/*
 * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
 *           (C) 2000 Antti Koivisto (koivisto@kde.org)
 *           (C) 2000 Dirk Mueller (mueller@kde.org)
 * Copyright (C) 2003-2021 Apple Inc. All rights reserved.
 * Copyright (C) 2007 Nicholas Shanks <webkit@nickshanks.com>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 *
 * You should have received a copy of the GNU Library General Public License
 * along with this library; see the file COPYING.LIB.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 */

#pragma once

#include "FontPalette.h"
#include "FontRenderingMode.h"
#include "FontSelectionAlgorithm.h"
#include "FontTaggedSettings.h"
#include "TextFlags.h"
#include "WebKitFontFamilyNames.h"
#include <unicode/uscript.h>
#include <wtf/Markable.h>
#include <wtf/MathExtras.h>

namespace WebCore {

using namespace WebKitFontFamilyNames;

struct FloatMarkableTraits {
    constexpr static bool isEmptyValue(float value)
    {
        return value != value;
    }

    constexpr static float emptyValue()
    {
        return std::numeric_limits<float>::quiet_NaN();
    }
};

class FontDescription {
public:
    WEBCORE_EXPORT FontDescription();

    bool operator==(const FontDescription&) const;
    bool operator!=(const FontDescription& other) const { return !(*this == other); }

    float computedSize() const { return m_computedSize; }
    unsigned computedPixelSize() const { return unsigned(m_computedSize + 0.5f); }
    std::optional<FontSelectionValue> italic() const { return m_fontSelectionRequest.slope; }
    std::optional<float> fontSizeAdjust() const { return m_sizeAdjust; }
    FontSelectionValue stretch() const { return m_fontSelectionRequest.width; }
    FontSelectionValue weight() const { return m_fontSelectionRequest.weight; }
    FontSelectionRequest fontSelectionRequest() const { return m_fontSelectionRequest; }
    FontRenderingMode renderingMode() const { return static_cast<FontRenderingMode>(m_renderingMode); }
    TextRenderingMode textRenderingMode() const { return static_cast<TextRenderingMode>(m_textRendering); }
    UScriptCode script() const { return static_cast<UScriptCode>(m_script); }
    const AtomString& computedLocale() const { return m_locale; } // This is what you should be using for things like text shaping and font fallback
    const AtomString& specifiedLocale() const { return m_specifiedLocale; } // This is what you should be using for web-exposed things like -webkit-locale

    FontOrientation orientation() const { return static_cast<FontOrientation>(m_orientation); }
    NonCJKGlyphOrientation nonCJKGlyphOrientation() const { return static_cast<NonCJKGlyphOrientation>(m_nonCJKGlyphOrientation); }
    FontWidthVariant widthVariant() const { return static_cast<FontWidthVariant>(m_widthVariant); }
    const FontFeatureSettings& featureSettings() const { return m_featureSettings; }
    const FontVariationSettings& variationSettings() const { return m_variationSettings; }
    FontSynthesisLonghandValue fontSynthesisWeight() const { return static_cast<FontSynthesisLonghandValue>(m_fontSynthesisWeight); }
    FontSynthesisLonghandValue fontSynthesisStyle() const { return static_cast<FontSynthesisLonghandValue>(m_fontSynthesisStyle); }
    FontSynthesisLonghandValue fontSynthesisSmallCaps() const { return static_cast<FontSynthesisLonghandValue>(m_fontSynthesisCaps); }
    bool hasAutoFontSynthesisWeight() const { return fontSynthesisWeight() == FontSynthesisLonghandValue::Auto; }
    bool hasAutoFontSynthesisStyle() const { return fontSynthesisStyle() == FontSynthesisLonghandValue::Auto; }
    bool hasAutoFontSynthesisSmallCaps() const { return fontSynthesisSmallCaps() == FontSynthesisLonghandValue::Auto; }
    FontVariantLigatures variantCommonLigatures() const { return static_cast<FontVariantLigatures>(m_variantCommonLigatures); }
    FontVariantLigatures variantDiscretionaryLigatures() const { return static_cast<FontVariantLigatures>(m_variantDiscretionaryLigatures); }
    FontVariantLigatures variantHistoricalLigatures() const { return static_cast<FontVariantLigatures>(m_variantHistoricalLigatures); }
    FontVariantLigatures variantContextualAlternates() const { return static_cast<FontVariantLigatures>(m_variantContextualAlternates); }
    FontVariantPosition variantPosition() const { return static_cast<FontVariantPosition>(m_variantPosition); }
    FontVariantCaps variantCaps() const { return static_cast<FontVariantCaps>(m_variantCaps); }
    FontVariantNumericFigure variantNumericFigure() const { return static_cast<FontVariantNumericFigure>(m_variantNumericFigure); }
    FontVariantNumericSpacing variantNumericSpacing() const { return static_cast<FontVariantNumericSpacing>(m_variantNumericSpacing); }
    FontVariantNumericFraction variantNumericFraction() const { return static_cast<FontVariantNumericFraction>(m_variantNumericFraction); }
    FontVariantNumericOrdinal variantNumericOrdinal() const { return static_cast<FontVariantNumericOrdinal>(m_variantNumericOrdinal); }
    FontVariantNumericSlashedZero variantNumericSlashedZero() const { return static_cast<FontVariantNumericSlashedZero>(m_variantNumericSlashedZero); }
    FontVariantAlternates variantAlternates() const { return m_variantAlternates; }
    FontVariantEastAsianVariant variantEastAsianVariant() const { return static_cast<FontVariantEastAsianVariant>(m_variantEastAsianVariant); }
    FontVariantEastAsianWidth variantEastAsianWidth() const { return static_cast<FontVariantEastAsianWidth>(m_variantEastAsianWidth); }
    FontVariantEastAsianRuby variantEastAsianRuby() const { return static_cast<FontVariantEastAsianRuby>(m_variantEastAsianRuby); }
    FontVariantSettings variantSettings() const
    {
        return { variantCommonLigatures(),
            variantDiscretionaryLigatures(),
            variantHistoricalLigatures(),
            variantContextualAlternates(),
            variantPosition(),
            variantCaps(),
            variantNumericFigure(),
            variantNumericSpacing(),
            variantNumericFraction(),
            variantNumericOrdinal(),
            variantNumericSlashedZero(),
            variantAlternates(),
            variantEastAsianVariant(),
            variantEastAsianWidth(),
            variantEastAsianRuby() };
    }
    FontOpticalSizing opticalSizing() const { return static_cast<FontOpticalSizing>(m_opticalSizing); }
    FontStyleAxis fontStyleAxis() const { return m_fontStyleAxis ? FontStyleAxis::ital : FontStyleAxis::slnt; }
    AllowUserInstalledFonts shouldAllowUserInstalledFonts() const { return static_cast<AllowUserInstalledFonts>(m_shouldAllowUserInstalledFonts); }
    bool shouldDisableLigaturesForSpacing() const { return m_shouldDisableLigaturesForSpacing; }
    FontPalette fontPalette() const { return m_fontPalette; }

    void setComputedSize(float s) { m_computedSize = clampToFloat(s); }
    void setFontSizeAdjust(std::optional<float> sizeAdjust) { m_sizeAdjust = sizeAdjust; }
    void setItalic(std::optional<FontSelectionValue> italic) { m_fontSelectionRequest.slope = italic; }
    void setStretch(FontSelectionValue stretch) { m_fontSelectionRequest.width = stretch; }
    void setIsItalic(bool isItalic) { setItalic(isItalic ? std::optional<FontSelectionValue> { italicValue() } : std::optional<FontSelectionValue> { }); }
    void setWeight(FontSelectionValue weight) { m_fontSelectionRequest.weight = weight; }
    void setRenderingMode(FontRenderingMode mode) { m_renderingMode = static_cast<unsigned>(mode); }
    void setTextRenderingMode(TextRenderingMode rendering) { m_textRendering = static_cast<unsigned>(rendering); }
    void setOrientation(FontOrientation orientation) { m_orientation = static_cast<unsigned>(orientation); }
    void setNonCJKGlyphOrientation(NonCJKGlyphOrientation orientation) { m_nonCJKGlyphOrientation = static_cast<unsigned>(orientation); }
    void setWidthVariant(FontWidthVariant widthVariant) { m_widthVariant = static_cast<unsigned>(widthVariant); } // Make sure new callers of this sync with FontPlatformData::isForTextCombine()!
    void setSpecifiedLocale(const AtomString&);
    void setFeatureSettings(FontFeatureSettings&& settings) { m_featureSettings = WTFMove(settings); }
    void setVariationSettings(FontVariationSettings&& settings) { m_variationSettings = WTFMove(settings); }
    void setFontSynthesisWeight(FontSynthesisLonghandValue value) { m_fontSynthesisWeight =  static_cast<unsigned>(value); }
    void setFontSynthesisStyle(FontSynthesisLonghandValue value) { m_fontSynthesisStyle = static_cast<unsigned>(value); }
    void setFontSynthesisSmallCaps(FontSynthesisLonghandValue value) { m_fontSynthesisCaps = static_cast<unsigned>(value); }
    void setVariantCommonLigatures(FontVariantLigatures variant) { m_variantCommonLigatures = static_cast<unsigned>(variant); }
    void setVariantDiscretionaryLigatures(FontVariantLigatures variant) { m_variantDiscretionaryLigatures = static_cast<unsigned>(variant); }
    void setVariantHistoricalLigatures(FontVariantLigatures variant) { m_variantHistoricalLigatures = static_cast<unsigned>(variant); }
    void setVariantContextualAlternates(FontVariantLigatures variant) { m_variantContextualAlternates = static_cast<unsigned>(variant); }
    void setVariantPosition(FontVariantPosition variant) { m_variantPosition = static_cast<unsigned>(variant); }
    void setVariantCaps(FontVariantCaps variant) { m_variantCaps = static_cast<unsigned>(variant); }
    void setVariantNumericFigure(FontVariantNumericFigure variant) { m_variantNumericFigure = static_cast<unsigned>(variant); }
    void setVariantNumericSpacing(FontVariantNumericSpacing variant) { m_variantNumericSpacing = static_cast<unsigned>(variant); }
    void setVariantNumericFraction(FontVariantNumericFraction variant) { m_variantNumericFraction = static_cast<unsigned>(variant); }
    void setVariantNumericOrdinal(FontVariantNumericOrdinal variant) { m_variantNumericOrdinal = static_cast<unsigned>(variant); }
    void setVariantNumericSlashedZero(FontVariantNumericSlashedZero variant) { m_variantNumericSlashedZero = static_cast<unsigned>(variant); }
    void setVariantAlternates(FontVariantAlternates variant) { m_variantAlternates = variant; }
    void setVariantEastAsianVariant(FontVariantEastAsianVariant variant) { m_variantEastAsianVariant = static_cast<unsigned>(variant); }
    void setVariantEastAsianWidth(FontVariantEastAsianWidth variant) { m_variantEastAsianWidth = static_cast<unsigned>(variant); }
    void setVariantEastAsianRuby(FontVariantEastAsianRuby variant) { m_variantEastAsianRuby = static_cast<unsigned>(variant); }
    void setOpticalSizing(FontOpticalSizing sizing) { m_opticalSizing = static_cast<unsigned>(sizing); }
    void setFontStyleAxis(FontStyleAxis axis) { m_fontStyleAxis = axis == FontStyleAxis::ital; }
    void setShouldAllowUserInstalledFonts(AllowUserInstalledFonts shouldAllowUserInstalledFonts) { m_shouldAllowUserInstalledFonts = static_cast<unsigned>(shouldAllowUserInstalledFonts); }
    void setShouldDisableLigaturesForSpacing(bool shouldDisableLigaturesForSpacing) { m_shouldDisableLigaturesForSpacing = shouldDisableLigaturesForSpacing; }
    void setFontPalette(FontPalette fontPalette) { m_fontPalette = fontPalette; }

    static AtomString platformResolveGenericFamily(UScriptCode, const AtomString& locale, const AtomString& familyName);

    template<class Encoder>
    void encode(Encoder&) const;

    template<class Decoder>
    static std::optional<FontDescription> decode(Decoder&);

private:
    // FIXME: Investigate moving these into their own object on the heap (to save memory).
    FontFeatureSettings m_featureSettings;
    FontVariationSettings m_variationSettings;
    FontVariantAlternates m_variantAlternates;
    FontPalette m_fontPalette;
    AtomString m_locale;
    AtomString m_specifiedLocale;

    FontSelectionRequest m_fontSelectionRequest;
    Markable<float, FloatMarkableTraits> m_sizeAdjust; // Size adjust for font-size-adjust
    float m_computedSize { 0 }; // Computed size adjusted for the minimum font size and the zoom factor.
    unsigned m_orientation : 1; // FontOrientation - Whether the font is rendering on a horizontal line or a vertical line.
    unsigned m_nonCJKGlyphOrientation : 1; // NonCJKGlyphOrientation - Only used by vertical text. Determines the default orientation for non-ideograph glyphs.
    unsigned m_widthVariant : 2; // FontWidthVariant
    unsigned m_renderingMode : 1; // Used to switch between CG and GDI text on Windows.
    unsigned m_textRendering : 2; // TextRenderingMode
    unsigned m_script : 7; // Used to help choose an appropriate font for generic font families.
    unsigned m_fontSynthesisWeight : 1;
    unsigned m_fontSynthesisStyle : 1;
    unsigned m_fontSynthesisCaps : 1;
    unsigned m_variantCommonLigatures : 2; // FontVariantLigatures
    unsigned m_variantDiscretionaryLigatures : 2; // FontVariantLigatures
    unsigned m_variantHistoricalLigatures : 2; // FontVariantLigatures
    unsigned m_variantContextualAlternates : 2; // FontVariantLigatures
    unsigned m_variantPosition : 2; // FontVariantPosition
    unsigned m_variantCaps : 3; // FontVariantCaps
    unsigned m_variantNumericFigure : 2; // FontVariantNumericFigure
    unsigned m_variantNumericSpacing : 2; // FontVariantNumericSpacing
    unsigned m_variantNumericFraction : 2; // FontVariantNumericFraction
    unsigned m_variantNumericOrdinal : 1; // FontVariantNumericOrdinal
    unsigned m_variantNumericSlashedZero : 1; // FontVariantNumericSlashedZero
    unsigned m_variantEastAsianVariant : 3; // FontVariantEastAsianVariant
    unsigned m_variantEastAsianWidth : 2; // FontVariantEastAsianWidth
    unsigned m_variantEastAsianRuby : 1; // FontVariantEastAsianRuby
    unsigned m_opticalSizing : 1; // FontOpticalSizing
    unsigned m_fontStyleAxis : 1; // Whether "font-style: italic" or "font-style: oblique 20deg" was specified
    unsigned m_shouldAllowUserInstalledFonts : 1; // AllowUserInstalledFonts: If this description is allowed to match a user-installed font
    unsigned m_shouldDisableLigaturesForSpacing : 1; // If letter-spacing is nonzero, we need to disable ligatures, which affects font preparation
};

inline bool FontDescription::operator==(const FontDescription& other) const
{
    return m_computedSize == other.m_computedSize
        && m_fontSelectionRequest == other.m_fontSelectionRequest
        && m_renderingMode == other.m_renderingMode
        && m_textRendering == other.m_textRendering
        && m_orientation == other.m_orientation
        && m_nonCJKGlyphOrientation == other.m_nonCJKGlyphOrientation
        && m_widthVariant == other.m_widthVariant
        && m_specifiedLocale == other.m_specifiedLocale
        && m_featureSettings == other.m_featureSettings
        && m_variationSettings == other.m_variationSettings
        && m_fontSynthesisWeight == other.m_fontSynthesisWeight
        && m_fontSynthesisStyle == other.m_fontSynthesisStyle
        && m_fontSynthesisCaps == other.m_fontSynthesisCaps
        && m_variantCommonLigatures == other.m_variantCommonLigatures
        && m_variantDiscretionaryLigatures == other.m_variantDiscretionaryLigatures
        && m_variantHistoricalLigatures == other.m_variantHistoricalLigatures
        && m_variantContextualAlternates == other.m_variantContextualAlternates
        && m_variantPosition == other.m_variantPosition
        && m_variantCaps == other.m_variantCaps
        && m_variantNumericFigure == other.m_variantNumericFigure
        && m_variantNumericSpacing == other.m_variantNumericSpacing
        && m_variantNumericFraction == other.m_variantNumericFraction
        && m_variantNumericOrdinal == other.m_variantNumericOrdinal
        && m_variantNumericSlashedZero == other.m_variantNumericSlashedZero
        && m_variantAlternates == other.m_variantAlternates
        && m_variantEastAsianVariant == other.m_variantEastAsianVariant
        && m_variantEastAsianWidth == other.m_variantEastAsianWidth
        && m_variantEastAsianRuby == other.m_variantEastAsianRuby
        && m_opticalSizing == other.m_opticalSizing
        && m_fontStyleAxis == other.m_fontStyleAxis
        && m_shouldAllowUserInstalledFonts == other.m_shouldAllowUserInstalledFonts
        && m_shouldDisableLigaturesForSpacing == other.m_shouldDisableLigaturesForSpacing
        && m_fontPalette == other.m_fontPalette
        && m_sizeAdjust == other.m_sizeAdjust;
}

template<class Encoder>
void FontDescription::encode(Encoder& encoder) const
{
    encoder << featureSettings();
    encoder << variationSettings();
    encoder << computedLocale();
    encoder << italic();
    encoder << stretch();
    encoder << weight();
    encoder << m_computedSize;
    encoder << orientation();
    encoder << nonCJKGlyphOrientation();
    encoder << widthVariant();
    encoder << renderingMode();
    encoder << textRenderingMode();
    encoder << fontSynthesisWeight();
    encoder << fontSynthesisStyle();
    encoder << fontSynthesisSmallCaps();
    encoder << variantCommonLigatures();
    encoder << variantDiscretionaryLigatures();
    encoder << variantHistoricalLigatures();
    encoder << variantContextualAlternates();
    encoder << variantPosition();
    encoder << variantCaps();
    encoder << variantNumericFigure();
    encoder << variantNumericSpacing();
    encoder << variantNumericFraction();
    encoder << variantNumericOrdinal();
    encoder << variantNumericSlashedZero();
    encoder << variantAlternates();
    encoder << variantEastAsianVariant();
    encoder << variantEastAsianWidth();
    encoder << variantEastAsianRuby();
    encoder << opticalSizing();
    encoder << fontStyleAxis();
    encoder << shouldAllowUserInstalledFonts();
    encoder << shouldDisableLigaturesForSpacing();
    encoder << fontPalette();
    encoder << fontSizeAdjust();
}

template<class Decoder>
std::optional<FontDescription> FontDescription::decode(Decoder& decoder)
{
    FontDescription fontDescription;
    std::optional<FontFeatureSettings> featureSettings;
    decoder >> featureSettings;
    if (!featureSettings)
        return std::nullopt;

    std::optional<FontVariationSettings> variationSettings;
    decoder >> variationSettings;
    if (!variationSettings)
        return std::nullopt;

    std::optional<AtomString> locale;
    decoder >> locale;
    if (!locale)
        return std::nullopt;

    std::optional<std::optional<FontSelectionValue>> italic;
    decoder >> italic;
    if (!italic)
        return std::nullopt;

    std::optional<FontSelectionValue> stretch;
    decoder >> stretch;
    if (!stretch)
        return std::nullopt;

    std::optional<FontSelectionValue> weight;
    decoder >> weight;
    if (!weight)
        return std::nullopt;

    std::optional<float> computedSize;
    decoder >> computedSize;
    if (!computedSize)
        return std::nullopt;

    std::optional<FontOrientation> orientation;
    decoder >> orientation;
    if (!orientation)
        return std::nullopt;

    std::optional<NonCJKGlyphOrientation> nonCJKGlyphOrientation;
    decoder >> nonCJKGlyphOrientation;
    if (!nonCJKGlyphOrientation)
        return std::nullopt;

    std::optional<FontWidthVariant> widthVariant;
    decoder >> widthVariant;
    if (!widthVariant)
        return std::nullopt;

    std::optional<FontRenderingMode> renderingMode;
    decoder >> renderingMode;
    if (!renderingMode)
        return std::nullopt;

    std::optional<TextRenderingMode> textRenderingMode;
    decoder >> textRenderingMode;
    if (!textRenderingMode)
        return std::nullopt;

    std::optional<FontSynthesisLonghandValue> fontSynthesisWeight;
    decoder >> fontSynthesisWeight;
    if (!fontSynthesisWeight)
        return std::nullopt;

    std::optional<FontSynthesisLonghandValue> fontSynthesisStyle;
    decoder >> fontSynthesisStyle;
    if (!fontSynthesisStyle)
        return std::nullopt;

    std::optional<FontSynthesisLonghandValue> fontSynthesisSmallCaps;
    decoder >> fontSynthesisSmallCaps;
    if (!fontSynthesisSmallCaps)
        return std::nullopt;

    std::optional<std::optional<float>> sizeAdjust;
    decoder >> sizeAdjust;
    if (!sizeAdjust)
        return std::nullopt;

    std::optional<FontVariantLigatures> variantCommonLigatures;
    decoder >> variantCommonLigatures;
    if (!variantCommonLigatures)
        return std::nullopt;

    std::optional<FontVariantLigatures> variantDiscretionaryLigatures;
    decoder >> variantDiscretionaryLigatures;
    if (!variantDiscretionaryLigatures)
        return std::nullopt;

    std::optional<FontVariantLigatures> variantHistoricalLigatures;
    decoder >> variantHistoricalLigatures;
    if (!variantHistoricalLigatures)
        return std::nullopt;

    std::optional<FontVariantLigatures> variantContextualAlternates;
    decoder >> variantContextualAlternates;
    if (!variantContextualAlternates)
        return std::nullopt;

    std::optional<FontVariantPosition> variantPosition;
    decoder >> variantPosition;
    if (!variantPosition)
        return std::nullopt;

    std::optional<FontVariantCaps> variantCaps;
    decoder >> variantCaps;
    if (!variantCaps)
        return std::nullopt;

    std::optional<FontVariantNumericFigure> variantNumericFigure;
    decoder >> variantNumericFigure;
    if (!variantNumericFigure)
        return std::nullopt;

    std::optional<FontVariantNumericSpacing> variantNumericSpacing;
    decoder >> variantNumericSpacing;
    if (!variantNumericSpacing)
        return std::nullopt;

    std::optional<FontVariantNumericFraction> variantNumericFraction;
    decoder >> variantNumericFraction;
    if (!variantNumericFraction)
        return std::nullopt;

    std::optional<FontVariantNumericOrdinal> variantNumericOrdinal;
    decoder >> variantNumericOrdinal;
    if (!variantNumericOrdinal)
        return std::nullopt;

    std::optional<FontVariantNumericSlashedZero> variantNumericSlashedZero;
    decoder >> variantNumericSlashedZero;
    if (!variantNumericSlashedZero)
        return std::nullopt;

    std::optional<FontVariantAlternates> variantAlternates;
    decoder >> variantAlternates;
    if (!variantAlternates)
        return std::nullopt;

    std::optional<FontVariantEastAsianVariant> variantEastAsianVariant;
    decoder >> variantEastAsianVariant;
    if (!variantEastAsianVariant)
        return std::nullopt;

    std::optional<FontVariantEastAsianWidth> variantEastAsianWidth;
    decoder >> variantEastAsianWidth;
    if (!variantEastAsianWidth)
        return std::nullopt;

    std::optional<FontVariantEastAsianRuby> variantEastAsianRuby;
    decoder >> variantEastAsianRuby;
    if (!variantEastAsianRuby)
        return std::nullopt;

    std::optional<FontOpticalSizing> opticalSizing;
    decoder >> opticalSizing;
    if (!opticalSizing)
        return std::nullopt;

    std::optional<FontStyleAxis> fontStyleAxis;
    decoder >> fontStyleAxis;
    if (!fontStyleAxis)
        return std::nullopt;

    std::optional<AllowUserInstalledFonts> shouldAllowUserInstalledFonts;
    decoder >> shouldAllowUserInstalledFonts;
    if (!shouldAllowUserInstalledFonts)
        return std::nullopt;

    std::optional<bool> shouldDisableLigaturesForSpacing;
    decoder >> shouldDisableLigaturesForSpacing;
    if (!shouldDisableLigaturesForSpacing)
        return std::nullopt;

    std::optional<FontPalette> fontPalette;
    decoder >> fontPalette;
    if (!fontPalette)
        return std::nullopt;

    fontDescription.setFeatureSettings(WTFMove(*featureSettings));
    fontDescription.setVariationSettings(WTFMove(*variationSettings));
    fontDescription.setSpecifiedLocale(*locale);
    fontDescription.setItalic(*italic);
    fontDescription.setStretch(*stretch);
    fontDescription.setWeight(*weight);
    fontDescription.setComputedSize(*computedSize);
    fontDescription.setOrientation(*orientation);
    fontDescription.setNonCJKGlyphOrientation(*nonCJKGlyphOrientation);
    fontDescription.setWidthVariant(*widthVariant);
    fontDescription.setRenderingMode(*renderingMode);
    fontDescription.setTextRenderingMode(*textRenderingMode);
    fontDescription.setFontSynthesisWeight(*fontSynthesisWeight);
    fontDescription.setFontSynthesisStyle(*fontSynthesisStyle);
    fontDescription.setFontSynthesisSmallCaps(*fontSynthesisSmallCaps);
    fontDescription.setVariantCommonLigatures(*variantCommonLigatures);
    fontDescription.setVariantDiscretionaryLigatures(*variantDiscretionaryLigatures);
    fontDescription.setVariantHistoricalLigatures(*variantHistoricalLigatures);
    fontDescription.setVariantContextualAlternates(*variantContextualAlternates);
    fontDescription.setVariantPosition(*variantPosition);
    fontDescription.setVariantCaps(*variantCaps);
    fontDescription.setVariantNumericFigure(*variantNumericFigure);
    fontDescription.setVariantNumericSpacing(*variantNumericSpacing);
    fontDescription.setVariantNumericFraction(*variantNumericFraction);
    fontDescription.setVariantNumericOrdinal(*variantNumericOrdinal);
    fontDescription.setVariantNumericSlashedZero(*variantNumericSlashedZero);
    fontDescription.setVariantAlternates(*variantAlternates);
    fontDescription.setVariantEastAsianVariant(*variantEastAsianVariant);
    fontDescription.setVariantEastAsianWidth(*variantEastAsianWidth);
    fontDescription.setVariantEastAsianRuby(*variantEastAsianRuby);
    fontDescription.setOpticalSizing(*opticalSizing);
    fontDescription.setFontStyleAxis(*fontStyleAxis);
    fontDescription.setShouldAllowUserInstalledFonts(*shouldAllowUserInstalledFonts);
    fontDescription.setShouldDisableLigaturesForSpacing(*shouldDisableLigaturesForSpacing);
    fontDescription.setFontPalette(*fontPalette);
    fontDescription.setFontSizeAdjust(*sizeAdjust);

    return fontDescription;
}

}
