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#include "qxsdstatemachinebuilder_p.h"

#include "qxsdelement_p.h"

#include "qxsdmodelgroup_p.h"

#include "qxsdschemahelper_p.h"

QT_BEGIN_NAMESPACE

using namespace QPatternist;

/*

 * This methods takes a list of objects and returns a list of list

 * of all combinations the objects can be ordered.

 *

 * e.g. input = [ 1, 2, 3 ]

 *      output = [

 *                  [ 1, 2, 3 ],

 *                  [ 1, 3, 2 ],

 *                  [ 2, 1, 3 ],

 *                  [ 2, 3, 1 ],

 *                  [ 3, 1, 2 ],

 *                  [ 3, 2, 1 ]

 *               ]

 *

 * The method is used to create all possible combinations for the particles

 * in an <all> model group.

 */

template <typename T>

QList< QList<T> > allCombinations(const QList<T> &input)

{

    if (input.count() == 1)

        return (QList< QList<T> >() << input);

    QList< QList<T> > result;

    for (int i = 0; i < input.count(); ++i) {

        QList<T> subList = input;

        T value = subList.takeAt(i);

        QList< QList<T> > subLists = allCombinations(subList);

        for (int j = 0; j < subLists.count(); ++j) {

            subLists[j].prepend(value);

        }

        result << subLists;

    }

    return result;

}

XsdStateMachineBuilder::XsdStateMachineBuilder(XsdStateMachine<XsdTerm::Ptr> *machine, const NamePool::Ptr &namePool, Mode mode)

    : m_stateMachine(machine), m_namePool(namePool), m_mode(mode)

{

}

XsdStateMachine<XsdTerm::Ptr>::StateId XsdStateMachineBuilder::reset()

{

    Q_ASSERT(m_stateMachine);

    m_stateMachine->clear();

    return m_stateMachine->addState(XsdStateMachine<XsdTerm::Ptr>::EndState);

}

XsdStateMachine<XsdTerm::Ptr>::StateId XsdStateMachineBuilder::addStartState(XsdStateMachine<XsdTerm::Ptr>::StateId state)

{

    const XsdStateMachine<XsdTerm::Ptr>::StateId startState = m_stateMachine->addState(XsdStateMachine<XsdTerm::Ptr>::StartState);

    m_stateMachine->addEpsilonTransition(startState, state);

    return startState;

}

/*

 * Create the FSA according to Algorithm Tp(S) from http://www.ltg.ed.ac.uk/~ht/XML_Europe_2003.html

 */

XsdStateMachine<XsdTerm::Ptr>::StateId XsdStateMachineBuilder::buildParticle(const XsdParticle::Ptr &particle, XsdStateMachine<XsdTerm::Ptr>::StateId endState)

{

    XsdStateMachine<XsdTerm::Ptr>::StateId currentStartState = endState;

    XsdStateMachine<XsdTerm::Ptr>::StateId currentEndState = endState;

    // 2

    if (particle->maximumOccursUnbounded()) {

        const XsdStateMachine<XsdTerm::Ptr>::StateId t = m_stateMachine->addState(XsdStateMachine<XsdTerm::Ptr>::InternalState);

        const XsdStateMachine<XsdTerm::Ptr>::StateId n = buildTerm(particle->term(), t);

        m_stateMachine->addEpsilonTransition(t, n);

        m_stateMachine->addEpsilonTransition(n, endState);

        currentEndState = t;

        currentStartState = t;

    } else { // 3

        int count = (particle->maximumOccurs() - particle->minimumOccurs());

        if (count > 100)

            count = 100;

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

            currentStartState = buildTerm(particle->term(), currentEndState);

            m_stateMachine->addEpsilonTransition(currentStartState, endState);

            currentEndState = currentStartState;

        }

    }

    int minOccurs = particle->minimumOccurs();

    if (minOccurs > 100)

        minOccurs = 100;

    for (int i = 0; i < minOccurs; ++i) {

        currentStartState = buildTerm(particle->term(), currentEndState);

        currentEndState = currentStartState;

    }

    return currentStartState;

}

/*

 * Create the FSA according to Algorithm Tt(S) from http://www.ltg.ed.ac.uk/~ht/XML_Europe_2003.html

 */

XsdStateMachine<XsdTerm::Ptr>::StateId XsdStateMachineBuilder::buildTerm(const XsdTerm::Ptr &term, XsdStateMachine<XsdTerm::Ptr>::StateId endState)

{

    if (term->isWildcard()) { // 1

        const XsdStateMachine<XsdTerm::Ptr>::StateId b = m_stateMachine->addState(XsdStateMachine<XsdTerm::Ptr>::InternalState);

        m_stateMachine->addTransition(b, term, endState);

        return b;

    } else if (term->isElement()) { // 2

        const XsdStateMachine<XsdTerm::Ptr>::StateId b = m_stateMachine->addState(XsdStateMachine<XsdTerm::Ptr>::InternalState);

        m_stateMachine->addTransition(b, term, endState);

        const XsdElement::Ptr element(term);

        if (m_mode == CheckingMode) {

            const XsdElement::List substGroups = element->substitutionGroups();

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

                m_stateMachine->addTransition(b, substGroups.at(i), endState);

        } else if (m_mode == ValidatingMode) {

            const XsdElement::List substGroups = element->substitutionGroups();

            for (int i = 0; i < substGroups.count(); ++i) {

                if (XsdSchemaHelper::substitutionGroupOkTransitive(element, substGroups.at(i), m_namePool))

                    m_stateMachine->addTransition(b, substGroups.at(i), endState);

            }

        }

        return b;

    } else if (term->isModelGroup()) {

        const XsdModelGroup::Ptr group(term);

        if (group->compositor() == XsdModelGroup::ChoiceCompositor) { // 3

            const XsdStateMachine<XsdTerm::Ptr>::StateId b = m_stateMachine->addState(XsdStateMachine<XsdTerm::Ptr>::InternalState);

            for (int i = 0; i < group->particles().count(); ++i) {

                const XsdParticle::Ptr particle(group->particles().at(i));

                if (particle->maximumOccurs() != 0) {

                    const XsdStateMachine<XsdTerm::Ptr>::StateId state = buildParticle(particle, endState);

                    m_stateMachine->addEpsilonTransition(b, state);

                }

            }

            return b;

        } else if (group->compositor() == XsdModelGroup::SequenceCompositor) { // 4

            XsdStateMachine<XsdTerm::Ptr>::StateId currentStartState = endState;

            XsdStateMachine<XsdTerm::Ptr>::StateId currentEndState = endState;

            for (int i = (group->particles().count() - 1); i >= 0; --i) { // iterate reverse

                const XsdParticle::Ptr particle(group->particles().at(i));

                if (particle->maximumOccurs() != 0) {

                    currentStartState = buildParticle(particle, currentEndState);

                    currentEndState = currentStartState;

                }

            }

            return currentStartState;

        } else if (group->compositor() == XsdModelGroup::AllCompositor) {

            const XsdStateMachine<XsdTerm::Ptr>::StateId newStartState = m_stateMachine->addState(XsdStateMachine<XsdTerm::Ptr>::InternalState);

            const QList<XsdParticle::List> list = allCombinations(group->particles());

            for (int i = 0; i < list.count(); ++i) {

                XsdStateMachine<XsdTerm::Ptr>::StateId currentStartState = endState;

                XsdStateMachine<XsdTerm::Ptr>::StateId currentEndState = endState;

                const XsdParticle::List particles = list.at(i);

                for (int j = (particles.count() - 1); j >= 0; --j) { // iterate reverse

                    const XsdParticle::Ptr particle(particles.at(j));

                    if (particle->maximumOccurs() != 0) {

                        currentStartState = buildParticle(particle, currentEndState);

                        currentEndState = currentStartState;

                    }

                }

                m_stateMachine->addEpsilonTransition(newStartState, currentStartState);

            }

            if (list.isEmpty())

                return endState;

            else

                return newStartState;

        }

    }

    Q_ASSERT(false);

    return 0;

}

static void internalParticleLookupMap(const XsdParticle::Ptr &particle, QHash<XsdTerm::Ptr, XsdParticle::Ptr> &hash)

{

    hash.insert(particle->term(), particle);

    if (particle->term()->isModelGroup()) {

        const XsdModelGroup::Ptr group(particle->term());

        const XsdParticle::List particles = group->particles();

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

            internalParticleLookupMap(particles.at(i), hash);

    }

}

QHash<XsdTerm::Ptr, XsdParticle::Ptr> XsdStateMachineBuilder::particleLookupMap(const XsdParticle::Ptr &particle)

{

    QHash<XsdTerm::Ptr, XsdParticle::Ptr> result;

    internalParticleLookupMap(particle, result);

    return result;

}

QT_END_NAMESPACE