/****************************************************************************
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** Copyright (C) 2014 Klaralvdalens Datakonsult AB (KDAB).
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** packaging of this file.  Please review the following information to
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#ifndef GLTFPARSER_H
#define GLTFPARSER_H

#include <Qt3DRenderer/meshdata.h>
#include <Qt3DRenderer/qattribute.h>
#include <Qt3DCore/qentity.h>
#include <Qt3DRenderer/qtechnique.h>
#include <Qt3DRenderer/qbuffer.h>
#include <QJsonDocument>
#include <QMultiHash>
#include <Qt3DCore/qabstractmesh.h>
#include <QImage>

#include <Qt3DRenderer/abstractsceneparser.h>

QT_BEGIN_NAMESPACE

class QFile;

namespace Qt3D {

class QMaterial;
class ShaderProgram;
class QEffect;
class Camera;
class CameraLens;
class Texture;

class GLTFParser : public AbstractSceneParser
{
    Q_OBJECT

public:
    GLTFParser();

    static bool isGLTFPath(const QString &path);
    void setBasePath(const QString& path);
    bool setJSON( QJsonDocument json );

    // SceneParserInterface interface
    void setFilePath(const QString &path) Q_DECL_OVERRIDE;
    bool isPathExtensionSupported(const QString &path) Q_DECL_OVERRIDE;

    /**
     * @brief instantiate Create Nodes based on glTf JSON document
     * @return A new scene-graph fragment based on the provided glTf
     */
    QEntity *node(QString id) Q_DECL_OVERRIDE;
    QEntity *scene(QString id) Q_DECL_OVERRIDE;


    QEntity *defaultScene();
    MeshDataPtr mesh(QString id);
    QMaterial *material(QString id);
    CameraLens *camera(QString id);

private:


    class GLTFParserMesh : public QAbstractMesh
    {
    public:
        GLTFParserMesh(QNode *parent = 0);

        bool load() Q_DECL_OVERRIDE;
        void setData(MeshDataPtr data);
    };

    void parse();

    void processJSONMesh( QString id, QJsonObject jsonObj );
    void processJSONAccessor(QString id, const QJsonObject &json);
    void processJSONBuffer(QString id, const QJsonObject &json);
    void processJSONBufferView(QString id, const QJsonObject &json);

    void processName( const QJsonObject& json, QObject* ins );

    QJsonDocument m_json;
    QString m_basePath;
    bool m_parseDone;
    QString m_defaultScene;

    // multi-hash because our MeshData corresponds to a single primitive
    // in glTf.
    QMultiHash<QString, MeshDataPtr> m_meshDict;

    // GLTF assigns materials at the mesh level, but we do them as siblings,
    // so record the association here for when we instantiate meshes
    QMap<MeshData*, QString> m_meshMaterialDict;

    QMap<QString, AttributePtr> m_attributeDict;

    class BufferData
    {
    public:
        BufferData();

        BufferData(QJsonObject json);

        quint64 length;
        QString path;
        // type if ever useful
    };

    QMap<QString, QMaterial*> m_materialCache;

    QMap<QString, BufferData> m_bufferDatas;
    QMap<QString, BufferPtr> m_buffers;

    QMap<QString, QString> m_shaderPaths;
    QMap<QString, ShaderProgram*> m_programs;

    QMap<QString, QTechnique *> m_techniques;
    // glTF doesn't deal in effects, but we need a trivial one to wrap
    // up our techniques
    QMap<QString, QEffect*> m_effectProxies;

    QMap<QString, Texture*> m_textures;
    QMap<QString, QImage> m_images;

    QFile* resolveLocalData(QString path);

    void processJSONShader(QString id, QJsonObject jsonObj);
    void processJSONProgram(QString id, QJsonObject jsonObj);
    void processJSONTechnique(QString id, QJsonObject jsonObj);

    void processJSONImage(QString id, QJsonObject jsonObj);
    void processJSONTexture(QString id, QJsonObject jsonObj);

    QVariant parameterValueFromJSON(QParameter *p, QJsonValue val);

    Render::DrawState *buildState(const QByteArray& nm, QJsonValue obj);
};

}

QT_END_NAMESPACE

#endif // GLTFPARSER_H