/****************************************************************************
**
** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
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** This file is part of the Declarative module of the Qt Toolkit.
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** Public License version 3.0 as published by the Free Software Foundation
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****************************************************************************/

#ifndef SPRITEENGINE_H
#define SPRITEENGINE_H

#include <QObject>
#include <QVector>
#include <QTimer>
#include <QTime>
#include <QList>
#include <QDeclarativeListProperty>
#include <QImage>
#include <QPair>

QT_BEGIN_HEADER

QT_BEGIN_NAMESPACE

QT_MODULE(Declarative)

class QSGSprite;
class QSGStochasticState : public QObject //For internal use
{
    Q_OBJECT
    Q_PROPERTY(int duration READ duration WRITE setDuration NOTIFY durationChanged)
    Q_PROPERTY(int durationVariation READ durationVariance WRITE setDurationVariance NOTIFY durationVarianceChanged)
    Q_PROPERTY(QVariantMap to READ to WRITE setTo NOTIFY toChanged)
    Q_PROPERTY(QString name READ name WRITE setName NOTIFY nameChanged)
    Q_PROPERTY(qreal speedModifiesDuration READ speedModifer WRITE setSpeedModifier NOTIFY speedModifierChanged)
    Q_PROPERTY(int frames READ frames WRITE setFrames NOTIFY framesChanged)

public:
    QSGStochasticState(QObject* parent = 0)
        : QObject(parent)
        , m_frames(1)
        , m_duration(1000)
    {
    }

    int duration() const
    {
        return m_duration;
    }

    QString name() const
    {
        return m_name;
    }

    QVariantMap to() const
    {
        return m_to;
    }

    qreal speedModifer() const
    {
        return m_speedModifier;
    }

    int durationVariance() const
    {
        return m_durationVariance;
    }


    int variedDuration() const
    {
        return m_duration
                + (m_durationVariance * ((qreal)qrand()/RAND_MAX) * 2)
                - m_durationVariance;
    }

    int frames() const
    {
        return m_frames;
    }

signals:
    void durationChanged(int arg);

    void nameChanged(QString arg);

    void toChanged(QVariantMap arg);

    void speedModifierChanged(qreal arg);

    void durationVarianceChanged(int arg);

    void entered();//### Just playing around - don't expect full state API
    void framesChanged(int arg);

public slots:
    void setDuration(int arg)
    {
        if (m_duration != arg) {
            m_duration = arg;
            emit durationChanged(arg);
        }
    }

    void setName(QString arg)
    {
        if (m_name != arg) {
            m_name = arg;
            emit nameChanged(arg);
        }
    }

    void setTo(QVariantMap arg)
    {
        if (m_to != arg) {
            m_to = arg;
            emit toChanged(arg);
        }
    }

    void setSpeedModifier(qreal arg)
    {
        if (m_speedModifier != arg) {
            m_speedModifier = arg;
            emit speedModifierChanged(arg);
        }
    }

    void setDurationVariance(int arg)
    {
        if (m_durationVariance != arg) {
            m_durationVariance = arg;
            emit durationVarianceChanged(arg);
        }
    }

    void setFrames(int arg)
    {
        if (m_frames != arg) {
            m_frames = arg;
            emit framesChanged(arg);
        }
    }

private:
    QString m_name;
    int m_frames;
    QVariantMap m_to;
    int m_duration;
    qreal m_speedModifier;
    int m_durationVariance;

    friend class QSGStochasticEngine;
};

class QSGStochasticEngine : public QObject
{
    Q_OBJECT
    //TODO: Optimize single state case?
    Q_PROPERTY(QString globalGoal READ globalGoal WRITE setGlobalGoal NOTIFY globalGoalChanged)
    Q_PROPERTY(QDeclarativeListProperty<QSGStochasticState> states READ states)
public:
    explicit QSGStochasticEngine(QObject *parent = 0);
    QSGStochasticEngine(QList<QSGStochasticState*> states, QObject *parent=0);
    ~QSGStochasticEngine();

    QDeclarativeListProperty<QSGStochasticState> states()
    {
        return QDeclarativeListProperty<QSGStochasticState>(this, m_states);
    }

    QString globalGoal() const
    {
        return m_globalGoal;
    }

    int count() const {return m_things.count();}
    void setCount(int c);



    void setGoal(int state, int sprite=0, bool jump=false);
    void start(int index=0, int state=0);
    void stop(int index=0);
    int curState(int index=0) {return m_things[index];}

    QSGStochasticState* state(int idx){return m_states[idx];}
    int stateIndex(QSGStochasticState* s){return m_states.indexOf(s);}
    int stateCount() {return m_states.count();}
private:
signals:

    void globalGoalChanged(QString arg);
    void stateChanged(int idx);

public slots:
    void setGlobalGoal(QString arg)
    {
        if (m_globalGoal != arg) {
            m_globalGoal = arg;
            emit globalGoalChanged(arg);
        }
    }

    uint updateSprites(uint time);

protected:
    friend class QSGParticleSystem;
    void restart(int index);
    void addToUpdateList(uint t, int idx);
    int goalSeek(int curState, int idx, int dist=-1);
    QList<QSGStochasticState*> m_states;
    //### Consider struct or class for the four data variables?
    QVector<int> m_things;//int is the index in m_states of the current state
    QVector<int> m_goals;
    QVector<int> m_duration;
    QVector<int> m_startTimes;
    QList<QPair<uint, QList<int> > > m_stateUpdates;//### This could be done faster - priority queue?

    QTime m_advanceTime;
    uint m_timeOffset;
    QString m_globalGoal;
    int m_maxFrames;
    int m_imageStateCount;
};

class QSGSpriteEngine : public QSGStochasticEngine
{
    Q_OBJECT
    Q_PROPERTY(QDeclarativeListProperty<QSGSprite> sprites READ sprites)
public:
    explicit QSGSpriteEngine(QObject *parent = 0);
    QSGSpriteEngine(QList<QSGSprite*> sprites, QObject *parent=0);
    ~QSGSpriteEngine();
    QDeclarativeListProperty<QSGSprite> sprites()
    {
        return QDeclarativeListProperty<QSGSprite>(this, m_sprites);
    }


    int spriteState(int sprite=0);
    int spriteStart(int sprite=0);
    int spriteFrames(int sprite=0);
    int spriteDuration(int sprite=0);
    int spriteCount();//Like state count, but for the image states
    int maxFrames();
    QImage assembledImage();
private:
    QList<QSGSprite*> m_sprites;
};

//Common use is to have your own list property which is transparently an engine
inline void spriteAppend(QDeclarativeListProperty<QSGSprite> *p, QSGSprite* s)
{
    reinterpret_cast<QList<QSGSprite *> *>(p->data)->append(s);
    p->object->metaObject()->invokeMethod(p->object, "createEngine");
}

inline QSGSprite* spriteAt(QDeclarativeListProperty<QSGSprite> *p, int idx)
{
    return reinterpret_cast<QList<QSGSprite *> *>(p->data)->at(idx);
}

inline void spriteClear(QDeclarativeListProperty<QSGSprite> *p)
{
    reinterpret_cast<QList<QSGSprite *> *>(p->data)->clear();
    p->object->metaObject()->invokeMethod(p->object, "createEngine");
}

inline int spriteCount(QDeclarativeListProperty<QSGSprite> *p)
{
    return reinterpret_cast<QList<QSGSprite *> *>(p->data)->count();
}

QT_END_NAMESPACE

QT_END_HEADER

#endif // SPRITEENGINE_H