// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "impeller/renderer/backend/vulkan/texture_vk.h"

#include "impeller/renderer/backend/vulkan/command_buffer_vk.h"
#include "impeller/renderer/backend/vulkan/command_encoder_vk.h"
#include "impeller/renderer/backend/vulkan/formats_vk.h"

namespace impeller {

TextureVK::TextureVK(std::weak_ptr<Context> context,
                     std::shared_ptr<TextureSourceVK> source)
    : Texture(source->GetTextureDescriptor()),
      context_(std::move(context)),
      source_(std::move(source)) {}

TextureVK::~TextureVK() = default;

void TextureVK::SetLabel(std::string_view label) {
  auto context = context_.lock();
  if (!context) {
    // The context may have died.
    return;
  }
  ContextVK::Cast(*context).SetDebugName(GetImage(), label);
  ContextVK::Cast(*context).SetDebugName(GetImageView(), label);
}

bool TextureVK::OnSetContents(const uint8_t* contents,
                              size_t length,
                              size_t slice) {
  if (!IsValid() || !contents) {
    return false;
  }

  const auto& desc = GetTextureDescriptor();

  // Out of bounds access.
  if (length != desc.GetByteSizeOfBaseMipLevel()) {
    VALIDATION_LOG << "Illegal to set contents for invalid size.";
    return false;
  }

  auto context = context_.lock();
  if (!context) {
    VALIDATION_LOG << "Context died before setting contents on texture.";
    return false;
  }

  auto staging_buffer =
      context->GetResourceAllocator()->CreateBufferWithCopy(contents, length);

  if (!staging_buffer) {
    VALIDATION_LOG << "Could not create staging buffer.";
    return false;
  }

  auto cmd_buffer = context->CreateCommandBuffer();

  if (!cmd_buffer) {
    return false;
  }

  const auto encoder = CommandBufferVK::Cast(*cmd_buffer).GetEncoder();

  if (!encoder->Track(staging_buffer) || !encoder->Track(source_)) {
    return false;
  }

  const auto& vk_cmd_buffer = encoder->GetCommandBuffer();

  LayoutTransition transition;
  transition.cmd_buffer = vk_cmd_buffer;
  transition.new_layout = vk::ImageLayout::eTransferDstOptimal;
  transition.src_access = {};
  transition.src_stage = vk::PipelineStageFlagBits::eTopOfPipe;
  transition.dst_access = vk::AccessFlagBits::eTransferWrite;
  transition.dst_stage = vk::PipelineStageFlagBits::eTransfer;

  if (!SetLayout(transition)) {
    return false;
  }

  vk::BufferImageCopy copy;
  copy.bufferOffset = 0u;
  copy.bufferRowLength = 0u;    // 0u means tightly packed per spec.
  copy.bufferImageHeight = 0u;  // 0u means tightly packed per spec.
  copy.imageOffset.x = 0u;
  copy.imageOffset.y = 0u;
  copy.imageOffset.z = 0u;
  copy.imageExtent.width = desc.size.width;
  copy.imageExtent.height = desc.size.height;
  copy.imageExtent.depth = 1u;
  copy.imageSubresource.aspectMask = vk::ImageAspectFlagBits::eColor;
  copy.imageSubresource.mipLevel = 0u;
  copy.imageSubresource.baseArrayLayer = slice;
  copy.imageSubresource.layerCount = 1u;

  vk_cmd_buffer.copyBufferToImage(
      DeviceBufferVK::Cast(*staging_buffer).GetBuffer(),  // src buffer
      GetImage(),                                         // dst image
      transition.new_layout,                              // dst image layout
      1u,                                                 // region count
      &copy                                               // regions
  );

  return cmd_buffer->SubmitCommands();
}

bool TextureVK::OnSetContents(std::shared_ptr<const fml::Mapping> mapping,
                              size_t slice) {
  // Vulkan has no threading restrictions. So we can pass this data along to the
  // client rendering API immediately.
  return OnSetContents(mapping->GetMapping(), mapping->GetSize(), slice);
}

bool TextureVK::IsValid() const {
  return !!source_;
}

ISize TextureVK::GetSize() const {
  return GetTextureDescriptor().size;
}

vk::Image TextureVK::GetImage() const {
  return source_->GetImage();
}

vk::ImageView TextureVK::GetImageView() const {
  return source_->GetImageView();
}

std::shared_ptr<const TextureSourceVK> TextureVK::GetTextureSource() const {
  return source_;
}

bool TextureVK::SetLayout(const LayoutTransition& transition) const {
  return source_ ? source_->SetLayout(transition) : false;
}

vk::ImageLayout TextureVK::SetLayoutWithoutEncoding(
    vk::ImageLayout layout) const {
  return source_ ? source_->SetLayoutWithoutEncoding(layout)
                 : vk::ImageLayout::eUndefined;
}

vk::ImageLayout TextureVK::GetLayout() const {
  return source_ ? source_->GetLayout() : vk::ImageLayout::eUndefined;
}

}  // namespace impeller