/* -*- 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/. */

#ifndef MOZILLA_GFX_WEBRENDERCOMPOSITABLE_HOLDER_H
#define MOZILLA_GFX_WEBRENDERCOMPOSITABLE_HOLDER_H

#include <queue>

#include "CompositableHost.h"
#include "mozilla/gfx/Point.h"
#include "mozilla/layers/TextureHost.h"
#include "mozilla/layers/WebRenderTextureHostWrapper.h"
#include "mozilla/Maybe.h"
#include "mozilla/webrender/WebRenderAPI.h"
#include "mozilla/webrender/WebRenderTypes.h"
#include "nsClassHashtable.h"

namespace mozilla {

namespace wr {
class DisplayListBuilder;
class WebRenderAPI;
class WebRenderPipelineInfo;
}  // namespace wr

namespace layers {

class CompositableHost;
class CompositorVsyncScheduler;
class WebRenderImageHost;
class WebRenderTextureHost;
class WebRenderTextureHostWrapper;

class AsyncImagePipelineManager final {
 public:
  NS_INLINE_DECL_THREADSAFE_REFCOUNTING(AsyncImagePipelineManager)

  explicit AsyncImagePipelineManager(
      nsTArray<RefPtr<wr::WebRenderAPI>>&& aApis);

 protected:
  ~AsyncImagePipelineManager();

 public:
  void Destroy();

  void AddPipeline(const wr::PipelineId& aPipelineId,
                   WebRenderBridgeParent* aWrBridge);
  void RemovePipeline(const wr::PipelineId& aPipelineId,
                      const wr::Epoch& aEpoch);
  WebRenderBridgeParent* GetWrBridge(const wr::PipelineId& aPipelineId);

  void HoldExternalImage(const wr::PipelineId& aPipelineId,
                         const wr::Epoch& aEpoch, TextureHost* aTexture);
  void HoldExternalImage(const wr::PipelineId& aPipelineId,
                         const wr::Epoch& aEpoch,
                         WebRenderTextureHostWrapper* aWrTextureWrapper);
  void HoldExternalImage(const wr::PipelineId& aPipelineId,
                         const wr::Epoch& aEpoch,
                         const wr::ExternalImageId& aImageId);

  // This is called from the Renderer thread to notify this class about the
  // pipelines in the most recently completed render. A copy of the update
  // information is put into mUpdatesQueue.
  void NotifyPipelinesUpdated(RefPtr<wr::WebRenderPipelineInfo> aInfo,
                              bool aRender);

  // This is run on the compositor thread to process mUpdatesQueue. We make
  // this a public entry point because we need to invoke it from other places.
  void ProcessPipelineUpdates();

  TimeStamp GetCompositionTime() const { return mCompositionTime; }
  void SetCompositionTime(TimeStamp aTimeStamp) {
    mCompositionTime = aTimeStamp;
    if (!mCompositionTime.IsNull() && !mCompositeUntilTime.IsNull() &&
        mCompositionTime >= mCompositeUntilTime) {
      mCompositeUntilTime = TimeStamp();
    }
  }
  void CompositeUntil(TimeStamp aTimeStamp) {
    if (mCompositeUntilTime.IsNull() || mCompositeUntilTime < aTimeStamp) {
      mCompositeUntilTime = aTimeStamp;
    }
  }
  TimeStamp GetCompositeUntilTime() const { return mCompositeUntilTime; }

  void AddAsyncImagePipeline(const wr::PipelineId& aPipelineId,
                             WebRenderImageHost* aImageHost,
                             wr::RenderRoot aRenderRoot);
  void RemoveAsyncImagePipeline(const wr::PipelineId& aPipelineId,
                                wr::TransactionBuilder& aTxn);

  void UpdateAsyncImagePipeline(const wr::PipelineId& aPipelineId,
                                const LayoutDeviceRect& aScBounds,
                                const gfx::Matrix4x4& aScTransform,
                                const gfx::MaybeIntSize& aScaleToSize,
                                const wr::ImageRendering& aFilter,
                                const wr::MixBlendMode& aMixBlendMode);
  void ApplyAsyncImagesOfImageBridge(
      wr::RenderRootArray<Maybe<wr::TransactionBuilder>>& aSceneBuilderTxns,
      wr::RenderRootArray<Maybe<wr::TransactionBuilder>>& aFastTxns);
  void ApplyAsyncImageForPipeline(const wr::PipelineId& aPipelineId,
                                  wr::TransactionBuilder& aTxn,
                                  wr::TransactionBuilder& aTxnForImageBridge,
                                  wr::RenderRoot aRenderRoot);

  void SetEmptyDisplayList(const wr::PipelineId& aPipelineId,
                           wr::TransactionBuilder& aTxn,
                           wr::TransactionBuilder& aTxnForImageBridge);

  void AppendImageCompositeNotification(
      const ImageCompositeNotificationInfo& aNotification) {
    mImageCompositeNotifications.AppendElement(aNotification);
  }

  void FlushImageNotifications(
      nsTArray<ImageCompositeNotificationInfo>* aNotifications) {
    aNotifications->AppendElements(std::move(mImageCompositeNotifications));
  }

  void SetWillGenerateFrameAllRenderRoots();
  void SetWillGenerateFrame(wr::RenderRoot aRenderRoot);
  bool GetAndResetWillGenerateFrame(wr::RenderRoot aRenderRoot);

  wr::ExternalImageId GetNextExternalImageId();

 private:
  void ProcessPipelineRendered(const wr::PipelineId& aPipelineId,
                               const wr::Epoch& aEpoch,
                               const uint64_t aUpdatesCount);
  void ProcessPipelineRemoved(const wr::RemovedPipeline& aRemovedPipeline,
                              const uint64_t aUpdatesCount);

  wr::Epoch GetNextImageEpoch();
  uint32_t GetNextResourceId() { return ++mResourceId; }
  wr::IdNamespace GetNamespace() { return mIdNamespace; }
  wr::ImageKey GenerateImageKey() {
    wr::ImageKey key;
    key.mNamespace = GetNamespace();
    key.mHandle = GetNextResourceId();
    return key;
  }

  struct ForwardingTextureHost {
    ForwardingTextureHost(const wr::Epoch& aEpoch, TextureHost* aTexture)
        : mEpoch(aEpoch), mTexture(aTexture) {}
    wr::Epoch mEpoch;
    CompositableTextureHostRef mTexture;
  };

  struct ForwardingTextureHostWrapper {
    ForwardingTextureHostWrapper(const wr::Epoch& aEpoch,
                                 WebRenderTextureHostWrapper* aWrTextureWrapper)
        : mEpoch(aEpoch), mWrTextureWrapper(aWrTextureWrapper) {}
    wr::Epoch mEpoch;
    RefPtr<WebRenderTextureHostWrapper> mWrTextureWrapper;
  };

  struct ForwardingExternalImage {
    ForwardingExternalImage(const wr::Epoch& aEpoch,
                            const wr::ExternalImageId& aImageId)
        : mEpoch(aEpoch), mImageId(aImageId) {}
    ~ForwardingExternalImage();
    wr::Epoch mEpoch;
    wr::ExternalImageId mImageId;
  };

  struct PipelineTexturesHolder {
    // Holds forwarding WebRenderTextureHosts.
    std::queue<ForwardingTextureHost> mTextureHosts;
    std::queue<ForwardingTextureHostWrapper> mTextureHostWrappers;
    std::queue<UniquePtr<ForwardingExternalImage>> mExternalImages;
    Maybe<wr::Epoch> mDestroyedEpoch;
    WebRenderBridgeParent* MOZ_NON_OWNING_REF mWrBridge = nullptr;
  };

  struct AsyncImagePipeline {
    AsyncImagePipeline();
    void Update(const LayoutDeviceRect& aScBounds,
                const gfx::Matrix4x4& aScTransform,
                const gfx::MaybeIntSize& aScaleToSize,
                const wr::ImageRendering& aFilter,
                const wr::MixBlendMode& aMixBlendMode) {
      mIsChanged |= !mScBounds.IsEqualEdges(aScBounds) ||
                    mScTransform != aScTransform ||
                    mScaleToSize != aScaleToSize || mFilter != aFilter ||
                    mMixBlendMode != aMixBlendMode;
      mScBounds = aScBounds;
      mScTransform = aScTransform;
      mScaleToSize = aScaleToSize;
      mFilter = aFilter;
      mMixBlendMode = aMixBlendMode;
    }

    bool mInitialised;
    wr::RenderRoot mRenderRoot;
    bool mIsChanged;
    bool mUseExternalImage;
    LayoutDeviceRect mScBounds;
    gfx::Matrix4x4 mScTransform;
    gfx::MaybeIntSize mScaleToSize;
    wr::ImageRendering mFilter;
    wr::MixBlendMode mMixBlendMode;
    RefPtr<WebRenderImageHost> mImageHost;
    CompositableTextureHostRef mCurrentTexture;
    RefPtr<WebRenderTextureHostWrapper> mWrTextureWrapper;
    nsTArray<wr::ImageKey> mKeys;
  };

  void ApplyAsyncImageForPipeline(const wr::Epoch& aEpoch,
                                  const wr::PipelineId& aPipelineId,
                                  AsyncImagePipeline* aPipeline,
                                  wr::TransactionBuilder& aSceneBuilderTxn,
                                  wr::TransactionBuilder& aMaybeFastTxn);
  Maybe<TextureHost::ResourceUpdateOp> UpdateImageKeys(
      const wr::Epoch& aEpoch, const wr::PipelineId& aPipelineId,
      AsyncImagePipeline* aPipeline, nsTArray<wr::ImageKey>& aKeys,
      wr::TransactionBuilder& aSceneBuilderTxn,
      wr::TransactionBuilder& aMaybeFastTxn);
  Maybe<TextureHost::ResourceUpdateOp> UpdateWithoutExternalImage(
      TextureHost* aTexture, wr::ImageKey aKey, TextureHost::ResourceUpdateOp,
      wr::TransactionBuilder& aTxn);

  // If texture is direct binding texture, keep it until it is not used by GPU.
  void HoldUntilNotUsedByGPU(const CompositableTextureHostRef& aTextureHost,
                             uint64_t aUpdatesCount);
  void CheckForTextureHostsNotUsedByGPU();

  nsTArray<RefPtr<wr::WebRenderAPI>> mApis;
  const wr::IdNamespace mIdNamespace;
  const bool mUseTripleBuffering;
  uint32_t mResourceId;

  nsClassHashtable<nsUint64HashKey, PipelineTexturesHolder>
      mPipelineTexturesHolders;
  nsClassHashtable<nsUint64HashKey, AsyncImagePipeline> mAsyncImagePipelines;
  wr::Epoch mAsyncImageEpoch;
  wr::RenderRootArray<bool> mWillGenerateFrame;
  bool mDestroyed;

  // Render time for the current composition.
  TimeStamp mCompositionTime;

  // When nonnull, during rendering, some compositable indicated that it will
  // change its rendering at this time. In order not to miss it, we composite
  // on every vsync until this time occurs (this is the latest such time).
  TimeStamp mCompositeUntilTime;

  nsTArray<ImageCompositeNotificationInfo> mImageCompositeNotifications;

  // The lock that protects mUpdatesQueue
  Mutex mUpdatesLock;
  // Used for checking if PipelineUpdates could be processed.
  Atomic<uint64_t> mUpdatesCount;
  struct PipelineUpdates {
    PipelineUpdates(RefPtr<wr::WebRenderPipelineInfo> aPipelineInfo,
                    const uint64_t aUpdatesCount, const bool aRendered);
    bool NeedsToWait(const uint64_t aUpdatesCount) {
      MOZ_ASSERT(mUpdatesCount <= aUpdatesCount);
      if (mUpdatesCount == aUpdatesCount && !mRendered) {
        // RenderTextureHosts related to this might be still used by GPU.
        return true;
      }
      return false;
    }
    RefPtr<wr::WebRenderPipelineInfo> mPipelineInfo;
    const uint64_t mUpdatesCount;
    const bool mRendered;
  };
  std::queue<UniquePtr<PipelineUpdates>> mUpdatesQueues;

  // Queue to store TextureHosts that might still be used by GPU.
  std::queue<std::pair<uint64_t, CompositableTextureHostRef>>
      mTexturesInUseByGPU;
};

}  // namespace layers
}  // namespace mozilla

#endif /* MOZILLA_GFX_WEBRENDERCOMPOSITABLE_HOLDER_H */