorNotifications(SensorType aSensor) {
  AssertMainThread();
  PROXY_IF_SANDBOXED(EnableSensorNotifications(aSensor));
}

void DisableSensorNotifications(SensorType aSensor) {
  AssertMainThread();
  PROXY_IF_SANDBOXED(DisableSensorNotifications(aSensor));
}

typedef mozilla::ObserverList<SensorData> SensorObserverList;
static SensorObserverList* gSensorObservers = nullptr;

static SensorObserverList& GetSensorObservers(SensorType sensor_type) {
  MOZ_ASSERT(sensor_type < NUM_SENSOR_TYPE);

  if (!gSensorObservers) {
    gSensorObservers = new SensorObserverList[NUM_SENSOR_TYPE];
  }
  return gSensorObservers[sensor_type];
}

void RegisterSensorObserver(SensorType aSensor, ISensorObserver* aObserver) {
  SensorObserverList& observers = GetSensorObservers(aSensor);

  AssertMainThread();

  observers.AddObserver(aObserver);
  if (observers.Length() == 1) {
    EnableSensorNotifications(aSensor);
  }
}

void UnregisterSensorObserver(SensorType aSensor, ISensorObserver* aObserver) {
  AssertMainThread();

  if (!gSensorObservers) {
    HAL_ERR("Un-registering a sensor when none have been registered");
    return;
  }

  SensorObserverList& observers = GetSensorObservers(aSensor);
  if (!observers.RemoveObserver(aObserver) || observers.Length() > 0) {
    return;
  }
  DisableSensorNotifications(aSensor);

  for (int i = 0; i < NUM_SENSOR_TYPE; i++) {
    if (gSensorObservers[i].Length() > 0) {
      return;
    }
  }

  // We want to destroy gSensorObservers if all observer lists are
  // empty, but we have to defer the deallocation via a runnable to
  // mainthread (since we may be inside NotifySensorChange()/Broadcast()
  // when it calls UnregisterSensorObserver()).
  SensorObserverList* sensorlists = gSensorObservers;
  gSensorObservers = nullptr;

  // Unlike DispatchToMainThread, DispatchToCurrentThread doesn't leak a
  // runnable if it fails (and we assert we're on MainThread).
  if (NS_FAILED(NS_DispatchToCurrentThread(NS_NewRunnableFunction(
          "UnregisterSensorObserver",
          [sensorlists]() -> void { delete[] sensorlists; })))) {
    // Still need to delete sensorlists if the dispatch fails
    delete[] sensorlists;
  }
}

void NotifySensorChange(const SensorData& aSensorData) {
  SensorObserverList& observers = GetSensorObservers(aSensorData.sensor());

  AssertMainThread();

  observers.Broadcast(aSensorData);
}

void RegisterNetworkObserver(NetworkObserver* aObserver) {
  AssertMainThread();
  NetworkObservers().AddObserver(aObserver);
}

void UnregisterNetworkObserver(NetworkObserver* aObserver) {
  AssertMainThread();
  NetworkObservers().RemoveObserver(aObserver);
}

void GetCurrentNetworkInformation(NetworkInformation* aInfo) {
  AssertMainThread();
  *aInfo = NetworkObservers().GetCurrentInformation();
}

void NotifyNetworkChange(const NetworkInformation& aInfo) {
  NetworkObservers().CacheInformation(aInfo);
  NetworkObservers().BroadcastCachedInformation();
}

void RegisterWakeLockObserver(WakeLockObserver* aObserver) {
  AssertMainThread();
  WakeLockObservers().AddObserver(aObserver);
}

void UnregisterWakeLockObserver(WakeLockObserver* aObserver) {
  AssertMainThread();
  WakeLockObservers().RemoveObserver(aObserver);
}

void ModifyWakeLock(const nsAString& aTopic, WakeLockControl aLockAdjust,
                    WakeLockControl aHiddenAdjust,
                    uint64_t aProcessID /* = CONTENT_PROCESS_ID_UNKNOWN */) {
  AssertMainThread();

  if (aProcessID == CONTENT_PROCESS_ID_UNKNOWN) {
    aProcessID = InSandbox() ? ContentChild::GetSingleton()->GetID()
                             : CONTENT_PROCESS_ID_MAIN;
  }

  PROXY_IF_SANDBOXED(
      ModifyWakeLock(aTopic, aLockAdjust, aHiddenAdjust, aProcessID));
}

void GetWakeLockInfo(const nsAString& aTopic,
                     WakeLockInformation* aWakeLockInfo) {
  AssertMainThread();
  PROXY_IF_SANDBOXED(GetWakeLockInfo(aTopic, aWakeLockInfo));
}

void NotifyWakeLockChange(const WakeLockInformation& aInfo) {
  AssertMainThread();
  WakeLockObservers().BroadcastInformation(aInfo);
}

void RegisterScreenConfigurationObserver(
    ScreenConfigurationObserver* aObserver) {
  AssertMainThread();
  ScreenConfigurationObservers().AddObserver(aObserver);
}

void UnregisterScreenConfigurationObserver(
    ScreenConfigurationObserver* aObserver) {
  AssertMainThread();
  ScreenConfigurationObservers().RemoveObserver(aObserver);
}

void GetCurrentScreenConfiguration(ScreenConfiguration* aScreenConfiguration) {
  AssertMainThread();
  *aScreenConfiguration =
      ScreenConfigurationObservers().GetCurrentInformation();
}

void NotifyScreenConfigurationChange(
    const ScreenConfiguration& aScreenConfiguration) {
  ScreenConfigurationObservers().CacheInformation(aScreenConfiguration);
  ScreenConfigurationObservers().BroadcastCachedInformation();
}

bool LockScreenOrientation(const dom::ScreenOrientationInternal& aOrientation) {
  AssertMainThread();
  RETURN_PROXY_IF_SANDBOXED(LockScreenOrientation(aOrientation), false);
}

void UnlockScreenOrientation() {
  AssertMainThread();
  PROXY_IF_SANDBOXED(UnlockScreenOrientation());
}

bool SetProcessPrioritySupported() {
  RETURN_PROXY_IF_SANDBOXED(SetProcessPrioritySupported(), false);
}

void SetProcessPriority(int aPid, ProcessPriority aPriority) {
  // n.b. The sandboxed implementation crashes; SetProcessPriority works only
  // from the main process.
  PROXY_IF_SANDBOXED(SetProcessPriority(aPid, aPriority));
}

void SetCurrentThreadPriority(hal::ThreadPriority aThreadPriority) {
  PROXY_IF_SANDBOXED(SetCurrentThreadPriority(aThreadPriority));
}

void SetThreadPriority(PlatformThreadId aThreadId,
                       hal::ThreadPriority aThreadPriority) {
  PROXY_IF_SANDBOXED(SetThreadPriority(aThreadId, aThreadPriority));
}

// From HalTypes.h.
const char* ProcessPriorityToString(ProcessPriority aPriority) {
  switch (aPriority) {
    case PROCESS_PRIORITY_MASTER:
      return "MASTER";
    case PROCESS_PRIORITY_PREALLOC:
      return "PREALLOC";
    case PROCESS_PRIORITY_FOREGROUND_HIGH:
      return "FOREGROUND_HIGH";
    case PROCESS_PRIORITY_FOREGROUND:
      return "FOREGROUND";
    case PROCESS_PRIORITY_FOREGROUND_KEYBOARD:
      return "FOREGROUND_KEYBOARD";
    case PROCESS_PRIORITY_BACKGROUND_PERCEIVABLE:
      return "BACKGROUND_PERCEIVABLE";
    case PROCESS_PRIORITY_BACKGROUND:
      return "BACKGROUND";
    case PROCESS_PRIORITY_UNKNOWN:
      return "UNKNOWN";
    default:
      MOZ_ASSERT(false);
      return "???";
  }
}

const char* ThreadPriorityToString(ThreadPriority aPriority) {
  switch (aPriority) {
    case THREAD_PRIORITY_COMPOSITOR:
      return "COMPOSITOR";
    default:
      MOZ_ASSERT(false);
      return "???";
  }
}

void StartDiskSpaceWatcher() {
  AssertMainProcess();
  AssertMainThread();
  PROXY_IF_SANDBOXED(StartDiskSpaceWatcher());
}

void StopDiskSpaceWatcher() {
  AssertMainProcess();
  AssertMainThread();
  PROXY_IF_SANDBOXED(StopDiskSpaceWatcher());
}

}  // namespace hal
}  // namespace mozilla