// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.

#include "TextHighlighterVisitor.h"
#include <Utils/ValueUtils.h>
#include <Views/RawTextViewManager.h>
#include <Views/TextViewManager.h>
#include <Views/VirtualTextViewManager.h>
#include "TextVisitorScope.h"

namespace winrt {
using namespace xaml::Documents;
} // namespace winrt

namespace Microsoft::ReactNative {

void TextHighlighterVisitor::VisitRawText(ShadowNodeBase *node) {
  const auto textNode = static_cast<RawTextShadowNode *>(node);
  m_startIndex += textNode->GetView().as<winrt::Run>().Text().size();
}

void TextHighlighterVisitor::VisitVirtualText(ShadowNodeBase *node) {
  const auto textNode = static_cast<VirtualTextShadowNode *>(node);
  const auto foregroundColor = textNode->foregroundColor;
  const auto backgroundColor = textNode->backgroundColor;
  const auto needsHighlighter = RequiresTextHighlighter(foregroundColor, backgroundColor);
  TextVisitorScope<Color> foregroundScope{m_foregroundColors, foregroundColor};
  TextVisitorScope<Color> backgroundScope{m_backgroundColors, backgroundColor};

  const auto startIndex = m_startIndex;
  const auto initialHighlighterCount = highlighters.size();
  Super::VisitVirtualText(node);

  if (needsHighlighter) {
    winrt::TextHighlighter highlighter;
    highlighter.Background(SolidBrushFromColor(m_backgroundColors.top().value()));
    const auto inheritedForegroundColor = m_foregroundColors.top();
    if (inheritedForegroundColor.has_value()) {
      highlighter.Foreground(SolidBrushFromColor(inheritedForegroundColor.value()));
    }
    highlighter.Ranges().Append({startIndex, m_startIndex - startIndex});
    highlighters.push_back(highlighter);
  } else if (highlighters.size() == initialHighlighterCount) {
    textNode->hasDescendantTextHighlighter = false;
  }
}

bool TextHighlighterVisitor::RequiresTextHighlighter(Color foregroundColor, Color backgroundColor) {
  return backgroundColor || m_backgroundColors.top() && foregroundColor;
}

} // namespace Microsoft::ReactNative