/****************************************************************************
**
** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
** Contact: http://www.qt-project.org/
**
** This file is part of the QtXmlPatterns module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** GNU Lesser General Public License Usage
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** License version 2.1 as published by the Free Software Foundation and
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** rights. These rights are described in the Nokia Qt LGPL Exception
** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
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** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU General
** Public License version 3.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of this
** file. Please review the following information to ensure the GNU General
** Public License version 3.0 requirements will be met:
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** $QT_END_LICENSE$
**
****************************************************************************/

#include "qbuiltintypes_p.h"
#include "qcommonsequencetypes_p.h"
#include "qgenericsequencetype_p.h"

#include "qcontextitem_p.h"

QT_BEGIN_NAMESPACE

using namespace QPatternist;

Item ContextItem::evaluateSingleton(const DynamicContext::Ptr &context) const
{
    return context->contextItem();
}

Expression::Ptr ContextItem::compress(const StaticContext::Ptr &context)
{
    m_itemType = context->contextItemType();
    return EmptyContainer::compress(context);
}

Expression::Ptr ContextItem::typeCheck(const StaticContext::Ptr &context,
                                       const SequenceType::Ptr &reqType)
{
    m_itemType = context->contextItemType();
    return EmptyContainer::typeCheck(context, reqType);
}

SequenceType::Ptr ContextItem::staticType() const
{
    /* We test m_itemType here because Patternist View calls staticType() before the typeCheck()
     * stage. */
    if(m_itemType)
        return makeGenericSequenceType(m_itemType, Cardinality::exactlyOne());
    else
        return CommonSequenceTypes::ExactlyOneItem;
}

Expression::Properties ContextItem::properties() const
{
    return DisableElimination | RequiresContextItem | EvaluationCacheRedundant;
}

ExpressionVisitorResult::Ptr ContextItem::accept(const ExpressionVisitor::Ptr &visitor) const
{
    return visitor->visit(this);
}

Expression::ID ContextItem::id() const
{
    return IDContextItem;
}

ItemType::Ptr ContextItem::expectedContextItemType() const
{
    return BuiltinTypes::item;
}

const SourceLocationReflection *ContextItem::actualReflection() const
{
    if(m_expr)
        return m_expr.data();
    else
        return this;
}

void ContextItem::announceFocusType(const ItemType::Ptr &type)
{
    Q_ASSERT(type);
    m_itemType = type;
}

QT_END_NAMESPACE