// Copyright 2019 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/egl_image_backing.h"

#include <optional>

#include "base/memory/raw_ptr.h"
#include "gpu/command_buffer/common/shared_image_usage.h"
#include "gpu/command_buffer/service/gl_utils.h"
#include "gpu/command_buffer/service/shared_context_state.h"
#include "gpu/command_buffer/service/shared_image/shared_image_gl_utils.h"
#include "gpu/command_buffer/service/shared_image/shared_image_representation.h"
#include "gpu/command_buffer/service/shared_image/skia_gl_image_representation.h"
#include "gpu/command_buffer/service/texture_manager.h"
#include "ui/gl/buildflags.h"
#include "ui/gl/gl_fence_egl.h"
#include "ui/gl/gl_utils.h"
#include "ui/gl/scoped_binders.h"
#include "ui/gl/shared_gl_fence_egl.h"

#if BUILDFLAG(USE_DAWN) && BUILDFLAG(DAWN_ENABLE_BACKEND_OPENGLES)
#include "gpu/command_buffer/service/shared_image/dawn_egl_image_representation.h"
#endif

namespace gpu {

class EGLImageBacking::TextureHolder : public base::RefCounted<TextureHolder> {
 public:
  explicit TextureHolder(gles2::Texture* texture) : texture_(texture) {}
  explicit TextureHolder(
      scoped_refptr<gles2::TexturePassthrough> texture_passthrough)
      : texture_passthrough_(std::move(texture_passthrough)) {}

  void MarkContextLost() {
    context_lost_ = true;
    if (texture_passthrough_)
      texture_passthrough_->MarkContextLost();
  }

  gles2::Texture* texture() { return texture_; }
  const scoped_refptr<gles2::TexturePassthrough>& texture_passthrough() const {
    return texture_passthrough_;
  }

 private:
  friend class base::RefCounted<TextureHolder>;

  ~TextureHolder() {
    if (texture_) {
      texture_.ExtractAsDangling()->RemoveLightweightRef(!context_lost_);
    }
  }

  raw_ptr<gles2::Texture> texture_ = nullptr;
  const scoped_refptr<gles2::TexturePassthrough> texture_passthrough_;
  bool context_lost_ = false;
};

// Implementation of GLTextureImageRepresentation which uses GL texture
// which is an EGLImage sibling.
class EGLImageBacking::GLRepresentationShared {
 public:
  using TextureHolder = EGLImageBacking::TextureHolder;
  GLRepresentationShared(
      EGLImageBacking* backing,
      std::vector<scoped_refptr<TextureHolder>> texture_holders)
      : backing_(backing), texture_holders_(std::move(texture_holders)) {}

  GLRepresentationShared(const GLRepresentationShared&) = delete;
  GLRepresentationShared& operator=(const GLRepresentationShared&) = delete;

  ~GLRepresentationShared() {
    EndAccess();
    if (!backing_->have_context()) {
      for (auto texture_holder : texture_holders_) {
        texture_holder->MarkContextLost();
      }
    }
    texture_holders_.clear();
  }

  bool BeginAccess(GLenum mode) {
    if (mode == GL_SHARED_IMAGE_ACCESS_MODE_READ_CHROMIUM) {
      if (!backing_->BeginRead(this))
        return false;
      mode_ = RepresentationAccessMode::kRead;
    } else if (mode == GL_SHARED_IMAGE_ACCESS_MODE_READWRITE_CHROMIUM) {
      if (!backing_->BeginWrite())
        return false;
      mode_ = RepresentationAccessMode::kWrite;
    } else {
      NOTREACHED();
    }
    return true;
  }

  void EndAccess() {
    if (mode_ == RepresentationAccessMode::kNone)
      return;

    // Pass this fence to its backing.
    if (mode_ == RepresentationAccessMode::kRead) {
      backing_->EndRead(this);
    } else if (mode_ == RepresentationAccessMode::kWrite) {
      backing_->EndWrite();
    } else {
      NOTREACHED();
    }
    mode_ = RepresentationAccessMode::kNone;
  }

  const scoped_refptr<TextureHolder>& texture_holder(int plane_index) const {
    return texture_holders_[plane_index];
  }

 private:
  const raw_ptr<EGLImageBacking> backing_;
  std::vector<scoped_refptr<TextureHolder>> texture_holders_;
  RepresentationAccessMode mode_ = RepresentationAccessMode::kNone;
};

class EGLImageBacking::GLTextureEGLImageRepresentation
    : public GLTextureImageRepresentation {
 public:
  GLTextureEGLImageRepresentation(
      SharedImageManager* manager,
      EGLImageBacking* backing,
      MemoryTypeTracker* tracker,
      std::vector<scoped_refptr<TextureHolder>> texture_holders)
      : GLTextureImageRepresentation(manager, backing, tracker),
        shared_(backing, std::move(texture_holders)) {}

  GLTextureEGLImageRepresentation(const GLTextureEGLImageRepresentation&) =
      delete;
  GLTextureEGLImageRepresentation& operator=(
      const GLTextureEGLImageRepresentation&) = delete;

  ~GLTextureEGLImageRepresentation() override = default;

  bool BeginAccess(GLenum mode) override { return shared_.BeginAccess(mode); }

  void EndAccess() override { shared_.EndAccess(); }

  gles2::Texture* GetTexture(int plane_index) override {
    CHECK(format().IsValidPlaneIndex(plane_index));
    return shared_.texture_holder(plane_index)->texture();
  }

  bool SupportsMultipleConcurrentReadAccess() override { return true; }

 private:
  GLRepresentationShared shared_;
};

class EGLImageBacking::GLTexturePassthroughEGLImageRepresentation
    : public GLTexturePassthroughImageRepresentation {
 public:
  GLTexturePassthroughEGLImageRepresentation(
      SharedImageManager* manager,
      EGLImageBacking* backing,
      MemoryTypeTracker* tracker,
      std::vector<scoped_refptr<TextureHolder>> texture_holders)
      : GLTexturePassthroughImageRepresentation(manager, backing, tracker),
        shared_(backing, std::move(texture_holders)) {}

  GLTexturePassthroughEGLImageRepresentation(
      const GLTexturePassthroughEGLImageRepresentation&) = delete;
  GLTexturePassthroughEGLImageRepresentation& operator=(
      const GLTexturePassthroughEGLImageRepresentation&) = delete;

  ~GLTexturePassthroughEGLImageRepresentation() override = default;

  bool BeginAccess(GLenum mode) override { return shared_.BeginAccess(mode); }

  void EndAccess() override { shared_.EndAccess(); }

  const scoped_refptr<gles2::TexturePassthrough>& GetTexturePassthrough(
      int plane_index) override {
    CHECK(format().IsValidPlaneIndex(plane_index));
    // TODO(crbug.com/40166788): Remove this CHECK.
    CHECK(shared_.texture_holder(plane_index)->texture_passthrough());
    return shared_.texture_holder(plane_index)->texture_passthrough();
  }

  bool SupportsMultipleConcurrentReadAccess() override { return true; }

 private:
  GLRepresentationShared shared_;
};

EGLImageBacking::EGLImageBacking(
    const Mailbox& mailbox,
    viz::SharedImageFormat format,
    const gfx::Size& size,
    const gfx::ColorSpace& color_space,
    GrSurfaceOrigin surface_origin,
    SkAlphaType alpha_type,
    SharedImageUsageSet usage,
    std::string debug_label,
    size_t estimated_size,
    const std::vector<GLCommonImageBackingFactory::FormatInfo>& format_info,
    const GpuDriverBugWorkarounds& workarounds,
    bool use_passthrough,
    base::span<const uint8_t> pixel_data)
    : ClearTrackingSharedImageBacking(mailbox,
                                      format,
                                      size,
                                      color_space,
                                      surface_origin,
                                      alpha_type,
                                      usage,
                                      std::move(debug_label),
                                      estimated_size,
                                      true /*is_thread_safe*/),
      format_info_(format_info),
      use_passthrough_(use_passthrough) {
  created_on_context_ = gl::g_current_gl_context;
  // On some GPUs (NVidia) keeping reference to egl image itself is not enough,
  // we must keep reference to at least one sibling. Note that this workaround
  // is currently enabled for all android devices.
  // When we have pixel data, we want to initialize the texture with pixel data
  // first before creating eglimage from it. Hence using GenEGLImageSibling()
  // call to do that.
  if (workarounds.dont_delete_source_texture_for_egl_image) {
    source_texture_holders_ = GenEGLImageSiblings(pixel_data);
  } else if (!pixel_data.empty()) {
    auto texture_holder = GenEGLImageSiblings(pixel_data);
  }
}

EGLImageBacking::~EGLImageBacking() {
  CHECK(source_texture_holders_.empty());
}

SharedImageBackingType EGLImageBacking::GetType() const {
  return SharedImageBackingType::kEGLImage;
}

void EGLImageBacking::Update(std::unique_ptr<gfx::GpuFence> in_fence) {
  NOTREACHED();
}

template <class T>
std::unique_ptr<T> EGLImageBacking::ProduceGLTextureInternal(
    SharedImageManager* manager,
    MemoryTypeTracker* tracker) {
  // On some GPUs (Mali, mostly Android 9, like J7) glTexSubImage fails on egl
  // image sibling. So we use the original texture if we're on the same gl
  // context. see https://crbug.com/1117370
  // If we're on the same context we're on the same thread, so
  // source_texture_holder_ is accessed only from thread we created it and
  // doesn't need lock.
  if (created_on_context_ == gl::g_current_gl_context &&
      !source_texture_holders_.empty()) {
    return std::make_unique<T>(manager, this, tracker, source_texture_holders_);
  }

  auto texture_holders =
      GenEGLImageSiblings(/*pixel_data=*/base::span<const uint8_t>());
  if (texture_holders.empty()) {
    return nullptr;
  }
  return std::make_unique<T>(manager, this, tracker,
                             std::move(texture_holders));
}

std::unique_ptr<GLTextureImageRepresentation> EGLImageBacking::ProduceGLTexture(
    SharedImageManager* manager,
    MemoryTypeTracker* tracker) {
  return ProduceGLTextureInternal<GLTextureEGLImageRepresentation>(manager,
                                                                   tracker);
}

std::unique_ptr<GLTexturePassthroughImageRepresentation>
EGLImageBacking::ProduceGLTexturePassthrough(SharedImageManager* manager,
                                             MemoryTypeTracker* tracker) {
  return ProduceGLTextureInternal<GLTexturePassthroughEGLImageRepresentation>(
      manager, tracker);
}

std::unique_ptr<SkiaGaneshImageRepresentation>
EGLImageBacking::ProduceSkiaGanesh(
    SharedImageManager* manager,
    MemoryTypeTracker* tracker,
    scoped_refptr<SharedContextState> context_state) {
  std::unique_ptr<GLTextureImageRepresentationBase> gl_representation;
  if (use_passthrough_) {
    gl_representation = ProduceGLTexturePassthrough(manager, tracker);
  } else {
    gl_representation = ProduceGLTexture(manager, tracker);
  }
  if (!gl_representation) {
    return nullptr;
  }
  return SkiaGLImageRepresentation::Create(std::move(gl_representation),
                                           std::move(context_state), manager,
                                           this, tracker);
}

std::unique_ptr<DawnImageRepresentation> EGLImageBacking::ProduceDawn(
    SharedImageManager* manager,
    MemoryTypeTracker* tracker,
    const wgpu::Device& device,
    wgpu::BackendType backend_type,
    std::vector<wgpu::TextureFormat> view_formats,
    scoped_refptr<SharedContextState> context_state) {
#if BUILDFLAG(USE_DAWN) && BUILDFLAG(DAWN_ENABLE_BACKEND_OPENGLES)
  if (backend_type == wgpu::BackendType::OpenGLES) {
    std::unique_ptr<GLTextureImageRepresentationBase> gl_representation;
    if (use_passthrough_) {
      gl_representation = ProduceGLTexturePassthrough(manager, tracker);
    } else {
      gl_representation = ProduceGLTexture(manager, tracker);
    }
    if (!gl_representation) {
      return nullptr;
    }
    void* egl_image = nullptr;
    {
      AutoLock auto_lock(this);
      egl_image = egl_images_[0].get();
    }
    // TODO(crbug.com/40278761): Add multiplanar support to this representation.
    return std::make_unique<DawnEGLImageRepresentation>(
        std::move(gl_representation), egl_image, manager, this, tracker,
        device.Get(), std::move(view_formats));
  }
#endif  // BUILDFLAG(USE_DAWN) && BUILDFLAG(DAWN_ENABLE_BACKEND_OPENGLES)
  return nullptr;
}

bool EGLImageBacking::BeginWrite() {
  AutoLock auto_lock(this);

  if (is_writing_ || !active_readers_.empty()) {
    DLOG(ERROR) << "BeginWrite should only be called when there are no other "
                   "readers or writers";
    return false;
  }
  is_writing_ = true;

  // When multiple threads wants to write to the same backing, writer needs to
  // wait on previous reads and writes to be finished.
  if (!read_fences_.empty()) {
    for (const auto& read_fence : read_fences_) {
      read_fence.second->ServerWait();
    }
    // Once all the read fences have been waited upon, its safe to clear all of
    // them. Note that when there is an active writer, no one can read and hence
    // can not update |read_fences_|.
    read_fences_.clear();
  }

  if (write_fence_)
    write_fence_->ServerWait();

  return true;
}

void EGLImageBacking::EndWrite() {
  AutoLock auto_lock(this);

  if (!is_writing_) {
    DLOG(ERROR) << "Attempt to end write to a SharedImageBacking without a "
                   "successful begin write";
    return;
  }

  is_writing_ = false;
  write_fence_ = gl::GLFenceEGL::Create();
}

bool EGLImageBacking::BeginRead(const GLRepresentationShared* reader) {
  AutoLock auto_lock(this);

  if (is_writing_) {
    DLOG(ERROR) << "BeginRead should only be called when there are no writers";
    return false;
  }

  if (active_readers_.contains(reader)) {
    LOG(ERROR) << "BeginRead was called twice on the same representation";
    return false;
  }
  active_readers_.insert(reader);
  if (write_fence_)
    write_fence_->ServerWait();

  return true;
}

void EGLImageBacking::EndRead(const GLRepresentationShared* reader) {
  {
    AutoLock auto_lock(this);

    if (!active_readers_.contains(reader)) {
      DLOG(ERROR) << "Attempt to end read to a SharedImageBacking without a "
                     "successful begin read";
      return;
    }
    active_readers_.erase(reader);
  }

  AutoLock auto_lock(this);
  read_fences_[gl::g_current_gl_context] =
      base::MakeRefCounted<gl::SharedGLFenceEGL>();
}

gl::ScopedEGLImage EGLImageBacking::GenEGLImageSibling(
    base::span<const uint8_t> pixel_data,
    std::vector<GLuint>& service_ids,
    int plane) {
  GLenum target = GL_TEXTURE_2D;
  gl::GLApi* api = gl::g_current_gl_context;

  api->glGenTexturesFn(1, &service_ids[plane]);
  gl::ScopedTextureBinder texture_binder(target, service_ids[plane]);
  api->glTexParameteriFn(target, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
  api->glTexParameteriFn(target, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
  api->glTexParameteriFn(target, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
  api->glTexParameteriFn(target, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

  gfx::Size plane_size = format().GetPlaneSize(plane, size());
  const auto& format_info = format_info_[plane];
  // Note that we only want to upload pixel data to a texture during init
  // time before we create `egl_images_` from it. If pixel data is
  // empty we only allocate memory for the texture object which is
  // required to create EGLImage.
  if (format_info.supports_storage && IsTexStorage2DAvailable()) {
    api->glTexStorage2DEXTFn(target, 1,
                             format_info.adjusted_storage_internal_format,
                             plane_size.width(), plane_size.height());

    if (!pixel_data.empty()) {
      CHECK_EQ(plane, 0);
      ScopedUnpackState scoped_unpack_state(
          /*uploading_data=*/true);
      api->glTexSubImage2DFn(target, 0, 0, 0, plane_size.width(),
                             plane_size.height(), format_info.adjusted_format,
                             format_info.gl_type, pixel_data.data());
    }
  } else if (format_info.is_compressed) {
    ScopedUnpackState scoped_unpack_state(!pixel_data.empty());
    api->glCompressedTexImage2DFn(target, 0, format_info.image_internal_format,
                                  plane_size.width(), plane_size.height(), 0,
                                  pixel_data.size(), pixel_data.data());
  } else {
    ScopedUnpackState scoped_unpack_state(!pixel_data.empty());
    api->glTexImage2DFn(target, 0, format_info.image_internal_format,
                        plane_size.width(), plane_size.height(), 0,
                        format_info.adjusted_format, format_info.gl_type,
                        pixel_data.data());
  }

  // Use service id of the texture as a source to create the EGLImage.
  const EGLint egl_attrib_list[] = {
      EGL_GL_TEXTURE_LEVEL_KHR, 0, EGL_IMAGE_PRESERVED_KHR, EGL_TRUE, EGL_NONE};
  return gl::MakeScopedEGLImage(
      eglGetCurrentContext(), EGL_GL_TEXTURE_2D_KHR,
      reinterpret_cast<EGLClientBuffer>(service_ids[plane]), egl_attrib_list);
}

std::vector<scoped_refptr<EGLImageBacking::TextureHolder>>
EGLImageBacking::GenEGLImageSiblings(base::span<const uint8_t> pixel_data) {
  GLenum target = GL_TEXTURE_2D;
  gl::GLApi* api = gl::g_current_gl_context;
  int num_planes = format().NumberOfPlanes();
  std::vector<GLuint> service_ids;
  service_ids.resize(num_planes);
  std::vector<EGLImageKHR> egl_images;
  egl_images.reserve(num_planes);
  // Note that we needed to use `create_egl_images` flag and add some additional
  // logic to handle it in order to make the locks more granular since
  // BindToTexture() do not need to be behind the lock. We don't need to bind
  // the `egl_images_` first time when it's created.
  bool create_egl_images = false;
  {
    AutoLock auto_lock(this);
    create_egl_images = egl_images_.empty();
    if (create_egl_images) {
      for (int plane = 0; plane < num_planes; plane++) {
        gl::ScopedEGLImage egl_image =
            GenEGLImageSibling(pixel_data, service_ids, plane);
        // Check `egl_image` validity and add to `egl_images_` only when created
        // a new one.
        if (!egl_image.get()) {
          for (int i = 0; i <= plane; i++) {
            // Delete all textures created so far.
            api->glDeleteTexturesFn(1, &service_ids[i]);
          }
          egl_images_.clear();
          return {};
        }
        egl_images_.push_back(std::move(egl_image));
      }
    }
    for (int plane = 0; plane < num_planes; plane++) {
      egl_images.push_back(egl_images_[plane].get());
    }

    if (!pixel_data.empty()) {
      // If pixel data is being uploaded to the texture, that means we are
      // sending commands to the gpu. Hence consider it as a write and add a
      // fence to synchronize it with corresponding reads. This case happens
      // when tab windows are composited by viz for tablet ui. Initial pixel
      // data gets uploaded on the gpu main thread and being read on DrDc
      // thread.
      write_fence_ = gl::GLFenceEGL::Create();
    }
  }

  if (!create_egl_images) {
    // `pixel_data` if present should only be used to initialize textures when
    // we create `egl_images_` from it and not after it has been already
    // created.
    DCHECK(pixel_data.empty());
    for (int plane = 0; plane < num_planes; plane++) {
      api->glGenTexturesFn(1, &service_ids[plane]);
      gl::ScopedTextureBinder texture_binder(target, service_ids[plane]);
      api->glTexParameteriFn(target, GL_TEXTURE_MIN_FILTER, GL_LINEAR);
      api->glTexParameteriFn(target, GL_TEXTURE_MAG_FILTER, GL_LINEAR);
      api->glTexParameteriFn(target, GL_TEXTURE_WRAP_S, GL_CLAMP_TO_EDGE);
      api->glTexParameteriFn(target, GL_TEXTURE_WRAP_T, GL_CLAMP_TO_EDGE);

      // If we already have the `egl_images_`, just bind them to the new
      // texture to make an EGLImage sibling.
      glEGLImageTargetTexture2DOES(target, egl_images[plane]);
      DCHECK_EQ(static_cast<EGLint>(EGL_SUCCESS), eglGetError());
      DCHECK_EQ(static_cast<GLenum>(GL_NO_ERROR), glGetError());
    }
  }

  // Mark the backing as cleared if pixel data has been uploaded. Note that
  // SetCleared() acquires the lock. Hence it is kept outside of previous lock
  // above.
  if (!pixel_data.empty()) {
    SetCleared();
  }

  std::vector<scoped_refptr<EGLImageBacking::TextureHolder>> texture_holders;
  texture_holders.reserve(num_planes);
  for (int plane = 0; plane < num_planes; plane++) {
    if (use_passthrough_) {
      auto texture_passthrough =
          base::MakeRefCounted<gpu::gles2::TexturePassthrough>(
              service_ids[plane], GL_TEXTURE_2D);
      texture_holders.push_back(
          base::MakeRefCounted<TextureHolder>(std::move(texture_passthrough)));
    } else {
      auto* texture = gles2::CreateGLES2TextureWithLightRef(service_ids[plane],
                                                            GL_TEXTURE_2D);
      gfx::Size plane_size = format().GetPlaneSize(plane, size());
      // If the backing is already cleared, no need to clear it again.
      gfx::Rect cleared_rect;
      if (IsCleared()) {
        cleared_rect = gfx::Rect(plane_size);
      }

      // Set the level info.
      texture->SetLevelInfo(GL_TEXTURE_2D, 0, format_info_[plane].gl_format,
                            plane_size.width(), plane_size.height(), 1, 0,
                            format_info_[plane].gl_format,
                            format_info_[plane].gl_type, cleared_rect);

      texture->SetImmutable(/*immutable=*/true, /*immutable_storage=*/false);
      texture_holders.push_back(
          base::MakeRefCounted<TextureHolder>(std::move(texture)));
    }
  }
  return texture_holders;
}

void EGLImageBacking::MarkForDestruction() {
  AutoLock auto_lock(this);
  DCHECK(!have_context() || created_on_context_ == gl::g_current_gl_context);

  if (!have_context()) {
    for (auto source_texture_holder : source_texture_holders_) {
      source_texture_holder->MarkContextLost();
    }
  }
  source_texture_holders_.clear();
}

}  // namespace gpu