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#include "qabstractaspect.h"
#include "qabstractaspect_p.h"

#include <Qt3DCore/qentity.h>
#include <Qt3DCore/qpropertyupdatedchange.h>

#include <Qt3DCore/private/corelogging_p.h>
#include <Qt3DCore/private/qaspectjobmanager_p.h>
#include <Qt3DCore/private/qaspectmanager_p.h>
#include <Qt3DCore/private/qchangearbiter_p.h>
#include <Qt3DCore/private/qnodevisitor_p.h>
#include <Qt3DCore/private/qscene_p.h>

QT_BEGIN_NAMESPACE

namespace Qt3DCore {

QAbstractAspectPrivate::QAbstractAspectPrivate()
    : QObjectPrivate()
    , m_root(nullptr)
    , m_rootId()
    , m_aspectManager(nullptr)
    , m_jobManager(nullptr)
    , m_arbiter(nullptr)
{
}

QAbstractAspectPrivate::~QAbstractAspectPrivate()
{
}

QAbstractAspectPrivate *QAbstractAspectPrivate::get(QAbstractAspect *aspect)
{
    return aspect->d_func();
}

/*!
 * \internal
 * Called in the context of the main thread
 */
void QAbstractAspectPrivate::onEngineAboutToShutdown()
{
}

/*! \internal */
void QAbstractAspectPrivate::unregisterBackendType(const QMetaObject &mo)
{
    m_backendCreatorFunctors.remove(&mo);
}

/*!
 * \class Qt3DCore::QAbstractAspect
 * \inheaderfile Qt3DCore/QAbstractAspect
 * \inherits QObject
 * \inmodule Qt3DCore
 * \brief QAbstractAspect is the base class for aspects that provide a vertical slice of behavior.
 */

/*!
 * \fn void Qt3DCore::QAbstractAspect::registerBackendType(const Qt3DCore::QBackendNodeMapperPtr &functor)
 * Registers backend with \a functor.
 */

/*!
 * \macro QT3D_REGISTER_ASPECT(name, AspectType)
 * \relates Qt3DCore::QAbstractAspect
 *
 * Convenience macro for registering \a AspectType for instantiation by the
 * currently set Qt3DCore::QAspectFactory. This makes it possible to create an
 * instance of \a AspectType in the aspect thread by later passing \a name to
 * Qt3DCore::QAspectEngine::registerAspect(const QString &name).
 *
 * \note It is also possible to register a new aspect without using this macro
 * by instead using Qt3DCore::QAspectEngine::registerAspect(QAbstractAspect *aspect)
 * which will handle moving a previously created aspect instance to the aspect
 * thread context.
 *
 * KDAB has published a few articles about writing custom Qt3D aspects
 * \l {https://www.kdab.com/writing-custom-qt-3d-aspect/}{on their blog}. These
 * provide an excellent starting point if you wish to learn more about it.
 */


/*!
 * Constructs a new QAbstractAspect with \a parent
 */
QAbstractAspect::QAbstractAspect(QObject *parent)
    : QAbstractAspect(*new QAbstractAspectPrivate, parent) {}

/*!
 * \typedef Qt3DCore::QAspectJobPtr
 * \relates Qt3DCore::QAbstractAspect
 *
 * A shared pointer for QAspectJob.
 */

/*!
 * \typedef Qt3DCore::QBackendNodeMapperPtr
 * \relates Qt3DCore::QAbstractAspect
 *
 * A shared pointer for QBackendNodeMapper.
 */

/*!
 * \internal
 */
QAbstractAspect::QAbstractAspect(QAbstractAspectPrivate &dd, QObject *parent)
    : QObject(dd, parent)
{
}

/*!
    \internal
*/
QAbstractAspect::~QAbstractAspect()
{
}

/*!
 * \return root entity node id.
 */
QNodeId QAbstractAspect::rootEntityId() const Q_DECL_NOEXCEPT
{
    Q_D(const QAbstractAspect);
    return d->m_rootId;
}

/*!
 * Registers backend with \a obj and \a functor.
 */
void QAbstractAspect::registerBackendType(const QMetaObject &obj, const QBackendNodeMapperPtr &functor)
{
    Q_D(QAbstractAspect);
    d->m_backendCreatorFunctors.insert(&obj, functor);
}

void QAbstractAspect::unregisterBackendType(const QMetaObject &obj)
{
    Q_D(QAbstractAspect);
    d->m_backendCreatorFunctors.remove(&obj);
}

void QAbstractAspectPrivate::sceneNodeAdded(QSceneChangePtr &change)
{
    QNodeCreatedChangeBasePtr creationChange = qSharedPointerCast<QNodeCreatedChangeBase>(change);
    createBackendNode(creationChange);
}

void QAbstractAspectPrivate::sceneNodeRemoved(QSceneChangePtr &change)
{
    QNodeDestroyedChangePtr destructionChange = qSharedPointerCast<QNodeDestroyedChange>(change);
    clearBackendNode(destructionChange);
}

QVariant QAbstractAspect::executeCommand(const QStringList &args)
{
    Q_UNUSED(args);
    return QVariant();
}

QVector<QAspectJobPtr> QAbstractAspect::jobsToExecute(qint64 time)
{
    Q_UNUSED(time);
    return QVector<QAspectJobPtr>();
}

QBackendNode *QAbstractAspectPrivate::createBackendNode(const QNodeCreatedChangeBasePtr &change) const
{
    const QMetaObject *metaObj = change->metaObject();
    QBackendNodeMapperPtr backendNodeMapper;
    while (metaObj != nullptr && backendNodeMapper.isNull()) {
        backendNodeMapper = m_backendCreatorFunctors.value(metaObj);
        metaObj = metaObj->superClass();
    }

    if (!backendNodeMapper)
        return nullptr;

    QBackendNode *backend = backendNodeMapper->get(change->subjectId());
    if (backend != nullptr)
        return backend;
    backend = backendNodeMapper->create(change);

    if (!backend)
        return nullptr;

    // TODO: Find some place else to do all of this function from the arbiter
    backend->setPeerId(change->subjectId());

    // Backend could be null if the user decides that his functor should only
    // perform some action when encountering a given type of item but doesn't need to
    // return a QBackendNode pointer.

    QBackendNodePrivate *backendPriv = QBackendNodePrivate::get(backend);
    backendPriv->setEnabled(change->isNodeEnabled());

    // TO DO: Find a way to specify the changes to observe
    // Register backendNode with QChangeArbiter
    if (m_arbiter != nullptr) { // Unit tests may not have the arbiter registered
        qCDebug(Nodes) << q_func()->objectName() << "Creating backend node for node id"
                       << change->subjectId() << "of type" << change->metaObject()->className();
        m_arbiter->registerObserver(backendPriv, backend->peerId(), AllChanges);
        if (backend->mode() == QBackendNode::ReadWrite)
            m_arbiter->scene()->addObservable(backendPriv, backend->peerId());
    }

    backend->initializeFromPeer(change);

    return backend;
}

void QAbstractAspectPrivate::clearBackendNode(const QNodeDestroyedChangePtr &change) const
{
    // Each QNodeDestroyedChange may contain info about a whole sub-tree of nodes that
    // are being destroyed. Iterate over them and process each in turn
    const auto subTree = change->subtreeIdsAndTypes();
    for (const auto &idAndType : subTree) {
        const QMetaObject *metaObj = idAndType.type;
        QBackendNodeMapperPtr backendNodeMapper;

        // Find backend node mapper for this type
        while (metaObj != nullptr && backendNodeMapper.isNull()) {
            backendNodeMapper = m_backendCreatorFunctors.value(metaObj);
            metaObj = metaObj->superClass();
        }

        if (!backendNodeMapper)
            continue;

        // Request the mapper to destroy the corresponding backend node
        QBackendNode *backend = backendNodeMapper->get(idAndType.id);
        if (backend) {
            qCDebug(Nodes) << q_func()->objectName() << "Deleting backend node for node id"
                           << idAndType.id << "of type" << idAndType.type->className();
            QBackendNodePrivate *backendPriv = QBackendNodePrivate::get(backend);
            m_arbiter->unregisterObserver(backendPriv, backend->peerId());
            if (backend->mode() == QBackendNode::ReadWrite)
                m_arbiter->scene()->removeObservable(backendPriv, backend->peerId());
            backendNodeMapper->destroy(idAndType.id);
        }
    }
}

void QAbstractAspectPrivate::setRootAndCreateNodes(QEntity *rootObject, const QVector<QNodeCreatedChangeBasePtr> &changes)
{
    qCDebug(Aspects) << Q_FUNC_INFO << "rootObject =" << rootObject;
    if (rootObject == m_root)
        return;

    m_root = rootObject;
    m_rootId = rootObject->id();

    for (const auto &change : changes)
        createBackendNode(change);
}

QServiceLocator *QAbstractAspectPrivate::services() const
{
    return m_aspectManager ? m_aspectManager->serviceLocator() : nullptr;
}

QAbstractAspectJobManager *QAbstractAspectPrivate::jobManager() const
{
    return m_jobManager;
}

QVector<QAspectJobPtr> QAbstractAspectPrivate::jobsToExecute(qint64 time)
{
    Q_Q(QAbstractAspect);
    auto res = q->jobsToExecute(time);

    {
        QMutexLocker lock(&m_singleShotMutex);
        res << m_singleShotJobs;
        m_singleShotJobs.clear();
    }

    return res;
}

/*!
 * Called in the context of the aspect thread once the aspect has been registered.
 * This provides an opportunity for the aspect to do any initialization tasks that
 * require to be in the aspect thread context such as creating QObject subclasses that
 * must have affinity with this thread.
 *
 * \sa onUnregistered
 */
void QAbstractAspect::onRegistered()
{
}

/*!
 * Called in the context of the aspect thread during unregistration
 * of the aspect. This gives the aspect a chance to do any final pieces of
 * cleanup that it would not do when just changing to a new scene.
 *
 * \sa onRegistered
 */
void QAbstractAspect::onUnregistered()
{
}

/*!
 *
 * Called in the QAspectThread context
 */
void QAbstractAspect::onEngineStartup()
{
}

/*!
 *
 * Called in the QAspectThread context
 */
void QAbstractAspect::onEngineShutdown()
{
}

void QAbstractAspect::scheduleSingleShotJob(const Qt3DCore::QAspectJobPtr &job)
{
    Q_D(QAbstractAspect);
    QMutexLocker lock(&d->m_singleShotMutex);
    d->m_singleShotJobs.push_back(job);
}

namespace Debug {

AsynchronousCommandReply::AsynchronousCommandReply(const QString &commandName, QObject *parent)
    : QObject(parent)
    , m_commandName(commandName)
    , m_finished(false)
{
}

void AsynchronousCommandReply::setFinished(bool replyFinished)
{
    m_finished = replyFinished;
    if (m_finished)
        emit finished(this);
}

void AsynchronousCommandReply::setData(const QByteArray &data)
{
    m_data = data;
}

} // Debug


} // of namespace Qt3DCore

QT_END_NAMESPACE
