/* -*- 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 "WebRenderLayerManager.h"

#include "apz/src/AsyncPanZoomController.h"
#include "LayersLogging.h"
#include "mozilla/dom/TabChild.h"
#include "mozilla/layers/APZCTreeManager.h"
#include "mozilla/layers/AsyncCompositionManager.h"
#include "mozilla/layers/CompositorBridgeChild.h"
#include "mozilla/layers/TextureClient.h"
#include "mozilla/layers/WebRenderBridgeChild.h"
#include "mozilla/widget/PlatformWidgetTypes.h"
#include "nsThreadUtils.h"
#include "TreeTraversal.h"
#include "WebRenderBorderLayer.h"
#include "WebRenderCanvasLayer.h"
#include "WebRenderColorLayer.h"
#include "WebRenderContainerLayer.h"
#include "WebRenderImageLayer.h"
#include "WebRenderPaintedLayer.h"
#include "WebRenderTextLayer.h"

namespace mozilla {

using namespace gfx;

namespace layers {

WebRenderLayerManager*
WebRenderLayer::WrManager()
{
  return static_cast<WebRenderLayerManager*>(GetLayer()->Manager());
}

WebRenderBridgeChild*
WebRenderLayer::WrBridge()
{
  return WrManager()->WrBridge();
}

Rect
WebRenderLayer::RelativeToVisible(Rect aRect)
{
  IntRect bounds = GetLayer()->GetVisibleRegion().GetBounds().ToUnknownRect();
  aRect.MoveBy(-bounds.x, -bounds.y);
  return aRect;
}

Rect
WebRenderLayer::RelativeToTransformedVisible(Rect aRect)
{
  IntRect bounds = GetLayer()->GetVisibleRegion().GetBounds().ToUnknownRect();
  Rect transformed = GetLayer()->GetTransform().TransformBounds(IntRectToRect(bounds));
  aRect.MoveBy(-transformed.x, -transformed.y);
  return aRect;
}

Rect
WebRenderLayer::ParentStackingContextBounds(size_t aScrollMetadataIndex)
{
  // Walk up to find the parent stacking context. This will be created either
  // by the nearest scrollable metrics, or by the parent layer which must be a
  // ContainerLayer.
  Layer* layer = GetLayer();
  for (size_t i = aScrollMetadataIndex + 1; i < layer->GetScrollMetadataCount(); i++) {
    if (layer->GetFrameMetrics(i).IsScrollable()) {
      return layer->GetFrameMetrics(i).GetCompositionBounds().ToUnknownRect();
    }
  }
  if (layer->GetParent()) {
    return IntRectToRect(layer->GetParent()->GetVisibleRegion().GetBounds().ToUnknownRect());
  }
  return Rect();
}

Rect
WebRenderLayer::RelativeToParent(Rect aRect)
{
  Rect parentBounds = ParentStackingContextBounds(-1);
  aRect.MoveBy(-parentBounds.x, -parentBounds.y);
  return aRect;
}

Rect
WebRenderLayer::TransformedVisibleBoundsRelativeToParent()
{
  IntRect bounds = GetLayer()->GetVisibleRegion().GetBounds().ToUnknownRect();
  Rect transformed = GetLayer()->GetTransform().TransformBounds(IntRectToRect(bounds));
  return RelativeToParent(transformed);
}

Maybe<WrImageMask>
WebRenderLayer::buildMaskLayer() {
  Maybe<WrImageMask> mask = Nothing();
  WrImageMask imageMask;
  Layer* maskLayer = GetLayer()->GetMaskLayer();

  if (maskLayer) {
    RefPtr<SourceSurface> surface = WebRenderLayer::ToWebRenderLayer(maskLayer)->GetAsSourceSurface();
    if (surface) {
      Matrix transform;
      Matrix4x4 effectiveTransform = maskLayer->GetEffectiveTransform();
      DebugOnly<bool> maskIs2D = effectiveTransform.CanDraw2D(&transform);
      NS_ASSERTION(maskIs2D, "How did we end up with a 3D transform here?!");
      //XXX: let's assert that the mask transform is the same as the layer transform
      //transform.PostTranslate(-aDeviceOffset.x, -aDeviceOffset.y);
      {
          RefPtr<DataSourceSurface> dataSurface = surface->GetDataSurface();
          DataSourceSurface::ScopedMap map(dataSurface, DataSourceSurface::MapType::READ);
          gfx::IntSize size = surface->GetSize();
          MOZ_RELEASE_ASSERT(surface->GetFormat() == SurfaceFormat::A8, "bad format");
          wr::ByteBuffer buf(size.height * map.GetStride(), map.GetData());
          wr::ImageKey maskKey;
          WrBridge()->SendAddImage(size, map.GetStride(), SurfaceFormat::A8, buf, &maskKey);

          imageMask.image = maskKey.mHandle;
          imageMask.rect = wr::ToWrRect(Rect(0, 0, size.width, size.height));
          imageMask.repeat = false;
          WrManager()->AddImageKeyForDiscard(maskKey);
          mask = Some(imageMask);
      }
    }
  }
  return mask;
}




WrScrollFrameStackingContextGenerator::WrScrollFrameStackingContextGenerator(
        WebRenderLayer* aLayer)
  : mLayer(aLayer)
{
  Matrix4x4 identity;
  Layer* layer = mLayer->GetLayer();
  for (size_t i = layer->GetScrollMetadataCount(); i > 0; i--) {
    const FrameMetrics& fm = layer->GetFrameMetrics(i - 1);
    if (!fm.IsScrollable()) {
      continue;
    }
    Rect bounds = fm.GetCompositionBounds().ToUnknownRect();
    Rect overflow = (fm.GetExpandedScrollableRect() * fm.LayersPixelsPerCSSPixel()).ToUnknownRect();
    Point scrollPos = (fm.GetScrollOffset() * fm.LayersPixelsPerCSSPixel()).ToUnknownPoint();
    Rect parentBounds = mLayer->ParentStackingContextBounds(i);
    bounds.MoveBy(-parentBounds.x, -parentBounds.y);
    // Subtract the MT scroll position from the overflow here so that the WR
    // scroll offset (which is the APZ async scroll component) always fits in
    // the available overflow. If we didn't do this and WR did bounds checking
    // on the scroll offset, we'd fail those checks.
    overflow.MoveBy(bounds.x - scrollPos.x, bounds.y - scrollPos.y);
    if (gfxPrefs::LayersDump()) {
      printf_stderr("Pushing stacking context id %" PRIu64 " with bounds=%s overflow=%s\n",
        fm.GetScrollId(), Stringify(bounds).c_str(), Stringify(overflow).c_str());
    }

    mLayer->WrBridge()->AddWebRenderCommand(
      OpDPPushStackingContext(wr::ToWrRect(bounds),
                              wr::ToWrRect(overflow),
                              Nothing(),
                              layer->GetAnimations(),
                              identity,
                              WrMixBlendMode::Normal,
                              fm.GetScrollId()));
  }
}

WrScrollFrameStackingContextGenerator::~WrScrollFrameStackingContextGenerator()
{
  Layer* layer = mLayer->GetLayer();
  for (size_t i = 0; i < layer->GetScrollMetadataCount(); i++) {
    const FrameMetrics& fm = layer->GetFrameMetrics(i);
    if (!fm.IsScrollable()) {
      continue;
    }
    if (gfxPrefs::LayersDump()) printf_stderr("Popping stacking context id %" PRIu64"\n", fm.GetScrollId());
    mLayer->WrBridge()->AddWebRenderCommand(OpDPPopStackingContext());
  }
}


WebRenderLayerManager::WebRenderLayerManager(nsIWidget* aWidget)
  : mWidget(aWidget)
  , mLatestTransactionId(0)
  , mTarget(nullptr)
{
  MOZ_COUNT_CTOR(WebRenderLayerManager);
}

KnowsCompositor*
WebRenderLayerManager::AsKnowsCompositor()
{
  return mWrChild;
}

void
WebRenderLayerManager::Initialize(PCompositorBridgeChild* aCBChild,
                                  uint64_t aLayersId,
                                  TextureFactoryIdentifier* aTextureFactoryIdentifier)
{
  MOZ_ASSERT(mWrChild == nullptr);
  MOZ_ASSERT(aTextureFactoryIdentifier);

  TextureFactoryIdentifier textureFactoryIdentifier;
  PWebRenderBridgeChild* bridge = aCBChild->SendPWebRenderBridgeConstructor(wr::PipelineId(aLayersId),
                                                                            &textureFactoryIdentifier);
  MOZ_ASSERT(bridge);
  mWrChild = static_cast<WebRenderBridgeChild*>(bridge);
  LayoutDeviceIntSize size = mWidget->GetClientSize();
  WrBridge()->SendCreate(size.ToUnknownSize());
  WrBridge()->IdentifyTextureHost(textureFactoryIdentifier);
  *aTextureFactoryIdentifier = textureFactoryIdentifier;
}

void
WebRenderLayerManager::Destroy()
{
  if (IsDestroyed()) {
    return;
  }

  LayerManager::Destroy();
  DiscardImages();
  WrBridge()->Destroy();

  if (mTransactionIdAllocator) {
    // Make sure to notify the refresh driver just in case it's waiting on a
    // pending transaction. Do this at the top of the event loop so we don't
    // cause a paint to occur during compositor shutdown.
    RefPtr<TransactionIdAllocator> allocator = mTransactionIdAllocator;
    uint64_t id = mLatestTransactionId;

    RefPtr<Runnable> task = NS_NewRunnableFunction([allocator, id] () -> void {
      allocator->NotifyTransactionCompleted(id);
    });
    NS_DispatchToMainThread(task.forget());
  }
}

WebRenderLayerManager::~WebRenderLayerManager()
{
  Destroy();
  MOZ_COUNT_DTOR(WebRenderLayerManager);
}

CompositorBridgeChild*
WebRenderLayerManager::GetCompositorBridgeChild()
{
  return mWidget ? mWidget->GetRemoteRenderer() : nullptr;
}

int32_t
WebRenderLayerManager::GetMaxTextureSize() const
{
  return WrBridge()->GetMaxTextureSize();
}

bool
WebRenderLayerManager::BeginTransactionWithTarget(gfxContext* aTarget)
{
  mTarget = aTarget;
  return BeginTransaction();
}

bool
WebRenderLayerManager::BeginTransaction()
{
  return true;
}

bool
WebRenderLayerManager::EndEmptyTransaction(EndTransactionFlags aFlags)
{
  return false;
}

void
WebRenderLayerManager::EndTransaction(DrawPaintedLayerCallback aCallback,
                                      void* aCallbackData,
                                      EndTransactionFlags aFlags)
{
  DiscardImages();

  mPaintedLayerCallback = aCallback;
  mPaintedLayerCallbackData = aCallbackData;

  if (gfxPrefs::LayersDump()) {
    this->Dump();
  }

  // Since we don't do repeat transactions right now, just set the time
  mAnimationReadyTime = TimeStamp::Now();

  LayoutDeviceIntSize size = mWidget->GetClientSize();
  if (!WrBridge()->DPBegin(size.ToUnknownSize())) {
    return;
  }

  WebRenderLayer::ToWebRenderLayer(mRoot)->RenderLayer();

  bool sync = mTarget != nullptr;
  mLatestTransactionId = mTransactionIdAllocator->GetTransactionId();

  WrBridge()->DPEnd(sync, mLatestTransactionId);

  MakeSnapshotIfRequired(size);

  // this may result in Layers being deleted, which results in
  // PLayer::Send__delete__() and DeallocShmem()
  mKeepAlive.Clear();
}

void
WebRenderLayerManager::MakeSnapshotIfRequired(LayoutDeviceIntSize aSize)
{
  if (!mTarget || aSize.IsEmpty()) {
    return;
  }

  // XXX Add other TextureData supports.
  // Only BufferTexture is supported now.

  // TODO: fixup for proper surface format.
  RefPtr<TextureClient> texture =
    TextureClient::CreateForRawBufferAccess(WrBridge(),
                                            SurfaceFormat::B8G8R8A8,
                                            aSize.ToUnknownSize(),
                                            BackendType::SKIA,
                                            TextureFlags::DEFAULT);
  if (!texture) {
    return;
  }

  texture->InitIPDLActor(WrBridge());
  if (!texture->GetIPDLActor()) {
    return;
  }

  IntRect bounds = ToOutsideIntRect(mTarget->GetClipExtents());
  if (!WrBridge()->SendDPGetSnapshot(texture->GetIPDLActor())) {
    return;
  }

  TextureClientAutoLock autoLock(texture, OpenMode::OPEN_READ_ONLY);
  if (!autoLock.Succeeded()) {
    return;
  }
  RefPtr<DrawTarget> drawTarget = texture->BorrowDrawTarget();
  if (!drawTarget || !drawTarget->IsValid()) {
    return;
  }
  RefPtr<SourceSurface> snapshot = drawTarget->Snapshot();
/*
  static int count = 0;
  char filename[100];
  snprintf(filename, 100, "output%d.png", count++);
  printf_stderr("Writing to :%s\n", filename);
  gfxUtils::WriteAsPNG(snapshot, filename);
  */

  Rect dst(bounds.x, bounds.y, bounds.width, bounds.height);
  Rect src(0, 0, bounds.width, bounds.height);

  // The data we get from webrender is upside down. So flip and translate up so the image is rightside up.
  // Webrender always does a full screen readback.
  SurfacePattern pattern(snapshot, ExtendMode::CLAMP,
                         Matrix::Scaling(1.0, -1.0).PostTranslate(0.0, aSize.height));
  DrawTarget* dt = mTarget->GetDrawTarget();
  MOZ_RELEASE_ASSERT(dt);
  dt->FillRect(dst, pattern);

  mTarget = nullptr;
}

void
WebRenderLayerManager::AddImageKeyForDiscard(wr::ImageKey key)
{
  mImageKeys.push_back(key);
}

void
WebRenderLayerManager::DiscardImages()
{
  for (auto key : mImageKeys) {
      WrBridge()->SendDeleteImage(key);
  }
  mImageKeys.clear();
}

void
WebRenderLayerManager::Hold(Layer* aLayer)
{
  mKeepAlive.AppendElement(aLayer);
}

void
WebRenderLayerManager::SetLayerObserverEpoch(uint64_t aLayerObserverEpoch)
{
  WrBridge()->SendSetLayerObserverEpoch(aLayerObserverEpoch);
}

void
WebRenderLayerManager::DidComposite(uint64_t aTransactionId,
                                    const mozilla::TimeStamp& aCompositeStart,
                                    const mozilla::TimeStamp& aCompositeEnd)
{
  MOZ_ASSERT(mWidget);

  // |aTransactionId| will be > 0 if the compositor is acknowledging a shadow
  // layers transaction.
  if (aTransactionId) {
    nsIWidgetListener *listener = mWidget->GetWidgetListener();
    if (listener) {
      listener->DidCompositeWindow(aTransactionId, aCompositeStart, aCompositeEnd);
    }
    listener = mWidget->GetAttachedWidgetListener();
    if (listener) {
      listener->DidCompositeWindow(aTransactionId, aCompositeStart, aCompositeEnd);
    }
    mTransactionIdAllocator->NotifyTransactionCompleted(aTransactionId);
  }

  // These observers fire whether or not we were in a transaction.
  for (size_t i = 0; i < mDidCompositeObservers.Length(); i++) {
    mDidCompositeObservers[i]->DidComposite();
  }
}

void
WebRenderLayerManager::ClearLayer(Layer* aLayer)
{
  aLayer->ClearCachedResources();
  for (Layer* child = aLayer->GetFirstChild(); child;
       child = child->GetNextSibling()) {
    ClearLayer(child);
  }
}

void
WebRenderLayerManager::ClearCachedResources(Layer* aSubtree)
{
  WrBridge()->SendClearCachedResources();
  if (aSubtree) {
    ClearLayer(aSubtree);
  } else if (mRoot) {
    ClearLayer(mRoot);
  }
}

void
WebRenderLayerManager::UpdateTextureFactoryIdentifier(const TextureFactoryIdentifier& aNewIdentifier)
{
  WrBridge()->IdentifyTextureHost(aNewIdentifier);
}

TextureFactoryIdentifier
WebRenderLayerManager::GetTextureFactoryIdentifier()
{
  return WrBridge()->GetTextureFactoryIdentifier();
}

void
WebRenderLayerManager::AddDidCompositeObserver(DidCompositeObserver* aObserver)
{
  if (!mDidCompositeObservers.Contains(aObserver)) {
    mDidCompositeObservers.AppendElement(aObserver);
  }
}

void
WebRenderLayerManager::RemoveDidCompositeObserver(DidCompositeObserver* aObserver)
{
  mDidCompositeObservers.RemoveElement(aObserver);
}

void
WebRenderLayerManager::SetRoot(Layer* aLayer)
{
  mRoot = aLayer;
}

already_AddRefed<PaintedLayer>
WebRenderLayerManager::CreatePaintedLayer()
{
  return MakeAndAddRef<WebRenderPaintedLayer>(this);
}

already_AddRefed<ContainerLayer>
WebRenderLayerManager::CreateContainerLayer()
{
  return MakeAndAddRef<WebRenderContainerLayer>(this);
}

already_AddRefed<ImageLayer>
WebRenderLayerManager::CreateImageLayer()
{
  return MakeAndAddRef<WebRenderImageLayer>(this);
}

already_AddRefed<CanvasLayer>
WebRenderLayerManager::CreateCanvasLayer()
{
  return MakeAndAddRef<WebRenderCanvasLayer>(this);
}

already_AddRefed<ReadbackLayer>
WebRenderLayerManager::CreateReadbackLayer()
{
  return nullptr;
}

already_AddRefed<ColorLayer>
WebRenderLayerManager::CreateColorLayer()
{
  return MakeAndAddRef<WebRenderColorLayer>(this);
}

already_AddRefed<RefLayer>
WebRenderLayerManager::CreateRefLayer()
{
  return MakeAndAddRef<WebRenderRefLayer>(this);
}

already_AddRefed<TextLayer>
WebRenderLayerManager::CreateTextLayer()
{
  return MakeAndAddRef<WebRenderTextLayer>(this);
}

already_AddRefed<BorderLayer>
WebRenderLayerManager::CreateBorderLayer()
{
  return MakeAndAddRef<WebRenderBorderLayer>(this);
}

} // namespace layers
} // namespace mozilla