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#include <QStack>

#include <QStringList>

#include "qanyuri_p.h"

#include "qboolean_p.h"

#include "qcommonsequencetypes_p.h"

#include "qcommonvalues_p.h"

#include "qemptysequence_p.h"

#include "qitemmappingiterator_p.h"

#include "qnodesort_p.h"

#include "qpatternistlocale_p.h"

#include "private/qxmlutils_p.h"

#include "qsequencegeneratingfns_p.h"

QT_BEGIN_NAMESPACE

using namespace QPatternist;

IdFN::IdFN() : m_hasCreatedSorter(false)

{

}

Item IdFN::mapToItem(const QString &id,

                     const IDContext &context) const

{

    return context.second->elementById(context.first->namePool()->allocateQName(QString(), id));

}

/**

 * @short Helper class for IdFN.

 *

 * StringSplitter takes an Iterator which delivers strings of this kind:

 *

 * "a", "b c", "%invalidNCName", "  ", "d"

 *

 * and we deliver instead:

 *

 * "a", "b", "c", "d"

 *

 * That is, we:

 * - Remove invalid @c NCName

 * - Split IDREFs into individual NCNames

 *

 * @author Frans Englich <frans.englich@nokia.com>

 */

class StringSplitter : public QAbstractXmlForwardIterator<QString>

{

public:

    StringSplitter(const Item::Iterator::Ptr &source);

    virtual QString next();

    virtual QString current() const;

    virtual qint64 position() const;

private:

    QString loadNext();

    const Item::Iterator::Ptr   m_source;

    QStack<QString>             m_buffer;

    QString                     m_current;

    qint64                      m_position;

    bool                        m_sourceAtEnd;

};

StringSplitter::StringSplitter(const Item::Iterator::Ptr &source) : m_source(source)

                                                                  , m_position(0)

                                                                  , m_sourceAtEnd(false)

{

    Q_ASSERT(m_source);

    m_buffer.push(loadNext());

}

QString StringSplitter::next()

{

    /* We also check m_position, we want to load on our first run. */

    if(!m_buffer.isEmpty())

    {

        ++m_position;

        m_current = m_buffer.pop();

        return m_current;

    }

    else if(m_sourceAtEnd)

    {

        m_current.clear();

        m_position = -1;

        return QString();

    }

    return loadNext();

}

QString StringSplitter::loadNext()

{

    const Item sourceNext(m_source->next());

    if(sourceNext.isNull())

    {

        m_sourceAtEnd = true;

        /* We might have strings in m_buffer, let's empty it. */

        return next();

    }

    const QStringList candidates(sourceNext.stringValue().simplified().split(QLatin1Char(' ')));

    const int count = candidates.length();

    for(int i = 0; i < count; ++i)

    {

        const QString &at = candidates.at(i);

        if(QXmlUtils::isNCName(at))

            m_buffer.push(at);

    }

    /* So, now we have populated m_buffer, let's start from the beginning. */

    return next();

}

QString StringSplitter::current() const

{

    return m_current;

}

qint64 StringSplitter::position() const

{

    return m_position;

}

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

{

    const Item::Iterator::Ptr idrefs(m_operands.first()->evaluateSequence(context));

    const Item node(m_operands.last()->evaluateSingleton(context));

    checkTargetNode(node.asNode(), context, ReportContext::FODC0001);

    return makeItemMappingIterator<Item,

                                   QString,

                                   IdFN::ConstPtr,

                                   IDContext>(ConstPtr(this),

                                              StringSplitter::Ptr(new StringSplitter(idrefs)),

                                              qMakePair(context, node.asNode().model()));

}

Expression::Ptr IdFN::typeCheck(const StaticContext::Ptr &context,

                                const SequenceType::Ptr &reqType)

{

    if(m_hasCreatedSorter)

        return FunctionCall::typeCheck(context, reqType);

    else

    {

        const Expression::Ptr newMe(new NodeSortExpression(Expression::Ptr(this)));

        context->wrapExpressionWith(this, newMe);

        m_hasCreatedSorter = true;

        return newMe->typeCheck(context, reqType);

    }

}

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

{

    const Item::Iterator::Ptr ids(m_operands.first()->evaluateSequence(context));

    Item mId(ids->next());

    if(!mId)

        return CommonValues::emptyIterator;

    const Item node(m_operands.last()->evaluateSingleton(context));

    checkTargetNode(node.asNode(), context, ReportContext::FODC0001);

    return CommonValues::emptyIterator; /* TODO Haven't implemented further. */

}

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

{

    const Item itemURI(m_operands.first()->evaluateSingleton(context));

    if(!itemURI)

        return Item();

    /* These two lines were previously in a separate function but are now duplicated

     * in DocAvailableFN::evaluateEBV() and DocFN::typeCheck(),

     * as part of a workaround for solaris-cc-64. DocFN::typeCheck() is in qsequencefns.cpp

     * as part of that workaround. */

    const QUrl mayRela(AnyURI::toQUrl<ReportContext::FODC0005>(itemURI.stringValue(), context, this));

    const QUrl uri(context->resolveURI(mayRela, staticBaseURI()));

    Q_ASSERT(uri.isValid());

    Q_ASSERT(!uri.isRelative());

    const Item doc(context->resourceLoader()->openDocument(uri, context));

    return doc;

}

SequenceType::Ptr DocFN::staticType() const

{

    if(m_type)

        return m_type;

    else

        return CommonSequenceTypes::ZeroOrOneDocumentNode;

}

bool DocAvailableFN::evaluateEBV(const DynamicContext::Ptr &context) const

{

    const Item itemURI(m_operands.first()->evaluateSingleton(context));

    /* 15.5.4 fn:doc reads: "If $uri is the empty sequence, the result is an empty sequence."

     * Hence, we return false for the empty sequence, because this doesn't hold true:

     * "If this function returns true, then calling fn:doc($uri) within

     * the same execution scope must return a document node."(15.5.5 fn:doc-available) */

    if(!itemURI)

        return false;

    /* These two lines are duplicated in DocFN::evaluateSingleton(), as part

     * of a workaround for solaris-cc-64. */

    const QUrl mayRela(AnyURI::toQUrl<ReportContext::FODC0005>(itemURI.stringValue(), context, this));

    const QUrl uri(context->resolveURI(mayRela, staticBaseURI()));

    Q_ASSERT(!uri.isRelative());

    return context->resourceLoader()->isDocumentAvailable(uri);

}

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

{

    // TODO resolve with URI resolve

    if(m_operands.isEmpty())

    {

        // TODO check default collection

        context->error(QtXmlPatterns::tr("The default collection is undefined"),

                       ReportContext::FODC0002, this);

        return CommonValues::emptyIterator;

    }

    else

    {

        const Item itemURI(m_operands.first()->evaluateSingleton(context));

        if(itemURI)

        {

            const QUrl uri(AnyURI::toQUrl<ReportContext::FODC0004>(itemURI.stringValue(), context, this));

            // TODO 2. Resolve against static context base URI(store base URI at compile time)

            context->error(QtXmlPatterns::tr("%1 cannot be retrieved").arg(formatResourcePath(uri)),

                           ReportContext::FODC0004, this);

            return CommonValues::emptyIterator;

        }

        else

        {

            /* This is out default collection currently, */

            return CommonValues::emptyIterator;

        }

    }

}

QT_END_NAMESPACE