/****************************************************************************

**

** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).

** All rights reserved.

** Contact: Nokia Corporation (qt-info@nokia.com)

**

** This file is part of the QtXmlPatterns module of the Qt Toolkit.

**

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** No Commercial Usage

** This file contains pre-release code and may not be distributed.

** You may use this file in accordance with the terms and conditions

** contained in the Technology Preview License Agreement accompanying

** this package.

**

** GNU Lesser General Public License Usage

** Alternatively, this file may be used under the terms of the GNU Lesser

** General Public License version 2.1 as published by the Free Software

** Foundation and appearing in the file LICENSE.LGPL included in the

** packaging of this file.  Please review the following information to

** ensure the GNU Lesser General Public License version 2.1 requirements

** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.

**

** In addition, as a special exception, Nokia gives you certain additional

** rights.  These rights are described in the Nokia Qt LGPL Exception

** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.

**

** If you have questions regarding the use of this file, please contact

** Nokia at qt-info@nokia.com.

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** $QT_END_LICENSE$

**

****************************************************************************/

#include <QVariant>

#include <QStringList>

#include "qanyuri_p.h"

#include "qatomicstring_p.h"

#include "qbuiltintypes_p.h"

#include "qcommonsequencetypes_p.h"

#include "qgenericsequencetype_p.h"

#include "qinteger_p.h"

#include "qitem_p.h"

#include "qsequencetype_p.h"

#include "qvariableloader_p.h"

#include "qxmlquery_p.h"

QT_BEGIN_NAMESPACE

namespace QPatternist

{

    class VariantListIterator : public ListIteratorPlatform<QVariant, Item, VariantListIterator>

    {

    public:

        inline VariantListIterator(const QVariantList &list) : ListIteratorPlatform<QVariant, Item, VariantListIterator>(list)

        {

        }

    private:

        friend class ListIteratorPlatform<QVariant, Item, VariantListIterator>;

        inline Item inputToOutputItem(const QVariant &inputType) const

        {

            return AtomicValue::toXDM(inputType);

        }

    };

    class StringListIterator : public ListIteratorPlatform<QString, Item, StringListIterator>

    {

    public:

        inline StringListIterator(const QStringList &list) : ListIteratorPlatform<QString, Item, StringListIterator>(list)

        {

        }

    private:

        friend class ListIteratorPlatform<QString, Item, StringListIterator>;

        static inline Item inputToOutputItem(const QString &inputType)

        {

            return AtomicString::fromValue(inputType);

        }

    };

    /**

     * Takes two DynamicContext instances, and redirects the storage of temporary trees

     * to one of them.

     *

     * @since 4.5

     */

    class TemporaryTreesRedirectingContext : public DelegatingDynamicContext

    {

    public:

        TemporaryTreesRedirectingContext(const DynamicContext::Ptr &other,

                                         const DynamicContext::Ptr &modelStorage) : DelegatingDynamicContext(other)

                                                                                  , m_modelStorage(modelStorage)

        {

            Q_ASSERT(m_modelStorage);

        }

        virtual void addNodeModel(const QAbstractXmlNodeModel::Ptr &nodeModel)

        {

            m_modelStorage->addNodeModel(nodeModel);

        }

    private:

        const DynamicContext::Ptr m_modelStorage;

    };

}

using namespace QPatternist;

SequenceType::Ptr VariableLoader::announceExternalVariable(const QXmlName name,

                                                           const SequenceType::Ptr &declaredType)

{

    Q_UNUSED(declaredType);

    const QVariant &variant = m_bindingHash.value(name);

    if(variant.isNull())

        return SequenceType::Ptr();

    else if(variant.userType() == qMetaTypeId<QIODevice *>())

        return CommonSequenceTypes::ExactlyOneAnyURI;

    else if(variant.userType() == qMetaTypeId<QXmlQuery>())

    {

        const QXmlQuery variableQuery(qVariantValue<QXmlQuery>(variant));

        return variableQuery.d->expression()->staticType();

    }

    else

    {

        return makeGenericSequenceType(AtomicValue::qtToXDMType(qVariantValue<QXmlItem>(variant)),

                                       Cardinality::exactlyOne());

    }

}

Item::Iterator::Ptr VariableLoader::evaluateSequence(const QXmlName name,

                                                     const DynamicContext::Ptr &context)

{

    const QVariant &variant = m_bindingHash.value(name);

    Q_ASSERT_X(!variant.isNull(), Q_FUNC_INFO,

               "We assume that we have a binding.");

    /* Same code as in the default clause below. */

    if(variant.userType() == qMetaTypeId<QIODevice *>())

        return makeSingletonIterator(itemForName(name));

    else if(variant.userType() == qMetaTypeId<QXmlQuery>())

    {

        const QXmlQuery variableQuery(qVariantValue<QXmlQuery>(variant));

        return variableQuery.d->expression()->evaluateSequence(DynamicContext::Ptr(new TemporaryTreesRedirectingContext(variableQuery.d->dynamicContext(), context)));

    }

    const QVariant v(qVariantValue<QXmlItem>(variant).toAtomicValue());

    switch(v.type())

    {

        case QVariant::StringList:

            return Item::Iterator::Ptr(new StringListIterator(v.toStringList()));

        case QVariant::List:

            return Item::Iterator::Ptr(new VariantListIterator(v.toList()));

        default:

            return makeSingletonIterator(itemForName(name));

    }

}

Item VariableLoader::itemForName(const QXmlName &name) const

{

    const QVariant &variant = m_bindingHash.value(name);

    if(variant.userType() == qMetaTypeId<QIODevice *>())

        return Item(AnyURI::fromValue(QLatin1String("tag:trolltech.com,2007:QtXmlPatterns:QIODeviceVariable:") + m_namePool->stringForLocalName(name.localName())));

    const QXmlItem item(qVariantValue<QXmlItem>(variant));

    if(item.isNode())

        return Item::fromPublic(item);

    else

    {

        const QVariant atomicValue(item.toAtomicValue());

        /* If the atomicValue is null it means it doesn't exist in m_bindingHash, and therefore it must

         * be a QIODevice, since Patternist guarantees to only ask for variables that announceExternalVariable()

         * has accepted. */

        if(atomicValue.isNull())

            return Item(AnyURI::fromValue(QLatin1String("tag:trolltech.com,2007:QtXmlPatterns:QIODeviceVariable:") + m_namePool->stringForLocalName(name.localName())));

        else

            return AtomicValue::toXDM(atomicValue);

    }

}

Item VariableLoader::evaluateSingleton(const QXmlName name,

                                       const DynamicContext::Ptr &)

{

    return itemForName(name);

}

bool VariableLoader::isSameType(const QVariant &v1,

                                const QVariant &v2) const

{

    /* Are both of type QIODevice *? */

    if(v1.userType() == qMetaTypeId<QIODevice *>() && v1.userType() == v2.userType())

        return true;

    /* Ok, we have two QXmlItems. */

    const QXmlItem i1(qVariantValue<QXmlItem>(v1));

    const QXmlItem i2(qVariantValue<QXmlItem>(v2));

    if(i1.isNode())

    {

        Q_ASSERT(false);

        return false;

    }

    else if(i2.isAtomicValue())

        return i1.toAtomicValue().type() == i2.toAtomicValue().type();

    else

    {

        /* One is an atomic, the other is a node or they are null. */

        return false;

    }

}

void VariableLoader::removeBinding(const QXmlName &name)

{

    m_bindingHash.remove(name);

}

bool VariableLoader::hasBinding(const QXmlName &name) const

{

    return m_bindingHash.contains(name)

        || (m_previousLoader && m_previousLoader->hasBinding(name));

}

QVariant VariableLoader::valueFor(const QXmlName &name) const

{

    if(m_bindingHash.contains(name))

        return m_bindingHash.value(name);

    else if(m_previousLoader)

        return m_previousLoader->valueFor(name);

    else

        return QVariant();

}

void VariableLoader::addBinding(const QXmlName &name,

                                const QVariant &value)

{

    m_bindingHash.insert(name, value);

}

bool VariableLoader::invalidationRequired(const QXmlName &name,

                                          const QVariant &variant) const

{

    return hasBinding(name) && !isSameType(valueFor(name), variant);

}

QT_END_NAMESPACE