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#include "qcommonsequencetypes_p.h"

#include "qcommonvalues_p.h"

#include "qgenericpredicate_p.h"

#include "qgenericsequencetype_p.h"

#include "qinsertioniterator_p.h"

#include "qpatternistlocale_p.h"

#include "qcardinalityverifier_p.h"

QT_BEGIN_NAMESPACE

using namespace QPatternist;

QString CardinalityVerifier::wrongCardinality(const Cardinality &req,

                                              const Cardinality &got)

{

    return QtXmlPatterns::tr("Required cardinality is %1; got cardinality %2.")

                .arg(formatType(req), formatType(got));

}

Expression::Ptr CardinalityVerifier::verifyCardinality(const Expression::Ptr &operand,

                                                       const Cardinality &requiredCard,

                                                       const StaticContext::Ptr &context,

                                                       const ReportContext::ErrorCode code)

{

    const Cardinality opCard(operand->staticType()->cardinality());

    if(requiredCard.isMatch(opCard))

        return operand;

    else if(requiredCard.canMatch(opCard))

        return Expression::Ptr(new CardinalityVerifier(operand, requiredCard, code));

    else if(context->compatModeEnabled() &&

            !opCard.isEmpty())

    {

        return GenericPredicate::createFirstItem(operand);

    }

    else

    {

        /* Sequences within this cardinality can never match. */

        context->error(wrongCardinality(requiredCard, opCard), code, operand.data());

        return operand;

    }

}

CardinalityVerifier::CardinalityVerifier(const Expression::Ptr &operand,

                                         const Cardinality &card,

                                         const ReportContext::ErrorCode code)

                                         : SingleContainer(operand),

                                           m_reqCard(card),

                                           m_allowsMany(operand->staticType()->cardinality().allowsMany()),

                                           m_errorCode(code)

{

    Q_ASSERT_X(m_reqCard != Cardinality::zeroOrMore(), Q_FUNC_INFO,

               "It makes no sense to use CardinalityVerifier for cardinality zero-or-more.");

}

Item::Iterator::Ptr CardinalityVerifier::evaluateSequence(const DynamicContext::Ptr &context) const

{

    const Item::Iterator::Ptr it(m_operand->evaluateSequence(context));

    const Item next(it->next());

    if(next)

    {

        const Item next2(it->next());

        if(next2)

        {

            if(m_reqCard.allowsMany())

            {

                Item::List start;

                start.append(next);

                start.append(next2);

                return Item::Iterator::Ptr(new InsertionIterator(it, 1, makeListIterator(start)));

            }

            else

            {

                context->error(wrongCardinality(m_reqCard, Cardinality::twoOrMore()), m_errorCode, this);

                return CommonValues::emptyIterator;

            }

        }

        else

        {

            /* We might be instantiated for the empty sequence. */

            if(m_reqCard.isEmpty())

            {

                context->error(wrongCardinality(m_reqCard, Cardinality::twoOrMore()), m_errorCode, this);

                return CommonValues::emptyIterator;

            }

            else

                return makeSingletonIterator(next);

        }

    }

    else

    {

        if(m_reqCard.allowsEmpty())

            return CommonValues::emptyIterator;

        else

        {

            context->error(wrongCardinality(m_reqCard, Cardinality::twoOrMore()), m_errorCode, this);

            return CommonValues::emptyIterator;

        }

    }

}

Item CardinalityVerifier::evaluateSingleton(const DynamicContext::Ptr &context) const

{

    if(m_allowsMany)

    {

        const Item::Iterator::Ptr it(m_operand->evaluateSequence(context));

        const Item item(it->next());

        if(item)

        {

            if(it->next())

            {

                context->error(wrongCardinality(m_reqCard, Cardinality::twoOrMore()),

                               m_errorCode, this);

                return Item();

            }

            else

                return item;

        }

        else if(m_reqCard.allowsEmpty())

            return Item();

        else

        {

            context->error(wrongCardinality(m_reqCard), m_errorCode, this);

            return Item();

        }

    }

    else

    {

        const Item item(m_operand->evaluateSingleton(context));

        if(item)

            return item;

        else if(m_reqCard.allowsEmpty())

            return Item();

        else

        {

            context->error(wrongCardinality(m_reqCard), m_errorCode, this);

            return Item();

        }

    }

}

const SourceLocationReflection *CardinalityVerifier::actualReflection() const

{

    return m_operand->actualReflection();

}

Expression::Ptr CardinalityVerifier::compress(const StaticContext::Ptr &context)

{

    if(m_reqCard.isMatch(m_operand->staticType()->cardinality()))

        return m_operand->compress(context);

    else

        return SingleContainer::compress(context);

}

SequenceType::List CardinalityVerifier::expectedOperandTypes() const

{

    SequenceType::List result;

    result.append(CommonSequenceTypes::ZeroOrMoreItems);

    return result;

}

SequenceType::Ptr CardinalityVerifier::staticType() const

{

    return makeGenericSequenceType(m_operand->staticType()->itemType(), m_reqCard);

}

ExpressionVisitorResult::Ptr CardinalityVerifier::accept(const ExpressionVisitor::Ptr &visitor) const

{

    return visitor->visit(this);

}

Expression::ID CardinalityVerifier::id() const

{

    return IDCardinalityVerifier;

}

QT_END_NAMESPACE