/*

 * Copyright (C) 2006 Apple Computer, Inc.  All rights reserved.

 *

 * 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. 

 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of

 *     its contributors may be used to endorse or promote products derived

 *     from this software without specific prior written permission. 

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "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 OR ITS 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 "FontCache.h"

#include "Font.h"

#include "FontFallbackList.h"

#include "FontPlatformData.h"

#include "StringHash.h"

#include <wtf/HashMap.h>

namespace WebCore {

struct FontPlatformDataCacheKey {

    FontPlatformDataCacheKey(const AtomicString& family = AtomicString(), unsigned size = 0, bool bold = false, bool italic = false,

                             bool isPrinterFont = false)

        : m_family(family)

        , m_size(size)

        , m_bold(bold)

        , m_italic(italic)

        , m_printerFont(isPrinterFont)

    {

    }

    bool operator==(const FontPlatformDataCacheKey& other) const

    {

        return equalIgnoringCase(m_family, other.m_family) && m_size == other.m_size && 

               m_bold == other.m_bold && m_italic == other.m_italic && m_printerFont == other.m_printerFont;

    }

    AtomicString m_family;

    unsigned m_size;

    bool m_bold;

    bool m_italic;

    bool m_printerFont;

};

inline unsigned computeHash(const FontPlatformDataCacheKey& fontKey)

{

    unsigned hashCodes[3] = {

        CaseInsensitiveHash<String>::hash(fontKey.m_family),

        fontKey.m_size,

        static_cast<unsigned>(fontKey.m_bold) << 2 | static_cast<unsigned>(fontKey.m_italic) << 1 | static_cast<unsigned>(fontKey.m_printerFont)

    };

    return StringImpl::computeHash(reinterpret_cast<UChar*>(hashCodes), 3 * sizeof(unsigned) / sizeof(UChar));

}

struct FontPlatformDataCacheKeyHash {

    static unsigned hash(const FontPlatformDataCacheKey& font)

    {

        return computeHash(font);

    }

    static bool equal(const FontPlatformDataCacheKey& a, const FontPlatformDataCacheKey& b)

    {

        return a == b;

    }

};

struct FontPlatformDataCacheKeyTraits : WTF::GenericHashTraits<FontPlatformDataCacheKey> {

    static const bool emptyValueIsZero = true;

    static const bool needsDestruction = false;

    static const FontPlatformDataCacheKey& deletedValue()

    {

        static FontPlatformDataCacheKey key(nullAtom, 0xFFFFFFFFU, false, false);

        return key;

    }

    static const FontPlatformDataCacheKey& emptyValue()

    {

        static FontPlatformDataCacheKey key(nullAtom, 0, false, false);

        return key;

    }

};

typedef HashMap<FontPlatformDataCacheKey, FontPlatformData*, FontPlatformDataCacheKeyHash, FontPlatformDataCacheKeyTraits> FontPlatformDataCache;

static FontPlatformDataCache* gFontPlatformDataCache = 0;

static const AtomicString& alternateFamilyName(const AtomicString& familyName)

{

#if PLATFORM(SYMBIAN)

    return FontCache::systemFontFamilyName( familyName );

#else

    // Alias Courier <-> Courier New

    static AtomicString courier("Courier"), courierNew("Courier New");

    if (equalIgnoringCase(familyName, courier))

        return courierNew;

    if (equalIgnoringCase(familyName, courierNew))

        return courier;

    // Alias Times and Times New Roman.

    static AtomicString times("Times"), timesNewRoman("Times New Roman");

    if (equalIgnoringCase(familyName, times))

        return timesNewRoman;

    if (equalIgnoringCase(familyName, timesNewRoman))

        return times;

    // Alias Arial and Helvetica

    static AtomicString arial("Arial"), helvetica("Helvetica");

    if (equalIgnoringCase(familyName, arial))

        return helvetica;

    if (equalIgnoringCase(familyName, helvetica))

        return arial;

    return emptyAtom;

#endif

}

FontPlatformData* FontCache::getCachedFontPlatformData(const FontDescription& fontDescription, 

                                                       const AtomicString& familyName,

                                                       bool checkingAlternateName)

{

    if (!gFontPlatformDataCache) {

        gFontPlatformDataCache = new FontPlatformDataCache;

    }

    FontPlatformDataCacheKey key(familyName, fontDescription.computedPixelSize(), fontDescription.bold(), fontDescription.italic(),

                                 fontDescription.usePrinterFont());

    FontPlatformData* result = 0;

    bool foundResult;

    FontPlatformDataCache::iterator it = gFontPlatformDataCache->find(key);

    if (it == gFontPlatformDataCache->end()) {

        result = createFontPlatformData(fontDescription, familyName);

        gFontPlatformDataCache->set(key, result);

        foundResult = result;

    } else {

        result = it->second;

        foundResult = true;

    }

    if (!foundResult && !checkingAlternateName) {

        // We were unable to find a font.  We have a small set of fonts that we alias to other names, 

        // e.g., Arial/Helvetica, Courier/Courier New, etc.  Try looking up the font under the aliased name.

        const AtomicString& alternateName = alternateFamilyName(familyName);

        if (!alternateName.isEmpty())

            result = getCachedFontPlatformData(fontDescription, alternateName, true);

        if (result)

            gFontPlatformDataCache->set(key, new FontPlatformData(*result)); // Cache the result under the old name.

    }

    key.m_family = AtomicString();

    return result;

}

struct FontDataCacheKeyHash {

    static unsigned hash(const FontPlatformData& platformData)

    {

        return platformData.hash();

    }

    static bool equal(const FontPlatformData& a, const FontPlatformData& b)

    {

        return a == b;

    }

};

struct FontDataCacheKeyTraits : WTF::GenericHashTraits<FontPlatformData> {

    static const bool emptyValueIsZero = true;

    static const bool needsDestruction = false;

    static const FontPlatformData& deletedValue()

    {

        static FontPlatformData key = FontPlatformData::Deleted();

        return key;

    }

    static const FontPlatformData& emptyValue()

    {

        static FontPlatformData key;

        return key;

    }

};

typedef HashMap<FontPlatformData, FontData*, FontDataCacheKeyHash, FontDataCacheKeyTraits> FontDataCache;

static FontDataCache* gFontDataCache = 0;

FontData* FontCache::getCachedFontData(const FontPlatformData* platformData)

{

    if (!platformData)

        return 0;

    if (!gFontDataCache)

        gFontDataCache = new FontDataCache;

    FontData* result = gFontDataCache->get(*platformData);

    if (!result) {

        result = new FontData(*platformData);

        gFontDataCache->set(*platformData, result);

    }

    return result;

}

const FontData* FontCache::getFontData(const Font& font, int& familyIndex)

{

    FontPlatformData* result = 0;

    int startIndex = familyIndex;

    const FontFamily* startFamily = &font.fontDescription().family();

    for (int i = 0; startFamily && i < startIndex; i++)

        startFamily = startFamily->next();

    const FontFamily* currFamily = startFamily;

    while (currFamily && !result) {

        familyIndex++;

        if (currFamily->family().length())

            result = getCachedFontPlatformData(font.fontDescription(), currFamily->family());

        currFamily = currFamily->next();

    }

    if (!currFamily)

        familyIndex = cAllFamiliesScanned;

    if (!result)

        // We didn't find a font. Try to find a similar font using our own specific knowledge about our platform.

        // For example on OS X, we know to map any families containing the words Arabic, Pashto, or Urdu to the

        // Geeza Pro font.

        result = getSimilarFontPlatformData(font);

    if (!result && startIndex == 0)

        // We still don't have a result.  Hand back our last resort fallback font.  We only do the last resort fallback

        // when trying to find the primary font.  Otherwise our fallback will rely on the actual characters used.

        result = getLastResortFallbackFont(font);

    // Now that we have a result, we need to go from FontPlatformData -> FontData.

    return getCachedFontData(result);

}

} // namespace WebCore