// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "third_party/blink/renderer/core/paint/image_painter.h"

#include "third_party/blink/renderer/core/dom/document.h"
#include "third_party/blink/renderer/core/dom/element.h"
#include "third_party/blink/renderer/core/editing/frame_selection.h"
#include "third_party/blink/renderer/core/frame/local_dom_window.h"
#include "third_party/blink/renderer/core/frame/local_frame.h"
#include "third_party/blink/renderer/core/html/html_area_element.h"
#include "third_party/blink/renderer/core/html/html_image_element.h"
#include "third_party/blink/renderer/core/html/media/html_video_element.h"
#include "third_party/blink/renderer/core/inspector/inspector_trace_events.h"
#include "third_party/blink/renderer/core/layout/adjust_for_absolute_zoom.h"
#include "third_party/blink/renderer/core/layout/layout_image.h"
#include "third_party/blink/renderer/core/layout/layout_replaced.h"
#include "third_party/blink/renderer/core/page/chrome_client.h"
#include "third_party/blink/renderer/core/page/page.h"
#include "third_party/blink/renderer/core/paint/box_painter.h"
#include "third_party/blink/renderer/core/paint/outline_painter.h"
#include "third_party/blink/renderer/core/paint/paint_auto_dark_mode.h"
#include "third_party/blink/renderer/core/paint/paint_info.h"
#include "third_party/blink/renderer/core/paint/scoped_paint_state.h"
#include "third_party/blink/renderer/core/paint/timing/image_element_timing.h"
#include "third_party/blink/renderer/core/paint/timing/paint_timing_detector.h"
#include "third_party/blink/renderer/platform/geometry/path.h"
#include "third_party/blink/renderer/platform/geometry/path_builder.h"
#include "third_party/blink/renderer/platform/graphics/graphics_context.h"
#include "third_party/blink/renderer/platform/graphics/paint/display_item_cache_skipper.h"
#include "third_party/blink/renderer/platform/graphics/paint/drawing_recorder.h"
#include "third_party/blink/renderer/platform/graphics/scoped_image_rendering_settings.h"
#include "third_party/blink/renderer/platform/runtime_enabled_features.h"

namespace blink {
namespace {

ImagePaintTimingInfo ComputeImagePaintTimingInfo(
    const LayoutImage& layout_image,
    const Image& image,
    const ImageResourceContent* image_content,
    const GraphicsContext& context,
    const gfx::Rect& image_border) {
  // |report_paint_timing| for ImagePaintTimingInfo is set to false since we
  // expect all images to be contentful and non-generated
  if (!image_content) {
    return ImagePaintTimingInfo(/* image_may_be_lcp_candidate */ false,
                                /* report_paint_timing */ false);
  }
  return ImagePaintTimingInfo(PaintTimingDetector::NotifyImagePaint(
      layout_image, image.Size(), *image_content,
      context.GetPaintController().CurrentPaintChunkProperties(),
      image_border));
}

}  // namespace

void ImagePainter::Paint(const PaintInfo& paint_info) {
  layout_image_.LayoutReplaced::Paint(paint_info);

  if (paint_info.phase == PaintPhase::kOutline)
    PaintAreaElementFocusRing(paint_info);
}

void ImagePainter::PaintAreaElementFocusRing(const PaintInfo& paint_info) {
  Document& document = layout_image_.GetDocument();

  if (document.Printing() ||
      !document.GetFrame()->Selection().FrameIsFocusedAndActive())
    return;

  auto* area_element = DynamicTo<HTMLAreaElement>(document.FocusedElement());
  if (!area_element)
    return;

  if (area_element->ImageElement() != layout_image_.GetNode())
    return;

  // We use EnsureComputedStyle() instead of GetComputedStyle() here because
  // <area> is used and its style applied even if it has display:none.
  const ComputedStyle* area_element_style = area_element->EnsureComputedStyle();
  // If the outline width is 0 we want to avoid drawing anything even if we
  // don't use the value directly.
  if (!area_element_style->OutlineWidth())
    return;

  ScopedPaintState paint_state(layout_image_, paint_info);
  const auto paint_offset = paint_state.PaintOffset();

  const Path path =
      area_element->GetPath(&layout_image_, gfx::Vector2dF(paint_offset));
  if (path.IsEmpty())
    return;

  if (DrawingRecorder::UseCachedDrawingIfPossible(
          paint_info.context, layout_image_, DisplayItem::kImageAreaFocusRing))
    return;

  BoxDrawingRecorder recorder(paint_info.context, layout_image_,
                              DisplayItem::kImageAreaFocusRing, paint_offset);

  // FIXME: Clip path instead of context when Skia pathops is ready.
  // https://crbug.com/251206

  paint_info.context.Save();
  PhysicalRect focus_rect = layout_image_.PhysicalContentBoxRect();
  focus_rect.Move(paint_offset);
  paint_info.context.Clip(ToPixelSnappedRect(focus_rect));
  OutlinePainter::PaintFocusRingPath(paint_info.context, path,
                                     *area_element_style);
  paint_info.context.Restore();
}

void ImagePainter::PaintReplaced(const PaintInfo& paint_info,
                                 const PhysicalOffset& paint_offset) {
  const PhysicalSize content_size = layout_image_.PhysicalContentBoxSize();
  bool has_image = layout_image_.ImageResource()->HasImage();

  if (has_image) {
    if (content_size.IsEmpty())
      return;
  } else {
    if (paint_info.phase == PaintPhase::kSelectionDragImage)
      return;
    if (content_size.width <= 2 || content_size.height <= 2) {
      return;
    }
  }

  PhysicalRect content_rect(
      paint_offset + layout_image_.PhysicalContentBoxOffset(), content_size);

  PhysicalRect paint_rect = layout_image_.ReplacedContentRect();
  paint_rect.offset += paint_offset;

  // If |overflow| is supported for replaced elements, paint the complete image
  // and the painting will be clipped based on overflow value by clip paint
  // property nodes.
  PhysicalRect visual_rect =
      layout_image_.ClipsToContentBox() ? content_rect : paint_rect;

  // As an optimization for SVG sprite sheets, an image may use the cull rect
  // when generating the display item, which optimizes the following scenario:
  //   <div style="overflow: hidden; pos: rel; width: ..px; height: ..px;">
  //     <img src="spritesheet.svg" style="pos: abs; top: -..px; left: -..px;">
  // The bitmap image codepath does not support subrect decoding and vetoes some
  // optimizations if subrects are used to avoid bleeding (see:
  // https://crbug.com/1404998#c12), so we limit this optimization to SVG.
  if (layout_image_.CachedImage() &&
      layout_image_.CachedImage()->GetImage()->IsSVGImage()) {
    const gfx::Rect& cull_rect(paint_info.GetCullRect().Rect());
    // Depending on the cull rect requires that we invalidate when the cull rect
    // changes (see call to `UpdatePaintedRect`), which could do additional
    // invalidations following scroll updates. To avoid this, we only consider
    // "sprite sheet" cull rects which are fully contained in the visual rect.
    // `ToEnclosingRect` is used to ensure `visual_rect` will contain even if
    // `cull_rect` was rounded.
    if (ToEnclosingRect(visual_rect).Contains(cull_rect)) {
      visual_rect.Intersect(PhysicalRect(cull_rect));
    }
  }
  layout_image_.GetMutableForPainting().UpdatePaintedRect(visual_rect);

  GraphicsContext& context = paint_info.context;
  if (DrawingRecorder::UseCachedDrawingIfPossible(context, layout_image_,
                                                  paint_info.phase))
    return;

  // Disable cache in under-invalidation checking mode for animated image
  // because it may change before it's actually invalidated.
  std::optional<DisplayItemCacheSkipper> cache_skipper;
  if (RuntimeEnabledFeatures::PaintUnderInvalidationCheckingEnabled() &&
      layout_image_.ImageResource() &&
      layout_image_.ImageResource()->MaybeAnimated())
    cache_skipper.emplace(context);

  if (!has_image) {
    // Draw an outline rect where the image should be.
    BoxDrawingRecorder recorder(context, layout_image_, paint_info.phase,
                                paint_offset);
    context.SetStrokeColor(Color::kLightGray);
    context.SetStrokeThickness(1);
    gfx::RectF outline_rect(ToPixelSnappedRect(content_rect));
    outline_rect.Inset(0.5f);
    context.StrokeRect(outline_rect,
                       PaintAutoDarkMode(layout_image_.StyleRef(),
                                         DarkModeFilter::ElementRole::kBorder));
    return;
  }

  DrawingRecorder recorder(context, layout_image_, paint_info.phase,
                           ToEnclosingRect(visual_rect));
  PaintIntoRect(context, paint_rect, visual_rect);
}

void ImagePainter::PaintIntoRect(GraphicsContext& context,
                                 const PhysicalRect& dest_rect,
                                 const PhysicalRect& content_rect) {
  const LayoutImageResource& image_resource = *layout_image_.ImageResource();
  if (!image_resource.HasImage() || image_resource.ErrorOccurred())
    return;  // FIXME: should we just ASSERT these conditions? (audit all
             // callers).

  gfx::Rect pixel_snapped_dest_rect = ToPixelSnappedRect(dest_rect);
  if (pixel_snapped_dest_rect.IsEmpty())
    return;

  scoped_refptr<Image> image =
      image_resource.GetImage(gfx::SizeF(dest_rect.size));
  if (!image || image->IsNull())
    return;

  // Get the oriented source rect in order to correctly clip. We check the
  // default orientation first to avoid expensive transform operations.
  auto respect_orientation = image->HasDefaultOrientation()
                                 ? kDoNotRespectImageOrientation
                                 : image_resource.ImageOrientation();
  gfx::RectF src_rect(image->SizeAsFloat(respect_orientation));

  // If the content rect requires clipping, adjust |srcRect| and
  // |pixelSnappedDestRect| over using a clip.
  if (!content_rect.Contains(dest_rect)) {
    gfx::Rect pixel_snapped_content_rect = ToPixelSnappedRect(content_rect);
    pixel_snapped_content_rect.Intersect(pixel_snapped_dest_rect);
    if (pixel_snapped_content_rect.IsEmpty())
      return;
    src_rect = gfx::MapRect(gfx::RectF(pixel_snapped_content_rect),
                            gfx::RectF(pixel_snapped_dest_rect), src_rect);
    pixel_snapped_dest_rect = pixel_snapped_content_rect;
  }

  // Undo the image orientation in the source rect because subsequent code
  // expects the source rect in unoriented image space.
  if (respect_orientation == kRespectImageOrientation) {
    src_rect = image->CorrectSrcRectForImageOrientation(
        image->SizeAsFloat(respect_orientation), src_rect);
  }

  DEVTOOLS_TIMELINE_TRACE_EVENT_WITH_CATEGORIES(
      TRACE_DISABLED_BY_DEFAULT("devtools.timeline"), "PaintImage",
      inspector_paint_image_event::Data, layout_image_, src_rect,
      gfx::RectF(dest_rect));

  ScopedImageRenderingSettings image_rendering_settings_scope(
      context, layout_image_.StyleRef().GetInterpolationQuality(),
      layout_image_.StyleRef().GetDynamicRangeLimit());

  Node* node = layout_image_.GetNode();
  auto* image_element = DynamicTo<HTMLImageElement>(node);
  Image::ImageDecodingMode decode_mode =
      image_element
          ? image_element->GetDecodingModeForPainting(image->paint_image_id())
          : Image::kUnspecifiedDecode;

  auto image_auto_dark_mode = ImageClassifierHelper::GetImageAutoDarkMode(
      *layout_image_.GetFrame(), layout_image_.StyleRef(),
      gfx::RectF(pixel_snapped_dest_rect), src_rect);

  // At this point we have all the necessary information to report paint
  // timing data. Do so now in order to mark the resulting PaintImage as
  // an LCP candidate.
  ImageResourceContent* image_content = image_resource.CachedImage();
  if (image_content &&
      (IsA<HTMLImageElement>(node) || IsA<HTMLVideoElement>(node)) &&
      image_content->IsLoaded()) {
    LocalDOMWindow* window = layout_image_.GetDocument().domWindow();
    DCHECK(window);
    ImageElementTiming::From(*window).NotifyImagePainted(
        layout_image_, *image_content,
        context.GetPaintController().CurrentPaintChunkProperties(),
        pixel_snapped_dest_rect);
  }

  context.DrawImage(
      *image, decode_mode, image_auto_dark_mode,
      ComputeImagePaintTimingInfo(layout_image_, *image, image_content, context,
                                  pixel_snapped_dest_rect),
      gfx::RectF(pixel_snapped_dest_rect), &src_rect, SkBlendMode::kSrcOver,
      respect_orientation);
}

}  // namespace blink