/*
 * (C) 1999-2003 Lars Knoll (knoll@kde.org)
 * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2012, 2013 Apple Inc. All rights reserved.
 *
 * 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.
 */

#include "config.h"
#include "CSSPrimitiveValue.h"

#include "CSSBasicShapes.h"
#include "CSSCalculationValue.h"
#include "CSSFontFamily.h"
#include "CSSHelper.h"
#include "CSSMarkup.h"
#include "CSSPrimitiveValueMappings.h"
#include "CSSPropertyNames.h"
#include "CSSToLengthConversionData.h"
#include "CSSValueKeywords.h"
#include "CalculationValue.h"
#include "Color.h"
#include "Counter.h"
#include "DeprecatedCSSOMPrimitiveValue.h"
#include "FontCascade.h"
#include "Node.h"
#include "Pair.h"
#include "RGBColor.h"
#include "Rect.h"
#include "RenderStyle.h"
#include <wtf/NeverDestroyed.h>
#include <wtf/StdLibExtras.h>
#include <wtf/text/StringBuilder.h>
#include <wtf/text/StringConcatenateNumbers.h>

namespace WebCore {

static inline bool isValidCSSUnitTypeForDoubleConversion(CSSPrimitiveValue::UnitType unitType)
{
    switch (unitType) {
    case CSSPrimitiveValue::CSS_CALC:
    case CSSPrimitiveValue::CSS_CALC_PERCENTAGE_WITH_LENGTH:
    case CSSPrimitiveValue::CSS_CALC_PERCENTAGE_WITH_NUMBER:
    case CSSPrimitiveValue::CSS_CHS:
    case CSSPrimitiveValue::CSS_CM:
    case CSSPrimitiveValue::CSS_DEG:
    case CSSPrimitiveValue::CSS_DIMENSION:
    case CSSPrimitiveValue::CSS_EMS:
    case CSSPrimitiveValue::CSS_QUIRKY_EMS:
    case CSSPrimitiveValue::CSS_EXS:
    case CSSPrimitiveValue::CSS_FR:
    case CSSPrimitiveValue::CSS_GRAD:
    case CSSPrimitiveValue::CSS_HZ:
    case CSSPrimitiveValue::CSS_IN:
    case CSSPrimitiveValue::CSS_KHZ:
    case CSSPrimitiveValue::CSS_MM:
    case CSSPrimitiveValue::CSS_MS:
    case CSSPrimitiveValue::CSS_NUMBER:
    case CSSPrimitiveValue::CSS_PC:
    case CSSPrimitiveValue::CSS_PERCENTAGE:
    case CSSPrimitiveValue::CSS_PT:
    case CSSPrimitiveValue::CSS_PX:
    case CSSPrimitiveValue::CSS_RAD:
    case CSSPrimitiveValue::CSS_REMS:
    case CSSPrimitiveValue::CSS_S:
    case CSSPrimitiveValue::CSS_TURN:
    case CSSPrimitiveValue::CSS_VH:
    case CSSPrimitiveValue::CSS_VMAX:
    case CSSPrimitiveValue::CSS_VMIN:
    case CSSPrimitiveValue::CSS_VW:
        return true;
    case CSSPrimitiveValue::CSS_DPCM:
    case CSSPrimitiveValue::CSS_DPI:
    case CSSPrimitiveValue::CSS_DPPX:
#if ENABLE(CSS_IMAGE_RESOLUTION) || ENABLE(RESOLUTION_MEDIA_QUERY)
        return true;
#else
        return false;
#endif
    case CSSPrimitiveValue::CSS_ATTR:
    case CSSPrimitiveValue::CSS_COUNTER:
    case CSSPrimitiveValue::CSS_COUNTER_NAME:
    case CSSPrimitiveValue::CSS_FONT_FAMILY:
    case CSSPrimitiveValue::CSS_IDENT:
    case CSSPrimitiveValue::CSS_PAIR:
    case CSSPrimitiveValue::CSS_PROPERTY_ID:
    case CSSPrimitiveValue::CSS_QUAD:
    case CSSPrimitiveValue::CSS_RECT:
    case CSSPrimitiveValue::CSS_RGBCOLOR:
    case CSSPrimitiveValue::CSS_SHAPE:
    case CSSPrimitiveValue::CSS_STRING:
    case CSSPrimitiveValue::CSS_UNICODE_RANGE:
    case CSSPrimitiveValue::CSS_UNKNOWN:
    case CSSPrimitiveValue::CSS_URI:
    case CSSPrimitiveValue::CSS_VALUE_ID:
        return false;
    }

    ASSERT_NOT_REACHED();
    return false;
}

#if !ASSERT_DISABLED

static inline bool isStringType(CSSPrimitiveValue::UnitType type)
{
    switch (type) {
    case CSSPrimitiveValue::CSS_STRING:
    case CSSPrimitiveValue::CSS_URI:
    case CSSPrimitiveValue::CSS_ATTR:
    case CSSPrimitiveValue::CSS_COUNTER_NAME:
    case CSSPrimitiveValue::CSS_DIMENSION:
        return true;
    case CSSPrimitiveValue::CSS_CALC:
    case CSSPrimitiveValue::CSS_CALC_PERCENTAGE_WITH_LENGTH:
    case CSSPrimitiveValue::CSS_CALC_PERCENTAGE_WITH_NUMBER:
    case CSSPrimitiveValue::CSS_CHS:
    case CSSPrimitiveValue::CSS_CM:
    case CSSPrimitiveValue::CSS_COUNTER:
    case CSSPrimitiveValue::CSS_DEG:
    case CSSPrimitiveValue::CSS_DPCM:
    case CSSPrimitiveValue::CSS_DPI:
    case CSSPrimitiveValue::CSS_DPPX:
    case CSSPrimitiveValue::CSS_EMS:
    case CSSPrimitiveValue::CSS_QUIRKY_EMS:
    case CSSPrimitiveValue::CSS_EXS:
    case CSSPrimitiveValue::CSS_FONT_FAMILY:
    case CSSPrimitiveValue::CSS_FR:
    case CSSPrimitiveValue::CSS_GRAD:
    case CSSPrimitiveValue::CSS_HZ:
    case CSSPrimitiveValue::CSS_IDENT:
    case CSSPrimitiveValue::CSS_IN:
    case CSSPrimitiveValue::CSS_KHZ:
    case CSSPrimitiveValue::CSS_MM:
    case CSSPrimitiveValue::CSS_MS:
    case CSSPrimitiveValue::CSS_NUMBER:
    case CSSPrimitiveValue::CSS_PAIR:
    case CSSPrimitiveValue::CSS_PC:
    case CSSPrimitiveValue::CSS_PERCENTAGE:
    case CSSPrimitiveValue::CSS_PROPERTY_ID:
    case CSSPrimitiveValue::CSS_PT:
    case CSSPrimitiveValue::CSS_PX:
    case CSSPrimitiveValue::CSS_QUAD:
    case CSSPrimitiveValue::CSS_RAD:
    case CSSPrimitiveValue::CSS_RECT:
    case CSSPrimitiveValue::CSS_REMS:
    case CSSPrimitiveValue::CSS_RGBCOLOR:
    case CSSPrimitiveValue::CSS_S:
    case CSSPrimitiveValue::CSS_SHAPE:
    case CSSPrimitiveValue::CSS_TURN:
    case CSSPrimitiveValue::CSS_UNICODE_RANGE:
    case CSSPrimitiveValue::CSS_UNKNOWN:
    case CSSPrimitiveValue::CSS_VALUE_ID:
    case CSSPrimitiveValue::CSS_VH:
    case CSSPrimitiveValue::CSS_VMAX:
    case CSSPrimitiveValue::CSS_VMIN:
    case CSSPrimitiveValue::CSS_VW:
        return false;
    }

    ASSERT_NOT_REACHED();
    return false;
}

#endif // !ASSERT_DISABLED

CSSPrimitiveValue::UnitCategory CSSPrimitiveValue::unitCategory(CSSPrimitiveValue::UnitType type)
{
    // Here we violate the spec (http://www.w3.org/TR/DOM-Level-2-Style/css.html#CSS-CSSPrimitiveValue) and allow conversions
    // between CSS_PX and relative lengths (see cssPixelsPerInch comment in CSSHelper.h for the topic treatment).
    switch (type) {
    case CSS_NUMBER:
        return UNumber;
    case CSS_PERCENTAGE:
        return UPercent;
    case CSS_PX:
    case CSS_CM:
    case CSS_MM:
    case CSS_IN:
    case CSS_PT:
    case CSS_PC:
        return ULength;
    case CSS_MS:
    case CSS_S:
        return UTime;
    case CSS_DEG:
    case CSS_RAD:
    case CSS_GRAD:
    case CSS_TURN:
        return UAngle;
    case CSS_HZ:
    case CSS_KHZ:
        return UFrequency;
#if ENABLE(CSS_IMAGE_RESOLUTION) || ENABLE(RESOLUTION_MEDIA_QUERY)
    case CSS_DPPX:
    case CSS_DPI:
    case CSS_DPCM:
        return UResolution;
#endif
    default:
        return UOther;
    }
}

typedef HashMap<const CSSPrimitiveValue*, String> CSSTextCache;
static CSSTextCache& cssTextCache()
{
    static NeverDestroyed<CSSTextCache> cache;
    return cache;
}

unsigned short CSSPrimitiveValue::primitiveType() const
{
    if (m_primitiveUnitType == CSS_PROPERTY_ID || m_primitiveUnitType == CSS_VALUE_ID)
        return CSS_IDENT;

    // Web-exposed content expects font family values to have CSS_STRING primitive type
    // so we need to map our internal CSS_FONT_FAMILY type here.
    if (m_primitiveUnitType == CSS_FONT_FAMILY)
        return CSS_STRING;

    if (m_primitiveUnitType != CSSPrimitiveValue::CSS_CALC)
        return m_primitiveUnitType;

    switch (m_value.calc->category()) {
    case CalculationCategory::Number:
        return CSSPrimitiveValue::CSS_NUMBER;
    case CalculationCategory::Length:
        return CSSPrimitiveValue::CSS_PX;
    case CalculationCategory::Percent:
        return CSSPrimitiveValue::CSS_PERCENTAGE;
    case CalculationCategory::PercentNumber:
        return CSSPrimitiveValue::CSS_CALC_PERCENTAGE_WITH_NUMBER;
    case CalculationCategory::PercentLength:
        return CSSPrimitiveValue::CSS_CALC_PERCENTAGE_WITH_LENGTH;
    case CalculationCategory::Angle:
    case CalculationCategory::Time:
    case CalculationCategory::Frequency:
        return m_value.calc->primitiveType();
    case CalculationCategory::Other:
        return CSSPrimitiveValue::CSS_UNKNOWN;
    }
    return CSSPrimitiveValue::CSS_UNKNOWN;
}

static const AtomString& propertyName(CSSPropertyID propertyID)
{
    ASSERT_ARG(propertyID, (propertyID >= firstCSSProperty && propertyID < firstCSSProperty + numCSSProperties));

    return getPropertyNameAtomString(propertyID);
}

static const AtomString& valueName(CSSValueID valueID)
{
    ASSERT_ARG(valueID, (valueID >= firstCSSValueKeyword && valueID <= lastCSSValueKeyword));

    return getValueNameAtomString(valueID);
}

CSSPrimitiveValue::CSSPrimitiveValue(CSSValueID valueID)
    : CSSValue(PrimitiveClass)
{
    m_primitiveUnitType = CSS_VALUE_ID;
    m_value.valueID = valueID;
}

CSSPrimitiveValue::CSSPrimitiveValue(CSSPropertyID propertyID)
    : CSSValue(PrimitiveClass)
{
    m_primitiveUnitType = CSS_PROPERTY_ID;
    m_value.propertyID = propertyID;
}

CSSPrimitiveValue::CSSPrimitiveValue(double num, UnitType type)
    : CSSValue(PrimitiveClass)
{
    m_primitiveUnitType = type;
    ASSERT(std::isfinite(num));
    m_value.num = num;
}

CSSPrimitiveValue::CSSPrimitiveValue(const String& string, UnitType type)
    : CSSValue(PrimitiveClass)
{
    ASSERT(isStringType(type));
    m_primitiveUnitType = type;
    if ((m_value.string = string.impl()))
        m_value.string->ref();
}

CSSPrimitiveValue::CSSPrimitiveValue(const Color& color)
    : CSSValue(PrimitiveClass)
{
    m_primitiveUnitType = CSS_RGBCOLOR;
    m_value.color = new Color(color);
}

CSSPrimitiveValue::CSSPrimitiveValue(const Length& length)
    : CSSValue(PrimitiveClass)
{
    init(length);
}

CSSPrimitiveValue::CSSPrimitiveValue(const Length& length, const RenderStyle& style)
    : CSSValue(PrimitiveClass)
{
    switch (length.type()) {
    case Auto:
    case Intrinsic:
    case MinIntrinsic:
    case MinContent:
    case MaxContent:
    case FillAvailable:
    case FitContent:
    case Percent:
        init(length);
        return;
    case Fixed:
        m_primitiveUnitType = CSS_PX;
        m_value.num = adjustFloatForAbsoluteZoom(length.value(), style);
        return;
    case Calculated: {
        init(CSSCalcValue::create(length.calculationValue(), style));
        return;
    }
    case Relative:
    case Undefined:
        ASSERT_NOT_REACHED();
        return;
    }
    ASSERT_NOT_REACHED();
}

CSSPrimitiveValue::CSSPrimitiveValue(const LengthSize& lengthSize, const RenderStyle& style)
    : CSSValue(PrimitiveClass)
{
    init(lengthSize, style);
}

void CSSPrimitiveValue::init(const Length& length)
{
    switch (length.type()) {
    case Auto:
        m_primitiveUnitType = CSS_VALUE_ID;
        m_value.valueID = CSSValueAuto;
        return;
    case WebCore::Fixed:
        m_primitiveUnitType = CSS_PX;
        m_value.num = length.value();
        return;
    case Intrinsic:
        m_primitiveUnitType = CSS_VALUE_ID;
        m_value.valueID = CSSValueIntrinsic;
        return;
    case MinIntrinsic:
        m_primitiveUnitType = CSS_VALUE_ID;
        m_value.valueID = CSSValueMinIntrinsic;
        return;
    case MinContent:
        m_primitiveUnitType = CSS_VALUE_ID;
        m_value.valueID = CSSValueMinContent;
        return;
    case MaxContent:
        m_primitiveUnitType = CSS_VALUE_ID;
        m_value.valueID = CSSValueMaxContent;
        return;
    case FillAvailable:
        m_primitiveUnitType = CSS_VALUE_ID;
        m_value.valueID = CSSValueWebkitFillAvailable;
        return;
    case FitContent:
        m_primitiveUnitType = CSS_VALUE_ID;
        m_value.valueID = CSSValueFitContent;
        return;
    case Percent:
        m_primitiveUnitType = CSS_PERCENTAGE;
        ASSERT(std::isfinite(length.percent()));
        m_value.num = length.percent();
        return;
    case Calculated:
    case Relative:
    case Undefined:
        ASSERT_NOT_REACHED();
        return;
    }
    ASSERT_NOT_REACHED();
}

void CSSPrimitiveValue::init(const LengthSize& lengthSize, const RenderStyle& style)
{
    m_primitiveUnitType = CSS_PAIR;
    m_hasCachedCSSText = false;
    m_value.pair = &Pair::create(create(lengthSize.width, style), create(lengthSize.height, style)).leakRef();
}

void CSSPrimitiveValue::init(Ref<Counter>&& counter)
{
    m_primitiveUnitType = CSS_COUNTER;
    m_hasCachedCSSText = false;
    m_value.counter = &counter.leakRef();
}

void CSSPrimitiveValue::init(Ref<Rect>&& r)
{
    m_primitiveUnitType = CSS_RECT;
    m_hasCachedCSSText = false;
    m_value.rect = &r.leakRef();
}

void CSSPrimitiveValue::init(Ref<Quad>&& quad)
{
    m_primitiveUnitType = CSS_QUAD;
    m_hasCachedCSSText = false;
    m_value.quad = &quad.leakRef();
}

void CSSPrimitiveValue::init(Ref<Pair>&& p)
{
    m_primitiveUnitType = CSS_PAIR;
    m_hasCachedCSSText = false;
    m_value.pair = &p.leakRef();
}

void CSSPrimitiveValue::init(Ref<CSSBasicShape>&& shape)
{
    m_primitiveUnitType = CSS_SHAPE;
    m_hasCachedCSSText = false;
    m_value.shape = &shape.leakRef();
}

void CSSPrimitiveValue::init(RefPtr<CSSCalcValue>&& c)
{
    m_primitiveUnitType = CSS_CALC;
    m_hasCachedCSSText = false;
    m_value.calc = c.leakRef();
}

CSSPrimitiveValue::~CSSPrimitiveValue()
{
    cleanup();
}

void CSSPrimitiveValue::cleanup()
{
    auto type = static_cast<UnitType>(m_primitiveUnitType);
    switch (type) {
    case CSS_STRING:
    case CSS_URI:
    case CSS_ATTR:
    case CSS_COUNTER_NAME:
        if (m_value.string)
            m_value.string->deref();
        break;
    case CSS_DIMENSION:
    case CSS_COUNTER:
        m_value.counter->deref();
        break;
    case CSS_RECT:
        m_value.rect->deref();
        break;
    case CSS_QUAD:
        m_value.quad->deref();
        break;
    case CSS_PAIR:
        m_value.pair->deref();
        break;
    case CSS_CALC:
        m_value.calc->deref();
        break;
    case CSS_CALC_PERCENTAGE_WITH_NUMBER:
    case CSS_CALC_PERCENTAGE_WITH_LENGTH:
        ASSERT_NOT_REACHED();
        break;
    case CSS_SHAPE:
        m_value.shape->deref();
        break;
    case CSS_FONT_FAMILY:
        ASSERT(m_value.fontFamily);
        delete m_value.fontFamily;
        m_value.fontFamily = nullptr;
        break;
    case CSS_RGBCOLOR:
        ASSERT(m_value.color);
        delete m_value.color;
        m_value.color = nullptr;
        break;
    case CSS_NUMBER:
    case CSS_PERCENTAGE:
    case CSS_EMS:
    case CSS_QUIRKY_EMS:
    case CSS_EXS:
    case CSS_REMS:
    case CSS_CHS:
    case CSS_PX:
    case CSS_CM:
    case CSS_MM:
    case CSS_IN:
    case CSS_PT:
    case CSS_PC:
    case CSS_DEG:
    case CSS_RAD:
    case CSS_GRAD:
    case CSS_MS:
    case CSS_S:
    case CSS_HZ:
    case CSS_KHZ:
    case CSS_TURN:
    case CSS_VW:
    case CSS_VH:
    case CSS_VMIN:
    case CSS_VMAX:
    case CSS_DPPX:
    case CSS_DPI:
    case CSS_DPCM:
    case CSS_FR:
    case CSS_IDENT:
    case CSS_UNKNOWN:
    case CSS_UNICODE_RANGE:
    case CSS_PROPERTY_ID:
    case CSS_VALUE_ID:
        ASSERT(!isStringType(type));
        break;
    }
    m_primitiveUnitType = 0;
    if (m_hasCachedCSSText) {
        cssTextCache().remove(this);
        m_hasCachedCSSText = false;
    }
}

double CSSPrimitiveValue::computeDegrees() const
{
    switch (primitiveType()) {
    case CSS_DEG:
        return doubleValue();
    case CSS_RAD:
        return rad2deg(doubleValue());
    case CSS_GRAD:
        return grad2deg(doubleValue());
    case CSS_TURN:
        return turn2deg(doubleValue());
    default:
        ASSERT_NOT_REACHED();
        return 0;
    }
}

template<> int CSSPrimitiveValue::computeLength(const CSSToLengthConversionData& conversionData) const
{
    return roundForImpreciseConversion<int>(computeLengthDouble(conversionData));
}

template<> unsigned CSSPrimitiveValue::computeLength(const CSSToLengthConversionData& conversionData) const
{
    return roundForImpreciseConversion<unsigned>(computeLengthDouble(conversionData));
}

template<> Length CSSPrimitiveValue::computeLength(const CSSToLengthConversionData& conversionData) const
{
    return Length(clampTo<float>(computeLengthDouble(conversionData), minValueForCssLength, maxValueForCssLength), Fixed);
}

template<> short CSSPrimitiveValue::computeLength(const CSSToLengthConversionData& conversionData) const
{
    return roundForImpreciseConversion<short>(computeLengthDouble(conversionData));
}

template<> unsigned short CSSPrimitiveValue::computeLength(const CSSToLengthConversionData& conversionData) const
{
    return roundForImpreciseConversion<unsigned short>(computeLengthDouble(conversionData));
}

template<> float CSSPrimitiveValue::computeLength(const CSSToLengthConversionData& conversionData) const
{
    return static_cast<float>(computeLengthDouble(conversionData));
}

template<> double CSSPrimitiveValue::computeLength(const CSSToLengthConversionData& conversionData) const
{
    return computeLengthDouble(conversionData);
}

double CSSPrimitiveValue::computeLengthDouble(const CSSToLengthConversionData& conversionData) const
{
    if (m_primitiveUnitType == CSS_CALC)
        // The multiplier and factor is applied to each value in the calc expression individually
        return m_value.calc->computeLengthPx(conversionData);

    return computeNonCalcLengthDouble(conversionData, static_cast<UnitType>(primitiveType()), m_value.num);
}

double CSSPrimitiveValue::computeNonCalcLengthDouble(const CSSToLengthConversionData& conversionData, UnitType primitiveType, double value)
{
    double factor;
    bool applyZoom = true;

    switch (primitiveType) {
    case CSS_EMS:
    case CSS_QUIRKY_EMS:
        ASSERT(conversionData.style());
        factor = conversionData.computingFontSize() ? conversionData.style()->fontDescription().specifiedSize() : conversionData.style()->fontDescription().computedSize();
        break;
    case CSS_EXS:
        ASSERT(conversionData.style());
        // FIXME: We have a bug right now where the zoom will be applied twice to EX units.
        // We really need to compute EX using fontMetrics for the original specifiedSize and not use
        // our actual constructed rendering font.
        if (conversionData.style()->fontMetrics().hasXHeight())
            factor = conversionData.style()->fontMetrics().xHeight();
        else
            factor = (conversionData.computingFontSize() ? conversionData.style()->fontDescription().specifiedSize() : conversionData.style()->fontDescription().computedSize()) / 2.0;
        break;
    case CSS_REMS:
        if (conversionData.rootStyle())
            factor = conversionData.computingFontSize() ? conversionData.rootStyle()->fontDescription().specifiedSize() : conversionData.rootStyle()->fontDescription().computedSize();
        else
            factor = 1.0;
        break;
    case CSS_CHS:
        ASSERT(conversionData.style());
        factor = conversionData.style()->fontMetrics().zeroWidth();
        break;
    case CSS_PX:
        factor = 1.0;
        break;
    case CSS_CM:
        factor = cssPixelsPerInch / 2.54; // (2.54 cm/in)
        break;
    case CSS_MM:
        factor = cssPixelsPerInch / 25.4;
        break;
    case CSS_IN:
        factor = cssPixelsPerInch;
        break;
    case CSS_PT:
        factor = cssPixelsPerInch / 72.0;
        break;
    case CSS_PC:
        // 1 pc == 12 pt
        factor = cssPixelsPerInch * 12.0 / 72.0;
        break;
    case CSS_CALC_PERCENTAGE_WITH_LENGTH:
    case CSS_CALC_PERCENTAGE_WITH_NUMBER:
        ASSERT_NOT_REACHED();
        return -1.0;
    case CSS_VH:
        factor = conversionData.viewportHeightFactor();
        applyZoom = false;
        break;
    case CSS_VW:
        factor = conversionData.viewportWidthFactor();
        applyZoom = false;
        break;
    case CSS_VMAX:
        factor = conversionData.viewportMaxFactor();
        applyZoom = false;
        break;
    case CSS_VMIN:
        factor = conversionData.viewportMinFactor();
        applyZoom = false;
        break;
    default:
        ASSERT_NOT_REACHED();
        return -1.0;
    }

    // We do not apply the zoom factor when we are computing the value of the font-size property. The zooming
    // for font sizes is much more complicated, since we have to worry about enforcing the minimum font size preference
    // as well as enforcing the implicit "smart minimum."
    double result = value * factor;
    if (conversionData.computingFontSize() || isFontRelativeLength(primitiveType))
        return result;

    if (applyZoom)
        result *= conversionData.zoom();

    return result;
}

ExceptionOr<void> CSSPrimitiveValue::setFloatValue(unsigned short, double)
{
    // Keeping values immutable makes optimizations easier and allows sharing of the primitive value objects.
    // No other engine supports mutating style through this API. Computed style is always read-only anyway.
    // Supporting setter would require making primitive value copy-on-write and taking care of style invalidation.
    return Exception { NoModificationAllowedError };
}

double CSSPrimitiveValue::conversionToCanonicalUnitsScaleFactor(UnitType unitType)
{
    double factor = 1.0;
    // FIXME: the switch can be replaced by an array of scale factors.
    switch (unitType) {
    // These are "canonical" units in their respective categories.
    case CSS_PX:
    case CSS_DEG:
    case CSS_MS:
    case CSS_HZ:
        break;
    case CSS_CM:
        factor = cssPixelsPerInch / 2.54; // (2.54 cm/in)
        break;
    case CSS_DPCM:
        factor = 2.54 / cssPixelsPerInch; // (2.54 cm/in)
        break;
    case CSS_MM:
        factor = cssPixelsPerInch / 25.4;
        break;
    case CSS_IN:
        factor = cssPixelsPerInch;
        break;
    case CSS_DPI:
        factor = 1 / cssPixelsPerInch;
        break;
    case CSS_PT:
        factor = cssPixelsPerInch / 72.0;
        break;
    case CSS_PC:
        factor = cssPixelsPerInch * 12.0 / 72.0; // 1 pc == 12 pt
        break;
    case CSS_RAD:
        factor = 180 / piDouble;
        break;
    case CSS_GRAD:
        factor = 0.9;
        break;
    case CSS_TURN:
        factor = 360;
        break;
    case CSS_S:
    case CSS_KHZ:
        factor = 1000;
        break;
    default:
        break;
    }

    return factor;
}

ExceptionOr<float> CSSPrimitiveValue::getFloatValue(unsigned short unitType) const
{
    auto result = doubleValueInternal(static_cast<UnitType>(unitType));
    if (!result)
        return Exception { InvalidAccessError };
    return clampTo<float>(result.value());
}

double CSSPrimitiveValue::doubleValue(UnitType unitType) const
{
    return doubleValueInternal(unitType).valueOr(0);
}

double CSSPrimitiveValue::doubleValue() const
{
    return m_primitiveUnitType != CSS_CALC ? m_value.num : m_value.calc->doubleValue();
}


CSSPrimitiveValue::UnitType CSSPrimitiveValue::canonicalUnitTypeForCategory(UnitCategory category)
{
    // The canonical unit type is chosen according to the way CSSParser::validUnit() chooses the default unit
    // in each category (based on unitflags).
    switch (category) {
    case UNumber:
        return CSS_NUMBER;
    case ULength:
        return CSS_PX;
    case UPercent:
        return CSS_UNKNOWN; // Cannot convert between numbers and percent.
    case UTime:
        return CSS_MS;
    case UAngle:
        return CSS_DEG;
    case UFrequency:
        return CSS_HZ;
#if ENABLE(CSS_IMAGE_RESOLUTION) || ENABLE(RESOLUTION_MEDIA_QUERY)
    case UResolution:
        return CSS_DPPX;
#endif
    default:
        return CSS_UNKNOWN;
    }
}

Optional<double> CSSPrimitiveValue::doubleValueInternal(UnitType requestedUnitType) const
{
    if (!isValidCSSUnitTypeForDoubleConversion(static_cast<UnitType>(m_primitiveUnitType)) || !isValidCSSUnitTypeForDoubleConversion(requestedUnitType))
        return WTF::nullopt;

    UnitType sourceUnitType = static_cast<UnitType>(primitiveType());
    if (requestedUnitType == sourceUnitType || requestedUnitType == CSS_DIMENSION)
        return doubleValue();

    UnitCategory sourceCategory = unitCategory(sourceUnitType);
    ASSERT(sourceCategory != UOther);

    UnitType targetUnitType = requestedUnitType;
    UnitCategory targetCategory = unitCategory(targetUnitType);
    ASSERT(targetCategory != UOther);

    // Cannot convert between unrelated unit categories if one of them is not UNumber.
    if (sourceCategory != targetCategory && sourceCategory != UNumber && targetCategory != UNumber)
        return WTF::nullopt;

    if (targetCategory == UNumber) {
        // We interpret conversion to CSS_NUMBER as conversion to a canonical unit in this value's category.
        targetUnitType = canonicalUnitTypeForCategory(sourceCategory);
        if (targetUnitType == CSS_UNKNOWN)
            return WTF::nullopt;
    }

    if (sourceUnitType == CSS_NUMBER) {
        // We interpret conversion from CSS_NUMBER in the same way as CSSParser::validUnit() while using non-strict mode.
        sourceUnitType = canonicalUnitTypeForCategory(targetCategory);
        if (sourceUnitType == CSS_UNKNOWN)
            return WTF::nullopt;
    }

    double convertedValue = doubleValue();

    // First convert the value from m_primitiveUnitType to canonical type.
    double factor = conversionToCanonicalUnitsScaleFactor(sourceUnitType);
    convertedValue *= factor;

    // Now convert from canonical type to the target unitType.
    factor = conversionToCanonicalUnitsScaleFactor(targetUnitType);
    convertedValue /= factor;

    return convertedValue;
}

ExceptionOr<void> CSSPrimitiveValue::setStringValue(unsigned short, const String&)
{
    // Keeping values immutable makes optimizations easier and allows sharing of the primitive value objects.
    // No other engine supports mutating style through this API. Computed style is always read-only anyway.
    // Supporting setter would require making primitive value copy-on-write and taking care of style invalidation.
    return Exception { NoModificationAllowedError };
}

ExceptionOr<String> CSSPrimitiveValue::getStringValue() const
{
    switch (m_primitiveUnitType) {
    case CSS_STRING:
    case CSS_ATTR:
    case CSS_URI:
        return m_value.string;
    case CSS_FONT_FAMILY:
        return String { m_value.fontFamily->familyName };
    case CSS_VALUE_ID:
        return String { valueName(m_value.valueID).string() };
    case CSS_PROPERTY_ID:
        return String { propertyName(m_value.propertyID).string() };
    default:
        return Exception { InvalidAccessError };
    }
}

String CSSPrimitiveValue::stringValue() const
{
    switch (m_primitiveUnitType) {
    case CSS_STRING:
    case CSS_ATTR:
    case CSS_URI:
        return m_value.string;
    case CSS_FONT_FAMILY:
        return m_value.fontFamily->familyName;
    case CSS_VALUE_ID:
        return valueName(m_value.valueID);
    case CSS_PROPERTY_ID:
        return propertyName(m_value.propertyID);
    default:
        return String();
    }
}

ExceptionOr<Counter&> CSSPrimitiveValue::getCounterValue() const
{
    if (m_primitiveUnitType != CSS_COUNTER)
        return Exception { InvalidAccessError };
    return *m_value.counter;
}

ExceptionOr<Rect&> CSSPrimitiveValue::getRectValue() const
{
    if (m_primitiveUnitType != CSS_RECT)
        return Exception { InvalidAccessError };
    return *m_value.rect;
}

ExceptionOr<Ref<RGBColor>> CSSPrimitiveValue::getRGBColorValue() const
{
    if (m_primitiveUnitType != CSS_RGBCOLOR)
        return Exception { InvalidAccessError };

    // FIXME: This should not return a new object for each invocation.
    return RGBColor::create(m_value.color->rgb());
}

NEVER_INLINE String CSSPrimitiveValue::formatNumberValue(StringView suffix) const
{
    return makeString(m_value.num, suffix);
}

ALWAYS_INLINE String CSSPrimitiveValue::formatNumberForCustomCSSText() const
{
    switch (m_primitiveUnitType) {
    case CSS_UNKNOWN:
        return String();
    case CSS_NUMBER:
        return formatNumberValue("");
    case CSS_PERCENTAGE:
        return formatNumberValue("%");
    case CSS_EMS:
    case CSS_QUIRKY_EMS:
        return formatNumberValue("em");
    case CSS_EXS:
        return formatNumberValue("ex");
    case CSS_REMS:
        return formatNumberValue("rem");
    case CSS_CHS:
        return formatNumberValue("ch");
    case CSS_PX:
        return formatNumberValue("px");
    case CSS_CM:
        return formatNumberValue("cm");
#if ENABLE(CSS_IMAGE_RESOLUTION) || ENABLE(RESOLUTION_MEDIA_QUERY)
    case CSS_DPPX:
        return formatNumberValue("dppx");
    case CSS_DPI:
        return formatNumberValue("dpi");
    case CSS_DPCM:
        return formatNumberValue("dpcm");
#endif
    case CSS_MM:
        return formatNumberValue("mm");
    case CSS_IN:
        return formatNumberValue("in");
    case CSS_PT:
        return formatNumberValue("pt");
    case CSS_PC:
        return formatNumberValue("pc");
    case CSS_DEG:
        return formatNumberValue("deg");
    case CSS_RAD:
        return formatNumberValue("rad");
    case CSS_GRAD:
        return formatNumberValue("grad");
    case CSS_MS:
        return formatNumberValue("ms");
    case CSS_S:
        return formatNumberValue("s");
    case CSS_HZ:
        return formatNumberValue("hz");
    case CSS_KHZ:
        return formatNumberValue("khz");
    case CSS_TURN:
        return formatNumberValue("turn");
    case CSS_FR:
        return formatNumberValue("fr");
    case CSS_DIMENSION:
        // FIXME: We currently don't handle CSS_DIMENSION properly as we don't store
        // the actual dimension, just the numeric value as a string.
    case CSS_STRING:
        // FIME-NEWPARSER: Once we have CSSCustomIdentValue hooked up, this can just be
        // serializeString, since custom identifiers won't be the same value as strings
        // any longer.
        return serializeAsStringOrCustomIdent(m_value.string);
    case CSS_FONT_FAMILY:
        return serializeFontFamily(m_value.fontFamily->familyName);
    case CSS_URI:
        return serializeURL(m_value.string);
    case CSS_VALUE_ID:
        return valueName(m_value.valueID);
    case CSS_PROPERTY_ID:
        return propertyName(m_value.propertyID);
    case CSS_ATTR:
        return "attr(" + String(m_value.string) + ')';
    case CSS_COUNTER_NAME:
        return "counter(" + String(m_value.string) + ')';
    case CSS_COUNTER: {
        StringBuilder result;
        String separator = m_value.counter->separator();
        if (separator.isEmpty())
            result.appendLiteral("counter(");
        else
            result.appendLiteral("counters(");

        result.append(m_value.counter->identifier());
        if (!separator.isEmpty()) {
            result.appendLiteral(", ");
            serializeString(separator, result);
        }
        String listStyle = m_value.counter->listStyle();
        if (!listStyle.isEmpty())
            result.append(", ", listStyle);
        result.append(')');

        return result.toString();
    }
    case CSS_RECT:
        return rectValue()->cssText();
    case CSS_QUAD:
        return quadValue()->cssText();
    case CSS_RGBCOLOR:
        return color().cssText();
    case CSS_PAIR:
        return pairValue()->cssText();
    case CSS_CALC:
        return m_value.calc->cssText();
    case CSS_SHAPE:
        return m_value.shape->cssText();
    case CSS_VW:
        return formatNumberValue("vw");
    case CSS_VH:
        return formatNumberValue("vh");
    case CSS_VMIN:
        return formatNumberValue("vmin");
    case CSS_VMAX:
        return formatNumberValue("vmax");
    }
    return String();
}

String CSSPrimitiveValue::customCSSText() const
{
    // FIXME: return the original value instead of a generated one (e.g. color
    // name if it was specified) - check what spec says about this

    CSSTextCache& cssTextCache = WebCore::cssTextCache();

    if (m_hasCachedCSSText) {
        ASSERT(cssTextCache.contains(this));
        return cssTextCache.get(this);
    }

    String text = formatNumberForCustomCSSText();

    ASSERT(!cssTextCache.contains(this));
    m_hasCachedCSSText = true;
    cssTextCache.set(this, text);
    return text;
}

bool CSSPrimitiveValue::equals(const CSSPrimitiveValue& other) const
{
    if (m_primitiveUnitType != other.m_primitiveUnitType)
        return false;

    switch (m_primitiveUnitType) {
    case CSS_UNKNOWN:
        return false;
    case CSS_NUMBER:
    case CSS_PERCENTAGE:
    case CSS_EMS:
    case CSS_QUIRKY_EMS:
    case CSS_EXS:
    case CSS_REMS:
    case CSS_PX:
    case CSS_CM:
#if ENABLE(CSS_IMAGE_RESOLUTION) || ENABLE(RESOLUTION_MEDIA_QUERY)
    case CSS_DPPX:
    case CSS_DPI:
    case CSS_DPCM:
#endif
    case CSS_MM:
    case CSS_IN:
    case CSS_PT:
    case CSS_PC:
    case CSS_DEG:
    case CSS_RAD:
    case CSS_GRAD:
    case CSS_MS:
    case CSS_S:
    case CSS_HZ:
    case CSS_KHZ:
    case CSS_TURN:
    case CSS_VW:
    case CSS_VH:
    case CSS_VMIN:
    case CSS_FR:
        return m_value.num == other.m_value.num;
    case CSS_PROPERTY_ID:
        return propertyName(m_value.propertyID) == propertyName(other.m_value.propertyID);
    case CSS_VALUE_ID:
        return valueName(m_value.valueID) == valueName(other.m_value.valueID);
    case CSS_DIMENSION:
    case CSS_STRING:
    case CSS_URI:
    case CSS_ATTR:
    case CSS_COUNTER_NAME:
        return equal(m_value.string, other.m_value.string);
    case CSS_COUNTER:
        return m_value.counter && other.m_value.counter && m_value.counter->equals(*other.m_value.counter);
    case CSS_RECT:
        return m_value.rect && other.m_value.rect && m_value.rect->equals(*other.m_value.rect);
    case CSS_QUAD:
        return m_value.quad && other.m_value.quad && m_value.quad->equals(*other.m_value.quad);
    case CSS_RGBCOLOR:
        return color() == other.color();
    case CSS_PAIR:
        return m_value.pair && other.m_value.pair && m_value.pair->equals(*other.m_value.pair);
    case CSS_CALC:
        return m_value.calc && other.m_value.calc && m_value.calc->equals(*other.m_value.calc);
    case CSS_SHAPE:
        return m_value.shape && other.m_value.shape && m_value.shape->equals(*other.m_value.shape);
    case CSS_FONT_FAMILY:
        return fontFamily() == other.fontFamily();
    }
    return false;
}

Ref<DeprecatedCSSOMPrimitiveValue> CSSPrimitiveValue::createDeprecatedCSSOMPrimitiveWrapper(CSSStyleDeclaration& styleDeclaration) const
{
    return DeprecatedCSSOMPrimitiveValue::create(*this, styleDeclaration);
}

// https://drafts.css-houdini.org/css-properties-values-api/#dependency-cycles-via-relative-units
void CSSPrimitiveValue::collectDirectComputationalDependencies(HashSet<CSSPropertyID>& values) const
{
    switch (m_primitiveUnitType) {
    case CSS_EMS:
    case CSS_QUIRKY_EMS:
    case CSS_EXS:
    case CSS_CHS:
        values.add(CSSPropertyFontSize);
        break;
    case CSS_CALC:
        m_value.calc->collectDirectComputationalDependencies(values);
        break;
    }
}

void CSSPrimitiveValue::collectDirectRootComputationalDependencies(HashSet<CSSPropertyID>& values) const
{
    switch (m_primitiveUnitType) {
    case CSS_REMS:
        values.add(CSSPropertyFontSize);
        break;
    case CSS_CALC:
        m_value.calc->collectDirectRootComputationalDependencies(values);
        break;
    }
}

} // namespace WebCore