/*
Open Asset Import Library (assimp)
----------------------------------------------------------------------

Copyright (c) 2006-2020, assimp team


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  copyright notice, this list of conditions and the
  following disclaimer.

* Redistributions in binary form must reproduce the above
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"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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*/

/** @file Declaration of the LWO importer class. */
#ifndef AI_LWOLOADER_H_INCLUDED
#define AI_LWOLOADER_H_INCLUDED

#include <assimp/types.h>
#include <assimp/material.h>
#include <assimp/DefaultLogger.hpp>

#include "LWOFileData.h"
#include <assimp/BaseImporter.h>

#include <map>

struct aiTexture;
struct aiNode;
struct aiMaterial;

namespace Assimp    {
using namespace LWO;

// ---------------------------------------------------------------------------
/** Class to load LWO files.
 *
 *  @note  Methods named "xxxLWO2[xxx]" are used with the newer LWO2 format.
 *         Methods named "xxxLWOB[xxx]" are used with the older LWOB format.
 *         Methods named "xxxLWO[xxx]" are used with both formats.
 *         Methods named "xxx" are used to preprocess the loaded data -
 *         they aren't specific to one format version
*/
// ---------------------------------------------------------------------------
class LWOImporter : public BaseImporter
{
public:
    LWOImporter();
    ~LWOImporter();

    // -------------------------------------------------------------------
    /** Returns whether the class can handle the format of the given file.
     * See BaseImporter::CanRead() for details.
     */
    bool CanRead( const std::string& pFile, IOSystem* pIOHandler,
        bool checkSig) const;

    // -------------------------------------------------------------------
    /** Called prior to ReadFile().
    * The function is a request to the importer to update its configuration
    * basing on the Importer's configuration property list.
    */
    void SetupProperties(const Importer* pImp);

protected:

    // -------------------------------------------------------------------
    // Get list of supported extensions
    const aiImporterDesc* GetInfo () const;

    // -------------------------------------------------------------------
    /** Imports the given file into the given scene structure.
    * See BaseImporter::InternReadFile() for details
    */
    void InternReadFile( const std::string& pFile, aiScene* pScene,
        IOSystem* pIOHandler);

private:

    // -------------------------------------------------------------------
    /** Loads a LWO file in the older LWOB format (LW < 6)
     */
    void LoadLWOBFile();

    // -------------------------------------------------------------------
    /** Loads a LWO file in the newer LWO2 format (LW >= 6)
     */
    void LoadLWO2File();


    // -------------------------------------------------------------------
    /** Parsing functions used for all file format versions
    */
    inline void GetS0(std::string& out,unsigned int max);
    inline float GetF4();
    inline uint32_t GetU4();
    inline uint16_t GetU2();
    inline uint8_t  GetU1();


    // -------------------------------------------------------------------
    /** Loads a surface chunk from an LWOB file
     *  @param size Maximum size to be read, in bytes.
     */
    void LoadLWOBSurface(unsigned int size);

    // -------------------------------------------------------------------
    /** Loads a surface chunk from an LWO2 file
     *  @param size Maximum size to be read, in bytes.
     */
    void LoadLWO2Surface(unsigned int size);

    // -------------------------------------------------------------------
    /** Loads a texture block from a LWO2 file.
     *  @param size Maximum size to be read, in bytes.
     *  @param head Header of the SUF.BLOK header
     */
    void LoadLWO2TextureBlock(LE_NCONST IFF::SubChunkHeader* head,
        unsigned int size );

    // -------------------------------------------------------------------
    /** Loads a shader block from a LWO2 file.
     *  @param size Maximum size to be read, in bytes.
     *  @param head Header of the SUF.BLOK header
     */
    void LoadLWO2ShaderBlock(LE_NCONST IFF::SubChunkHeader* head,
        unsigned int size );

    // -------------------------------------------------------------------
    /** Loads an image map from a LWO2 file
     *  @param size Maximum size to be read, in bytes.
     *  @param tex Texture object to be filled
     */
    void LoadLWO2ImageMap(unsigned int size, LWO::Texture& tex );
    void LoadLWO2Gradient(unsigned int size, LWO::Texture& tex );
    void LoadLWO2Procedural(unsigned int size, LWO::Texture& tex );

    // loads the header - used by thethree functions above
    void LoadLWO2TextureHeader(unsigned int size, LWO::Texture& tex );

    // -------------------------------------------------------------------
    /** Loads the LWO tag list from the file
     *  @param size Maximum size to be read, in bytes.
     */
    void LoadLWOTags(unsigned int size);

    // -------------------------------------------------------------------
    /** Load polygons from a POLS chunk
     *  @param length Size of the chunk
    */
    void LoadLWO2Polygons(unsigned int length);
    void LoadLWOBPolygons(unsigned int length);

    // -------------------------------------------------------------------
    /** Load polygon tags from a PTAG chunk
     *  @param length Size of the chunk
    */
    void LoadLWO2PolygonTags(unsigned int length);

    // -------------------------------------------------------------------
    /** Load a vertex map from a VMAP/VMAD chunk
     *  @param length Size of the chunk
     *  @param perPoly Operate on per-polygon base?
    */
    void LoadLWO2VertexMap(unsigned int length, bool perPoly);

    // -------------------------------------------------------------------
    /** Load polygons from a PNTS chunk
     *  @param length Size of the chunk
    */
    void LoadLWOPoints(unsigned int length);

    // -------------------------------------------------------------------
    /** Load a clip from a CLIP chunk
     *  @param length Size of the chunk
    */
    void LoadLWO2Clip(unsigned int length);

    // -------------------------------------------------------------------
    /** Load an envelope from an EVL chunk
     *  @param length Size of the chunk
    */
    void LoadLWO2Envelope(unsigned int length);

    // -------------------------------------------------------------------
    /** Count vertices and faces in a LWOB/LWO2 file
    */
    void CountVertsAndFacesLWO2(unsigned int& verts,
        unsigned int& faces,
        uint16_t*& cursor,
        const uint16_t* const end,
        unsigned int max = UINT_MAX);

    void CountVertsAndFacesLWOB(unsigned int& verts,
        unsigned int& faces,
        LE_NCONST uint16_t*& cursor,
        const uint16_t* const end,
        unsigned int max = UINT_MAX);

    // -------------------------------------------------------------------
    /** Read vertices and faces in a LWOB/LWO2 file
    */
    void CopyFaceIndicesLWO2(LWO::FaceList::iterator& it,
        uint16_t*& cursor,
        const uint16_t* const end);

    // -------------------------------------------------------------------
    void CopyFaceIndicesLWOB(LWO::FaceList::iterator& it,
        LE_NCONST uint16_t*& cursor,
        const uint16_t* const end,
        unsigned int max = UINT_MAX);

    // -------------------------------------------------------------------
    /** Resolve the tag and surface lists that have been loaded.
    *   Generates the mMapping table.
    */
    void ResolveTags();

    // -------------------------------------------------------------------
    /** Resolve the clip list that has been loaded.
    *   Replaces clip references with real clips.
    */
    void ResolveClips();

    // -------------------------------------------------------------------
    /** Add a texture list to an output material description.
     *
     *  @param pcMat Output material
     *  @param in Input texture list
     *  @param type Type identifier of the texture list
    */
    bool HandleTextures(aiMaterial* pcMat, const TextureList& in,
        aiTextureType type);

    // -------------------------------------------------------------------
    /** Adjust a texture path
    */
    void AdjustTexturePath(std::string& out);

    // -------------------------------------------------------------------
    /** Convert a LWO surface description to an ASSIMP material
    */
    void ConvertMaterial(const LWO::Surface& surf,aiMaterial* pcMat);


    // -------------------------------------------------------------------
    /** Get a list of all UV/VC channels required by a specific surface.
     *
     *  @param surf Working surface
     *  @param layer Working layer
     *  @param out Output list. The members are indices into the
     *    UV/VC channel lists of the layer
    */
    void FindUVChannels(/*const*/ LWO::Surface& surf,
        LWO::SortedRep& sorted,
        /*const*/ LWO::Layer& layer,
        unsigned int out[AI_MAX_NUMBER_OF_TEXTURECOORDS]);

    // -------------------------------------------------------------------
    char FindUVChannels(LWO::TextureList& list,
        LWO::Layer& layer,LWO::UVChannel& uv, unsigned int next);

    // -------------------------------------------------------------------
    void FindVCChannels(const LWO::Surface& surf,
        LWO::SortedRep& sorted,
        const LWO::Layer& layer,
        unsigned int out[AI_MAX_NUMBER_OF_COLOR_SETS]);

    // -------------------------------------------------------------------
    /** Generate the final node graph
     *  Unused nodes are deleted.
     *  @param apcNodes Flat list of nodes
    */
    void GenerateNodeGraph(std::map<uint16_t,aiNode*>& apcNodes);

    // -------------------------------------------------------------------
    /** Add children to a node
     *  @param node Node to become a father
     *  @param parent Index of the node
     *  @param apcNodes Flat list of nodes - used nodes are set to nullptr.
    */
    void AddChildren(aiNode* node, uint16_t parent,
        std::vector<aiNode*>& apcNodes);

    // -------------------------------------------------------------------
    /** Read a variable sized integer
     *  @param inout Input and output buffer
    */
    int ReadVSizedIntLWO2(uint8_t*& inout);

    // -------------------------------------------------------------------
    /** Assign a value from a VMAP to a vertex and all vertices
     *  attached to it.
     *  @param base VMAP destination data
     *  @param numRead Number of float's to be read
     *  @param idx Absolute index of the first vertex
     *  @param data Value of the VMAP to be assigned - read numRead
     *    floats from this array.
    */
    void DoRecursiveVMAPAssignment(VMapEntry* base, unsigned int numRead,
        unsigned int idx, float* data);

    // -------------------------------------------------------------------
    /** Compute normal vectors for a mesh
     *  @param mesh Input mesh
     *  @param smoothingGroups Smoothing-groups-per-face array
     *  @param surface Surface for the mesh
    */
    void ComputeNormals(aiMesh* mesh, const std::vector<unsigned int>& smoothingGroups,
        const LWO::Surface& surface);


    // -------------------------------------------------------------------
    /** Setup a new texture after the corresponding chunk was
     *  encountered in the file.
     *  @param list Texture list
     *  @param size Maximum number of bytes to be read
     *  @return Pointer to new texture
    */
    LWO::Texture* SetupNewTextureLWOB(LWO::TextureList& list,
        unsigned int size);

protected:

    /** true if the file is a LWO2 file*/
    bool mIsLWO2;

    /** true if the file is a LXOB file*/
    bool mIsLXOB;

    /** Temporary list of layers from the file */
    LayerList* mLayers;

    /** Pointer to the current layer */
    LWO::Layer* mCurLayer;

    /** Temporary tag list from the file */
    TagList* mTags;

    /** Mapping table to convert from tag to surface indices.
        UINT_MAX indicates that a no corresponding surface is available */
    TagMappingTable* mMapping;

    /** Temporary surface list from the file */
    SurfaceList* mSurfaces;

    /** Temporary clip list from the file */
    ClipList mClips;

    /** Temporary envelope list from the file */
    EnvelopeList mEnvelopes;

    /** file buffer */
    uint8_t* mFileBuffer;

    /** Size of the file, in bytes */
    unsigned int fileSize;

    /** Output scene */
    aiScene* mScene;

    /** Configuration option: speed flag set? */
    bool configSpeedFlag;

    /** Configuration option: index of layer to be loaded */
    unsigned int configLayerIndex;

    /** Configuration option: name of layer to be loaded */
    std::string  configLayerName;

    /** True if we have a named layer */
    bool hasNamedLayer;
};


// ------------------------------------------------------------------------------------------------
inline
float LWOImporter::GetF4() {
    float f;
    ::memcpy(&f, mFileBuffer, 4);
    mFileBuffer += 4;
    AI_LSWAP4(f);
    return f;
}

// ------------------------------------------------------------------------------------------------
inline uint32_t LWOImporter::GetU4()
{
    uint32_t f;
    ::memcpy(&f, mFileBuffer, 4);
    mFileBuffer += 4;
    AI_LSWAP4(f);
    return f;
}

// ------------------------------------------------------------------------------------------------
inline uint16_t LWOImporter::GetU2()
{
    uint16_t f;
    ::memcpy(&f, mFileBuffer, 2);
    mFileBuffer += 2;
    AI_LSWAP2(f);
    return f;
}

// ------------------------------------------------------------------------------------------------
inline uint8_t LWOImporter::GetU1()
{
    return *mFileBuffer++;
}

// ------------------------------------------------------------------------------------------------
inline int LWOImporter::ReadVSizedIntLWO2(uint8_t*& inout)
{
    int i;
    int c = *inout;inout++;
    if(c != 0xFF)
    {
        i = c << 8;
        c = *inout;inout++;
        i |= c;
    }
    else
    {
        c = *inout;inout++;
        i = c << 16;
        c = *inout;inout++;
        i |= c << 8;
        c = *inout;inout++;
        i |= c;
    }
    return i;
}

// ------------------------------------------------------------------------------------------------
inline void LWOImporter::GetS0(std::string& out,unsigned int max)
{
    unsigned int iCursor = 0;
    const char*sz = (const char*)mFileBuffer;
    while (*mFileBuffer)
    {
        if (++iCursor > max)
        {
            ASSIMP_LOG_WARN("LWO: Invalid file, string is is too long");
            break;
        }
        ++mFileBuffer;
    }
    size_t len = (size_t) ((const char*)mFileBuffer-sz);
    out = std::string(sz,len);
    mFileBuffer += (len&0x1 ? 1 : 2);
}



} // end of namespace Assimp

#endif // AI_LWOIMPORTER_H_INCLUDED
