// Copyright 2022 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "gpu/command_buffer/service/shared_image/raw_draw_image_backing.h"

#include "base/logging.h"
#include "base/notimplemented.h"
#include "base/types/optional_util.h"
#include "cc/paint/paint_op_buffer.h"
#include "components/viz/common/resources/shared_image_format_utils.h"
#include "gpu/command_buffer/common/shared_image_info.h"
#include "gpu/command_buffer/common/shared_image_usage.h"
#include "gpu/command_buffer/service/shared_context_state.h"
#include "gpu/command_buffer/service/shared_image/shared_image_representation.h"
#include "gpu/command_buffer/service/skia_utils.h"
#include "third_party/skia/include/core/SkCanvas.h"
#include "third_party/skia/include/core/SkColorSpace.h"
#include "third_party/skia/include/gpu/GpuTypes.h"
#include "third_party/skia/include/gpu/ganesh/GrDirectContext.h"
#include "third_party/skia/include/gpu/ganesh/SkSurfaceGanesh.h"
#include "third_party/skia/include/private/chromium/GrPromiseImageTexture.h"

namespace gpu {

class RawDrawImageBacking::RasterRawDrawImageRepresentation
    : public RasterImageRepresentation {
 public:
  RasterRawDrawImageRepresentation(SharedImageManager* manager,
                                   SharedImageBacking* backing,
                                   MemoryTypeTracker* tracker)
      : RasterImageRepresentation(manager, backing, tracker) {}
  ~RasterRawDrawImageRepresentation() override = default;

  cc::PaintOpBuffer* BeginWriteAccess(
      scoped_refptr<SharedContextState> context_state,
      int final_msaa_count,
      const SkSurfaceProps& surface_props,
      const std::optional<SkColor4f>& clear_color,
      bool visible) override {
    return raw_draw_backing()->BeginRasterWriteAccess(
        std::move(context_state), final_msaa_count, surface_props, clear_color,
        visible);
  }

  void EndWriteAccess(base::OnceClosure callback) override {
    raw_draw_backing()->EndRasterWriteAccess(std::move(callback));
  }

  cc::PaintOpBuffer* BeginReadAccess(
      std::optional<SkColor4f>& clear_color) override {
    return raw_draw_backing()->BeginRasterReadAccess(clear_color);
  }

  void EndReadAccess() override { raw_draw_backing()->EndReadAccess(); }

 private:
  RawDrawImageBacking* raw_draw_backing() {
    return static_cast<RawDrawImageBacking*>(backing());
  }
};

class RawDrawImageBacking::SkiaRawDrawImageRepresentation
    : public SkiaGaneshImageRepresentation {
 public:
  SkiaRawDrawImageRepresentation(GrDirectContext* gr_context,
                                 SharedImageManager* manager,
                                 SharedImageBacking* backing,
                                 MemoryTypeTracker* tracker)
      : SkiaGaneshImageRepresentation(gr_context, manager, backing, tracker) {}

  bool SupportsMultipleConcurrentReadAccess() override { return true; }

  std::vector<sk_sp<SkSurface>> BeginWriteAccess(
      int final_msaa_count,
      const SkSurfaceProps& surface_props,
      const gfx::Rect& update_rect,
      std::vector<GrBackendSemaphore>* begin_semaphores,
      std::vector<GrBackendSemaphore>* end_semaphores,
      std::unique_ptr<skgpu::MutableTextureState>* end_state) override {
    NOTIMPLEMENTED();
    return {};
  }

  std::vector<sk_sp<GrPromiseImageTexture>> BeginWriteAccess(
      std::vector<GrBackendSemaphore>* begin_semaphores,
      std::vector<GrBackendSemaphore>* end_semaphores,
      std::unique_ptr<skgpu::MutableTextureState>* end_state) override {
    NOTIMPLEMENTED();
    return {};
  }

  void EndWriteAccess() override { NOTIMPLEMENTED(); }

  std::vector<sk_sp<GrPromiseImageTexture>> BeginReadAccess(
      std::vector<GrBackendSemaphore>* begin_semaphores,
      std::vector<GrBackendSemaphore>* end_semaphores,
      std::unique_ptr<skgpu::MutableTextureState>* end_state) override {
    auto promise_texture = raw_draw_backing()->BeginSkiaReadAccess();
    if (!promise_texture)
      return {};
    return {promise_texture};
  }

  void EndReadAccess() override { raw_draw_backing()->EndReadAccess(); }

 private:
  RawDrawImageBacking* raw_draw_backing() {
    return static_cast<RawDrawImageBacking*>(backing());
  }
};

RawDrawImageBacking::RawDrawImageBacking(const Mailbox& mailbox,
                                         const SharedImageInfo& si_info)
    : ClearTrackingSharedImageBacking(mailbox,
                                      si_info,
                                      /*estimated_size=*/0,
                                      /*is_thread_safe=*/true) {}

RawDrawImageBacking::~RawDrawImageBacking() {
  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
  AutoLock auto_lock(this);
  DCHECK_EQ(read_count_, 0);
  DCHECK(!is_write_);
  ResetPaintOpBuffer();
  DestroyBackendTexture();
}

SharedImageBackingType RawDrawImageBacking::GetType() const {
  return SharedImageBackingType::kRawDraw;
}

void RawDrawImageBacking::Update(std::unique_ptr<gfx::GpuFence> in_fence) {
  NOTIMPLEMENTED();
}

std::unique_ptr<RasterImageRepresentation> RawDrawImageBacking::ProduceRaster(
    SharedImageManager* manager,
    MemoryTypeTracker* tracker) {
  return std::make_unique<RasterRawDrawImageRepresentation>(manager, this,
                                                            tracker);
}

std::unique_ptr<SkiaGaneshImageRepresentation>
RawDrawImageBacking::ProduceSkiaGanesh(
    SharedImageManager* manager,
    MemoryTypeTracker* tracker,
    scoped_refptr<SharedContextState> context_state) {
  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
  if (!context_state_)
    context_state_ = context_state;
  DCHECK(context_state_ == context_state);
  return std::make_unique<SkiaRawDrawImageRepresentation>(
      context_state->gr_context(), manager, this, tracker);
}

void RawDrawImageBacking::ResetPaintOpBuffer() {
  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
  if (!paint_op_buffer_) {
    DCHECK(!clear_color_);
    DCHECK(!paint_op_release_callback_);
    DCHECK(!backend_texture_.isValid());
    DCHECK(!promise_texture_);
    return;
  }

  clear_color_.reset();
  paint_op_buffer_->Reset();

  if (paint_op_release_callback_)
    std::move(paint_op_release_callback_).Run();
}

bool RawDrawImageBacking::CreateBackendTextureAndFlushPaintOps(bool flush) {
  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
  DCHECK(!backend_texture_.isValid());
  DCHECK(!promise_texture_);

  if (context_state_->context_lost())
    return false;

  auto sk_color = viz::ToClosestSkColorType(format());
  const std::string label =
      "RawDrawImageBacking" + CreateLabelForSharedImageUsage(usage());
  GrDirectContext* direct_context = context_state_->gr_context();
  CHECK(direct_context);
  backend_texture_ = direct_context->createBackendTexture(
      size().width(), size().height(), sk_color, skgpu::Mipmapped::kNo,
      GrRenderable::kYes, GrProtected::kNo, label);
  if (!backend_texture_.isValid()) {
    DLOG(ERROR) << "createBackendTexture() failed with SkColorType:"
                << sk_color;
    return false;
  }
  promise_texture_ = GrPromiseImageTexture::Make(backend_texture_);

  auto surface = SkSurfaces::WrapBackendTexture(
      direct_context, backend_texture_, surface_origin(), final_msaa_count_,
      sk_color, color_space().ToSkColorSpace(), &surface_props_);
  if (!surface) {
    DLOG(ERROR) << "SkSurfaces::WrapBackendTexture() failed! SkColorType:"
                << sk_color;
    DestroyBackendTexture();
    return false;
  }

  if (clear_color_)
    surface->getCanvas()->clear(*clear_color_);

  if (paint_op_buffer_) {
    cc::PlaybackParams playback_params(nullptr, SkM44());
    paint_op_buffer_->Playback(surface->getCanvas(), playback_params);
  }

  if (flush) {
    direct_context->flush(surface.get());
  } else {
    // For a MSAA SkSurface, if gr_context->flush() is called, all draws on the
    // SkSurface will be flush into a temp MSAA buffer, but the it will not
    // resolved the temp MSAA buffer to the wrapped backend texture.
    // So call resolveMSAA() to insert resolve op in surface's command stream,
    // and when gr_context->flush() is call, the surface will be resolved.
    SkSurfaces::ResolveMSAA(surface);
  }

  UpdateEstimatedSize(format().EstimatedSizeInBytes(size()));

  return true;
}

void RawDrawImageBacking::DestroyBackendTexture() {
  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
  if (backend_texture_.isValid()) {
    DCHECK(context_state_);
    DeleteGrBackendTexture(context_state_.get(), &backend_texture_);
    backend_texture_ = {};
    promise_texture_.reset();
  }
}

cc::PaintOpBuffer* RawDrawImageBacking::BeginRasterWriteAccess(
    scoped_refptr<SharedContextState> context_state,
    int final_msaa_count,
    const SkSurfaceProps& surface_props,
    const std::optional<SkColor4f>& clear_color,
    bool visible) {
  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
  AutoLock auto_lock(this);
  if (read_count_) {
    LOG(ERROR) << "The backing is being read.";
    return nullptr;
  }

  if (is_write_) {
    LOG(ERROR) << "The backing is being written.";
    return nullptr;
  }

  is_write_ = true;

  ResetPaintOpBuffer();
  // Should we keep the backing?
  DestroyBackendTexture();

  if (!paint_op_buffer_) {
    paint_op_buffer_.emplace();
  }

  DCHECK(!context_state_ || context_state_ == context_state);
  context_state_ = std::move(context_state);

  final_msaa_count_ = final_msaa_count;
  surface_props_ = surface_props;
  clear_color_ = clear_color;
  visible_ = visible;

  return base::OptionalToPtr(paint_op_buffer_);
}

void RawDrawImageBacking::EndRasterWriteAccess(base::OnceClosure callback) {
  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
  AutoLock auto_lock(this);
  DCHECK_EQ(read_count_, 0);
  DCHECK(is_write_);
  DCHECK(!paint_op_release_callback_);

  is_write_ = false;

  // If |paint_op_buffer_| contains SaveLayerOps, it usually means a SVG image
  // is drawn. For some complex SVG re-rasterizing is expensive, it causes
  // janky scrolling for some page which SVG images are heavily used.
  // Workaround the problem by return nullptr here, and then SkiaRenderer will
  // fallback to using |backing_texture_|.
  // TODO(crbug.com/40212988): only cache raster results for the SaveLayerOp
  // covered area.
  if (visible_ && paint_op_buffer_->has_save_layer_ops()) {
    // If the raster task priority is high, we will execute paint ops
    // immediately.
    CreateBackendTextureAndFlushPaintOps(/*flush=*/true);
    if (callback)
      std::move(callback).Run();
  }

  if (callback) {
    paint_op_release_callback_ = std::move(callback);
  }
}

cc::PaintOpBuffer* RawDrawImageBacking::BeginRasterReadAccess(
    std::optional<SkColor4f>& clear_color) {
  // paint ops will be read on compositor thread, so do not check thread with
  // DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
  AutoLock auto_lock(this);
  if (is_write_) {
    LOG(ERROR) << "The backing is being written.";
    return nullptr;
  }

  // If |backend_texture_| is valid, |paint_op_buffer_| should be played back
  // to the |backend_texture_| already, and |paint_op_buffer_| could be
  // released already. So we return nullptr here, and then SkiaRenderer will
  // fallback to using |backend_texture_|.
  if (backend_texture_.isValid())
    return nullptr;

  // If |paint_op_buffer_| contains SaveLayerOps, it usually means a SVG image
  // is drawn. For some complex SVG re-rasterizing is expensive, it causes
  // janky scrolling for some page which SVG images are heavily used.
  // Workaround the problem by return nullptr here, and then SkiaRenderer will
  // fallback to using |backing_texture_|.
  // TODO(crbug.com/40212988): only cache raster results for the SaveLayerOp
  // covered area.
  if (paint_op_buffer_ && paint_op_buffer_->has_save_layer_ops())
    return nullptr;

  read_count_++;

  if (!paint_op_buffer_) {
    paint_op_buffer_.emplace();
  }

  clear_color = clear_color_;
  return base::OptionalToPtr(paint_op_buffer_);
}

sk_sp<GrPromiseImageTexture> RawDrawImageBacking::BeginSkiaReadAccess() {
  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
  AutoLock auto_lock(this);
  if (!backend_texture_.isValid() &&
      !CreateBackendTextureAndFlushPaintOps(/*flush=*/false))
    return nullptr;

  DCHECK(promise_texture_);
  read_count_++;
  return promise_texture_;
}

void RawDrawImageBacking::EndReadAccess() {
  DCHECK_CALLED_ON_VALID_THREAD(thread_checker_);
  AutoLock auto_lock(this);
  DCHECK_GE(read_count_, 0);
  DCHECK(!is_write_);
  read_count_--;

  // If the |backend_texture_| is valid, the |paint_op_buffer_| should have
  // been played back to the |backend_texture_| already, so we can release
  // the |paint_op_buffer_| now.
  if (read_count_ == 0 && backend_texture_.isValid())
    ResetPaintOpBuffer();
}

}  // namespace gpu