/*

 * Copyright 2005 Frerich Raabe <raabe@kde.org>

 * Copyright (C) 2006 Apple Computer, Inc.

 *

 * 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 THE AUTHOR 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 "XPathValue.h"

#if ENABLE(XPATH)

#include "Node.h"

#include "XPathExpressionNode.h"

#include "XPathUtil.h"

#include <limits>

#include <wtf/MathExtras.h>

#include <wtf/StdLibExtras.h>

using std::numeric_limits;

namespace WebCore {

namespace XPath {

const Value::AdoptTag Value::adopt = {};

const NodeSet& Value::toNodeSet() const

{

    if (!isNodeSet())

        Expression::evaluationContext().hadTypeConversionError = true;

    if (!m_data) {

        DEFINE_STATIC_LOCAL(NodeSet, emptyNodeSet, ());

        return emptyNodeSet;

    }

    return m_data->m_nodeSet;

}    

NodeSet& Value::modifiableNodeSet()

{

    if (!isNodeSet())

        Expression::evaluationContext().hadTypeConversionError = true;

    if (!m_data)

        m_data = ValueData::create();

    m_type = NodeSetValue;

    return m_data->m_nodeSet;

}

bool Value::toBoolean() const

{

    switch (m_type) {

        case NodeSetValue:

            return !m_data->m_nodeSet.isEmpty();

        case BooleanValue:

            return m_bool;

        case NumberValue:

            return m_number != 0 && !isnan(m_number);

        case StringValue:

            return !m_data->m_string.isEmpty();

    }

    ASSERT_NOT_REACHED();

    return false;

}

double Value::toNumber() const

{

    switch (m_type) {

        case NodeSetValue:

            return Value(toString()).toNumber();

        case NumberValue:

            return m_number;

        case StringValue: {

            const String& str = m_data->m_string.simplifyWhiteSpace();

            // String::toDouble() supports exponential notation, which is not allowed in XPath.

            unsigned len = str.length();

            for (unsigned i = 0; i < len; ++i) {

                UChar c = str[i];

                if (!isASCIIDigit(c) && c != '.'  && c != '-')

                    return numeric_limits<double>::quiet_NaN();

            }

            bool canConvert;

            double value = str.toDouble(&canConvert);

            if (canConvert)

                return value;

            return numeric_limits<double>::quiet_NaN();

        }

        case BooleanValue:

            return m_bool;

    }

    ASSERT_NOT_REACHED();

    return 0.0;

}

String Value::toString() const

{

    switch (m_type) {

        case NodeSetValue:

            if (m_data->m_nodeSet.isEmpty()) 

                return "";

            return stringValue(m_data->m_nodeSet.firstNode());

        case StringValue:

            return m_data->m_string;

        case NumberValue:

            if (isnan(m_number))

                return "NaN";

            if (m_number == 0)

                return "0";

            if (isinf(m_number))

                return signbit(m_number) ? "-Infinity" : "Infinity";

            return String::number(m_number);

        case BooleanValue:

            return m_bool ? "true" : "false";

    }

    ASSERT_NOT_REACHED();

    return String();

}

}

}

#endif // ENABLE(XPATH)