/*

    Copyright (C) 2007 Eric Seidel <eric@webkit.org>

    Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>

    Copyright (C) Research In Motion Limited 2010. 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"

#if ENABLE(SVG_FONTS)

#include "SVGFontElement.h"

#include "Document.h"

#include "Font.h"

#include "GlyphPageTreeNode.h"

#include "SVGGlyphElement.h"

#include "SVGHKernElement.h"

#include "SVGMissingGlyphElement.h"

#include "SVGNames.h"

#include "SVGVKernElement.h"

#include <wtf/ASCIICType.h>

using namespace WTF;

namespace WebCore {

using namespace SVGNames;

SVGFontElement::SVGFontElement(const QualifiedName& tagName, Document* doc)

    : SVGStyledElement(tagName, doc) 

    , m_isGlyphCacheValid(false)

{

}

SVGFontElement::~SVGFontElement()

{

}

void SVGFontElement::synchronizeProperty(const QualifiedName& attrName)

{

    SVGStyledElement::synchronizeProperty(attrName);

    if (attrName == anyQName() || SVGExternalResourcesRequired::isKnownAttribute(attrName))

        synchronizeExternalResourcesRequired();

}

void SVGFontElement::invalidateGlyphCache()

{

    if (m_isGlyphCacheValid) {

        m_glyphMap.clear();

        m_horizontalKerningPairs.clear();

        m_verticalKerningPairs.clear();

    }

    m_isGlyphCacheValid = false;

}

SVGMissingGlyphElement* SVGFontElement::firstMissingGlyphElement() const

{

    for (Node* child = firstChild(); child; child = child->nextSibling()) {

        if (child->hasTagName(missing_glyphTag))

            return static_cast<SVGMissingGlyphElement*>(child);

    }

    return 0;

}

void SVGFontElement::ensureGlyphCache() const

{

    if (m_isGlyphCacheValid)

        return;

    for (Node* child = firstChild(); child; child = child->nextSibling()) {

        if (child->hasTagName(glyphTag)) {

            SVGGlyphElement* glyph = static_cast<SVGGlyphElement*>(child);

            String unicode = glyph->getAttribute(unicodeAttr);

            if (unicode.length())

                m_glyphMap.add(unicode, glyph->buildGlyphIdentifier());

        } else if (child->hasTagName(hkernTag)) {

            SVGHKernElement* hkern = static_cast<SVGHKernElement*>(child);

            hkern->buildHorizontalKerningPair(m_horizontalKerningPairs);

        } else if (child->hasTagName(vkernTag)) {

            SVGVKernElement* vkern = static_cast<SVGVKernElement*>(child);

            vkern->buildVerticalKerningPair(m_verticalKerningPairs);

        }

    }

    m_isGlyphCacheValid = true;

}

static bool stringMatchesUnicodeRange(const String& unicodeString, const UnicodeRanges& ranges, const HashSet<String>& unicodeValues)

{

    if (unicodeString.isEmpty())

        return false;

    if (!ranges.isEmpty()) {

        UChar firstChar = unicodeString[0];

        const UnicodeRanges::const_iterator end = ranges.end();

        for (UnicodeRanges::const_iterator it = ranges.begin(); it != end; ++it) {

            if (firstChar >= it->first && firstChar <= it->second)

                return true;

        }

    }

    if (!unicodeValues.isEmpty())

        return unicodeValues.contains(unicodeString);

    return false;

}

static bool stringMatchesGlyphName(const String& glyphName, const HashSet<String>& glyphValues)

{

    if (glyphName.isEmpty())

        return false;

    if (!glyphValues.isEmpty())

        return glyphValues.contains(glyphName);

    return false;

}

static bool matches(const String& u1, const String& g1, const String& u2, const String& g2, const SVGKerningPair& kerningPair)

{

    if (!stringMatchesUnicodeRange(u1, kerningPair.unicodeRange1, kerningPair.unicodeName1)

        && !stringMatchesGlyphName(g1, kerningPair.glyphName1))

        return false;

    if (!stringMatchesUnicodeRange(u2, kerningPair.unicodeRange2, kerningPair.unicodeName2)

        && !stringMatchesGlyphName(g2, kerningPair.glyphName2))

        return false;

    return true;

}

static float kerningForPairOfStringsAndGlyphs(KerningPairVector& kerningPairs, const String& u1, const String& g1, const String& u2, const String& g2)

{

    KerningPairVector::const_iterator it = kerningPairs.end() - 1;

    const KerningPairVector::const_iterator begin = kerningPairs.begin() - 1;

    for (; it != begin; --it) {

        if (matches(u1, g1, u2, g2, *it))

            return it->kerning;

    }

    return 0.0f;

}

float SVGFontElement::horizontalKerningForPairOfStringsAndGlyphs(const String& u1, const String& g1, const String& u2, const String& g2) const

{

    if (m_horizontalKerningPairs.isEmpty())

        return 0.0f;

    return kerningForPairOfStringsAndGlyphs(m_horizontalKerningPairs, u1, g1, u2, g2);

}

float SVGFontElement::verticalKerningForPairOfStringsAndGlyphs(const String& u1, const String& g1, const String& u2, const String& g2) const

{

    if (m_verticalKerningPairs.isEmpty())

        return 0.0f;

    return kerningForPairOfStringsAndGlyphs(m_verticalKerningPairs, u1, g1, u2, g2);

}

void SVGFontElement::getGlyphIdentifiersForString(const String& string, Vector<SVGGlyphIdentifier>& glyphs) const

{

    ensureGlyphCache();

    m_glyphMap.get(string, glyphs);

}

}

#endif // ENABLE(SVG_FONTS)