/****************************************************************************
**
** Copyright (C) 2021 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of Qt Quick 3D.
**
** $QT_BEGIN_LICENSE:GPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 3 or (at your option) any later version
** approved by the KDE Free Qt Foundation. The licenses are as published by
** the Free Software Foundation and appearing in the file LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qquick3dparticleaffector_p.h"
#include "qquick3dparticleutils_p.h"

QT_BEGIN_NAMESPACE

/*!
    \qmltype Affector3D
    \inherits Node
    \inqmlmodule QtQuick3D.Particles3D
    \brief Affectors modify the attributes of particles during their lifetime.
    \since 6.2

    The Affector3D is an abstract base class of affectors like \l Gravity3D, \l Wander3D, and \l PointRotator3D.

    By default affectors affect all particles in the system, but this can be limited by defining
    the \l particles list. If the system has multiple affectors, the order of affectors may
    result in different outcome, as affectors are applied one after another.
*/

QQuick3DParticleAffector::QQuick3DParticleAffector(QQuick3DNode *parent)
    : QQuick3DNode(parent)
{
}

QQuick3DParticleAffector::~QQuick3DParticleAffector()
{
    for (const auto &connection : qAsConst(m_connections))
        QObject::disconnect(connection);
    if (m_system)
        m_system->unRegisterParticleAffector(this);
}

/*!
    \qmlproperty ParticleSystem3D Affector3D::system

    This property defines the \l ParticleSystem3D for the affector. If system is direct parent of the affector,
    this property does not need to be defined.
*/
QQuick3DParticleSystem *QQuick3DParticleAffector::system() const
{
    return m_system;
}

void QQuick3DParticleAffector::setSystem(QQuick3DParticleSystem *system)
{
    if (m_system == system)
        return;

    if (m_system)
        m_system->unRegisterParticleAffector(this);

    m_system = system;
    if (m_system)
        m_system->registerParticleAffector(this);

    m_systemSharedParent = getSharedParentNode(this, m_system);

    Q_EMIT systemChanged();
    Q_EMIT update();
}

/*!
    \qmlproperty bool Affector3D::enabled

    If enabled is set to \c false, this affector will not alter any particles.
    Usually this is used to conditionally turn an affector on or off.

    The default value is \c true.
*/
bool QQuick3DParticleAffector::enabled() const
{
    return m_enabled;
}

void QQuick3DParticleAffector::setEnabled(bool enabled)
{
    if (m_enabled == enabled)
        return;

    m_enabled = enabled;
    Q_EMIT enabledChanged();
    Q_EMIT update();
}

void QQuick3DParticleAffector::componentComplete()
{
    if (!m_system && qobject_cast<QQuick3DParticleSystem*>(parent()))
        setSystem(qobject_cast<QQuick3DParticleSystem*>(parent()));
}

void QQuick3DParticleAffector::prepareToAffect()
{
}

// Particles

/*!
    \qmlproperty List<Particle3D> Affector3D::particles

    This list controls which logical particles will be affected.
    When empty, all particles in the system are affected.
*/
QQmlListProperty<QQuick3DParticle> QQuick3DParticleAffector::particles()
{
    return {this, this,
             &QQuick3DParticleAffector::appendParticle,
             &QQuick3DParticleAffector::particleCount,
             &QQuick3DParticleAffector::particle,
             &QQuick3DParticleAffector::clearParticles,
             &QQuick3DParticleAffector::replaceParticle,
             &QQuick3DParticleAffector::removeLastParticle};
}

void QQuick3DParticleAffector::appendParticle(QQuick3DParticle *n) {
    m_particles.append(n);
    m_connections.insert(n, QObject::connect(n, &QObject::destroyed, [this](QObject *obj) {
        QQuick3DParticle *particle = qobject_cast<QQuick3DParticle *>(obj);
        m_particles.removeAll(particle);
        QObject::disconnect(m_connections[particle]);
        m_connections.remove(particle);
    }));
}

qsizetype QQuick3DParticleAffector::particleCount() const
{
    return m_particles.count();
}

QQuick3DParticle *QQuick3DParticleAffector::particle(qsizetype index) const
{
    return m_particles.at(index);
}

void QQuick3DParticleAffector::clearParticles() {
    m_particles.clear();
}

void QQuick3DParticleAffector::replaceParticle(qsizetype index, QQuick3DParticle *n)
{
    QQuick3DParticle *remove = m_particles[index];
    QObject::disconnect(m_connections[remove]);
    m_connections.remove(remove);
    m_particles[index] = n;
    m_connections.insert(n, QObject::connect(n, &QObject::destroyed, [this](QObject *obj) {
        QQuick3DParticle *particle = qobject_cast<QQuick3DParticle *>(obj);
        m_particles.removeAll(particle);
        QObject::disconnect(m_connections[particle]);
        m_connections.remove(particle);
    }));
}

void QQuick3DParticleAffector::removeLastParticle()
{
    QQuick3DParticle *last = m_particles.last();
    QObject::disconnect(m_connections[last]);
    m_connections.remove(last);
    m_particles.removeLast();
}

// Particles - static
void QQuick3DParticleAffector::appendParticle(QQmlListProperty<QQuick3DParticle> *list, QQuick3DParticle *p) {
    reinterpret_cast<QQuick3DParticleAffector *>(list->data)->appendParticle(p);
}

void QQuick3DParticleAffector::clearParticles(QQmlListProperty<QQuick3DParticle> *list) {
    reinterpret_cast<QQuick3DParticleAffector *>(list->data)->clearParticles();
}

void QQuick3DParticleAffector::replaceParticle(QQmlListProperty<QQuick3DParticle> *list, qsizetype i, QQuick3DParticle *p)
{
    reinterpret_cast<QQuick3DParticleAffector *>(list->data)->replaceParticle(i, p);
}

void QQuick3DParticleAffector::removeLastParticle(QQmlListProperty<QQuick3DParticle> *list)
{
    reinterpret_cast<QQuick3DParticleAffector *>(list->data)->removeLastParticle();
}

QQuick3DParticle *QQuick3DParticleAffector::particle(QQmlListProperty<QQuick3DParticle> *list, qsizetype i) {
    return reinterpret_cast<QQuick3DParticleAffector *>(list->data)->particle(i);
}

qsizetype QQuick3DParticleAffector::particleCount(QQmlListProperty<QQuick3DParticle> *list) {
    return reinterpret_cast<QQuick3DParticleAffector *>(list->data)->particleCount();
}

QT_END_NAMESPACE
