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#include "qquickcustomaffector_p.h"
#include <private/qv8engine_p.h>
#include <private/qdeclarativeengine_p.h>
#include <QDeclarativeEngine>
#include <QDebug>
QT_BEGIN_NAMESPACE

//TODO: Move docs (and inheritence) to real base when docs can propagate. Currently this pretends to be the base class!
/*!
    \qmlsignal QtQuick.Particles2::Affector::affectParticles(Array particles, real dt)

    This handler is called when particles are selected to be affected. particles contains
    an array of particle objects which can be directly manipulated.

    dt is the time since the last time it was affected. Use dt to normalize
    trajectory manipulations to real time.

    Note that JS is slower to execute, so it is not recommended to use this in
    high-volume particle systems.
*/

/*!
    \qmlproperty StochasticDirection QtQuick.Particles2::Affector::position

    Affected particles will have their position set to this direction,
    relative to the ParticleSystem. When interpreting directions as points,
    imagine it as an arrow with the base at the 0,0 of the ParticleSystem and the
    tip at where the specified position will be.
*/

/*!
    \qmlproperty StochasticDirection QtQuick.Particles2::Affector::speed

    Affected particles will have their speed set to this direction.
*/


/*!
    \qmlproperty StochasticDirection QtQuick.Particles2::Affector::acceleration

    Affected particles will have their acceleration set to this direction.
*/


/*!
    \qmlproperty bool QtQuick.Particles2::Affector::relative

    Whether the affected particles have their existing position/speed/acceleration added
    to the new one.

    Default is true.
*/
QQuickCustomAffector::QQuickCustomAffector(QQuickItem *parent) :
    QQuickParticleAffector(parent)
    , m_position(&m_nullVector)
    , m_speed(&m_nullVector)
    , m_acceleration(&m_nullVector)
    , m_relative(true)
{
}

bool QQuickCustomAffector::isAffectConnected()
{
    static int idx = QObjectPrivate::get(this)->signalIndex("affectParticles(QDeclarativeV8Handle,qreal)");
    return QObjectPrivate::get(this)->isSignalConnected(idx);
}

void QQuickCustomAffector::affectSystem(qreal dt)
{
    if (!isAffectConnected()) {
        QQuickParticleAffector::affectSystem(dt);
        return;
    }
    if (!m_enabled)
        return;
    updateOffsets();

    QList<QQuickParticleData*> toAffect;
    foreach (QQuickParticleGroupData* gd, m_system->groupData)
        if (activeGroup(m_system->groupData.key(gd)))
            foreach (QQuickParticleData* d, gd->data)
                if (shouldAffect(d))
                    toAffect << d;

    if (toAffect.isEmpty())
        return;

    if (m_onceOff)
        dt = 1.0;

    v8::HandleScope handle_scope;
    v8::Context::Scope scope(QDeclarativeEnginePrivate::getV8Engine(qmlEngine(this))->context());
    v8::Handle<v8::Array> array = v8::Array::New(toAffect.size());
    for (int i=0; i<toAffect.size(); i++)
        array->Set(i, toAffect[i]->v8Value().toHandle());

    if (dt >= simulationCutoff || dt <= simulationDelta) {
        affectProperties(toAffect, dt);
        emit affectParticles(QDeclarativeV8Handle::fromHandle(array), dt);
    } else {
        int realTime = m_system->timeInt;
        m_system->timeInt -= dt * 1000.0;
        while (dt > simulationDelta) {
            m_system->timeInt += simulationDelta * 1000.0;
            dt -= simulationDelta;
            affectProperties(toAffect, simulationDelta);
            emit affectParticles(QDeclarativeV8Handle::fromHandle(array), simulationDelta);
        }
        m_system->timeInt = realTime;
        if (dt > 0.0) {
            affectProperties(toAffect, dt);
            emit affectParticles(QDeclarativeV8Handle::fromHandle(array), dt);
        }
    }

    foreach (QQuickParticleData* d, toAffect)
        if (d->update == 1.0)
            postAffect(d);
}

bool QQuickCustomAffector::affectParticle(QQuickParticleData *d, qreal dt)
{
    //This does the property based affecting, called by superclass if signal isn't hooked up.
    bool changed = false;
    QPointF curPos(d->curX(), d->curY());

    if (m_acceleration != &m_nullVector){
        QPointF pos = m_acceleration->sample(curPos);
        if (m_relative) {
            pos *= dt;
            pos += QPointF(d->curAX(), d->curAY());
        }
        d->setInstantaneousAX(pos.x());
        d->setInstantaneousAY(pos.y());
        changed = true;
    }

    if (m_speed != &m_nullVector){
        QPointF pos = m_speed->sample(curPos);
        if (m_relative) {
            pos *= dt;
            pos += QPointF(d->curVX(), d->curVY());
        }
        d->setInstantaneousVX(pos.x());
        d->setInstantaneousVY(pos.y());
        changed = true;
    }

    if (m_position != &m_nullVector){
        QPointF pos = m_position->sample(curPos);
        if (m_relative) {
            pos *= dt;
            pos += curPos;
        }
        d->setInstantaneousX(pos.x());
        d->setInstantaneousY(pos.y());
        changed = true;
    }

    return changed;
}

void QQuickCustomAffector::affectProperties(const QList<QQuickParticleData*> particles, qreal dt)
{
    foreach (QQuickParticleData* d, particles)
        if ( affectParticle(d, dt) )
            d->update = 1.0;
}

QT_END_NAMESPACE