namespace {

// Converts a SkColor to a ColorF.
D2D1_COLOR_F SkColorToColorF(SkColor color) {
  return D2D1::ColorF(static_cast<float>(SkColorGetR(color)) / 0xFF,
                      static_cast<float>(SkColorGetG(color)) / 0xFF,
                      static_cast<float>(SkColorGetB(color)) / 0xFF,
                      static_cast<float>(SkColorGetA(color)) / 0xFF);
}

D2D1_RECT_F RectToRectF(int x, int y, int w, int h) {
  return D2D1::RectF(static_cast<float>(x), static_cast<float>(y),
                     static_cast<float>(x + w), static_cast<float>(y + h));
}

D2D1_RECT_F RectToRectF(const gfx::Rect& rect) {
  return RectToRectF(rect.x(), rect.y(), rect.width(), rect.height());
}

D2D1_POINT_2F PointToPoint2F(int x, int y) {
  return D2D1::Point2F(static_cast<float>(x), static_cast<float>(y));
}

D2D1_BITMAP_INTERPOLATION_MODE FilterToInterpolationMode(bool filter) {
  return filter ? D2D1_BITMAP_INTERPOLATION_MODE_LINEAR
                : D2D1_BITMAP_INTERPOLATION_MODE_NEAREST_NEIGHBOR;
}

// Creates a Direct2D bitmap object from the contents of a SkBitmap. The caller
// is responsible for releasing this object.
ID2D1Bitmap* CreateD2D1BitmapFromSkBitmap(ID2D1RenderTarget* render_target,
                                          const SkBitmap& bitmap) {
  ID2D1Bitmap* d2d1_bitmap = NULL;
  HRESULT hr = render_target->CreateBitmap(
      D2D1::SizeU(bitmap.width(), bitmap.height()),
      NULL,
      NULL,
      D2D1::BitmapProperties(
          D2D1::PixelFormat(DXGI_FORMAT_B8G8R8A8_UNORM,
                            D2D1_ALPHA_MODE_IGNORE)),
      &d2d1_bitmap);
  if (FAILED(hr))
    return NULL;
  bitmap.lockPixels();
  d2d1_bitmap->CopyFromMemory(NULL, bitmap.getPixels(), bitmap.rowBytes());
  bitmap.unlockPixels();
  return d2d1_bitmap;
}

// Creates a Direct2D bitmap brush from the contents of a SkBitmap. The caller
// is responsible for releasing this object.
ID2D1Brush* CreateD2D1BrushFromSkBitmap(ID2D1RenderTarget* render_target,
                                        const SkBitmap& bitmap,
                                        D2D1_EXTEND_MODE extend_mode_x,
                                        D2D1_EXTEND_MODE extend_mode_y) {
  base::win::ScopedComPtr<ID2D1Bitmap> d2d1_bitmap(
      CreateD2D1BitmapFromSkBitmap(render_target, bitmap));

  ID2D1BitmapBrush* brush = NULL;
  render_target->CreateBitmapBrush(
      d2d1_bitmap,
      D2D1::BitmapBrushProperties(extend_mode_x, extend_mode_y),
      D2D1::BrushProperties(),
      &brush);
  return brush;
}

// A platform wrapper for a Direct2D brush that makes sure the underlying
// ID2D1Brush COM object is released when this object is destroyed.
class Direct2DBrush : public gfx::Brush {
 public:
  explicit Direct2DBrush(ID2D1Brush* brush) : brush_(brush) {
  }

  ID2D1Brush* brush() const { return brush_.get(); }

 private:
  base::win::ScopedComPtr<ID2D1Brush> brush_;

  DISALLOW_COPY_AND_ASSIGN(Direct2DBrush);
};


}  // namespace

namespace gfx {

// static
ID2D1Factory* CanvasDirect2D::d2d1_factory_ = NULL;

////////////////////////////////////////////////////////////////////////////////
// CanvasDirect2D, public:

CanvasDirect2D::CanvasDirect2D(ID2D1RenderTarget* rt) : rt_(rt) {
  // A RenderState entry is pushed onto the stack to track the clip count prior
  // to any calls to Save*().
  state_.push(RenderState());
  rt_->BeginDraw();
}

CanvasDirect2D::~CanvasDirect2D() {
  // Unwind any clips that were pushed outside of any Save*()/Restore() pairs.
  int clip_count = state_.top().clip_count;
  for (int i = 0; i < clip_count; ++i)
    rt_->PopAxisAlignedClip();
  rt_->EndDraw();
}

// static
ID2D1Factory* CanvasDirect2D::GetD2D1Factory() {
  if (!d2d1_factory_)
    D2D1CreateFactory(D2D1_FACTORY_TYPE_SINGLE_THREADED, &d2d1_factory_);
  return d2d1_factory_;
}

////////////////////////////////////////////////////////////////////////////////
// CanvasDirect2D, Canvas implementation:

void CanvasDirect2D::Save() {
  SaveInternal(NULL);
}

void CanvasDirect2D::SaveLayerAlpha(uint8 alpha) {
  SaveLayerAlpha(alpha, gfx::Rect());
}

void CanvasDirect2D::SaveLayerAlpha(uint8 alpha,
                                    const gfx::Rect& layer_bounds) {
  D2D1_RECT_F bounds = D2D1::InfiniteRect();
  if (!layer_bounds.IsEmpty())
    bounds = RectToRectF(layer_bounds);
  ID2D1Layer* layer = NULL;
  HRESULT hr = rt_->CreateLayer(NULL, &layer);
  if (SUCCEEDED(hr)) {
    rt_->PushLayer(D2D1::LayerParameters(bounds,
                                         NULL,
                                         D2D1_ANTIALIAS_MODE_PER_PRIMITIVE,
                                         D2D1::IdentityMatrix(),
                                         static_cast<float>(alpha) / 0xFF,
                                         NULL,
                                         D2D1_LAYER_OPTIONS_NONE),
                   layer);
  }
  SaveInternal(layer);
}

void CanvasDirect2D::Restore() {
  ID2D1Layer* layer = state_.top().layer;
  if (layer) {
    rt_->PopLayer();
    layer->Release();
  }

  int clip_count = state_.top().clip_count;
  for (int i = 0; i < clip_count; ++i)
    rt_->PopAxisAlignedClip();

  state_.pop();
  // The state_ stack should never be empty - we should always have at least one
  // entry to hold a clip count when there is no active save/restore entry.
  CHECK(!state_.empty()) << "Called Restore() once too often!";

  rt_->RestoreDrawingState(drawing_state_block_);
}

bool CanvasDirect2D::ClipRectInt(int x, int y, int w, int h) {
  rt_->PushAxisAlignedClip(RectToRectF(x, y, w, h),
                           D2D1_ANTIALIAS_MODE_PER_PRIMITIVE);
  // Increment the clip count so the call to PushAxisAlignedClip() can be
  // balanced with a call to PopAxisAlignedClip in the next Restore().
  ++state_.top().clip_count;
  return w > 0 && h > 0;
}

void CanvasDirect2D::TranslateInt(int x, int y) {
  D2D1_MATRIX_3X2_F raw;
  rt_->GetTransform(&raw);
  D2D1::Matrix3x2F transform(raw._11, raw._12, raw._21, raw._22, raw._31,
                             raw._32);
  transform = D2D1::Matrix3x2F::Translation(static_cast<float>(x),
                                            static_cast<float>(y)) * transform;
  rt_->SetTransform(transform);
}

void CanvasDirect2D::ScaleInt(int x, int y) {
  D2D1_MATRIX_3X2_F raw;
  rt_->GetTransform(&raw);
  D2D1::Matrix3x2F transform(raw._11, raw._12, raw._21, raw._22, raw._31,
                             raw._32);
  transform = D2D1::Matrix3x2F::Scale(static_cast<float>(x),
                                      static_cast<float>(y)) * transform;
  rt_->SetTransform(transform);
}

void CanvasDirect2D::FillRectInt(const SkColor& color,
                                 int x, int y, int w, int h) {
  base::win::ScopedComPtr<ID2D1SolidColorBrush> solid_brush;
  rt_->CreateSolidColorBrush(SkColorToColorF(color), solid_brush.Receive());
  rt_->FillRectangle(RectToRectF(x, y, w, h), solid_brush);
}

void CanvasDirect2D::FillRectInt(const SkColor& color,
                                 int x, int y, int w, int h,
                                 SkXfermode::Mode mode) {
  NOTIMPLEMENTED();
}

void CanvasDirect2D::FillRectInt(const gfx::Brush* brush,
                                 int x, int y, int w, int h) {
  const Direct2DBrush* d2d_brush = static_cast<const Direct2DBrush*>(brush);
  rt_->FillRectangle(RectToRectF(x, y, w, h), d2d_brush->brush());
}

void CanvasDirect2D::DrawRectInt(const SkColor& color,
                                 int x, int y, int w, int h) {
  base::win::ScopedComPtr<ID2D1SolidColorBrush> solid_brush;
  rt_->CreateSolidColorBrush(SkColorToColorF(color), solid_brush.Receive());
  rt_->DrawRectangle(RectToRectF(x, y, w, h), solid_brush);
}

void CanvasDirect2D::DrawRectInt(const SkColor& color,
                                 int x, int y, int w, int h,
                                 SkXfermode::Mode mode) {
  NOTIMPLEMENTED();
}

void CanvasDirect2D::DrawRectInt(int x, int y, int w, int h,
                                 const SkPaint& paint) {
  NOTIMPLEMENTED();
}

void CanvasDirect2D::DrawLineInt(const SkColor& color,
                                 int x1, int y1,
                                 int x2, int y2) {
  base::win::ScopedComPtr<ID2D1SolidColorBrush> solid_brush;
  rt_->CreateSolidColorBrush(SkColorToColorF(color), solid_brush.Receive());
  rt_->DrawLine(PointToPoint2F(x1, y1), PointToPoint2F(x2, y2), solid_brush);
}

void CanvasDirect2D::DrawBitmapInt(const SkBitmap& bitmap, int x, int y) {
  base::win::ScopedComPtr<ID2D1Bitmap> d2d1_bitmap(
      CreateD2D1BitmapFromSkBitmap(rt_, bitmap));
  rt_->DrawBitmap(d2d1_bitmap,
                  RectToRectF(x, y, bitmap.width(), bitmap.height()),
                  1.0f,
                  D2D1_BITMAP_INTERPOLATION_MODE_NEAREST_NEIGHBOR,
                  RectToRectF(0, 0, bitmap.width(), bitmap.height()));
}

void CanvasDirect2D::DrawBitmapInt(const SkBitmap& bitmap,
                                   int x, int y,
                                   const SkPaint& paint) {
  NOTIMPLEMENTED();
}

void CanvasDirect2D::DrawBitmapInt(const SkBitmap& bitmap,
                                   int src_x, int src_y, int src_w, int src_h,
                                   int dest_x, int dest_y,
                                   int dest_w, int dest_h,
                                   bool filter) {
  base::win::ScopedComPtr<ID2D1Bitmap> d2d1_bitmap(
      CreateD2D1BitmapFromSkBitmap(rt_, bitmap));
  rt_->DrawBitmap(d2d1_bitmap,
                  RectToRectF(dest_x, dest_y, dest_w, dest_h),
                  1.0f,
                  FilterToInterpolationMode(filter),
                  RectToRectF(src_x, src_y, src_w, src_h));
}

void CanvasDirect2D::DrawBitmapInt(const SkBitmap& bitmap,
                                   int src_x, int src_y, int src_w, int src_h,
                                   int dest_x, int dest_y,
                                   int dest_w, int dest_h,
                                   bool filter,
                                   const SkPaint& paint) {
  NOTIMPLEMENTED();
}

void CanvasDirect2D::DrawStringInt(const string16& text,
                                   const gfx::Font& font,
                                   const SkColor& color,
                                   int x, int y, int w, int h) {
  NOTIMPLEMENTED();
}

void CanvasDirect2D::DrawStringInt(const string16& text,
                                   const gfx::Font& font,
                                   const SkColor& color,
                                   const gfx::Rect& display_rect) {
  NOTIMPLEMENTED();
}

void CanvasDirect2D::DrawStringInt(const string16& text,
                                   const gfx::Font& font,
                                   const SkColor& color,
                                   int x, int y, int w, int h,
                                   int flags) {
  NOTIMPLEMENTED();
}

void CanvasDirect2D::DrawFocusRect(int x, int y, int width, int height) {
  NOTIMPLEMENTED();
}

void CanvasDirect2D::TileImageInt(const SkBitmap& bitmap,
                                  int x, int y, int w, int h) {
  base::win::ScopedComPtr<ID2D1Brush> brush(
      CreateD2D1BrushFromSkBitmap(rt_, bitmap, D2D1_EXTEND_MODE_WRAP,
                                  D2D1_EXTEND_MODE_WRAP));
  rt_->FillRectangle(RectToRectF(x, y, w, h), brush);
}

void CanvasDirect2D::TileImageInt(const SkBitmap& bitmap,
                                  int src_x, int src_y,
                                  int dest_x, int dest_y, int w, int h) {
  NOTIMPLEMENTED();
}

gfx::NativeDrawingContext CanvasDirect2D::BeginPlatformPaint() {
  DCHECK(!interop_rt_.get());
  interop_rt_.QueryFrom(rt_);
  HDC dc = NULL;
  if (interop_rt_.get())
    interop_rt_->GetDC(D2D1_DC_INITIALIZE_MODE_COPY, &dc);
  return dc;
}

void CanvasDirect2D::EndPlatformPaint() {
  DCHECK(interop_rt_.get());
  interop_rt_->ReleaseDC(NULL);
  interop_rt_.release();
}

void CanvasDirect2D::Transform(const ui::Transform& transform) {
  NOTIMPLEMENTED();
}

ui::TextureID CanvasDirect2D::GetTextureID() {
  NOTIMPLEMENTED();
  return 0;
}

CanvasSkia* CanvasDirect2D::AsCanvasSkia() {
  return NULL;
}

const CanvasSkia* CanvasDirect2D::AsCanvasSkia() const {
  return NULL;
}

////////////////////////////////////////////////////////////////////////////////
// CanvasDirect2D, private:

void CanvasDirect2D::SaveInternal(ID2D1Layer* layer) {
  if (!drawing_state_block_)
    GetD2D1Factory()->CreateDrawingStateBlock(drawing_state_block_.Receive());
  rt_->SaveDrawingState(drawing_state_block_.get());
  state_.push(RenderState(layer));
}

}  // namespace gfx
