/// \file   X3DExporter.hpp
/// \brief  X3D-format files exporter for Assimp.
/// \date   2016
/// \author smal.root@gmail.com
// Thanks to acorn89 for support.

#ifndef INCLUDED_AI_X3D_EXPORTER_H
#define INCLUDED_AI_X3D_EXPORTER_H

// Header files, Assimp.
#include <assimp/material.h>
#include <assimp/scene.h>
#include <assimp/DefaultLogger.hpp>
#include <assimp/Exporter.hpp>

// Header files, stdlib.
#include <list>
#include <string>

namespace Assimp {

/// \class X3DExporter
/// Class which export aiScene to X3D file.
///
/// Limitations.
///
/// Pay attention that X3D is format for interactive graphic and simulations for web browsers. aiScene can not contain all features of the X3D format.
/// Also, aiScene contain rasterized-like data. For example, X3D can describe circle all cylinder with one tag, but aiScene contain result of tessellation:
/// vertices, faces etc. Yes, you can use algorithm for detecting figures or shapes, but that's not a good idea at all.
///
/// Supported nodes:
///		Core component:
///			"MetadataBoolean", "MetadataDouble", "MetadataFloat", "MetadataInteger", "MetadataSet", "MetadataString"
///		Geometry3D component:
///			"IndexedFaceSet"
///		Grouping component:
///			"Group", "Transform"
///		Lighting component:
///			"DirectionalLight", "PointLight", "SpotLight"
///		Rendering component:
///			"ColorRGBA", "Coordinate", "Normal"
///		Shape component:
///			"Shape", "Appearance", "Material"
///		Texturing component:
///			"ImageTexture", "TextureCoordinate", "TextureTransform"
///
class X3DExporter {
    /***********************************************/
    /******************** Types ********************/
    /***********************************************/

    struct SAttribute {
        const std::string Name;
        const std::string Value;
        SAttribute() :
                Name(),
                Value() {
            // empty
        }
        SAttribute(const std::string &name, const std::string &value) :
                Name(name),
                Value(value) {
            // empty
        }

        SAttribute(SAttribute &&rhs) AI_NO_EXCEPT :
                Name(rhs.Name),
                Value(rhs.Value) {
            // empty
        }
    };

    /***********************************************/
    /****************** Constants ******************/
    /***********************************************/

    const aiScene *const mScene;

    /***********************************************/
    /****************** Variables ******************/
    /***********************************************/

    IOStream *mOutFile;
    std::map<size_t, std::string> mDEF_Map_Mesh;
    std::map<size_t, std::string> mDEF_Map_Material;

private:
    std::string mIndentationString;

    /***********************************************/
    /****************** Functions ******************/
    /***********************************************/

    /// \fn void IndentationStringSet(const size_t pNewLevel)
    /// Set value of the indentation string.
    /// \param [in] pNewLevel - new level of the indentation.
    void IndentationStringSet(const size_t pNewLevel);

    /// \fn void XML_Write(const std::string& pData)
    /// Write data to XML-file.
    /// \param [in] pData - reference to string which must be written.
    void XML_Write(const std::string &pData);

    /// \fn aiMatrix4x4 Matrix_GlobalToCurrent(const aiNode& pNode) const
    /// Calculate transformation matrix for transformation from global coordinate system to pointed aiNode.
    /// \param [in] pNode - reference to local node.
    /// \return calculated matrix.
    aiMatrix4x4 Matrix_GlobalToCurrent(const aiNode &pNode) const;

    /// \fn void AttrHelper_CommaToPoint(std::string& pStringWithComma)
    /// Convert commas in string to points. That's needed because "std::to_string" result depends on locale (regional settings).
    /// \param [in, out] pStringWithComma - reference to string, which must be modified.
    void AttrHelper_CommaToPoint(std::string &pStringWithComma) {
        for (char &c : pStringWithComma) {
            if (c == ',') c = '.';
        }
    }

    /// \fn void AttrHelper_FloatToString(const float pValue, std::string& pTargetString)
    /// Converts float to string.
    /// \param [in] pValue - value for converting.
    /// \param [out] pTargetString - reference to string where result will be placed. Will be cleared before using.
    void AttrHelper_FloatToString(const float pValue, std::string &pTargetString);

    /// \fn void AttrHelper_Vec3DArrToString(const aiVector3D* pArray, const size_t pArray_Size, std::string& pTargetString)
    /// Converts array of vectors to string.
    /// \param [in] pArray - pointer to array of vectors.
    /// \param [in] pArray_Size - count of elements in array.
    /// \param [out] pTargetString - reference to string where result will be placed. Will be cleared before using.
    void AttrHelper_Vec3DArrToString(const aiVector3D *pArray, const size_t pArray_Size, std::string &pTargetString);

    /// \fn void AttrHelper_Vec2DArrToString(const aiVector2D* pArray, const size_t pArray_Size, std::string& pTargetString)
    /// \overload void AttrHelper_Vec3DArrToString(const aiVector3D* pArray, const size_t pArray_Size, std::string& pTargetString)
    void AttrHelper_Vec2DArrToString(const aiVector2D *pArray, const size_t pArray_Size, std::string &pTargetString);

    /// \fn void AttrHelper_Vec3DAsVec2fArrToString(const aiVector3D* pArray, const size_t pArray_Size, std::string& pTargetString)
    /// \overload void AttrHelper_Vec3DArrToString(const aiVector3D* pArray, const size_t pArray_Size, std::string& pTargetString)
    /// Only x, y is used from aiVector3D.
    void AttrHelper_Vec3DAsVec2fArrToString(const aiVector3D *pArray, const size_t pArray_Size, std::string &pTargetString);

    /// \fn void AttrHelper_Col4DArrToString(const aiColor4D* pArray, const size_t pArray_Size, std::string& pTargetString)
    /// \overload void AttrHelper_Vec3DArrToString(const aiVector3D* pArray, const size_t pArray_Size, std::string& pTargetString)
    /// Converts array of colors to string.
    void AttrHelper_Col4DArrToString(const aiColor4D *pArray, const size_t pArray_Size, std::string &pTargetString);

    /// \fn void AttrHelper_Col3DArrToString(const aiColor3D* pArray, const size_t pArray_Size, std::string& pTargetString)
    /// \overload void AttrHelper_Col4DArrToString(const aiColor4D* pArray, const size_t pArray_Size, std::string& pTargetString)
    /// Converts array of colors to string.
    void AttrHelper_Col3DArrToString(const aiColor3D *pArray, const size_t pArray_Size, std::string &pTargetString);

    /// \fn void AttrHelper_FloatToAttrList(std::list<SAttribute> pList, const std::string& pName, const float pValue, const float pDefaultValue)
    /// \overload void AttrHelper_Col3DArrToString(const aiColor3D* pArray, const size_t pArray_Size, std::string& pTargetString)
    void AttrHelper_FloatToAttrList(std::list<SAttribute> &pList, const std::string &pName, const float pValue, const float pDefaultValue);

    /// \fn void AttrHelper_Color3ToAttrList(std::list<SAttribute> pList, const std::string& pName, const aiColor3D& pValue, const aiColor3D& pDefaultValue)
    /// Add attribute to list if value not equal to default.
    /// \param [in] pList - target list of the attributes.
    /// \param [in] pName - name of new attribute.
    /// \param [in] pValue - value of the new attribute.
    /// \param [in] pDefaultValue - default value for checking: if pValue is equal to pDefaultValue then attribute will not be added.
    void AttrHelper_Color3ToAttrList(std::list<SAttribute> &pList, const std::string &pName, const aiColor3D &pValue, const aiColor3D &pDefaultValue);

    /// \fn void NodeHelper_OpenNode(const std::string& pNodeName, const size_t pTabLevel, const bool pEmptyElement, const std::list<SAttribute>& pAttrList)
    /// Begin new XML-node element.
    /// \param [in] pNodeName - name of the element.
    /// \param [in] pTabLevel - indentation level.
    /// \param [in] pEmtyElement - if true then empty element will be created.
    /// \param [in] pAttrList - list of the attributes for element.
    void NodeHelper_OpenNode(const std::string &pNodeName, const size_t pTabLevel, const bool pEmptyElement, const std::list<SAttribute> &pAttrList);

    /// \fn void NodeHelper_OpenNode(const std::string& pNodeName, const size_t pTabLevel, const bool pEmptyElement = false)
    /// \overload void NodeHelper_OpenNode(const std::string& pNodeName, const size_t pTabLevel, const bool pEmptyElement, const std::list<SAttribute>& pAttrList)
    void NodeHelper_OpenNode(const std::string &pNodeName, const size_t pTabLevel, const bool pEmptyElement = false);

    /// \fn void NodeHelper_CloseNode(const std::string& pNodeName, const size_t pTabLevel)
    /// End XML-node element.
    /// \param [in] pNodeName - name of the element.
    /// \param [in] pTabLevel - indentation level.
    void NodeHelper_CloseNode(const std::string &pNodeName, const size_t pTabLevel);

    /// \fn void Export_Node(const aiNode* pNode, const size_t pTabLevel)
    /// Export data from scene to XML-file: aiNode.
    /// \param [in] pNode - source aiNode.
    /// \param [in] pTabLevel - indentation level.
    void Export_Node(const aiNode *pNode, const size_t pTabLevel);

    /// \fn void Export_Mesh(const size_t pIdxMesh, const size_t pTabLevel)
    /// Export data from scene to XML-file: aiMesh.
    /// \param [in] pMesh - index of the source aiMesh.
    /// \param [in] pTabLevel - indentation level.
    void Export_Mesh(const size_t pIdxMesh, const size_t pTabLevel);

    /// \fn void Export_Material(const size_t pIdxMaterial, const size_t pTabLevel)
    /// Export data from scene to XML-file: aiMaterial.
    /// \param [in] pIdxMaterial - index of the source aiMaterial.
    /// \param [in] pTabLevel - indentation level.
    void Export_Material(const size_t pIdxMaterial, const size_t pTabLevel);

    /// \fn void Export_MetadataBoolean(const aiString& pKey, const bool pValue, const size_t pTabLevel)
    /// Export data from scene to XML-file: aiMetadata.
    /// \param [in] pKey - source data: value of the metadata key.
    /// \param [in] pValue - source data: value of the metadata value.
    /// \param [in] pTabLevel - indentation level.
    void Export_MetadataBoolean(const aiString &pKey, const bool pValue, const size_t pTabLevel);

    /// \fn void Export_MetadataDouble(const aiString& pKey, const double pValue, const size_t pTabLevel)
    /// \overload void Export_MetadataBoolean(const aiString& pKey, const bool pValue, const size_t pTabLevel)
    void Export_MetadataDouble(const aiString &pKey, const double pValue, const size_t pTabLevel);

    /// \fn void Export_MetadataFloat(const aiString& pKey, const float pValue, const size_t pTabLevel)
    /// \overload void Export_MetadataBoolean(const aiString& pKey, const bool pValue, const size_t pTabLevel)
    void Export_MetadataFloat(const aiString &pKey, const float pValue, const size_t pTabLevel);

    /// \fn void Export_MetadataInteger(const aiString& pKey, const int32_t pValue, const size_t pTabLevel)
    /// \overload void Export_MetadataBoolean(const aiString& pKey, const bool pValue, const size_t pTabLevel)
    void Export_MetadataInteger(const aiString &pKey, const int32_t pValue, const size_t pTabLevel);

    /// \fn void Export_MetadataString(const aiString& pKey, const aiString& pValue, const size_t pTabLevel)
    /// \overload void Export_MetadataBoolean(const aiString& pKey, const bool pValue, const size_t pTabLevel)
    void Export_MetadataString(const aiString &pKey, const aiString &pValue, const size_t pTabLevel);

    /// \fn bool CheckAndExport_Light(const aiNode& pNode, const size_t pTabLevel)
    /// Check if node point to light source. If yes then export light source.
    /// \param [in] pNode - reference to node for checking.
    /// \param [in] pTabLevel - indentation level.
    /// \return true - if node assigned with light and it was exported, else - return false.
    bool CheckAndExport_Light(const aiNode &pNode, const size_t pTabLevel);

    /***********************************************/
    /************** Functions: LOG set *************/
    /***********************************************/

    /// \fn void LogError(const std::string& pMessage)
    /// Short variant for calling \ref DefaultLogger::get()->error()
    void LogError(const std::string &pMessage) { DefaultLogger::get()->error(pMessage); }

public:
    /// \fn X3DExporter()
    /// Default constructor.
    X3DExporter(const char *pFileName, IOSystem *pIOSystem, const aiScene *pScene, const ExportProperties *pProperties);

    /// \fn ~X3DExporter()
    /// Default destructor.
    ~X3DExporter() {}

}; // class X3DExporter

} // namespace Assimp

#endif // INCLUDED_AI_X3D_EXPORTER_H
