// Copyright 2023 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "chrome/browser/ui/views/media_preview/camera_preview/video_stream_view.h"

#include <utility>

#include "chrome/browser/ui/views/chrome_layout_provider.h"
#include "chrome/browser/ui/views/media_preview/camera_preview/video_format_comparison.h"
#include "chrome/grit/generated_resources.h"
#include "content/public/browser/context_factory.h"
#include "gpu/config/gpu_feature_info.h"
#include "media/base/video_transformation.h"
#include "media/base/video_util.h"
#include "ui/base/l10n/l10n_util.h"
#include "ui/base/metadata/metadata_impl_macros.h"
#include "ui/base/ui_base_features.h"
#include "ui/color/color_provider.h"
#include "ui/compositor/compositor.h"
#include "ui/gfx/canvas.h"
#include "ui/views/accessibility/view_accessibility.h"

VideoStreamView::VideoStreamView()
    : targeted_aspect_ratio_(video_format_comparison::kDefaultAspectRatio),
      rounded_radius_(ChromeLayoutProvider::Get()->GetCornerRadiusMetric(
          views::Emphasis::kHigh)),
      // Placeholder initialization. OnThemeChanged() is expected to be called
      // to re-assign `preview_base_color_` value.
      preview_base_color_(SK_ColorBLACK) {
  GetViewAccessibility().SetRole(ax::mojom::Role::kImage);
  GetViewAccessibility().SetName(l10n_util::GetStringUTF16(
      IDS_MEDIA_PREVIEW_VIDEO_STREAM_ACCESSIBLE_NAME));

  raster_context_provider_ =
      content::GetContextFactory()->SharedMainThreadRasterContextProvider();
  if (raster_context_provider_) {
    raster_context_provider_->AddObserver(this);
  }
}

VideoStreamView::~VideoStreamView() {
  ClearFrame();
  if (raster_context_provider_) {
    raster_context_provider_->RemoveObserver(this);
  }
}

void VideoStreamView::OnContextLost() {
  if (raster_context_provider_) {
    raster_context_provider_->RemoveObserver(this);
  }

  raster_context_provider_ =
      content::GetContextFactory()->SharedMainThreadRasterContextProvider();
  if (raster_context_provider_) {
    raster_context_provider_->AddObserver(this);
  }
}

void VideoStreamView::ScheduleFramePaint(
    scoped_refptr<media::VideoFrame> frame) {
  latest_frame_ = std::move(frame);
  SchedulePaint();
}

void VideoStreamView::ClearFrame() {
  video_renderer_.ResetCache();
  latest_frame_.reset();
  rendered_frame_count_ = 0;
  PreferredSizeChanged();
  SchedulePaint();
}

size_t VideoStreamView::GetRenderedFrameCount() {
  return rendered_frame_count_;
}

void VideoStreamView::OnPaint(gfx::Canvas* canvas) {
  const auto background_rect = SkRect::MakeWH(width(), height());
  canvas->sk_canvas()->clipRRect(
      SkRRect::MakeRectXY(background_rect, rounded_radius_, rounded_radius_),
      /*do_anti_alias=*/true);

  cc::PaintFlags background_flags;
  background_flags.setAntiAlias(true);
  background_flags.setColor(preview_base_color_);
  canvas->sk_canvas()->drawRect(background_rect, background_flags);

  if (!latest_frame_) {
    return;
  }

  ++rendered_frame_count_;

  if (latest_frame_->HasSharedImage()) {
    // When passed a VideoFrame with a SharedImage in it,
    // PaintCanvasVideoRenderer historically could paint only if GPU
    // rasterization was supported on the passed-in context provider. This is no
    // longer the case, but examination would need to be done to determine
    // whether it is now appropriate to remove these checks. Note that we put
    // these checks underneath the increment above to preserve historical
    // behavior.
    if (!features::IsUiGpuRasterizationEnabled()) {
      return;
    }

    if (!raster_context_provider_) {
      return;
    }

    const auto& gpu_feature_info =
        raster_context_provider_->GetGpuFeatureInfo();
    if (gpu_feature_info
            .status_values[gpu::GPU_FEATURE_TYPE_GPU_TILE_RASTERIZATION] !=
        gpu::kGpuFeatureStatusEnabled) {
      return;
    }
  }

  media::PaintCanvasVideoRenderer::PaintParams paint_params;
  paint_params.dest_rect = gfx::RectF(media::ComputeLetterboxRegion(
      {width(), height()}, latest_frame_->natural_size()));
  paint_params.transformation.mirrored = true;

  cc::PaintFlags flags;
  // Select high quality frame scaling.
  flags.setFilterQuality(cc::PaintFlags::FilterQuality::kHigh);
  flags.setAntiAlias(true);

  video_renderer_.Paint(std::move(latest_frame_), canvas->sk_canvas(), flags,
                        paint_params, raster_context_provider_.get());
}

gfx::Size VideoStreamView::CalculatePreferredSize(
    const views::SizeBounds& /*available_size*/) const {
  return gfx::Size(width(), width() / targeted_aspect_ratio_);
}

void VideoStreamView::OnThemeChanged() {
  views::View::OnThemeChanged();
  preview_base_color_ = GetColorProvider()->GetColor(ui::kColorSysSurface2);
}

BEGIN_METADATA(VideoStreamView)
END_METADATA