/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* 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 "VRDisplayHost.h"
#include "gfxPrefs.h"
#include "gfxVR.h"
#include "ipc/VRLayerParent.h"
#include "mozilla/layers/TextureHost.h"
#include "mozilla/dom/GamepadBinding.h" // For GamepadMappingType
#include "VRThread.h"

#if defined(XP_WIN)

#include <d3d11.h>
#include "gfxWindowsPlatform.h"
#include "../layers/d3d11/CompositorD3D11.h"
#include "mozilla/gfx/DeviceManagerDx.h"
#include "mozilla/layers/TextureD3D11.h"

#elif defined(XP_MACOSX)

#include "mozilla/gfx/MacIOSurface.h"

#endif

#if defined(MOZ_WIDGET_ANDROID)
#include "mozilla/layers/CompositorThread.h"
#endif // defined(MOZ_WIDGET_ANDROID)


using namespace mozilla;
using namespace mozilla::gfx;
using namespace mozilla::layers;

VRDisplayHost::AutoRestoreRenderState::AutoRestoreRenderState(VRDisplayHost* aDisplay)
  : mDisplay(aDisplay)
  , mSuccess(true)
{
#if defined(XP_WIN)
  ID3D11DeviceContext1* context = mDisplay->GetD3DDeviceContext();
  ID3DDeviceContextState* state = mDisplay->GetD3DDeviceContextState();
  if (!context || !state) {
    mSuccess = false;
    return;
  }
  context->SwapDeviceContextState(state, getter_AddRefs(mPrevDeviceContextState));
#endif
}

VRDisplayHost::AutoRestoreRenderState::~AutoRestoreRenderState()
{
#if defined(XP_WIN)
  ID3D11DeviceContext1* context = mDisplay->GetD3DDeviceContext();
  if (context && mSuccess) {
    context->SwapDeviceContextState(mPrevDeviceContextState, nullptr);
  }
#endif
}

bool
VRDisplayHost::AutoRestoreRenderState::IsSuccess()
{
  return mSuccess;
}

VRDisplayHost::VRDisplayHost(VRDeviceType aType)
 : mDisplayInfo{}
 , mLastUpdateDisplayInfo{}
 , mFrameStarted(false)
{
  MOZ_COUNT_CTOR(VRDisplayHost);
  mDisplayInfo.mType = aType;
  mDisplayInfo.mDisplayID = VRSystemManager::AllocateDisplayID();
  mDisplayInfo.mPresentingGroups = 0;
  mDisplayInfo.mGroupMask = kVRGroupContent;
  mDisplayInfo.mFrameId = 0;
  mDisplayInfo.mDisplayState.mPresentingGeneration = 0;
  mDisplayInfo.mDisplayState.mDisplayName[0] = '\0';
}

VRDisplayHost::~VRDisplayHost()
{
  if (mSubmitThread) {
    mSubmitThread->Shutdown();
    mSubmitThread = nullptr;
  }
  MOZ_COUNT_DTOR(VRDisplayHost);
}

#if defined(XP_WIN)
bool
VRDisplayHost::CreateD3DObjects()
{
  if (!mDevice) {
    RefPtr<ID3D11Device> device = gfx::DeviceManagerDx::Get()->GetVRDevice();
    if (!device) {
      NS_WARNING("VRDisplayHost::CreateD3DObjects failed to get a D3D11Device");
      return false;
    }
    if (FAILED(device->QueryInterface(__uuidof(ID3D11Device1), getter_AddRefs(mDevice)))) {
      NS_WARNING("VRDisplayHost::CreateD3DObjects failed to get a D3D11Device1");
      return false;
    }
  }
  if (!mContext) {
    mDevice->GetImmediateContext1(getter_AddRefs(mContext));
    if (!mContext) {
      NS_WARNING("VRDisplayHost::CreateD3DObjects failed to get an immediate context");
      return false;
    }
  }
  if (!mDeviceContextState) {
    D3D_FEATURE_LEVEL featureLevels[] {
      D3D_FEATURE_LEVEL_11_1,
      D3D_FEATURE_LEVEL_11_0
    };
    mDevice->CreateDeviceContextState(0,
                                      featureLevels,
                                      2,
                                      D3D11_SDK_VERSION,
                                      __uuidof(ID3D11Device1),
                                      nullptr,
                                      getter_AddRefs(mDeviceContextState));
  }
  if (!mDeviceContextState) {
    NS_WARNING("VRDisplayHost::CreateD3DObjects failed to get a D3D11DeviceContextState");
    return false;
  }
  return true;
}

ID3D11Device1*
VRDisplayHost::GetD3DDevice()
{
  return mDevice;
}

ID3D11DeviceContext1*
VRDisplayHost::GetD3DDeviceContext()
{
  return mContext;
}

ID3DDeviceContextState*
VRDisplayHost::GetD3DDeviceContextState()
{
  return mDeviceContextState;
}

#endif // defined(XP_WIN)

void
VRDisplayHost::SetGroupMask(uint32_t aGroupMask)
{
  mDisplayInfo.mGroupMask = aGroupMask;
}

bool
VRDisplayHost::GetIsConnected()
{
  return mDisplayInfo.mDisplayState.mIsConnected;
}

void
VRDisplayHost::AddLayer(VRLayerParent *aLayer)
{
  mLayers.AppendElement(aLayer);
  mDisplayInfo.mPresentingGroups |= aLayer->GetGroup();
  if (mLayers.Length() == 1) {
    StartPresentation();
  }

  // Ensure that the content process receives the change immediately
  VRManager* vm = VRManager::Get();
  vm->RefreshVRDisplays();
}

void
VRDisplayHost::RemoveLayer(VRLayerParent *aLayer)
{
  mLayers.RemoveElement(aLayer);
  if (mLayers.Length() == 0) {
    StopPresentation();
  }
  mDisplayInfo.mPresentingGroups = 0;
  for (auto layer : mLayers) {
    mDisplayInfo.mPresentingGroups |= layer->GetGroup();
  }

  // Ensure that the content process receives the change immediately
  VRManager* vm = VRManager::Get();
  vm->RefreshVRDisplays();
}

void
VRDisplayHost::StartFrame()
{
  AUTO_PROFILER_TRACING("VR", "GetSensorState");

  mLastFrameStart = TimeStamp::Now();
  ++mDisplayInfo.mFrameId;
  mDisplayInfo.mLastSensorState[mDisplayInfo.mFrameId % kVRMaxLatencyFrames] = GetSensorState();
  mFrameStarted = true;
}

void
VRDisplayHost::NotifyVSync()
{
  /**
   * We will trigger a new frame immediately after a successful frame texture
   * submission.  If content fails to call VRDisplay.submitFrame after
   * dom.vr.display.rafMaxDuration milliseconds has elapsed since the last
   * VRDisplay.requestAnimationFrame, we act as a "watchdog" and kick-off
   * a new VRDisplay.requestAnimationFrame to avoid a render loop stall and
   * to give content a chance to recover.
   *
   * If the lower level VR platform API's are rejecting submitted frames,
   * such as when the Oculus "Health and Safety Warning" is displayed,
   * we will not kick off the next frame immediately after VRDisplay.submitFrame
   * as it would result in an unthrottled render loop that would free run at
   * potentially extreme frame rates.  To ensure that content has a chance to
   * resume its presentation when the frames are accepted once again, we rely
   * on this "watchdog" to act as a VR refresh driver cycling at a rate defined
   * by dom.vr.display.rafMaxDuration.
   *
   * This number must be larger than the slowest expected frame time during
   * normal VR presentation, but small enough not to break content that
   * makes assumptions of reasonably minimal VSync rate.
   *
   * The slowest expected refresh rate for a VR display currently is an
   * Oculus CV1 when ASW (Asynchronous Space Warp) is enabled, at 45hz.
   * A dom.vr.display.rafMaxDuration value of 50 milliseconds results in a 20hz
   * rate, which avoids inadvertent triggering of the watchdog during
   * Oculus ASW even if every second frame is dropped.
   */
  bool bShouldStartFrame = false;

  if (mDisplayInfo.mPresentingGroups == 0) {
    // If this display isn't presenting, refresh the sensors and trigger
    // VRDisplay.requestAnimationFrame at the normal 2d display refresh rate.
    bShouldStartFrame = true;
  } else {
    // If content fails to call VRDisplay.submitFrame, we must eventually
    // time-out and trigger a new frame.
    if (mLastFrameStart.IsNull()) {
      bShouldStartFrame = true;
    } else {
      TimeDuration duration = TimeStamp::Now() - mLastFrameStart;
      if (duration.ToMilliseconds() > gfxPrefs::VRDisplayRafMaxDuration()) {
        bShouldStartFrame = true;
      }
    }
  }

  if (bShouldStartFrame) {
    VRManager *vm = VRManager::Get();
    MOZ_ASSERT(vm);
    vm->NotifyVRVsync(mDisplayInfo.mDisplayID);
  }
}

void
VRDisplayHost::SubmitFrameInternal(const layers::SurfaceDescriptor &aTexture,
                                   uint64_t aFrameId,
                                   const gfx::Rect& aLeftEyeRect,
                                   const gfx::Rect& aRightEyeRect)
{
#if !defined(MOZ_WIDGET_ANDROID)
  MOZ_ASSERT(mSubmitThread->GetThread() == NS_GetCurrentThread());
#endif // !defined(MOZ_WIDGET_ANDROID)
  AUTO_PROFILER_TRACING("VR", "SubmitFrameAtVRDisplayHost");

  if (!SubmitFrame(aTexture, aFrameId, aLeftEyeRect, aRightEyeRect)) {
    return;
  }

#if defined(XP_WIN) || defined(XP_MACOSX) || defined(MOZ_WIDGET_ANDROID)

  /**
   * Trigger the next VSync immediately after we are successfully
   * submitting frames.  As SubmitFrame is responsible for throttling
   * the render loop, if we don't successfully call it, we shouldn't trigger
   * NotifyVRVsync immediately, as it will run unbounded.
   * If NotifyVRVsync is not called here due to SubmitFrame failing, the
   * fallback "watchdog" code in VRDisplayHost::NotifyVSync() will cause
   * frames to continue at a lower refresh rate until frame submission
   * succeeds again.
   */
  VRManager* vm = VRManager::Get();
  MessageLoop* loop = VRListenerThreadHolder::Loop();

  loop->PostTask(NewRunnableMethod<const uint32_t>(
    "gfx::VRManager::NotifyVRVsync",
    vm, &VRManager::NotifyVRVsync, mDisplayInfo.mDisplayID
  ));
#endif
}

void
VRDisplayHost::SubmitFrame(VRLayerParent* aLayer,
                           const layers::SurfaceDescriptor &aTexture,
                           uint64_t aFrameId,
                           const gfx::Rect& aLeftEyeRect,
                           const gfx::Rect& aRightEyeRect)
{
  if ((mDisplayInfo.mGroupMask & aLayer->GetGroup()) == 0) {
    // Suppress layers hidden by the group mask
    return;
  }

  // Ensure that we only accept the first SubmitFrame call per RAF cycle.
  if (!mFrameStarted || aFrameId != mDisplayInfo.mFrameId) {
    return;
  }

  mFrameStarted = false;

  RefPtr<Runnable> submit =
    NewRunnableMethod<StoreCopyPassByConstLRef<layers::SurfaceDescriptor>, uint64_t,
      StoreCopyPassByConstLRef<gfx::Rect>, StoreCopyPassByConstLRef<gfx::Rect>>(
      "gfx::VRDisplayHost::SubmitFrameInternal", this, &VRDisplayHost::SubmitFrameInternal,
      aTexture, aFrameId, aLeftEyeRect, aRightEyeRect);

#if !defined(MOZ_WIDGET_ANDROID)
  if (!mSubmitThread) {
    mSubmitThread = new VRThread(NS_LITERAL_CSTRING("VR_SubmitFrame"));
  }
  mSubmitThread->Start();
  mSubmitThread->PostTask(submit.forget());
#else
  CompositorThreadHolder::Loop()->PostTask(submit.forget());
#endif // defined(MOZ_WIDGET_ANDROID)
}

bool
VRDisplayHost::CheckClearDisplayInfoDirty()
{
  if (mDisplayInfo == mLastUpdateDisplayInfo) {
    return false;
  }
  mLastUpdateDisplayInfo = mDisplayInfo;
  return true;
}

VRControllerHost::VRControllerHost(VRDeviceType aType, dom::GamepadHand aHand,
                                   uint32_t aDisplayID)
 : mControllerInfo{}
 , mVibrateIndex(0)
{
  MOZ_COUNT_CTOR(VRControllerHost);
  mControllerInfo.mType = aType;
  mControllerInfo.mControllerState.hand = aHand;
  mControllerInfo.mMappingType = dom::GamepadMappingType::_empty;
  mControllerInfo.mDisplayID = aDisplayID;
  mControllerInfo.mControllerID = VRSystemManager::AllocateControllerID();
}

VRControllerHost::~VRControllerHost()
{
  MOZ_COUNT_DTOR(VRControllerHost);
}

const VRControllerInfo&
VRControllerHost::GetControllerInfo() const
{
  return mControllerInfo;
}

void
VRControllerHost::SetButtonPressed(uint64_t aBit)
{
  mControllerInfo.mControllerState.buttonPressed = aBit;
}

uint64_t
VRControllerHost::GetButtonPressed()
{
  return mControllerInfo.mControllerState.buttonPressed;
}

void
VRControllerHost::SetButtonTouched(uint64_t aBit)
{
  mControllerInfo.mControllerState.buttonTouched = aBit;
}

uint64_t
VRControllerHost::GetButtonTouched()
{
  return mControllerInfo.mControllerState.buttonTouched;
}

void
VRControllerHost::SetPose(const dom::GamepadPoseState& aPose)
{
  mPose = aPose;
}

const dom::GamepadPoseState&
VRControllerHost::GetPose()
{
  return mPose;
}

dom::GamepadHand
VRControllerHost::GetHand()
{
  return mControllerInfo.mControllerState.hand;
}

void
VRControllerHost::SetVibrateIndex(uint64_t aIndex)
{
  mVibrateIndex = aIndex;
}

uint64_t
VRControllerHost::GetVibrateIndex()
{
  return mVibrateIndex;
}