//
//  GeometryCache.h
//  interface
//
//  Created by Andrzej Kapolka on 6/21/13.
//  Copyright (c) 2013 High Fidelity, Inc. All rights reserved.
//

#ifndef __interface__GeometryCache__
#define __interface__GeometryCache__

// include this before QOpenGLBuffer, which includes an earlier version of OpenGL
#include "InterfaceConfig.h"

#include <QMap>
#include <QOpenGLBuffer>

#include <ResourceCache.h>

#include "FBXReader.h"

class NetworkGeometry;
class NetworkMesh;
class NetworkTexture;

/// Stores cached geometry.
class GeometryCache : public ResourceCache {
public:
    
    ~GeometryCache();
    
    void renderHemisphere(int slices, int stacks);
    void renderSquare(int xDivisions, int yDivisions);
    void renderHalfCylinder(int slices, int stacks);
    void renderGrid(int xDivisions, int yDivisions);

    /// Loads geometry from the specified URL.
    /// \param fallback a fallback URL to load if the desired one is unavailable
    /// \param delayLoad if true, don't load the geometry immediately; wait until load is first requested
    QSharedPointer<NetworkGeometry> getGeometry(const QUrl& url, const QUrl& fallback = QUrl(), bool delayLoad = false);
    
protected:

    virtual QSharedPointer<Resource> createResource(const QUrl& url,
        const QSharedPointer<Resource>& fallback, bool delayLoad, const void* extra);
        
private:
    
    typedef QPair<int, int> IntPair;
    typedef QPair<GLuint, GLuint> VerticesIndices;
    
    QHash<IntPair, VerticesIndices> _hemisphereVBOs;
    QHash<IntPair, VerticesIndices> _squareVBOs;
    QHash<IntPair, VerticesIndices> _halfCylinderVBOs;
    QHash<IntPair, QOpenGLBuffer> _gridBuffers;
    
    QHash<QUrl, QWeakPointer<NetworkGeometry> > _networkGeometry;
};

/// Geometry loaded from the network.
class NetworkGeometry : public Resource {
    Q_OBJECT

public:
    
    /// A hysteresis value indicating that we have no state memory.
    static const float NO_HYSTERESIS;
    
    NetworkGeometry(const QUrl& url, const QSharedPointer<NetworkGeometry>& fallback, bool delayLoad,
        const QVariantHash& mapping = QVariantHash(), const QUrl& textureBase = QUrl());

    /// Checks whether the geometry and its textures are loaded.
    bool isLoadedWithTextures() const;

    /// Returns a pointer to the geometry appropriate for the specified distance.
    /// \param hysteresis a hysteresis parameter that prevents rapid model switching
    QSharedPointer<NetworkGeometry> getLODOrFallback(float distance, float& hysteresis, bool delayLoad = false) const;

    const FBXGeometry& getFBXGeometry() const { return _geometry; }
    const QVector<NetworkMesh>& getMeshes() const { return _meshes; }

    /// Returns the average color of all meshes in the geometry.
    glm::vec4 computeAverageColor() const;

    virtual void setLoadPriority(const QPointer<QObject>& owner, float priority);
    virtual void setLoadPriorities(const QHash<QPointer<QObject>, float>& priorities);
    virtual void clearLoadPriority(const QPointer<QObject>& owner);
    
protected:

    virtual void downloadFinished(QNetworkReply* reply);
    virtual void reinsert() const;
    
    Q_INVOKABLE void setGeometry(const FBXGeometry& geometry);
    
private:
    
    friend class GeometryCache;
    
    void setLODParent(const QWeakPointer<NetworkGeometry>& lodParent) { _lodParent = lodParent; }
    
    QVariantHash _mapping;
    QUrl _textureBase;
    QSharedPointer<NetworkGeometry> _fallback;
    
    QMap<float, QSharedPointer<NetworkGeometry> > _lods;
    FBXGeometry _geometry;
    QVector<NetworkMesh> _meshes;
    
    QWeakPointer<NetworkGeometry> _lodParent;
};

/// The state associated with a single mesh part.
class NetworkMeshPart {
public:
    
    QSharedPointer<NetworkTexture> diffuseTexture;
    QSharedPointer<NetworkTexture> normalTexture;
    
    bool isTranslucent() const;
};

/// The state associated with a single mesh.
class NetworkMesh {
public:
    
    QOpenGLBuffer indexBuffer;
    QOpenGLBuffer vertexBuffer;
    
    QVector<NetworkMeshPart> parts;
    
    int getTranslucentPartCount() const;
};

#endif /* defined(__interface__GeometryCache__) */