// Copyright 2016 The Chromium 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 "skia/public/mojom/bitmap_skbitmap_mojom_traits.h"

namespace mojo {
namespace {

// Maximum reasonable width and height. We don't try to deserialize bitmaps
// bigger than these dimensions. Arbitrarily chosen.
constexpr int kMaxWidth = 32 * 1024;
constexpr int kMaxHeight = 32 * 1024;

}  // namespace

// static
bool StructTraits<skia::mojom::BitmapDataView, SkBitmap>::IsNull(
    const SkBitmap& b) {
  return b.isNull();
}

// static
void StructTraits<skia::mojom::BitmapDataView, SkBitmap>::SetToNull(
    SkBitmap* b) {
  b->reset();
}

// static
const SkImageInfo& StructTraits<skia::mojom::BitmapDataView,
                                SkBitmap>::image_info(const SkBitmap& b) {
  return b.info();
}

// static
uint64_t StructTraits<skia::mojom::BitmapDataView, SkBitmap>::row_bytes(
    const SkBitmap& b) {
  return b.rowBytes();
}

// static
mojo_base::BigBufferView StructTraits<skia::mojom::BitmapDataView,
                                      SkBitmap>::pixel_data(const SkBitmap& b) {
  return mojo_base::BigBufferView(base::make_span(
      static_cast<uint8_t*>(b.getPixels()), b.computeByteSize()));
}

// static
bool StructTraits<skia::mojom::BitmapDataView, SkBitmap>::Read(
    skia::mojom::BitmapDataView data,
    SkBitmap* b) {
  SkImageInfo image_info;
  if (!data.ReadImageInfo(&image_info))
    return false;

  // Ensure width and height are reasonable.
  if (image_info.width() > kMaxWidth || image_info.height() > kMaxHeight)
    return false;

  *b = SkBitmap();
  if (!b->tryAllocPixels(image_info, data.row_bytes())) {
    return false;
  }

  // If the image is empty, return success after setting the image info.
  if (image_info.width() == 0 || image_info.height() == 0)
    return true;

  mojo_base::BigBufferView pixel_data_view;
  if (!data.ReadPixelData(&pixel_data_view))
    return false;

  base::span<const uint8_t> pixel_data_bytes = pixel_data_view.data();
  if (b->width() != image_info.width() || b->height() != image_info.height() ||
      static_cast<uint64_t>(b->rowBytes()) != data.row_bytes() ||
      b->computeByteSize() != pixel_data_bytes.size() || !b->readyToDraw()) {
    return false;
  }

  std::copy(pixel_data_bytes.begin(), pixel_data_bytes.end(),
            static_cast<uint8_t*>(b->getPixels()));
  b->notifyPixelsChanged();
  return true;
}

// static
bool StructTraits<skia::mojom::InlineBitmapDataView, SkBitmap>::IsNull(
    const SkBitmap& b) {
  return b.isNull();
}

// static
void StructTraits<skia::mojom::InlineBitmapDataView, SkBitmap>::SetToNull(
    SkBitmap* b) {
  b->reset();
}

// static
const SkImageInfo& StructTraits<skia::mojom::InlineBitmapDataView,
                                SkBitmap>::image_info(const SkBitmap& b) {
  return StructTraits<skia::mojom::BitmapDataView, SkBitmap>::image_info(b);
}

// static
uint64_t StructTraits<skia::mojom::InlineBitmapDataView, SkBitmap>::row_bytes(
    const SkBitmap& b) {
  return StructTraits<skia::mojom::BitmapDataView, SkBitmap>::row_bytes(b);
}

// static
base::span<const uint8_t>
StructTraits<skia::mojom::InlineBitmapDataView, SkBitmap>::pixel_data(
    const SkBitmap& b) {
  return base::make_span(static_cast<uint8_t*>(b.getPixels()),
                         b.computeByteSize());
}

// static
bool StructTraits<skia::mojom::InlineBitmapDataView, SkBitmap>::Read(
    skia::mojom::InlineBitmapDataView data,
    SkBitmap* b) {
  SkImageInfo image_info;
  if (!data.ReadImageInfo(&image_info))
    return false;

  // Ensure width and height are reasonable.
  if (image_info.width() > kMaxWidth || image_info.height() > kMaxHeight)
    return false;

  *b = SkBitmap();
  if (!b->tryAllocPixels(image_info, data.row_bytes()))
    return false;

  // If the image is empty, return success after setting the image info.
  if (image_info.width() == 0 || image_info.height() == 0)
    return true;

  mojo::ArrayDataView<uint8_t> data_view;
  data.GetPixelDataDataView(&data_view);
  if (b->width() != image_info.width() || b->height() != image_info.height() ||
      static_cast<uint64_t>(b->rowBytes()) != data.row_bytes() ||
      b->computeByteSize() != data_view.size() || !b->readyToDraw()) {
    return false;
  }

  auto bitmap_buffer = base::make_span(static_cast<uint8_t*>(b->getPixels()),
                                       b->computeByteSize());
  if (!data.ReadPixelData(&bitmap_buffer) ||
      bitmap_buffer.size() != b->computeByteSize()) {
    return false;
  }

  b->notifyPixelsChanged();
  return true;
}

}  // namespace mojo
