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#ifndef FOLLOWEMITTER_H
#define FOLLOWEMITTER_H
#include "particleemitter.h"
#include "particleaffector.h"

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

QT_MODULE(Declarative)


class FollowEmitter : public ParticleEmitter
{
    Q_OBJECT
    Q_PROPERTY(QString follow READ follow WRITE setFollow NOTIFY followChanged)
    //### Remove, and just document that particles per second is per particle? But has count issues
    Q_PROPERTY(int particlesPerParticlePerSecond READ particlesPerParticlePerSecond WRITE setParticlesPerParticlePerSecond NOTIFY particlesPerParticlePerSecondChanged)

    //TODO: Document that FollowEmitter's box is where it follows. It emits in a rect centered on the followed particle
    //TODO: A set of properties that can involve the particle size of the followed
    Q_PROPERTY(ParticleExtruder* emissionShape READ emissonShape WRITE setEmissionShape NOTIFY emissionShapeChanged)
    Q_PROPERTY(qreal emissionHeight READ emitterYVariation WRITE setEmitterYVariation NOTIFY emitterYVariationChanged)
    Q_PROPERTY(qreal emissionWidth READ emitterXVariation WRITE setEmitterXVariation NOTIFY emitterXVariationChanged)

public:
    explicit FollowEmitter(QSGItem *parent = 0);
    virtual void emitWindow(int timeStamp);
    virtual void reset();

    int particlesPerParticlePerSecond() const
    {
        return m_particlesPerParticlePerSecond;
    }

    qreal emitterXVariation() const
    {
        return m_emitterXVariation;
    }

    qreal emitterYVariation() const
    {
        return m_emitterYVariation;
    }

    QString follow() const
    {
        return m_follow;
    }

    ParticleExtruder* emissonShape() const
    {
        return m_emissionExtruder;
    }

signals:

    void particlesPerParticlePerSecondChanged(int arg);

    void emitterXVariationChanged(qreal arg);

    void emitterYVariationChanged(qreal arg);

    void followChanged(QString arg);

    void emissionShapeChanged(ParticleExtruder* arg);

public slots:

    void setParticlesPerParticlePerSecond(int arg)
    {
        if (m_particlesPerParticlePerSecond != arg) {
            m_particlesPerParticlePerSecond = arg;
            emit particlesPerParticlePerSecondChanged(arg);
        }
    }
    void setEmitterXVariation(qreal arg)
    {
        if (m_emitterXVariation != arg) {
            m_emitterXVariation = arg;
            emit emitterXVariationChanged(arg);
        }
    }

    void setEmitterYVariation(qreal arg)
    {
        if (m_emitterYVariation != arg) {
            m_emitterYVariation = arg;
            emit emitterYVariationChanged(arg);
        }
    }

    void setFollow(QString arg)
    {
        if (m_follow != arg) {
            m_follow = arg;
            emit followChanged(arg);
        }
    }

    void setEmissionShape(ParticleExtruder* arg)
    {
        if (m_emissionExtruder != arg) {
            m_emissionExtruder = arg;
            emit emissionShapeChanged(arg);
        }
    }

private slots:
    void recalcParticlesPerSecond();

private:
    QSet<ParticleData*> m_pending;
    QVector<qreal> m_lastEmission;
    int m_particlesPerParticlePerSecond;
    qreal m_lastTimeStamp;
    qreal m_emitterXVariation;
    qreal m_emitterYVariation;
    QString m_follow;
    int m_followCount;
    ParticleExtruder* m_emissionExtruder;
    ParticleExtruder* m_defaultEmissionExtruder;
};

QT_END_NAMESPACE
QT_END_HEADER
#endif // FOLLOWEMITTER_H