//
//  FBXReader.h
//  interface/src/renderer
//
//  Created by Andrzej Kapolka on 9/18/13.
//  Copyright 2013 High Fidelity, Inc.
//
//  Distributed under the Apache License, Version 2.0.
//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
//

#ifndef hifi_FBXReader_h
#define hifi_FBXReader_h

#include <QMetaType>
#include <QUrl>
#include <QVarLengthArray>
#include <QVariant>
#include <QVector>

#include <glm/glm.hpp>
#include <glm/gtc/quaternion.hpp>

#include <Extents.h>
#include <Transform.h>

#include <model/Geometry.h>
#include <model/Material.h>

class QIODevice;
class FBXNode;

typedef QList<FBXNode> FBXNodeList;

/// The names of the joints in the Maya HumanIK rig, terminated with an empty string.
extern const char* HUMANIK_JOINTS[];

/// A node within an FBX document.
class FBXNode {
public:
    
    QByteArray name;
    QVariantList properties;
    FBXNodeList children;
};

/// A single blendshape extracted from an FBX document.
class FBXBlendshape {
public:
    
    QVector<int> indices;
    QVector<glm::vec3> vertices;
    QVector<glm::vec3> normals;
};

struct FBXJointShapeInfo {
    // same units and frame as FBXJoint.translation
    QVector<glm::vec3> points;
};

/// A single joint (transformation node) extracted from an FBX document.
class FBXJoint {
public:

    FBXJointShapeInfo shapeInfo;
    QVector<int> freeLineage;
    bool isFree;
    int parentIndex;
    float distanceToParent;

    // http://download.autodesk.com/us/fbx/20112/FBX_SDK_HELP/SDKRef/a00209.html

    glm::vec3 translation;   // T
    glm::mat4 preTransform;  // Roff * Rp
    glm::quat preRotation;   // Rpre
    glm::quat rotation;      // R
    glm::quat postRotation;  // Rpost
    glm::mat4 postTransform; // Rp-1 * Soff * Sp * S * Sp-1

    // World = ParentWorld * T * (Roff * Rp) * Rpre * R * Rpost * (Rp-1 * Soff * Sp * S * Sp-1)

    glm::mat4 transform;
    glm::vec3 rotationMin;  // radians
    glm::vec3 rotationMax;  // radians
    glm::quat inverseDefaultRotation;
    glm::quat inverseBindRotation;
    glm::mat4 bindTransform;
    QString name;
    bool isSkeletonJoint;
    bool bindTransformFoundInCluster;
};


/// A single binding to a joint in an FBX document.
class FBXCluster {
public:
    
    int jointIndex;
    glm::mat4 inverseBindMatrix;
};

/// A texture map in an FBX document.
class FBXTexture {
public:
    QString name;
    QByteArray filename;
    QByteArray content;
    
    Transform transform;
    int texcoordSet;
    QString texcoordSetName;
    
    bool isBumpmap{ false };
    
    bool isNull() const { return name.isEmpty() && filename.isEmpty() && content.isEmpty(); }
};

/// A single part of a mesh (with the same material).
class FBXMeshPart {
public:

    QVector<int> quadIndices; // original indices from the FBX mesh
    QVector<int> quadTrianglesIndices; // original indices from the FBX mesh of the quad converted as triangles
    QVector<int> triangleIndices; // original indices from the FBX mesh

    QString materialID;
};

class FBXMaterial {
public:
    FBXMaterial() {};
    FBXMaterial(const glm::vec3& diffuseColor, const glm::vec3& specularColor, const glm::vec3& emissiveColor,
        const glm::vec2& emissiveParams, float shininess, float opacity) :
        diffuseColor(diffuseColor),
        specularColor(specularColor),
        emissiveColor(emissiveColor),
        emissiveParams(emissiveParams),
        shininess(shininess),
        opacity(opacity)  {}

    glm::vec3 diffuseColor{ 1.0f };
    float diffuseFactor = 1.0f;
    glm::vec3 specularColor{ 0.02f };
    float specularFactor = 1.0f;

    glm::vec3 emissiveColor{ 0.0f };
    glm::vec2 emissiveParams{ 0.0f, 1.0f };
    float shininess = 23.0f;
    float opacity = 1.0f;

    QString materialID;
    model::MaterialPointer _material;

    FBXTexture diffuseTexture;
    FBXTexture opacityTexture;
    FBXTexture normalTexture;
    FBXTexture specularTexture;
    FBXTexture emissiveTexture;

    bool needTangentSpace() const;
};

/// A single mesh (with optional blendshapes) extracted from an FBX document.
class FBXMesh {
public:
    
    QVector<FBXMeshPart> parts;
    
    QVector<glm::vec3> vertices;
    QVector<glm::vec3> normals;
    QVector<glm::vec3> tangents;
    QVector<glm::vec3> colors;
    QVector<glm::vec2> texCoords;
    QVector<glm::vec2> texCoords1;
    QVector<glm::vec4> clusterIndices;
    QVector<glm::vec4> clusterWeights;
    
    QVector<FBXCluster> clusters;

    Extents meshExtents;
    glm::mat4 modelTransform;

    bool isEye;
    
    QVector<FBXBlendshape> blendshapes;

    unsigned int meshIndex; // the order the meshes appeared in the object file

    model::MeshPointer _mesh;
};

class ExtractedMesh {
public:
    FBXMesh mesh;
    QMultiHash<int, int> newIndices;
    QVector<QHash<int, int> > blendshapeIndexMaps;
    QVector<QPair<int, int> > partMaterialTextures;
    QHash<QString, size_t> texcoordSetMap;
};

/// A single animation frame extracted from an FBX document.
class FBXAnimationFrame {
public:
    QVector<glm::quat> rotations;
    QVector<glm::vec3> translations;
};

/// A light in an FBX document.
class FBXLight {
public:
    QString name;
    Transform transform;
    float intensity;
    float fogValue;
    glm::vec3 color;

    FBXLight() :
        name(),
        transform(),
        intensity(1.0f),
        fogValue(0.0f),
        color(1.0f)
    {}
};

Q_DECLARE_METATYPE(FBXAnimationFrame)
Q_DECLARE_METATYPE(QVector<FBXAnimationFrame>)

/// A point where an avatar can sit
class SittingPoint {
public:
    QString name;
    glm::vec3 position; // relative postion
    glm::quat rotation; // relative orientation
};

inline bool operator==(const SittingPoint& lhs, const SittingPoint& rhs)
{
    return (lhs.name == rhs.name) && (lhs.position == rhs.position) && (lhs.rotation == rhs.rotation);
}

inline bool operator!=(const SittingPoint& lhs, const SittingPoint& rhs)
{
    return (lhs.name != rhs.name) || (lhs.position != rhs.position) || (lhs.rotation != rhs.rotation);
}

/// A set of meshes extracted from an FBX document.
class FBXGeometry {
public:

    QString author;
    QString applicationName; ///< the name of the application that generated the model

    QVector<FBXJoint> joints;
    QHash<QString, int> jointIndices; ///< 1-based, so as to more easily detect missing indices
    bool hasSkeletonJoints;
    
    QVector<FBXMesh> meshes;

    QHash<QString, FBXMaterial> materials;

    glm::mat4 offset;
    
    int leftEyeJointIndex = -1;
    int rightEyeJointIndex = -1;
    int neckJointIndex = -1;
    int rootJointIndex = -1;
    int leanJointIndex = -1;
    int headJointIndex = -1;
    int leftHandJointIndex = -1;
    int rightHandJointIndex = -1;
    int leftToeJointIndex = -1;
    int rightToeJointIndex = -1;

    float leftEyeSize = 0.0f;  // Maximum mesh extents dimension
    float rightEyeSize = 0.0f;

    QVector<int> humanIKJointIndices;
    
    glm::vec3 palmDirection;
    
    QVector<SittingPoint> sittingPoints;
    
    glm::vec3 neckPivot;
    
    Extents bindExtents;
    Extents meshExtents;
    
    QVector<FBXAnimationFrame> animationFrames;
        
    int getJointIndex(const QString& name) const { return jointIndices.value(name) - 1; }
    QStringList getJointNames() const;
    
    bool hasBlendedMeshes() const;

    /// Returns the unscaled extents of the model's mesh
    Extents getUnscaledMeshExtents() const;

    bool convexHullContains(const glm::vec3& point) const;

    QHash<int, QString> meshIndicesToModelNames;
    
    /// given a meshIndex this will return the name of the model that mesh belongs to if known
    QString getModelNameOfMesh(int meshIndex) const;
    
    QList<QString> blendshapeChannelNames;
};

Q_DECLARE_METATYPE(FBXGeometry)

/// Reads FBX geometry from the supplied model and mapping data.
/// \exception QString if an error occurs in parsing
FBXGeometry* readFBX(const QByteArray& model, const QVariantHash& mapping, const QString& url = "", bool loadLightmaps = true, float lightmapLevel = 1.0f);

/// Reads FBX geometry from the supplied model and mapping data.
/// \exception QString if an error occurs in parsing
FBXGeometry* readFBX(QIODevice* device, const QVariantHash& mapping, const QString& url = "", bool loadLightmaps = true, float lightmapLevel = 1.0f);

class TextureParam {
public:
    glm::vec2 UVTranslation;
    glm::vec2 UVScaling;
    glm::vec4 cropping;
    QString UVSet;

    glm::vec3 translation;
    glm::vec3 rotation;
    glm::vec3 scaling;
    uint8_t alphaSource;
    uint8_t currentTextureBlendMode;
    bool useMaterial;

    template <typename T>
    bool assign(T& ref, const T& v) {
        if (ref == v) {
            return false;
        } else {
            ref = v;
            isDefault = false;
            return true;
        }
    }

    bool isDefault;

    TextureParam() :
        UVTranslation(0.0f),
        UVScaling(1.0f),
        cropping(0.0f),
        UVSet("map1"),
        translation(0.0f),
        rotation(0.0f),
        scaling(1.0f),
        alphaSource(0),
        currentTextureBlendMode(0),
        useMaterial(true),
        isDefault(true)
    {}
    
    TextureParam(const TextureParam& src) :
        UVTranslation(src.UVTranslation),
        UVScaling(src.UVScaling),
        cropping(src.cropping),
        UVSet(src.UVSet),
        translation(src.translation),
        rotation(src.rotation),
        scaling(src.scaling),
        alphaSource(src.alphaSource),
        currentTextureBlendMode(src.currentTextureBlendMode),
        useMaterial(src.useMaterial),
        isDefault(src.isDefault)
    {}
    
};

class ExtractedMesh;

class FBXReader {
public:
    FBXGeometry* _fbxGeometry;

    FBXNode _fbxNode;
    static FBXNode parseFBX(QIODevice* device);

    FBXGeometry* extractFBXGeometry(const QVariantHash& mapping, const QString& url);

    ExtractedMesh extractMesh(const FBXNode& object, unsigned int& meshIndex);
    QHash<QString, ExtractedMesh> meshes;
    static void buildModelMesh(FBXMesh& extractedMesh, const QString& url);

    FBXTexture getTexture(const QString& textureID);

    QHash<QString, QString> _textureNames;
    QHash<QString, QByteArray> _textureFilenames;
    QHash<QByteArray, QByteArray> _textureContent;
    QHash<QString, TextureParam> _textureParams;


    QHash<QString, QString> diffuseTextures;
    QHash<QString, QString> bumpTextures;
    QHash<QString, QString> normalTextures;
    QHash<QString, QString> specularTextures;
    QHash<QString, QString> emissiveTextures;
    QHash<QString, QString> ambientTextures;

    QHash<QString, FBXMaterial> _fbxMaterials;

    void consolidateFBXMaterials();

    bool _loadLightmaps = true;
    float _lightmapOffset = 0.0f;
    float _lightmapLevel;

    QMultiMap<QString, QString> _connectionParentMap;
    QMultiMap<QString, QString> _connectionChildMap;

    static glm::vec3 getVec3(const QVariantList& properties, int index);
    static QVector<glm::vec4> createVec4Vector(const QVector<double>& doubleVector);
    static QVector<glm::vec4> createVec4VectorRGBA(const QVector<double>& doubleVector, glm::vec4& average);
    static QVector<glm::vec3> createVec3Vector(const QVector<double>& doubleVector);
    static QVector<glm::vec2> createVec2Vector(const QVector<double>& doubleVector);
    static glm::mat4 createMat4(const QVector<double>& doubleVector);

    static QVector<int> getIntVector(const FBXNode& node);
    static QVector<float> getFloatVector(const FBXNode& node);
    static QVector<double> getDoubleVector(const FBXNode& node);
};

#endif // hifi_FBXReader_h