/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "TextAttrs.h"

#include "AccAttributes.h"
#include "nsAccUtils.h"
#include "nsCoreUtils.h"
#include "StyleInfo.h"

#include "gfxTextRun.h"
#include "nsFontMetrics.h"
#include "nsLayoutUtils.h"
#include "nsContainerFrame.h"
#include "HyperTextAccessible.h"
#include "mozilla/AppUnits.h"

using namespace mozilla;
using namespace mozilla::a11y;

////////////////////////////////////////////////////////////////////////////////
// TextAttrsMgr
////////////////////////////////////////////////////////////////////////////////

void TextAttrsMgr::GetAttributes(AccAttributes* aAttributes) {
  MOZ_ASSERT(
      // 1. Hyper text accessible and attributes list must always be specified.
      mHyperTextAcc && aAttributes &&
          (
              // 2. If text attributes for a child of a container are being
              // requested, the offset accessible must be specified and it must
              // be text.
              (mOffsetAcc && mOffsetAcc->IsText()) ||
              // 3. If only default text attributes for a container are being
              // requested, the offset accessible must not be specified, but the
              // include default text attributes flag must be specified.
              (!mOffsetAcc && mIncludeDefAttrs)),
      "Wrong usage of TextAttrsMgr!");

  // Get the content and frame of the accessible. In the case of document
  // accessible it's role content and root frame.
  nsIContent* hyperTextElm = mHyperTextAcc->GetContent();
  if (!hyperTextElm) {
    return;  // XXX: we don't support text attrs on document with no body
  }

  nsIFrame* rootFrame = mHyperTextAcc->GetFrame();
  if (!rootFrame) {
    return;
  }

  nsIContent *offsetNode = nullptr, *offsetElm = nullptr;
  nsIFrame* frame = nullptr;
  if (mOffsetAcc) {
    offsetNode = mOffsetAcc->GetContent();
    offsetElm = nsCoreUtils::GetDOMElementFor(offsetNode);
    MOZ_ASSERT(offsetElm, "No element for offset accessible!");
    if (!offsetElm) return;

    frame = offsetElm->GetPrimaryFrame();
  }

  // "language" text attribute
  LangTextAttr langTextAttr(mHyperTextAcc, hyperTextElm, offsetNode);

  // "aria-invalid" text attribute
  InvalidTextAttr invalidTextAttr(hyperTextElm, offsetNode);

  // "background-color" text attribute
  BGColorTextAttr bgColorTextAttr(rootFrame, frame);

  // "color" text attribute
  ColorTextAttr colorTextAttr(rootFrame, frame);

  // "font-family" text attribute
  FontFamilyTextAttr fontFamilyTextAttr(rootFrame, frame);

  // "font-size" text attribute
  FontSizeTextAttr fontSizeTextAttr(rootFrame, frame);

  // "font-style" text attribute
  FontStyleTextAttr fontStyleTextAttr(rootFrame, frame);

  // "font-weight" text attribute
  FontWeightTextAttr fontWeightTextAttr(rootFrame, frame);

  // "auto-generated" text attribute
  AutoGeneratedTextAttr autoGenTextAttr(mHyperTextAcc, mOffsetAcc);

  // "text-underline(line-through)-style(color)" text attributes
  TextDecorTextAttr textDecorTextAttr(rootFrame, frame);

  // "text-position" text attribute
  TextPosTextAttr textPosTextAttr(rootFrame, frame, hyperTextElm, offsetNode);

  TextAttr* attrArray[] = {
      &langTextAttr,      &invalidTextAttr,    &bgColorTextAttr,
      &colorTextAttr,     &fontFamilyTextAttr, &fontSizeTextAttr,
      &fontStyleTextAttr, &fontWeightTextAttr, &autoGenTextAttr,
      &textDecorTextAttr, &textPosTextAttr};

  // Expose text attributes.
  for (TextAttr* attr : attrArray) {
    attr->Expose(aAttributes, mIncludeDefAttrs);
  }
}

////////////////////////////////////////////////////////////////////////////////
// LangTextAttr
////////////////////////////////////////////////////////////////////////////////

TextAttrsMgr::LangTextAttr::LangTextAttr(HyperTextAccessible* aRoot,
                                         nsIContent* aRootElm, nsIContent* aElm)
    : TTextAttr<nsString>(!aElm), mRootContent(aRootElm) {
  aRoot->Language(mRootNativeValue);
  mIsRootDefined = !mRootNativeValue.IsEmpty();

  if (aElm) {
    nsCoreUtils::GetLanguageFor(aElm, mRootContent, mNativeValue);
    mIsDefined = !mNativeValue.IsEmpty();
  }
}

TextAttrsMgr::LangTextAttr::~LangTextAttr() {}

void TextAttrsMgr::LangTextAttr::ExposeValue(AccAttributes* aAttributes,
                                             const nsString& aValue) {
  RefPtr<nsAtom> lang = NS_Atomize(aValue);
  aAttributes->SetAttribute(nsGkAtoms::language, lang);
}

////////////////////////////////////////////////////////////////////////////////
// InvalidTextAttr
////////////////////////////////////////////////////////////////////////////////

TextAttrsMgr::InvalidTextAttr::InvalidTextAttr(nsIContent* aRootElm,
                                               nsIContent* aElm)
    : TTextAttr<uint32_t>(!aElm), mRootElm(aRootElm) {
  mIsRootDefined = GetValue(mRootElm, &mRootNativeValue);
  if (aElm) mIsDefined = GetValue(aElm, &mNativeValue);
}

void TextAttrsMgr::InvalidTextAttr::ExposeValue(AccAttributes* aAttributes,
                                                const uint32_t& aValue) {
  switch (aValue) {
    case eFalse:
      aAttributes->SetAttribute(nsGkAtoms::invalid, nsGkAtoms::_false);
      break;

    case eGrammar:
      aAttributes->SetAttribute(nsGkAtoms::invalid, nsGkAtoms::grammar);
      break;

    case eSpelling:
      aAttributes->SetAttribute(nsGkAtoms::invalid, nsGkAtoms::spelling);
      break;

    case eTrue:
      aAttributes->SetAttribute(nsGkAtoms::invalid, nsGkAtoms::_true);
      break;
  }
}

bool TextAttrsMgr::InvalidTextAttr::GetValue(nsIContent* aElm,
                                             uint32_t* aValue) {
  nsIContent* elm = aElm;
  do {
    if (nsAccUtils::HasDefinedARIAToken(elm, nsGkAtoms::aria_invalid)) {
      static dom::Element::AttrValuesArray tokens[] = {
          nsGkAtoms::_false, nsGkAtoms::grammar, nsGkAtoms::spelling, nullptr};

      int32_t idx = nsAccUtils::FindARIAAttrValueIn(
          elm->AsElement(), nsGkAtoms::aria_invalid, tokens, eCaseMatters);
      switch (idx) {
        case 0:
          *aValue = eFalse;
          return true;
        case 1:
          *aValue = eGrammar;
          return true;
        case 2:
          *aValue = eSpelling;
          return true;
        default:
          *aValue = eTrue;
          return true;
      }
    }
  } while ((elm = elm->GetParent()) && elm != mRootElm);

  return false;
}

////////////////////////////////////////////////////////////////////////////////
// BGColorTextAttr
////////////////////////////////////////////////////////////////////////////////

TextAttrsMgr::BGColorTextAttr::BGColorTextAttr(nsIFrame* aRootFrame,
                                               nsIFrame* aFrame)
    : TTextAttr<nscolor>(!aFrame), mRootFrame(aRootFrame) {
  mIsRootDefined = GetColor(mRootFrame, &mRootNativeValue);
  if (aFrame) mIsDefined = GetColor(aFrame, &mNativeValue);
}

void TextAttrsMgr::BGColorTextAttr::ExposeValue(AccAttributes* aAttributes,
                                                const nscolor& aValue) {
  aAttributes->SetAttribute(nsGkAtoms::background_color, Color{aValue});
}

bool TextAttrsMgr::BGColorTextAttr::GetColor(nsIFrame* aFrame,
                                             nscolor* aColor) {
  nscolor backgroundColor = aFrame->StyleBackground()->BackgroundColor(aFrame);
  if (NS_GET_A(backgroundColor) > 0) {
    *aColor = backgroundColor;
    return true;
  }

  nsContainerFrame* parentFrame = aFrame->GetParent();
  if (!parentFrame) {
    *aColor = aFrame->PresContext()->DefaultBackgroundColor();
    return true;
  }

  // Each frame of parents chain for the initially passed 'aFrame' has
  // transparent background color. So background color isn't changed from
  // 'mRootFrame' to initially passed 'aFrame'.
  if (parentFrame == mRootFrame) return false;

  return GetColor(parentFrame, aColor);
}

////////////////////////////////////////////////////////////////////////////////
// ColorTextAttr
////////////////////////////////////////////////////////////////////////////////

TextAttrsMgr::ColorTextAttr::ColorTextAttr(nsIFrame* aRootFrame,
                                           nsIFrame* aFrame)
    : TTextAttr<nscolor>(!aFrame) {
  mRootNativeValue = aRootFrame->StyleText()->mColor.ToColor();
  mIsRootDefined = true;

  if (aFrame) {
    mNativeValue = aFrame->StyleText()->mColor.ToColor();
    mIsDefined = true;
  }
}

void TextAttrsMgr::ColorTextAttr::ExposeValue(AccAttributes* aAttributes,
                                              const nscolor& aValue) {
  aAttributes->SetAttribute(nsGkAtoms::color, Color{aValue});
}

////////////////////////////////////////////////////////////////////////////////
// FontFamilyTextAttr
////////////////////////////////////////////////////////////////////////////////

TextAttrsMgr::FontFamilyTextAttr::FontFamilyTextAttr(nsIFrame* aRootFrame,
                                                     nsIFrame* aFrame)
    : TTextAttr<nsString>(!aFrame) {
  mIsRootDefined = GetFontFamily(aRootFrame, mRootNativeValue);

  if (aFrame) mIsDefined = GetFontFamily(aFrame, mNativeValue);
}

void TextAttrsMgr::FontFamilyTextAttr::ExposeValue(AccAttributes* aAttributes,
                                                   const nsString& aValue) {
  RefPtr<nsAtom> family = NS_Atomize(aValue);
  aAttributes->SetAttribute(nsGkAtoms::font_family, family);
}

bool TextAttrsMgr::FontFamilyTextAttr::GetFontFamily(nsIFrame* aFrame,
                                                     nsString& aFamily) {
  RefPtr<nsFontMetrics> fm =
      nsLayoutUtils::GetFontMetricsForFrame(aFrame, 1.0f);

  gfxFontGroup* fontGroup = fm->GetThebesFontGroup();
  RefPtr<gfxFont> font = fontGroup->GetFirstValidFont();
  gfxFontEntry* fontEntry = font->GetFontEntry();
  aFamily.Append(NS_ConvertUTF8toUTF16(fontEntry->FamilyName()));
  return true;
}

////////////////////////////////////////////////////////////////////////////////
// FontSizeTextAttr
////////////////////////////////////////////////////////////////////////////////

TextAttrsMgr::FontSizeTextAttr::FontSizeTextAttr(nsIFrame* aRootFrame,
                                                 nsIFrame* aFrame)
    : TTextAttr<nscoord>(!aFrame) {
  mDC = aRootFrame->PresContext()->DeviceContext();

  mRootNativeValue = aRootFrame->StyleFont()->mSize.ToAppUnits();
  mIsRootDefined = true;

  if (aFrame) {
    mNativeValue = aFrame->StyleFont()->mSize.ToAppUnits();
    mIsDefined = true;
  }
}

void TextAttrsMgr::FontSizeTextAttr::ExposeValue(AccAttributes* aAttributes,
                                                 const nscoord& aValue) {
  // Convert from nscoord to pt.
  //
  // Note: according to IA2, "The conversion doesn't have to be exact.
  // The intent is to give the user a feel for the size of the text."
  //
  // ATK does not specify a unit and will likely follow IA2 here.
  //
  // XXX todo: consider sharing this code with layout module? (bug 474621)
  float px = NSAppUnitsToFloatPixels(aValue, mozilla::AppUnitsPerCSSPixel());
  // Each pt is 4/3 of a CSS pixel.
  FontSize fontSize{NS_lround(px * 3 / 4)};

  aAttributes->SetAttribute(nsGkAtoms::font_size, fontSize);
}

////////////////////////////////////////////////////////////////////////////////
// FontStyleTextAttr
////////////////////////////////////////////////////////////////////////////////

TextAttrsMgr::FontStyleTextAttr::FontStyleTextAttr(nsIFrame* aRootFrame,
                                                   nsIFrame* aFrame)
    : TTextAttr<FontSlantStyle>(!aFrame) {
  mRootNativeValue = aRootFrame->StyleFont()->mFont.style;
  mIsRootDefined = true;

  if (aFrame) {
    mNativeValue = aFrame->StyleFont()->mFont.style;
    mIsDefined = true;
  }
}

void TextAttrsMgr::FontStyleTextAttr::ExposeValue(
    AccAttributes* aAttributes, const FontSlantStyle& aValue) {
  if (aValue.IsNormal()) {
    aAttributes->SetAttribute(nsGkAtoms::font_style, nsGkAtoms::normal);
  } else if (aValue.IsItalic()) {
    RefPtr<nsAtom> atom = NS_Atomize("italic");
    aAttributes->SetAttribute(nsGkAtoms::font_style, atom);
  } else {
    nsAutoCString s;
    aValue.ToString(s);
    nsString wide;
    CopyUTF8toUTF16(s, wide);
    aAttributes->SetAttribute(nsGkAtoms::font_style, std::move(wide));
  }
}

////////////////////////////////////////////////////////////////////////////////
// FontWeightTextAttr
////////////////////////////////////////////////////////////////////////////////

TextAttrsMgr::FontWeightTextAttr::FontWeightTextAttr(nsIFrame* aRootFrame,
                                                     nsIFrame* aFrame)
    : TTextAttr<FontWeight>(!aFrame) {
  mRootNativeValue = GetFontWeight(aRootFrame);
  mIsRootDefined = true;

  if (aFrame) {
    mNativeValue = GetFontWeight(aFrame);
    mIsDefined = true;
  }
}

void TextAttrsMgr::FontWeightTextAttr::ExposeValue(AccAttributes* aAttributes,
                                                   const FontWeight& aValue) {
  int value = aValue.ToIntRounded();
  aAttributes->SetAttribute(nsGkAtoms::font_weight, value);
}

FontWeight TextAttrsMgr::FontWeightTextAttr::GetFontWeight(nsIFrame* aFrame) {
  // nsFont::width isn't suitable here because it's necessary to expose real
  // value of font weight (used font might not have some font weight values).
  RefPtr<nsFontMetrics> fm =
      nsLayoutUtils::GetFontMetricsForFrame(aFrame, 1.0f);

  gfxFontGroup* fontGroup = fm->GetThebesFontGroup();
  RefPtr<gfxFont> font = fontGroup->GetFirstValidFont();

  // When there doesn't exist a bold font in the family and so the rendering of
  // a non-bold font face is changed so that the user sees what looks like a
  // bold font, i.e. synthetic bolding is used. (Simply returns false on any
  // platforms that don't use the multi-strike synthetic bolding.)
  if (font->ApplySyntheticBold()) {
    return FontWeight::BOLD;
  }

  // On Windows, font->GetStyle()->weight will give the same weight as
  // fontEntry->Weight(), the weight of the first font in the font group,
  // which may not be the weight of the font face used to render the
  // characters. On Mac, font->GetStyle()->weight will just give the same
  // number as getComputedStyle(). fontEntry->Weight() will give the weight
  // range supported by the font face used, so we clamp the weight that was
  // requested by style to what is actually supported by the font.
  gfxFontEntry* fontEntry = font->GetFontEntry();
  return fontEntry->Weight().Clamp(font->GetStyle()->weight);
}

////////////////////////////////////////////////////////////////////////////////
// AutoGeneratedTextAttr
////////////////////////////////////////////////////////////////////////////////
TextAttrsMgr::AutoGeneratedTextAttr::AutoGeneratedTextAttr(
    HyperTextAccessible* aHyperTextAcc, LocalAccessible* aAccessible)
    : TTextAttr<bool>(!aAccessible) {
  mRootNativeValue = false;
  mIsRootDefined = false;

  if (aAccessible) {
    mIsDefined = mNativeValue =
        ((aAccessible->NativeRole() == roles::STATICTEXT) ||
         (aAccessible->NativeRole() == roles::LISTITEM_MARKER));
  }
}

void TextAttrsMgr::AutoGeneratedTextAttr::ExposeValue(
    AccAttributes* aAttributes, const bool& aValue) {
  aAttributes->SetAttribute(nsGkAtoms::auto_generated, aValue);
}

////////////////////////////////////////////////////////////////////////////////
// TextDecorTextAttr
////////////////////////////////////////////////////////////////////////////////

TextAttrsMgr::TextDecorValue::TextDecorValue(nsIFrame* aFrame) {
  const nsStyleTextReset* textReset = aFrame->StyleTextReset();
  mStyle = textReset->mTextDecorationStyle;
  mColor = textReset->mTextDecorationColor.CalcColor(aFrame);
  mLine =
      textReset->mTextDecorationLine & (StyleTextDecorationLine::UNDERLINE |
                                        StyleTextDecorationLine::LINE_THROUGH);
}

TextAttrsMgr::TextDecorTextAttr::TextDecorTextAttr(nsIFrame* aRootFrame,
                                                   nsIFrame* aFrame)
    : TTextAttr<TextDecorValue>(!aFrame) {
  mRootNativeValue = TextDecorValue(aRootFrame);
  mIsRootDefined = mRootNativeValue.IsDefined();

  if (aFrame) {
    mNativeValue = TextDecorValue(aFrame);
    mIsDefined = mNativeValue.IsDefined();
  }
}

void TextAttrsMgr::TextDecorTextAttr::ExposeValue(
    AccAttributes* aAttributes, const TextDecorValue& aValue) {
  if (aValue.IsUnderline()) {
    RefPtr<nsAtom> underlineStyle =
        StyleInfo::TextDecorationStyleToAtom(aValue.Style());
    aAttributes->SetAttribute(nsGkAtoms::textUnderlineStyle, underlineStyle);

    aAttributes->SetAttribute(nsGkAtoms::textUnderlineColor,
                              Color{aValue.Color()});
    return;
  }

  if (aValue.IsLineThrough()) {
    RefPtr<nsAtom> lineThroughStyle =
        StyleInfo::TextDecorationStyleToAtom(aValue.Style());
    aAttributes->SetAttribute(nsGkAtoms::textLineThroughStyle,
                              lineThroughStyle);

    aAttributes->SetAttribute(nsGkAtoms::textLineThroughColor,
                              Color{aValue.Color()});
  }
}

////////////////////////////////////////////////////////////////////////////////
// TextPosTextAttr
////////////////////////////////////////////////////////////////////////////////

TextAttrsMgr::TextPosTextAttr::TextPosTextAttr(nsIFrame* aRootFrame,
                                               nsIFrame* aFrame,
                                               nsIContent* aRootElm,
                                               nsIContent* aElm)
    : TTextAttr<Maybe<TextPosValue>>(!aFrame && !aElm), mRootElm(aRootElm) {
  // Get the text-position values for the roots and children.
  // If we find an ARIA text-position value on a DOM element - searching up
  // from the supplied root DOM element - use the associated frame as the root
  // frame. This ensures that we're using the proper root frame for comparison.
  nsIFrame* ariaFrame = nullptr;
  Maybe<TextPosValue> rootAria = GetAriaTextPosValue(aRootElm, ariaFrame);
  if (rootAria && ariaFrame) {
    aRootFrame = ariaFrame;
  }
  Maybe<TextPosValue> rootLayout = GetLayoutTextPosValue(aRootFrame);
  Maybe<TextPosValue> childLayout;
  Maybe<TextPosValue> childAria;
  if (aFrame) {
    childLayout = GetLayoutTextPosValue(aFrame);
  }
  if (aElm) {
    childAria = GetAriaTextPosValue(aElm);
  }

  // Aria values take precedence over layout values.
  mIsRootDefined = rootAria || rootLayout;
  mRootNativeValue = rootAria ? rootAria : rootLayout;
  mIsDefined = childAria || childLayout;
  mNativeValue = childAria ? childAria : childLayout;

  // If there's no child text-position information from ARIA, and the child
  // layout info is equivalent to the root layout info (i.e., it's inherited),
  // then we should prefer the root information.
  if (!childAria && childLayout == rootLayout) {
    mIsDefined = false;
  }
}

void TextAttrsMgr::TextPosTextAttr::ExposeValue(
    AccAttributes* aAttributes, const Maybe<TextPosValue>& aValue) {
  if (aValue.isNothing()) {
    return;
  }

  RefPtr<nsAtom> atom = nullptr;
  switch (*aValue) {
    case eTextPosBaseline:
      atom = nsGkAtoms::baseline;
      break;

    case eTextPosSub:
      atom = nsGkAtoms::sub;
      break;

    case eTextPosSuper:
      atom = NS_Atomize("super");
      break;
  }

  if (atom) {
    aAttributes->SetAttribute(nsGkAtoms::textPosition, atom);
  }
}

Maybe<TextAttrsMgr::TextPosValue>
TextAttrsMgr::TextPosTextAttr::GetAriaTextPosValue(nsIContent* aElm) const {
  nsIFrame* ariaFrame = nullptr;
  return GetAriaTextPosValue(aElm, ariaFrame);
}

Maybe<TextAttrsMgr::TextPosValue>
TextAttrsMgr::TextPosTextAttr::GetAriaTextPosValue(nsIContent* aElm,
                                                   nsIFrame*& ariaFrame) const {
  // Search for the superscript and subscript roles that imply text-position.
  const nsIContent* elm = aElm;
  do {
    if (elm->IsElement()) {
      const mozilla::dom::Element* domElm = elm->AsElement();
      static const dom::Element::AttrValuesArray tokens[] = {
          nsGkAtoms::subscript, nsGkAtoms::superscript, nullptr};
      const int32_t valueIdx = domElm->FindAttrValueIn(
          kNameSpaceID_None, nsGkAtoms::role, tokens, eCaseMatters);
      ariaFrame = domElm->GetPrimaryFrame();
      if (valueIdx == 0) {
        return Some(eTextPosSub);
      }
      if (valueIdx == 1) {
        return Some(eTextPosSuper);
      }
    }
  } while ((elm = elm->GetParent()) && elm != mRootElm);

  ariaFrame = nullptr;
  return Nothing{};
}

Maybe<TextAttrsMgr::TextPosValue>
TextAttrsMgr::TextPosTextAttr::GetLayoutTextPosValue(nsIFrame* aFrame) const {
  const auto& verticalAlign = aFrame->StyleDisplay()->mVerticalAlign;
  if (verticalAlign.IsKeyword()) {
    switch (verticalAlign.AsKeyword()) {
      case StyleVerticalAlignKeyword::Baseline:
        return Some(eTextPosBaseline);
      case StyleVerticalAlignKeyword::Sub:
        return Some(eTextPosSub);
      case StyleVerticalAlignKeyword::Super:
        return Some(eTextPosSuper);
      // No good guess for the rest, so do not expose value of text-position
      // attribute.
      default:
        return Nothing{};
    }
  }

  const auto& length = verticalAlign.AsLength();
  if (length.ConvertsToPercentage()) {
    const float percentValue = length.ToPercentage();
    return percentValue > 0 ? Some(eTextPosSuper)
                            : (percentValue < 0 ? Some(eTextPosSub)
                                                : Some(eTextPosBaseline));
  }

  if (length.ConvertsToLength()) {
    const nscoord coordValue = length.ToLength();
    return coordValue > 0
               ? Some(eTextPosSuper)
               : (coordValue < 0 ? Some(eTextPosSub) : Some(eTextPosBaseline));
  }

  if (const nsIContent* content = aFrame->GetContent()) {
    if (content->IsHTMLElement(nsGkAtoms::sup)) return Some(eTextPosSuper);
    if (content->IsHTMLElement(nsGkAtoms::sub)) return Some(eTextPosSub);
  }

  return Nothing{};
}