/*

 * CSS Media Query Evaluator

 *

 * Copyright (C) 2006 Kimmo Kinnunen <kimmo.t.kinnunen@nokia.com>.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR

 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR

 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,

 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,

 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR

 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY

 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE

 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#include "config.h"

#include "MediaQueryEvaluator.h"

#include "Chrome.h"

#include "CSSPrimitiveValue.h"

#include "CSSValueList.h"

#include "DeprecatedString.h"

#include "FloatRect.h"

#include "Frame.h"

#include "FrameView.h"

#include "IntRect.h"

#include "MediaFeatureNames.h"

#include "MediaList.h"

#include "MediaQuery.h"

#include "MediaQueryExp.h"

#include "Page.h"

#include "RenderStyle.h"

#include "PlatformScreen.h"

#include <wtf/HashMap.h>

namespace WebCore {

using namespace MediaFeatureNames;

enum MediaFeaturePrefix { MinPrefix, MaxPrefix, NoPrefix };

typedef bool (*EvalFunc)(CSSValue*, RenderStyle*, Page*,  MediaFeaturePrefix);

typedef HashMap<AtomicStringImpl*, EvalFunc> FunctionMap;

static FunctionMap* gFunctionMap;

/*

 * FIXME: following media features are not implemented: color_index, scan, resolution

 *

 * color_index, min-color-index, max_color_index: It's unknown how to retrieve

 * the information if the display mode is indexed

 * scan: The "scan" media feature describes the scanning process of

 * tv output devices. It's unknown how to retrieve this information from

 * the platform

 * resolution, min-resolution,  max-resolution: css parser doesn't seem to

 * support CSS_DIMENSION

 */

MediaQueryEvaluator::MediaQueryEvaluator(bool mediaFeatureResult)

    : m_page(0)

    , m_style(0)

    , m_expResult(mediaFeatureResult)

{

}

MediaQueryEvaluator:: MediaQueryEvaluator(const String& acceptedMediaType, bool mediaFeatureResult)

    : m_mediaType(acceptedMediaType)

    , m_page(0)

    , m_style(0)

    , m_expResult(mediaFeatureResult)

{

}

MediaQueryEvaluator:: MediaQueryEvaluator(const char* acceptedMediaType, bool mediaFeatureResult)

    : m_mediaType(acceptedMediaType)

    , m_page(0)

    , m_style(0)

    , m_expResult(mediaFeatureResult)

{

}

MediaQueryEvaluator:: MediaQueryEvaluator(const String& acceptedMediaType, Page* page, RenderStyle* style)

    : m_mediaType(acceptedMediaType.lower())

    , m_page(page)

    , m_style(style)

    , m_expResult(false) // doesn't matter when we have m_page and m_style

{

}

MediaQueryEvaluator::~MediaQueryEvaluator()

{

}

bool MediaQueryEvaluator::mediaTypeMatch(const String& mediaTypeToMatch) const

{

    return mediaTypeToMatch.isEmpty()

        || equalIgnoringCase(mediaTypeToMatch, "all")

        || equalIgnoringCase(mediaTypeToMatch, m_mediaType);

}

bool MediaQueryEvaluator::mediaTypeMatchSpecific(const char* mediaTypeToMatch) const

{

    // Like mediaTypeMatch, but without the special cases for "" and "all".

    ASSERT(mediaTypeToMatch);

    ASSERT(mediaTypeToMatch[0] != '\0');

    ASSERT(!equalIgnoringCase(mediaTypeToMatch, String("all")));

    return equalIgnoringCase(mediaTypeToMatch, m_mediaType);

}

static bool applyRestrictor(MediaQuery::Restrictor r, bool value)

{

    return r == MediaQuery::Not ? !value : value;

}

bool MediaQueryEvaluator::eval(const MediaList* mediaList) const

{

    if (!mediaList)

        return true;

    const Vector<MediaQuery*>* queries = mediaList->mediaQueries();

    if (!queries->size())

        return true; // empty query list evaluates to true

    // iterate over queries, stop if any of them eval to true (OR semantics)

    bool result = false;

    for (size_t i = 0; i < queries->size() && !result; ++i) {

        MediaQuery* query = queries->at(i);

        if (mediaTypeMatch(query->mediaType())) {

            const Vector<MediaQueryExp*>* exps = query->expressions();

            // iterate through expressions, stop if any of them eval to false

            // (AND semantics)

            size_t j = 0;

            for (; j < exps->size() && eval(exps->at(j)); ++j) /* empty*/;

            // assume true if we are at the end of the list,

            // otherwise assume false

            result = applyRestrictor(query->restrictor(), exps->size() == j);

        } else

            result = applyRestrictor(query->restrictor(), false);

    }

    return result;

}

static bool parseAspectRatio(CSSValue* value, int& a, int& b)

{

    if (value->isValueList()){

        CSSValueList* valueList = static_cast<CSSValueList*>(value);

        if (valueList->length() == 3) {

            CSSValue* i0 = valueList->item(0);

            CSSValue* i1 = valueList->item(1);

            CSSValue* i2 = valueList->item(2);

            if (i0->isPrimitiveValue() && static_cast<CSSPrimitiveValue*>(i0)->primitiveType() == CSSPrimitiveValue::CSS_NUMBER

                && i1->isPrimitiveValue() && static_cast<CSSPrimitiveValue*>(i1)->primitiveType() == CSSPrimitiveValue::CSS_STRING

                && i2->isPrimitiveValue() && static_cast<CSSPrimitiveValue*>(i2)->primitiveType() == CSSPrimitiveValue::CSS_NUMBER) {

                String str = static_cast<CSSPrimitiveValue*>(i1)->getStringValue();

                if (!str.isNull() && str.length() == 1 && str[0] == DeprecatedChar('/')) {

                    a = static_cast<CSSPrimitiveValue*>(i0)->getIntValue(CSSPrimitiveValue::CSS_NUMBER);

                    b = static_cast<CSSPrimitiveValue*>(i2)->getIntValue(CSSPrimitiveValue::CSS_NUMBER);

                    return true;

                }

            }

        }

    }

    return false;

}

inline bool cmpvalue(int a, int b, MediaFeaturePrefix op)

{

    switch (op) {

    case MinPrefix:

        return a >= b;

    case MaxPrefix:

        return a <= b;

    case NoPrefix:

        return a == b;

    }

    return false;

}

inline bool cmpvalue(float a, float b, MediaFeaturePrefix op)

{

    switch (op) {

    case MinPrefix:

        return a >= b;

    case MaxPrefix:

        return a <= b;

    case NoPrefix:

        return a == b;

    }

    return false;

}

static bool numberValue(CSSValue* value, float& result)

{

    if (value->isPrimitiveValue()

        && static_cast<CSSPrimitiveValue*>(value)->primitiveType() == CSSPrimitiveValue::CSS_NUMBER) {

        result = static_cast<CSSPrimitiveValue*>(value)->getFloatValue(CSSPrimitiveValue::CSS_NUMBER);

        return true;

    }

    return false;

}

static bool colorMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix op)

{

    int bitsPerComponent = screenDepthPerComponent(page->mainFrame()->view());

    float number;

    if (value)

        return numberValue(value, number) && cmpvalue(bitsPerComponent, (int)number, op);

    return bitsPerComponent != 0;

}

static bool monochromeMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix op)

{

    if (!screenIsMonochrome(page->mainFrame()->view()))

        return false;

    return colorMediaFeatureEval(value, style, page, op);

}

static bool device_aspect_ratioMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix op)

{

    if (value) {

        FloatRect sg = screenRect(page->mainFrame()->view());

        int a = 0;

        int b = 0;

        if (parseAspectRatio(value, a, b))

            return b != 0  && cmpvalue(a * (int)sg.height(), b * (int)sg.width(), op);

        return false;

    }

    // ({,min-,max-}device-aspect-ratio)

    // assume if we have a device, its aspect ratio is non-zero

    return true;

}

static bool device_pixel_ratioMediaFeatureEval(CSSValue *value, RenderStyle* style, Page* page, MediaFeaturePrefix op)

{

    if (value)

        return value->isPrimitiveValue() && cmpvalue(page->chrome()->scaleFactor(), static_cast<CSSPrimitiveValue*>(value)->getFloatValue(), op);

    return page->chrome()->scaleFactor() != 0;

}

static bool gridMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix op)

{

    // if output device is bitmap, grid: 0 == true

    // assume we have bitmap device

    float number;

    if (value && numberValue(value, number))

        return cmpvalue((int)number, 0, op);

    return false;

}

static bool device_heightMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix op)

{

    if (value) {

        FloatRect sg = screenRect(page->mainFrame()->view());

        return value->isPrimitiveValue() && cmpvalue((int)sg.height(), static_cast<CSSPrimitiveValue*>(value)->computeLengthInt(style), op);

    }

    // ({,min-,max-}device-height)

    // assume if we have a device, assume non-zero

    return true;

}

static bool device_widthMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix op)

{

    if (value) {

        FloatRect sg = screenRect(page->mainFrame()->view());

        return value->isPrimitiveValue() && cmpvalue((int)sg.width(), static_cast<CSSPrimitiveValue*>(value)->computeLengthInt(style), op);

    }

    // ({,min-,max-}device-width)

    // assume if we have a device, assume non-zero

    return true;

}

static bool heightMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix op)

{

    FrameView* view = page->mainFrame()->view();

    if (value)

        return value->isPrimitiveValue() && cmpvalue(view->visibleHeight(), static_cast<CSSPrimitiveValue*>(value)->computeLengthInt(style), op);

    return view->visibleHeight() != 0;

}

static bool widthMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix op)

{

    FrameView* view = page->mainFrame()->view();

    if (value)

        return value->isPrimitiveValue() && cmpvalue(view->visibleWidth(), static_cast<CSSPrimitiveValue*>(value)->computeLengthInt(style), op);

    return view->visibleWidth() != 0;

}

// rest of the functions are trampolines which set the prefix according to the media feature expression used

static bool min_colorMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix /*op*/)

{

    return colorMediaFeatureEval(value, style, page, MinPrefix);

}

static bool max_colorMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix /*op*/)

{

    return colorMediaFeatureEval(value, style, page, MaxPrefix);

}

static bool min_monochromeMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix /*op*/)

{

    return monochromeMediaFeatureEval(value, style, page, MinPrefix);

}

static bool max_monochromeMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix /*op*/)

{

    return monochromeMediaFeatureEval(value, style, page, MaxPrefix);

}

static bool min_device_aspect_ratioMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix /*op*/)

{

    return device_aspect_ratioMediaFeatureEval(value, style, page, MinPrefix);

}

static bool max_device_aspect_ratioMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix /*op*/)

{

    return device_aspect_ratioMediaFeatureEval(value, style, page, MaxPrefix);

}

static bool min_device_pixel_ratioMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix /*op*/)

{

    return device_pixel_ratioMediaFeatureEval(value, style, page, MinPrefix);

}

static bool max_device_pixel_ratioMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix /*op*/)

{

    return device_pixel_ratioMediaFeatureEval(value, style, page, MaxPrefix);

}

static bool min_heightMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix /*op*/)

{

    return heightMediaFeatureEval(value, style, page, MinPrefix);

}

static bool max_heightMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix /*op*/)

{

    return heightMediaFeatureEval(value, style, page, MaxPrefix);

}

static bool min_widthMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix /*op*/)

{

    return widthMediaFeatureEval(value, style, page, MinPrefix);

}

static bool max_widthMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix /*op*/)

{

    return widthMediaFeatureEval(value, style, page, MaxPrefix);

}

static bool min_device_heightMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix /*op*/)

{

    return device_heightMediaFeatureEval(value, style, page, MinPrefix);

}

static bool max_device_heightMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix /*op*/)

{

    return device_heightMediaFeatureEval(value, style, page, MaxPrefix);

}

static bool min_device_widthMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix /*op*/)

{

    return device_widthMediaFeatureEval(value, style, page, MinPrefix);

}

static bool max_device_widthMediaFeatureEval(CSSValue* value, RenderStyle* style, Page* page,  MediaFeaturePrefix /*op*/)

{

    return device_widthMediaFeatureEval(value, style, page, MaxPrefix);

}

static void createFunctionMap()

{

    // Create the table.

    gFunctionMap = new FunctionMap;

#define ADD_TO_FUNCTIONMAP(name, str)  \

    gFunctionMap->set(name##MediaFeature.impl(), name##MediaFeatureEval);

    CSS_MEDIAQUERY_NAMES_FOR_EACH_MEDIAFEATURE(ADD_TO_FUNCTIONMAP);

#undef ADD_TO_FUNCTIONMAP

}

bool MediaQueryEvaluator::eval(const MediaQueryExp* expr) const

{

    if (!m_page || !m_style)

        return m_expResult;

    if (!gFunctionMap)

        createFunctionMap();

    // call the media feature evaluation function. Assume no prefix

    // and let trampoline functions override the prefix if prefix is

    // used

    EvalFunc func = gFunctionMap->get(expr->mediaFeature().impl());

    if (func)

        return func(expr->value(), m_style, m_page, NoPrefix);

    return false;

}

} // namespace