/****************************************************************************
**
** Copyright (C) 2014 Klaralvdalens Datakonsult AB (KDAB).
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** This file is part of the Qt3D module of the Qt Toolkit.
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** ensure the GNU Lesser General Public License version 3 requirements
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** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or later 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
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****************************************************************************/

#include "qcomponent.h"
#include "qcomponent_p.h"
#include "qentity.h"
#include "qentity_p.h"
#include "qscene_p.h"
#include <Qt3DCore/qscenepropertychange.h>

QT_BEGIN_NAMESPACE

namespace Qt3DCore {

/*!
    \class Qt3DCore::QComponentPrivate
    \internal
*/
QComponentPrivate::QComponentPrivate()
    : QNodePrivate()
    , m_shareable(true)
    , m_enabled(true)
{
}

void QComponentPrivate::addEntity(QEntity *entity)
{
    m_entities.append(entity);

    if (m_scene != Q_NULLPTR && !m_scene->hasEntityForComponent(m_id, entity->id())) {
        if (!m_shareable && !m_scene->entitiesForComponent(m_id).isEmpty())
            qWarning() << "Trying to assign a non shareable component to more than one Entity";
        m_scene->addEntityForComponent(m_id, entity->id());
    }

    // We notify only if we have a QChangeArbiter
    if (m_changeArbiter != Q_NULLPTR) {
        Q_Q(QComponent);
        QScenePropertyChangePtr e(new QScenePropertyChange(ComponentAdded, QSceneChange::Node, q->id()));
        e->setPropertyName("entity");
        e->setValue(QVariant::fromValue(entity->id()));
        notifyObservers(e);
    }
}

void QComponentPrivate::removeEntity(QEntity *entity)
{
    // We notify only if we have a QChangeArbiter
    if (m_changeArbiter != Q_NULLPTR) {
        Q_Q(QComponent);
        QScenePropertyChangePtr e(new QScenePropertyChange(ComponentRemoved, QSceneChange::Node, q->id()));
        e->setPropertyName("entity");
        e->setValue(QVariant::fromValue(entity->id()));
        notifyObservers(e);
    }

    if (m_scene != Q_NULLPTR)
        m_scene->removeEntityForComponent(m_id, entity->id());

    m_entities.removeAll(entity);
}

/*!
    \class Qt3DCore::QComponent
    \inmodule Qt3DCore
    \inherits Qt3DCore::QNode
    \since 5.5

    \brief The base class of scene nodes that can be aggregated by Qt3DCore::QEntity
    instances as a component.

    A Qt3DCore::QComponent provides a vertical slice of behavior that can be assigned to and
    sometimes shared across Qt3DCore::QEntity instances.

    Qt3DCore::QComponent subclasses are often aggregated in groups that impart useful
    behavior to the aggregating entity. For example, to have an Entity that gets
    drawn by the Qt3D renderer aspect, an entity would most likely aggregate
    Qt3DCore::QTransform, Qt3DRender::QMesh, and Qt3DRender::QMaterial components.

    \sa Qt3DCore::QEntity
*/

/*!
    Constructs a new QComponent instance with \a parent as the parent.
    \note a QComponent should never be instanced directly,
    instance one of the subclasses instead.
*/
QComponent::QComponent(QNode *parent)
    : QNode(*new QComponentPrivate, parent)
{
}

QComponent::~QComponent()
{
    Q_ASSERT_X(QNodePrivate::get(this)->m_wasCleanedUp, Q_FUNC_INFO, "QNode::cleanup should have been called by now. A Qt3DCore::QComponent subclass didn't call QNode::cleanup in its destructor");

    Q_FOREACH (QEntity *entity, entities()) {
        QEntityPrivate *entityPimpl = static_cast<QEntityPrivate *>(QEntityPrivate::get(entity));
        if (entityPimpl)
            entityPimpl->m_components.removeAll(this);
    }
}

/*!
    Returns whether the QComponent is shareable across entities or not.
*/
bool QComponent::shareable() const
{
    Q_D(const QComponent);
    return d->m_shareable;
}

/*!
    Returns whether the QComponent is enabled or not.
*/
bool QComponent::isEnabled() const
{
    Q_D(const QComponent);
    return d->m_enabled;
}

/*!
    Set the QComponent to enabled if \a enabled is true.
    By default a Qt3DCore::QComponent is always enabled.

    \note the interpretation of what enabled means is aspect-dependent. Even if
    enabled is set to false, some aspects may still consider the component in
    some manner. This is documented on a class by class basis.
*/
void QComponent::setEnabled(bool enabled)
{
    Q_D(QComponent);
    if (d->m_enabled != enabled) {
        d->m_enabled = enabled;
        emit enabledChanged();
    }
}

/*!
    The QComponent can be shared across several entities if \a shareable is true.
*/
void QComponent::setShareable(bool shareable)
{
    Q_D(QComponent);
    if (d->m_shareable != shareable) {
        d->m_shareable = shareable;
        emit shareableChanged();
    }
}

void QComponent::copy(const QNode *ref)
{
    QNode::copy(ref);
    const QComponent *comp = static_cast<const QComponent *>(ref);
    setEnabled(comp->isEnabled());
    setShareable(comp->shareable());
}

/*!
    Returns a QVector containing all the entities that reference this component.
*/
QVector<QEntity *> QComponent::entities() const
{
    Q_D(const QComponent);
    return d->m_entities;
}

/*! \internal */
QComponent::QComponent(QComponentPrivate &dd, QNode *parent)
    : QNode(dd, parent)
{
}

} // namespace Qt3DCore

/*!
    \qmltype Component3D
    \instantiates Qt3DCore::QComponent
    \inqmlmodule Qt3D
    \inherits Node
    \since 5.5
*/

/*!
    \qmlproperty bool Qt3DCore::Component3D::shareable
*/

/*!
    \qmlproperty bool Qt3DCore::Component3D::enabled
*/

QT_END_NAMESPACE