// Copyright 2018 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/layout/inline/line_utils.h"

#include "third_party/blink/renderer/core/editing/position_with_affinity.h"
#include "third_party/blink/renderer/core/layout/inline/inline_caret_position.h"

namespace blink {

InlineCursor NGContainingLineBoxOf(const PositionWithAffinity& position) {
  const InlineCaretPosition caret_position =
      ComputeInlineCaretPosition(position);
  if (caret_position.IsNull())
    return InlineCursor();
  InlineCursor line = caret_position.cursor;
  line.MoveToContainingLine();
  if (RuntimeEnabledFeatures::EditingLineMovementWithRubyFixEnabled() && line &&
      line.Current().IsRubyAnnotationLine()) {
    line.MoveToPreviousLine();
  }
  return line;
}

bool InSameNGLineBox(const PositionWithAffinity& position1,
                     const PositionWithAffinity& position2) {
  const InlineCursor& line_box1 = NGContainingLineBoxOf(position1);
  if (!line_box1)
    return false;

  const InlineCursor& line_box2 = NGContainingLineBoxOf(position2);
  return line_box1 == line_box2;
}

FontHeight CalculateLeadingSpace(const LayoutUnit& line_height,
                                 const FontHeight& current_height) {
  // TODO(kojii): floor() is to make text dump compatible with legacy test
  // results. Revisit when we paint.
  LayoutUnit ascent_leading_spacing{
      ((line_height - current_height.LineHeight()) / 2).Floor()};
  LayoutUnit descent_leading_spacing =
      line_height - current_height.LineHeight() - ascent_leading_spacing;
  return FontHeight(ascent_leading_spacing, descent_leading_spacing);
}

}  // namespace blink