/* ========================================================================= *
 *                                                                           *
 *                               OpenMesh                                    *
 *           Copyright (c) 2001-2015, RWTH-Aachen University                 *
 *           Department of Computer Graphics and Multimedia                  *
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 * This file is part of OpenMesh.                                            *
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 * ========================================================================= */




//== INCLUDES =================================================================


// OpenMesh
#include <OpenMesh/Core/IO/reader/OBJReader.hh>
#include <OpenMesh/Core/IO/IOManager.hh>
#include <OpenMesh/Core/Utils/vector_cast.hh>
#include <OpenMesh/Core/Utils/color_cast.hh>
// STL
#if defined(OM_CC_MIPS)
#  include <ctype.h>
/// \bug Workaround for STLPORT 4.6: isspace seems not to be in namespace std!
#elif defined(_STLPORT_VERSION) && (_STLPORT_VERSION==0x460)
#  include <cctype>
#else
using std::isspace;
#endif

#ifndef WIN32
#endif

#include <fstream>

//=== NAMESPACES ==============================================================


namespace OpenMesh {
namespace IO {


//=== INSTANCIATE =============================================================


_OBJReader_  __OBJReaderInstance;
_OBJReader_& OBJReader() { return __OBJReaderInstance; }


//=== IMPLEMENTATION ==========================================================

//-----------------------------------------------------------------------------

void trimString( std::string& _string) {
  // Trim Both leading and trailing spaces

  size_t start = _string.find_first_not_of(" \t\r\n");
  size_t end   = _string.find_last_not_of(" \t\r\n");

  if(( std::string::npos == start ) || ( std::string::npos == end))
    _string = "";
  else
    _string = _string.substr( start, end-start+1 );
}

//-----------------------------------------------------------------------------

// remove duplicated indices from one face
void remove_duplicated_vertices(BaseImporter::VHandles& _indices)
{
  BaseImporter::VHandles::iterator endIter = _indices.end();
  for (BaseImporter::VHandles::iterator iter = _indices.begin(); iter != endIter; ++iter)
    endIter = std::remove(iter+1, endIter, *(iter));

  _indices.erase(endIter,_indices.end());
}

//-----------------------------------------------------------------------------

_OBJReader_::
_OBJReader_()
{
  IOManager().register_module(this);
}


//-----------------------------------------------------------------------------


bool
_OBJReader_::
read(const std::string& _filename, BaseImporter& _bi, Options& _opt)
{
  std::fstream in( _filename.c_str(), std::ios_base::in );

  if (!in.is_open() || !in.good())
  {
    omerr() << "[OBJReader] : cannot not open file "
          << _filename
          << std::endl;
    return false;
  }

  {
#if defined(WIN32)
    std::string::size_type dot_pos = _filename.find_last_of("\\/");
#else
    std::string::size_type dot_pos = _filename.rfind("/");
#endif
    path_ = (dot_pos == std::string::npos)
      ? "./"
      : std::string(_filename.substr(0,dot_pos+1));
  }

  bool result = read(in, _bi, _opt);

  in.close();
  return result;
}

//-----------------------------------------------------------------------------

bool
_OBJReader_::
read_material(std::fstream& _in)
{
  std::string line;
  std::string keyWrd;
  std::string textureName;

  std::stringstream  stream;

  std::string key;
  Material    mat;
  float       f1,f2,f3;
  bool        indef = false;
  int         textureId = 1;


  materials_.clear();
  mat.cleanup();

  while( _in && !_in.eof() )
  {
    std::getline(_in,line);
    if ( _in.bad() ){
      omerr() << "  Warning! Could not read file properly!\n";
      return false;
    }

    if ( line.empty() )
      continue;

    stream.str(line);
    stream.clear();

    stream >> keyWrd;

    if( ( isspace(line[0]) && line[0] != '\t' ) || line[0] == '#' )
    {
      if (indef && !key.empty() && mat.is_valid())
      {
        materials_[key] = mat;
        mat.cleanup();
      }
    }

    else if (keyWrd == "newmtl") // begin new material definition
    {
      stream >> key;
      indef = true;
    }

    else if (keyWrd == "Kd") // diffuse color
    {
      stream >> f1; stream >> f2; stream >> f3;

      if( !stream.fail() )
        mat.set_Kd(f1,f2,f3);
    }

    else if (keyWrd == "Ka") // ambient color
    {
      stream >> f1; stream >> f2; stream >> f3;

      if( !stream.fail() )
        mat.set_Ka(f1,f2,f3);
    }

    else if (keyWrd == "Ks") // specular color
    {
      stream >> f1; stream >> f2; stream >> f3;

      if( !stream.fail() )
        mat.set_Ks(f1,f2,f3);
    }
#if 0
    else if (keyWrd == "illum") // diffuse/specular shading model
    {
      ; // just skip this
    }

    else if (keyWrd == "Ns") // Shininess [0..200]
    {
      ; // just skip this
    }

    else if (keyWrd == "map_") // map images
    {
      // map_Ks, specular map
      // map_Ka, ambient map
      // map_Bump, bump map
      // map_d,  opacity map
      ; // just skip this
    }
#endif
    else if (keyWrd == "map_Kd" ) {
      // Get the rest of the line, removing leading or trailing spaces
      // This will define the filename of the texture
      std::getline(stream,textureName);
      trimString(textureName);
      if ( ! textureName.empty() )
        mat.set_map_Kd( textureName, textureId++ );
    }
    else if (keyWrd == "Tr") // transparency value
    {
      stream >> f1;

      if( !stream.fail() )
        mat.set_Tr(f1);
    }
    else if (keyWrd == "d") // transparency value
    {
      stream >> f1;

      if( !stream.fail() )
        mat.set_Tr(f1);
    }

    if ( _in && indef && mat.is_valid() && !key.empty())
      materials_[key] = mat;
  }
  return true;
}
//-----------------------------------------------------------------------------

bool
_OBJReader_::
read_vertices(std::istream& _in, BaseImporter& _bi, Options& _opt,
              std::vector<Vec3f> & normals,
              std::vector<Vec3f> & colors,
              std::vector<Vec3f> & texcoords3d,
              std::vector<Vec2f> & texcoords,
              std::vector<VertexHandle> & vertexHandles,
              Options & fileOptions)
{
    float x, y, z, u, v, w;
    float r, g, b;

    std::string line;
    std::string keyWrd;

    std::stringstream stream;


    // Options supplied by the user
    const Options & userOptions = _opt;

    while( _in && !_in.eof() )
    {
        std::getline(_in,line);
        if ( _in.bad() ){
          omerr() << "  Warning! Could not read file properly!\n";
          return false;
        }

        // Trim Both leading and trailing spaces
        trimString(line);

        // comment
        if ( line.size() == 0 || line[0] == '#' || isspace(line[0]) ) {
          continue;
        }

        stream.str(line);
        stream.clear();

        stream >> keyWrd;

        // vertex
        if (keyWrd == "v")
        {
          stream >> x; stream >> y; stream >> z;

          if ( !stream.fail() )
          {
            vertexHandles.push_back(_bi.add_vertex(OpenMesh::Vec3f(x,y,z)));
            stream >> r; stream >> g; stream >> b;

            if ( !stream.fail() )
            {
              if (  userOptions.vertex_has_color() ) {
                fileOptions += Options::VertexColor;
                colors.push_back(OpenMesh::Vec3f(r,g,b));
              }
            }
          }
        }

        // texture coord
        else if (keyWrd == "vt")
        {
          stream >> u; stream >> v;

          if ( !stream.fail()  ){

            if ( userOptions.vertex_has_texcoord() || userOptions.face_has_texcoord() ) {
              texcoords.push_back(OpenMesh::Vec2f(u, v));

              // Can be used for both!
              fileOptions += Options::VertexTexCoord;
              fileOptions += Options::FaceTexCoord;

              // try to read the w component as it is optional
              stream >> w;
              if ( !stream.fail()  )
                  texcoords3d.push_back(OpenMesh::Vec3f(u, v, w));

            }

          }else{
            omerr() << "Only single 2D or 3D texture coordinate per vertex"
                  << "allowed!" << std::endl;
            return false;
          }
        }

        // color per vertex
        else if (keyWrd == "vc")
        {
          stream >> r; stream >> g; stream >> b;

          if ( !stream.fail()   ){
            if ( userOptions.vertex_has_color() ) {
              colors.push_back(OpenMesh::Vec3f(r,g,b));
              fileOptions += Options::VertexColor;
            }
          }
        }

        // normal
        else if (keyWrd == "vn")
        {
          stream >> x; stream >> y; stream >> z;

          if ( !stream.fail() ) {
            if (userOptions.vertex_has_normal() ){
              normals.push_back(OpenMesh::Vec3f(x,y,z));
              fileOptions += Options::VertexNormal;
            }
          }
        }
    }

    return true;
}

//-----------------------------------------------------------------------------

bool
_OBJReader_::
read(std::istream& _in, BaseImporter& _bi, Options& _opt)
{
  std::string line;
  std::string keyWrd;

  std::vector<Vec3f>        normals;
  std::vector<Vec3f>        colors;
  std::vector<Vec3f>        texcoords3d;
  std::vector<Vec2f>        texcoords;
  std::vector<VertexHandle> vertexHandles;

  BaseImporter::VHandles    vhandles;
  std::vector<Vec3f>        face_texcoords3d;
  std::vector<Vec2f>        face_texcoords;

  std::string               matname;

  std::stringstream         stream, lineData, tmp;


  // Options supplied by the user
  Options userOptions = _opt;

  // Options collected via file parsing
  Options fileOptions;

  // pass 1: read vertices
  if ( !read_vertices(_in, _bi, _opt,
                      normals, colors, texcoords3d, texcoords,
                      vertexHandles, fileOptions) ){
      return false;
  }

  // reset stream for second pass
  _in.clear();
  _in.seekg(0, std::ios::beg);

  int nCurrentPositions = 0,
      nCurrentTexcoords = 0,
      nCurrentNormals   = 0;
  
  // pass 2: read faces
  while( _in && !_in.eof() )
  {
    std::getline(_in,line);
    if ( _in.bad() ){
      omerr() << "  Warning! Could not read file properly!\n";
      return false;
    }

    // Trim Both leading and trailing spaces
    trimString(line);

    // comment
    if ( line.size() == 0 || line[0] == '#' || isspace(line[0]) ) {
      continue;
    }

    stream.str(line);
    stream.clear();

    stream >> keyWrd;

    // material file
    if (keyWrd == "mtllib")
    {
      std::string matFile;

      // Get the rest of the line, removing leading or trailing spaces
      // This will define the filename of the texture
      std::getline(stream,matFile);
      trimString(matFile);

      matFile = path_ + matFile;

      //omlog() << "Load material file " << matFile << std::endl;

      std::fstream matStream( matFile.c_str(), std::ios_base::in );

      if ( matStream ){

        if ( !read_material( matStream ) )
            omerr() << "  Warning! Could not read file properly!\n";
        matStream.close();

      }else
          omerr() << "  Warning! Material file '" << matFile << "' not found!\n";

      //omlog() << "  " << materials_.size() << " materials loaded.\n";

      for ( MaterialList::iterator material = materials_.begin(); material != materials_.end(); ++material )
      {
        // Save the texture information in a property
        if ( (*material).second.has_map_Kd() )
          _bi.add_texture_information( (*material).second.map_Kd_index() , (*material).second.map_Kd() );
      }

    }

    // usemtl
    else if (keyWrd == "usemtl")
    {
      stream >> matname;
      if (materials_.find(matname)==materials_.end())
      {
        omerr() << "Warning! Material '" << matname
              << "' not defined in material file.\n";
        matname="";
      }
    }
    
    // track current number of parsed vertex attributes,
    // to allow for OBJs negative indices
    else if (keyWrd == "v")
    {
        ++nCurrentPositions;
    }
    else if (keyWrd == "vt")
    {
        ++nCurrentTexcoords;
    }
    else if (keyWrd == "vn")
    {
        ++nCurrentNormals;
    }

    // faces
    else if (keyWrd == "f")
    {
      int component(0), nV(0);
      int value;

      vhandles.clear();
      face_texcoords.clear();
      face_texcoords3d.clear();

      // read full line after detecting a face
      std::string faceLine;
      std::getline(stream,faceLine);
      lineData.str( faceLine );
      lineData.clear();

      FaceHandle fh;
      BaseImporter::VHandles faceVertices;

      // work on the line until nothing left to read
      while ( !lineData.eof() )
      {
        // read one block from the line ( vertex/texCoord/normal )
        std::string vertex;
        lineData >> vertex;

        do{

          //get the component (vertex/texCoord/normal)
          size_t found=vertex.find("/");

          // parts are seperated by '/' So if no '/' found its the last component
          if( found != std::string::npos ){

            // read the index value
            tmp.str( vertex.substr(0,found) );
            tmp.clear();

            // If we get an empty string this property is undefined in the file
            if ( vertex.substr(0,found).empty() ) {
              // Switch to next field
              vertex = vertex.substr(found+1);

              // Now we are at the next component
              ++component;

              // Skip further processing of this component
              continue;
            }

            // Read current value
            tmp >> value;

            // remove the read part from the string
            vertex = vertex.substr(found+1);

          } else {

            // last component of the vertex, read it.
            tmp.str( vertex );
            tmp.clear();
            tmp >> value;

            // Clear vertex after finished reading the line
            vertex="";

            // Nothing to read here ( garbage at end of line )
            if ( tmp.fail() ) {
              continue;
            }
          }

          // store the component ( each component is referenced by the index here! )
          switch (component)
          {
            case 0: // vertex
              if ( value < 0 ) {
                // Calculation of index :
                // -1 is the last vertex in the list
                // As obj counts from 1 and not zero add +1
                value = nCurrentPositions + value + 1;
              }
              // Obj counts from 1 and not zero .. array counts from zero therefore -1
              vhandles.push_back(VertexHandle(value-1));
              faceVertices.push_back(VertexHandle(value-1));
              if (fileOptions.vertex_has_color()) {
                if ((unsigned int)(value - 1) < colors.size()) {
                  _bi.set_color(vhandles.back(), colors[value - 1]);
                }
                else {
                  omerr() << "Error setting vertex color" << std::endl;
                }
              }                  
              break;
	      
            case 1: // texture coord
              if ( value < 0 ) {
                // Calculation of index :
                // -1 is the last vertex in the list
                // As obj counts from 1 and not zero add +1
                value = nCurrentTexcoords + value + 1;
              }
              assert(!vhandles.empty());


              if ( fileOptions.vertex_has_texcoord() && userOptions.vertex_has_texcoord() ) {

                if (!texcoords.empty() && (unsigned int) (value - 1) < texcoords.size()) {
                  // Obj counts from 1 and not zero .. array counts from zero therefore -1
                  _bi.set_texcoord(vhandles.back(), texcoords[value - 1]);
                  if(!texcoords3d.empty() && (unsigned int) (value -1) < texcoords3d.size())
                    _bi.set_texcoord(vhandles.back(), texcoords3d[value - 1]);
                } else {
                  omerr() << "Error setting Texture coordinates" << std::endl;
                }

                }

                if (fileOptions.face_has_texcoord() && userOptions.face_has_texcoord() ) {

                  if (!texcoords.empty() && (unsigned int) (value - 1) < texcoords.size()) {
                    face_texcoords.push_back( texcoords[value-1] );
                    if(!texcoords3d.empty() && (unsigned int) (value -1) < texcoords3d.size())
                      face_texcoords3d.push_back( texcoords3d[value-1] );
                  } else {
                    omerr() << "Error setting Texture coordinates" << std::endl;
                  }
                }


              break;

            case 2: // normal
              if ( value < 0 ) {
                // Calculation of index :
                // -1 is the last vertex in the list
                // As obj counts from 1 and not zero add +1
                value = nCurrentNormals + value + 1;
              }

              // Obj counts from 1 and not zero .. array counts from zero therefore -1
              if (fileOptions.vertex_has_normal() ) {
                assert(!vhandles.empty());                
                if ((unsigned int)(value - 1) < normals.size()) {
                    _bi.set_normal(vhandles.back(), normals[value - 1]);
                }
                else {
                    omerr() << "Error setting vertex normal" << std::endl;
                }                
              }
              break;
          }

          // Prepare for reading next component
          ++component;

          // Read until line does not contain any other info
        } while ( !vertex.empty() );

        component = 0;
        nV++;

      }

      // note that add_face can possibly triangulate the faces, which is why we have to
      // store the current number of faces first
      size_t n_faces = _bi.n_faces();
      remove_duplicated_vertices(faceVertices);

      //A minimum of three vertices are required.
      if (faceVertices.size() > 2)
        fh = _bi.add_face(faceVertices);

      if (!vhandles.empty() && fh.is_valid() )
      {
        _bi.add_face_texcoords(fh, vhandles[0], face_texcoords);
        _bi.add_face_texcoords(fh, vhandles[0], face_texcoords3d);
      }

      if ( !matname.empty()  )
      {
        std::vector<FaceHandle> newfaces;

        for( size_t i=0; i < _bi.n_faces()-n_faces; ++i )
          newfaces.push_back(FaceHandle(int(n_faces+i)));

        Material& mat = materials_[matname];

        if ( mat.has_Kd() ) {
          Vec3uc fc = color_cast<Vec3uc, Vec3f>(mat.Kd());

          if ( userOptions.face_has_color()) {

            for (std::vector<FaceHandle>::iterator it = newfaces.begin(); it != newfaces.end(); ++it)
              _bi.set_color(*it, fc);

            fileOptions += Options::FaceColor;
          }
        }

        // Set the texture index in the face index property
        if ( mat.has_map_Kd() ) {

          if (userOptions.face_has_texcoord()) {

            for (std::vector<FaceHandle>::iterator it = newfaces.begin(); it != newfaces.end(); ++it)
              _bi.set_face_texindex(*it, mat.map_Kd_index());

            fileOptions += Options::FaceTexCoord;

          }

        } else {

          // If we don't have the info, set it to no texture
          if (userOptions.face_has_texcoord()) {

            for (std::vector<FaceHandle>::iterator it = newfaces.begin(); it != newfaces.end(); ++it)
              _bi.set_face_texindex(*it, 0);

          }
        }

      } else {
        std::vector<FaceHandle> newfaces;

        for( size_t i=0; i < _bi.n_faces()-n_faces; ++i )
          newfaces.push_back(FaceHandle(int(n_faces+i)));

        // Set the texture index to zero as we don't have any information
        if ( userOptions.face_has_texcoord() )
          for (std::vector<FaceHandle>::iterator it = newfaces.begin(); it != newfaces.end(); ++it)
            _bi.set_face_texindex(*it, 0);
      }

    }

  }

  // If we do not have any faces,
  // assume this is a point cloud and read the normals and colors directly
  if (_bi.n_faces() == 0)
  {
    int i = 0;
    // add normal per vertex

    if (normals.size() == _bi.n_vertices()) {
      if ( fileOptions.vertex_has_normal() && userOptions.vertex_has_normal() ) {
        for (std::vector<VertexHandle>::iterator it = vertexHandles.begin(); it != vertexHandles.end(); ++it, i++)
          _bi.set_normal(*it, normals[i]);
      }
    }

    // add color per vertex
    i = 0;
    if (colors.size() >= _bi.n_vertices())
      if (fileOptions.vertex_has_color() && userOptions.vertex_has_color()) {
        for (std::vector<VertexHandle>::iterator it = vertexHandles.begin(); it != vertexHandles.end(); ++it, i++)
          _bi.set_color(*it, colors[i]);
      }

  }

  // Return, what we actually read
  _opt = fileOptions;

  return true;
}


//=============================================================================
} // namespace IO
} // namespace OpenMesh
//=============================================================================
