// Copyright (C) 2021 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only

#ifndef QQUICK3DSPRITEPARTICLE_H
#define QQUICK3DSPRITEPARTICLE_H

//
//  W A R N I N G
//  -------------
//
// This file is not part of the Qt API.  It exists purely as an
// implementation detail.  This header file may change from version to
// version without notice, or even be removed.
//
// We mean it.
//

#include <QColor>
#include <QVector4D>
#include <QtQml/QQmlListProperty>

#include <QtQuick3DParticles/private/qquick3dparticle_p.h>
#include <QtQuick3DParticles/private/qquick3dparticlesystem_p.h>
#include <QtQuick3DParticles/private/qquick3dparticledata_p.h>
#include <QtQuick3DParticles/private/qquick3dparticlespritesequence_p.h>
#include <QtQuick3D/private/qquick3dabstractlight_p.h>
#include <QtQuick3DRuntimeRender/private/qssgrenderparticles_p.h>

QT_BEGIN_NAMESPACE

class Q_QUICK3DPARTICLES_EXPORT QQuick3DParticleSpriteParticle : public QQuick3DParticle
{
    Q_OBJECT
    Q_PROPERTY(BlendMode blendMode READ blendMode WRITE setBlendMode NOTIFY blendModeChanged)
    Q_PROPERTY(QQuick3DTexture *sprite READ sprite WRITE setSprite NOTIFY spriteChanged)
    Q_PROPERTY(QQuick3DParticleSpriteSequence *spriteSequence READ spriteSequence WRITE setSpriteSequence NOTIFY spriteSequenceChanged)
    Q_PROPERTY(bool billboard READ billboard WRITE setBillboard NOTIFY billboardChanged)
    Q_PROPERTY(float particleScale READ particleScale WRITE setParticleScale NOTIFY particleScaleChanged)
    Q_PROPERTY(QQuick3DTexture *colorTable READ colorTable WRITE setColorTable NOTIFY colorTableChanged)
    Q_PROPERTY(QQmlListProperty<QQuick3DAbstractLight> lights READ lights NOTIFY lightsChanged REVISION(6, 3))
    Q_PROPERTY(float offsetX READ offsetX WRITE setOffsetX NOTIFY offsetXChanged REVISION(6, 3))
    Q_PROPERTY(float offsetY READ offsetY WRITE setOffsetY NOTIFY offsetYChanged REVISION(6, 3))
    Q_PROPERTY(bool castsReflections READ castsReflections WRITE setCastsReflections NOTIFY castsReflectionsChanged REVISION(6, 4))
    QML_NAMED_ELEMENT(SpriteParticle3D)
    QML_ADDED_IN_VERSION(6, 2)

public:
    enum BlendMode { SourceOver = 0, Screen, Multiply };
    Q_ENUM(BlendMode)

    QQuick3DParticleSpriteParticle(QQuick3DNode *parent = nullptr);
    ~QQuick3DParticleSpriteParticle() override;

    BlendMode blendMode() const;
    QQuick3DTexture *sprite() const;
    QQuick3DParticleSpriteSequence *spriteSequence() const;
    bool billboard() const;
    float particleScale() const;
    QQuick3DTexture *colorTable() const;
    Q_REVISION(6, 3) QQmlListProperty<QQuick3DAbstractLight> lights();
    float offsetX() const;
    float offsetY() const;
    Q_REVISION(6, 4) bool castsReflections() const;

public Q_SLOTS:
    void setBlendMode(QQuick3DParticleSpriteParticle::BlendMode blendMode);
    void setSprite(QQuick3DTexture *sprite);
    void setSpriteSequence(QQuick3DParticleSpriteSequence *spriteSequence);
    void setBillboard(bool billboard);
    void setParticleScale(float scale);
    void setColorTable(QQuick3DTexture *colorTable);
    void setOffsetX(float value);
    void setOffsetY(float value);
    Q_REVISION(6, 4) void setCastsReflections(bool castsReflections);

Q_SIGNALS:
    void blendModeChanged();
    void spriteChanged();
    void spriteSequenceChanged();
    void billboardChanged();
    void particleScaleChanged();
    void colorTableChanged();
    Q_REVISION(6, 3) void lightsChanged();
    Q_REVISION(6, 3) void offsetXChanged();
    Q_REVISION(6, 3) void offsetYChanged();
    Q_REVISION(6, 4) void castsReflectionsChanged();

protected:
    void itemChange(ItemChange, const ItemChangeData &) override;
    void reset() override;
    void componentComplete() override;
    int nextCurrentIndex(const QQuick3DParticleEmitter *emitter) override;
    virtual void setParticleData(int particleIndex,
                         const QVector3D &position,
                         const QVector3D &rotation,
                         const QVector4D &color,
                         float size, float age,
                         float animationFrame);
    virtual void resetParticleData(int particleIndex);
    virtual void commitParticles(float);
    void setDepthBias(float bias) override
    {
        QQuick3DParticle::setDepthBias(bias);
        markNodesDirty();
    }

private Q_SLOTS:
    void onLightDestroyed(QObject *object);

public:
    friend class QQuick3DParticleSystem;
    friend class QQuick3DParticleEmitter;
    friend class QQuick3DParticleSpriteSequence;

    enum FeatureLevel
    {
        Simple = 0,
        Mapped,
        Animated,
        SimpleVLight,
        MappedVLight,
        AnimatedVLight
    };

    struct SpriteParticleData
    {
        QVector3D position;
        QVector3D rotation;
        QVector4D color;
        float size = 0.0f;
        float age = 0.0f;
        float animationFrame = -1.0f;
        int emitterIndex = -1;
    };

    class ParticleUpdateNode : public QQuick3DNode
    {
    public:
        ParticleUpdateNode(QQuick3DNode *parent = nullptr)
            : QQuick3DNode(parent)
        {
        }
        QSSGRenderGraphObject *updateSpatialNode(QSSGRenderGraphObject *node) override;
        QQuick3DParticleSpriteParticle *m_particle = nullptr;
        bool m_nodeDirty = true;
    };
    friend class ParticleUpdateNode;

    struct PerEmitterData
    {
        ParticleUpdateNode *particleUpdateNode = nullptr;
        int particleCount = 0;
        int emitterIndex = -1;
        const QQuick3DParticleEmitter *emitter = nullptr;
    };

    PerEmitterData &perEmitterData(const QQuick3DNode *updateNode);
    PerEmitterData &perEmitterData(int emitterIndex);
    QSSGRenderGraphObject *updateParticleNode(const ParticleUpdateNode *updateNode, QSSGRenderGraphObject *node);

protected:
    virtual void handleMaxAmountChanged(int amount);
    virtual void handleSystemChanged(QQuick3DParticleSystem *system);
    void updateNodes();
    void deleteNodes();
    void markNodesDirty();

    QMap<const QQuick3DParticleEmitter *, PerEmitterData> m_perEmitterData;
    QVector<SpriteParticleData> m_spriteParticleData;
    int m_nextEmitterIndex = 0;
    FeatureLevel m_featureLevel = FeatureLevel::Simple;

private:
    static QSSGRenderParticles::FeatureLevel mapFeatureLevel(QQuick3DParticleSpriteParticle::FeatureLevel level);

    void updateParticleBuffer(ParticleUpdateNode *updateNode, QSSGRenderGraphObject *node);
    void updateAnimatedParticleBuffer(ParticleUpdateNode *updateNode, QSSGRenderGraphObject *node);
    void updateSceneManager(QQuick3DSceneManager *window);


    // Call this whenever features which may affect the level change
    void updateFeatureLevel();

    QHash<QByteArray, QMetaObject::Connection> m_connections;
    PerEmitterData n_noPerEmitterData;
    BlendMode m_blendMode = SourceOver;
    QQuick3DTexture *m_sprite = nullptr;
    QQuick3DTexture *m_colorTable = nullptr;
    float m_particleScale = 5.0f;
    bool m_billboard = false;
    bool m_useAnimatedParticle = false;

    // Lights
    Q_REVISION(6, 3) static void qmlAppendLight(QQmlListProperty<QQuick3DAbstractLight> *list, QQuick3DAbstractLight *light);
    Q_REVISION(6, 3) static QQuick3DAbstractLight *qmlLightAt(QQmlListProperty<QQuick3DAbstractLight> *list, qsizetype index);
    Q_REVISION(6, 3) static qsizetype qmlLightsCount(QQmlListProperty<QQuick3DAbstractLight> *list);
    Q_REVISION(6, 3) static void qmlClearLights(QQmlListProperty<QQuick3DAbstractLight> *list);
    QVector<QQuick3DAbstractLight *> m_lights;
    QVector3D m_offset = {};
    bool m_castsReflections = true;
};

QT_END_NAMESPACE

#endif