/* -*- 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 "gfxPrefs.h"
#include "GeckoProfiler.h"
#include "LayersLogging.h"
#include "mozilla/layers/CompositorBridgeChild.h"
#include "mozilla/layers/StackingContextHelper.h"
#include "mozilla/layers/TextureClient.h"
#include "mozilla/layers/WebRenderBridgeChild.h"
#include "WebRenderCanvasLayer.h"
#include "WebRenderColorLayer.h"
#include "WebRenderContainerLayer.h"
#include "WebRenderImageLayer.h"
#include "WebRenderPaintedLayer.h"
#include "WebRenderPaintedLayerBlob.h"
#include "WebRenderTextLayer.h"
#include "WebRenderDisplayItemLayer.h"
#include "nsDisplayList.h"

namespace mozilla {

using namespace gfx;

namespace layers {

WebRenderLayerManager::WebRenderLayerManager(nsIWidget* aWidget)
  : mWidget(aWidget)
  , mLatestTransactionId(0)
  , mNeedsComposite(false)
  , mIsFirstPaint(false)
  , mEndTransactionWithoutLayers(false)
  , mTarget(nullptr)
  , mPaintSequenceNumber(0)
{
  MOZ_COUNT_CTOR(WebRenderLayerManager);
}

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

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

  LayoutDeviceIntSize size = mWidget->GetClientSize();
  TextureFactoryIdentifier textureFactoryIdentifier;
  uint32_t id_namespace;
  PWebRenderBridgeChild* bridge = aCBChild->SendPWebRenderBridgeConstructor(aLayersId,
                                                                            size,
                                                                            &textureFactoryIdentifier,
                                                                            &id_namespace);
  MOZ_ASSERT(bridge);
  mWrChild = static_cast<WebRenderBridgeChild*>(bridge);
  WrBridge()->SendCreate(size.ToUnknownSize());
  WrBridge()->IdentifyTextureHost(textureFactoryIdentifier);
  WrBridge()->SetNamespace(id_namespace);
  *aTextureFactoryIdentifier = textureFactoryIdentifier;
}

void
WebRenderLayerManager::Destroy()
{
  DoDestroy(/* aIsSync */ false);
}

void
WebRenderLayerManager::DoDestroy(bool aIsSync)
{
  if (IsDestroyed()) {
    return;
  }

  mWidget->CleanupWebRenderWindowOverlay(WrBridge());

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

  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(
      "TransactionIdAllocator::NotifyTransactionCompleted",
      [allocator, id] () -> void {
      allocator->NotifyTransactionCompleted(id);
    });
    NS_DispatchToMainThread(task.forget());
  }

  // Forget the widget pointer in case we outlive our owning widget.
  mWidget = nullptr;
}

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

CompositorBridgeChild*
WebRenderLayerManager::GetCompositorBridgeChild()
{
  return WrBridge()->GetCompositorBridgeChild();
}

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

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

bool
WebRenderLayerManager::BeginTransaction()
{
  // Increment the paint sequence number even if test logging isn't
  // enabled in this process; it may be enabled in the parent process,
  // and the parent process expects unique sequence numbers.
  ++mPaintSequenceNumber;
  if (gfxPrefs::APZTestLoggingEnabled()) {
    mApzTestData.StartNewPaint(mPaintSequenceNumber);
  }
  return true;
}

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

  // We might used painted layer images so don't delete them yet.
  return EndTransactionInternal(nullptr, nullptr, aFlags);
}

/*static*/ int32_t
PopulateScrollData(WebRenderScrollData& aTarget, Layer* aLayer)
{
  MOZ_ASSERT(aLayer);

  // We want to allocate a WebRenderLayerScrollData object for this layer,
  // but don't keep a pointer to it since it might get memmove'd during the
  // recursion below. Instead keep the index and get the pointer later.
  size_t index = aTarget.AddNewLayerData();

  int32_t descendants = 0;
  for (Layer* child = aLayer->GetLastChild(); child; child = child->GetPrevSibling()) {
    descendants += PopulateScrollData(aTarget, child);
  }
  aTarget.GetLayerDataMutable(index)->Initialize(aTarget, aLayer, descendants);
  return descendants + 1;
}

void
WebRenderLayerManager::CreateWebRenderCommandsFromDisplayList(nsDisplayList* aDisplayList,
                                                              nsDisplayListBuilder* aDisplayListBuilder,
                                                              StackingContextHelper& aSc,
                                                              wr::DisplayListBuilder& aBuilder)
{
  nsDisplayList savedItems;
  nsDisplayItem* item;
  while ((item = aDisplayList->RemoveBottom()) != nullptr) {
    nsDisplayItem::Type itemType = item->GetType();

    // If the item is a event regions item, but is empty (has no regions in it)
    // then we should just throw it out
    if (itemType == nsDisplayItem::TYPE_LAYER_EVENT_REGIONS) {
      nsDisplayLayerEventRegions* eventRegions =
        static_cast<nsDisplayLayerEventRegions*>(item);
      if (eventRegions->IsEmpty()) {
        item->~nsDisplayItem();
        continue;
      }
    }

    // Peek ahead to the next item and try merging with it or swapping with it
    // if necessary.
    nsDisplayItem* aboveItem;
    while ((aboveItem = aDisplayList->GetBottom()) != nullptr) {
      if (aboveItem->TryMerge(item)) {
        aDisplayList->RemoveBottom();
        item->~nsDisplayItem();
        item = aboveItem;
        itemType = item->GetType();
      } else {
        break;
      }
    }

    nsDisplayList* itemSameCoordinateSystemChildren
      = item->GetSameCoordinateSystemChildren();
    if (item->ShouldFlattenAway(aDisplayListBuilder)) {
      aDisplayList->AppendToBottom(itemSameCoordinateSystemChildren);
      item->~nsDisplayItem();
      continue;
    }

    savedItems.AppendToTop(item);

    if (!item->CreateWebRenderCommands(aBuilder, aSc, mParentCommands, this,
                                       aDisplayListBuilder)) {
      // TODO: fallback
    }
  }
  aDisplayList->AppendToTop(&savedItems);
}

void
WebRenderLayerManager::EndTransactionWithoutLayer(nsDisplayList* aDisplayList,
                                                  nsDisplayListBuilder* aDisplayListBuilder)
{
  MOZ_ASSERT(aDisplayList && aDisplayListBuilder);
  mEndTransactionWithoutLayers = true;
  DiscardImages();
  WrBridge()->RemoveExpiredFontKeys();
  EndTransactionInternal(nullptr,
                         nullptr,
                         EndTransactionFlags::END_DEFAULT,
                         aDisplayList,
                         aDisplayListBuilder);
}

void
WebRenderLayerManager::EndTransaction(DrawPaintedLayerCallback aCallback,
                                      void* aCallbackData,
                                      EndTransactionFlags aFlags)
{
  mEndTransactionWithoutLayers = false;
  DiscardImages();
  WrBridge()->RemoveExpiredFontKeys();
  EndTransactionInternal(aCallback, aCallbackData, aFlags);
}

bool
WebRenderLayerManager::EndTransactionInternal(DrawPaintedLayerCallback aCallback,
                                              void* aCallbackData,
                                              EndTransactionFlags aFlags,
                                              nsDisplayList* aDisplayList,
                                              nsDisplayListBuilder* aDisplayListBuilder)
{
  AutoProfilerTracing tracing("Paint", "RenderLayers");
  mPaintedLayerCallback = aCallback;
  mPaintedLayerCallbackData = aCallbackData;
  mTransactionIncomplete = false;

  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 false;
  }
  DiscardCompositorAnimations();

  WrSize contentSize { (float)size.width, (float)size.height };
  wr::DisplayListBuilder builder(WrBridge()->GetPipeline(), contentSize);

  if (mEndTransactionWithoutLayers) {
    // aDisplayList being null here means this is an empty transaction following a layers-free
    // transaction, so we reuse the previously built displaylist.
    if (aDisplayList && aDisplayListBuilder) {
      StackingContextHelper sc;
      mParentCommands.Clear();
      CreateWebRenderCommandsFromDisplayList(aDisplayList, aDisplayListBuilder, sc, builder);
      builder.Finalize(contentSize, mBuiltDisplayList);
    }

    builder.PushBuiltDisplayList(mBuiltDisplayList);
    WrBridge()->AddWebRenderParentCommands(mParentCommands);
  } else {
    mRoot->StartPendingAnimations(mAnimationReadyTime);
    StackingContextHelper sc;

    WebRenderLayer::ToWebRenderLayer(mRoot)->RenderLayer(builder, sc);
  }

  mWidget->AddWindowOverlayWebRenderCommands(WrBridge(), builder);
  WrBridge()->ClearReadLocks();

  // We can't finish this transaction so return. This usually
  // happens in an empty transaction where we can't repaint a painted layer.
  // In this case, leave the transaction open and let a full transaction happen.
  if (mTransactionIncomplete) {
    DiscardLocalImages();
    WrBridge()->ProcessWebRenderParentCommands();
    return false;
  }

  WebRenderScrollData scrollData;
  if (AsyncPanZoomEnabled()) {
    scrollData.SetFocusTarget(mFocusTarget);
    mFocusTarget = FocusTarget();

    if (mIsFirstPaint) {
      scrollData.SetIsFirstPaint();
      mIsFirstPaint = false;
    }
    scrollData.SetPaintSequenceNumber(mPaintSequenceNumber);
    if (mRoot) {
      PopulateScrollData(scrollData, mRoot.get());
    }
  }

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

  {
    AutoProfilerTracing
      tracing("Paint", sync ? "ForwardDPTransactionSync":"ForwardDPTransaction");
    WrBridge()->DPEnd(builder, size.ToUnknownSize(), sync, mLatestTransactionId, scrollData);
  }

  MakeSnapshotIfRequired(size);
  mNeedsComposite = false;

  ClearDisplayItemLayers();

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

  return true;
}

void
WebRenderLayerManager::SetFocusTarget(const FocusTarget& aFocusTarget)
{
  mFocusTarget = aFocusTarget;
}

bool
WebRenderLayerManager::AsyncPanZoomEnabled() const
{
  return mWidget->AsyncPanZoomEnabled();
}

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::SNAPSHOT);
  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()
{
  if (WrBridge()->IPCOpen()) {
    for (auto key : mImageKeys) {
      WrBridge()->SendDeleteImage(key);
    }
  }
  mImageKeys.clear();
}

void
WebRenderLayerManager::AddCompositorAnimationsIdForDiscard(uint64_t aId)
{
  mDiscardedCompositorAnimationsIds.AppendElement(aId);
}

void
WebRenderLayerManager::DiscardCompositorAnimations()
{
  if (WrBridge()->IPCOpen() && !mDiscardedCompositorAnimationsIds.IsEmpty()) {
    WrBridge()->
      SendDeleteCompositorAnimations(mDiscardedCompositorAnimationsIds);
  }
  mDiscardedCompositorAnimationsIds.Clear();
}

void
WebRenderLayerManager::DiscardLocalImages()
{
  // Removes images but doesn't tell the parent side about them
  // This is useful in empty / failed transactions where we created
  // image keys but didn't tell the parent about them yet.
  mImageKeys.clear();
}

void
WebRenderLayerManager::Mutated(Layer* aLayer)
{
  LayerManager::Mutated(aLayer);
  AddMutatedLayer(aLayer);
}

void
WebRenderLayerManager::MutatedSimple(Layer* aLayer)
{
  LayerManager::Mutated(aLayer);
  AddMutatedLayer(aLayer);
}

void
WebRenderLayerManager::AddMutatedLayer(Layer* aLayer)
{
  mMutatedLayers.AppendElement(aLayer);
}

void
WebRenderLayerManager::ClearMutatedLayers()
{
  mMutatedLayers.Clear();
}

bool
WebRenderLayerManager::IsMutatedLayer(Layer* aLayer)
{
  return mMutatedLayers.Contains(aLayer);
}

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,
                                                      uint64_t aDeviceResetSeqNo)
{
  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::FlushRendering()
{
  CompositorBridgeChild* cBridge = GetCompositorBridgeChild();
  if (!cBridge) {
    return;
  }
  MOZ_ASSERT(mWidget);

  if (mWidget->SynchronouslyRepaintOnResize() || gfxPrefs::LayersForceSynchronousResize()) {
    cBridge->SendFlushRendering();
  } else {
    cBridge->SendFlushRenderingAsync();
  }
}

void
WebRenderLayerManager::WaitOnTransactionProcessed()
{
  CompositorBridgeChild* bridge = GetCompositorBridgeChild();
  if (bridge) {
    bridge->SendWaitOnTransactionProcessed();
  }
}

void
WebRenderLayerManager::SendInvalidRegion(const nsIntRegion& aRegion)
{
  // XXX Webrender does not support invalid region yet.
}

void
WebRenderLayerManager::ScheduleComposite()
{
  WrBridge()->SendForceComposite();
}

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

already_AddRefed<PaintedLayer>
WebRenderLayerManager::CreatePaintedLayer()
{
  if (gfxPrefs::WebRenderBlobImages()) {
    return MakeAndAddRef<WebRenderPaintedLayerBlob>(this);
  } else {
    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 nullptr;
}

already_AddRefed<DisplayItemLayer>
WebRenderLayerManager::CreateDisplayItemLayer()
{
  return MakeAndAddRef<WebRenderDisplayItemLayer>(this);
}

} // namespace layers
} // namespace mozilla