// Copyright (c) 2020 GeometryFactory
//
// This file is part of CGAL (www.cgal.org);
//
// $URL$
// $Id$
// SPDX-License-Identifier: LGPL-3.0-or-later OR LicenseRef-Commercial
//
// Author(s)     : Andreas Fabri
//                 Mael Rouxel-Labbé
//                 Maxime Gimeno

#ifndef CGAL_IO_GOCAD_H
#define CGAL_IO_GOCAD_H

#include <CGAL/IO/helpers.h>

#include <CGAL/assertions.h>
#include <CGAL/boost/graph/Named_function_parameters.h>
#include <CGAL/boost/graph/named_params_helper.h>
#include <CGAL/IO/io.h>
#include <CGAL/iterator.h>
#include <CGAL/Kernel_traits.h>
#include <CGAL/use.h>

#include <boost/range/value_type.hpp>

#include <fstream>
#include <iostream>
#include <vector>

namespace CGAL {

////////////////////////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////
/// Read

template <typename PointRange, typename PolygonRange, typename CGAL_BGL_NP_TEMPLATE_PARAMETERS>
bool read_GOCAD(std::istream& is,
                std::pair<std::string, std::string>& name_and_color,
                PointRange& points,
                PolygonRange& polygons,
                const CGAL_BGL_NP_CLASS&,
                bool verbose = true)
{
  if(!is)
  {
    if(verbose)
      std::cerr<<"File doesn't exist."<<std::endl;
    return false;
  }
  typedef typename boost::range_value<PointRange>::type     Point;
  typedef typename boost::range_value<PolygonRange>::type   Poly;

  set_ascii_mode(is); // GOCAD is ASCII only

  int offset = 0;
  std::string s;
  Point p;
  bool vertices_read = false,
      end_read = false;

  std::string line;
  std::size_t nb_gocad=1, //don't read the first one, it is optional anyway.
      nb_end=0;
  while(std::getline(is, line))
  {
    if(line.empty())
      continue;

    std::istringstream iss(line);
    if(!(iss >> s))
      continue; // can't read anything on the line, whitespace only?

    if(s == "TFACE")
    {
      break;
    }

    std::string::size_type idx;
    if((idx = s.find("name")) != std::string::npos)
    {
      std::size_t pos = s.find(":")+1;
      name_and_color.first = s.substr(pos, s.length());
    }

    if((idx = s.find("color")) != std::string::npos)
    {
      std::size_t pos = s.find(":")+1;
      name_and_color.second = s.substr(pos, s.length());
    }
  }

  while(std::getline(is, line))
  {
    if(line.empty())
      continue;

    std::istringstream iss(line);
    if(line.find("GOCAD ") != std::string::npos) //the whitespace matters, it is used to define a gocad type, but not in the coord system keyword, for example.
      nb_gocad++;

    if((line.find("VRTX") != std::string::npos))
    {
      int i;
      if(!(iss >> s >> i >> p))
      {
        if(verbose)
          std::cerr << "error while reading vertex." << std::endl;
        return false;
      }

      if(!vertices_read)
      {
        vertices_read = true;
        offset -= i; // Some files start with index 0 others with 1
      }

      points.push_back(p);
    }
    else if(line[0] == 'T')
    {
      iss >> s;
      if(s != "TRGL")
        continue;

      int i,j,k;
      if(!(iss >> i >> j >> k))
      {
        if(verbose)
          std::cerr << "error while reading triangle." << std::endl;
        return false;
      }

      Poly new_face(3);
      new_face[0] = offset + i;
      new_face[1] = offset + j;
      new_face[2] = offset + k;
      polygons.push_back(new_face);
    }
    else if(line == "END")
    {
      end_read=true;
      nb_end++;
    }
  }
  if(is.eof())
    is.clear(std::ios::goodbit);
  return end_read && nb_gocad == nb_end && !is.bad();
}

template <typename PointRange, typename PolygonRange, typename CGAL_BGL_NP_TEMPLATE_PARAMETERS>
bool read_GOCAD(std::istream& is,
                PointRange& points,
                PolygonRange& polygons,
                const CGAL_BGL_NP_CLASS& np)
{
  std::pair<std::string, std::string> dummy;
  return read_GOCAD(is, dummy, points, polygons, np);
}

template <typename PointRange, typename PolygonRange, typename CGAL_BGL_NP_TEMPLATE_PARAMETERS>
bool read_GOCAD(const char* fname,
                PointRange& points,
                PolygonRange& polygons,
                const CGAL_BGL_NP_CLASS& np)
{
  std::ifstream in(fname);
  std::pair<std::string, std::string> dummy;
  return read_GOCAD(in, dummy, points, polygons, np);
}

template <typename PointRange, typename PolygonRange, typename CGAL_BGL_NP_TEMPLATE_PARAMETERS>
bool read_GOCAD(const std::string& fname,
                PointRange& points,
                PolygonRange& polygons,
                const CGAL_BGL_NP_CLASS& np)
{
  return read_GOCAD(fname.c_str(), points, polygons, np);
}

/*!
 * \ingroup GocadIoFuncs
 *
 * reads the content of `is` into `points` and `polygons`, in the GOCAD format.
 *
 * \tparam PointRange a model of the concept `RandomAccessContainer` whose value type is the point type.
 * \tparam PolygonRange a model of the concept `SequenceContainer`
 *                      whose value_type is itself a model of the concept `SequenceContainer`
 *                      whose value_type is an integer type.

 *
 * \param is the input stream
 * \param points points of the soup of polygons.
 * \param polygons a `PolygonRange`. Each element in it describes a polygon
 *        using the indices of the points in `points`.
 *
 * \returns `true` if the reading was successful, `false` otherwise.
 * \see \ref IOStreamGocad
 */
template <typename PointRange, typename PolygonRange>
bool read_GOCAD(std::istream& is, PointRange& points, PolygonRange& polygons)
{
  std::pair<std::string, std::string> dummy;
  return read_GOCAD(is, dummy, points, polygons, parameters::all_default());
}

/*!
 * \ingroup GocadIoFuncs
 *
 * reads the content of the file `fname` into `points` and `polygons`, in the GOCAD format.
 *
 * \tparam PointRange a model of the concept `RandomAccessContainer` whose value type is the point type.
 * \tparam PolygonRange a model of the concept `SequenceContainer`
 *                      whose value_type is itself a model of the concept `SequenceContainer`
 *                      whose value_type is an integer type.

 *
 * \param fname the path to the input file
 * \param points points of the soup of polygons.
 * \param polygons a `PolygonRange`. Each element in it describes a polygon
 *        using the indices of the points in `points`.
 *
 * \returns `true` if the reading was successful, `false` otherwise.
 * \see \ref IOStreamGocad
 */
template <typename PointRange, typename PolygonRange>
bool read_GOCAD(const char* fname, PointRange& points, PolygonRange& polygons)
{
  return read_GOCAD(fname, points, polygons, parameters::all_default());
}

template <typename PointRange, typename PolygonRange>
bool read_GOCAD(const std::string& fname, PointRange& points, PolygonRange& polygons)
{
  return read_GOCAD(fname, points, polygons, parameters::all_default());
}

////////////////////////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////////
/// Write

namespace IO {
namespace internal {

template <typename PointRange,
          typename PolygonRange,
          typename CGAL_BGL_NP_TEMPLATE_PARAMETERS>
bool write_GOCAD(std::ostream& os,
                 const char* fname,
                 const PointRange& points,
                 const PolygonRange& polygons,
                 const CGAL_BGL_NP_CLASS& np)
{
  typedef typename boost::range_value<PolygonRange>::type                   Poly;

  using parameters::choose_parameter;
  using parameters::get_parameter;

  typedef typename CGAL::GetPointMap<PointRange, CGAL_BGL_NP_CLASS>::type   PointMap;
  PointMap point_map = choose_parameter<PointMap>(get_parameter(np, internal_np::point_map));

  set_ascii_mode(os); // GOCAD is ASCII only

  if(!os.good())
    return false;

  os << "GOCAD TSurf 1\n"
        "HEADER {\n"
        "name:";
  os << fname << std::endl;
  os << "*border:on\n"
        "*border*bstone:on\n"
        "}\n"
        "GOCAD_ORIGINAL_COORDINATE_SYSTEM\n"
        "NAME Default\n"
        "AXIS_NAME \"X\" \"Y\" \"Z\"\n"
        "AXIS_UNIT \"m\" \"m\" \"m\"\n"
        "ZPOSITIVE Elevation\n"
        "END_ORIGINAL_COORDINATE_SYSTEM\n"
        "TFACE\n";

  for(std::size_t i=0, end=points.size(); i<end; ++i)
    os << "VRTX " << i << " " << get(point_map, points[i]) << "\n";

  for(const Poly& poly : polygons)
  {
    os << "TRGL";
    for(const auto& id : poly)
      os << " " << id;
    os<< "\n";
  }

  os << "END" << std::endl;

  return os.good();
}

} // namespace internal
} // namespace IO

template <typename PointRange,
          typename PolygonRange,
          typename CGAL_BGL_NP_TEMPLATE_PARAMETERS>
bool write_GOCAD(std::ostream& os,
                 const PointRange& points,
                 const PolygonRange& polygons,
                 const CGAL_BGL_NP_CLASS& np)
{
  return IO::internal::write_GOCAD(os, "anonymous", points, polygons, np);
}

template <typename PointRange,
          typename PolygonRange,
          typename CGAL_BGL_NP_TEMPLATE_PARAMETERS>
bool write_GOCAD(const char* fname,
                 const PointRange& points,
                 const PolygonRange& polygons,
                 const CGAL_BGL_NP_CLASS& np)
{
  std::ofstream os(fname);
  return IO::internal::write_GOCAD(os, fname, points, polygons, np);
}

/*!
  \ingroup GocadIoFuncs

 * writes the content of `points` and `polygons` in `os`, in the TS format.
 *
 * \tparam PointRange a model of the concept `RandomAccessContainer` whose value type is the point type.
 * \tparam PolygonRange a model of the concept `SequenceContainer`
 *                      whose value_type is itself a model of the concept `SequenceContainer`
 *                      whose value_type is an integer type.

 *
 * \param os the output stream
 * \param points points of the soup of polygons.
 * \param polygons a `PolygonRange`. Each element in it describes a polygon
 *        using the indices of the points in `points`.
 *
 * \return `true` if the writing was successful, `false` otherwise.
 * \see \ref IOStreamGocad
*/
template <typename PointRange, typename PolygonRange>
bool write_GOCAD(std::ostream& os, const PointRange& points, const PolygonRange& polygons)
{
  return IO::internal::write_GOCAD(os, "anonymous", points, polygons, parameters::all_default());
}

/*!
  \ingroup GocadIoFuncs

 * writes the content of `points` and `polygons` in `fname`, in the TS format.
 *
 * \tparam PointRange a model of the concept `RandomAccessContainer` whose value type is the point type.
 * \tparam PolygonRange a model of the concept `SequenceContainer`
 *                      whose value_type is itself a model of the concept `SequenceContainer`
 *                      whose value_type is an integer type.

 *
 * \param fname the path to the output file
 * \param points points of the soup of polygons.
 * \param polygons a `PolygonRange`. Each element in it describes a polygon
 *        using the indices of the points in `points`.
 *
 * \return `true` if the writing was successful, `false` otherwise.
 * \see \ref IOStreamGocad
*/
template <typename PointRange, typename PolygonRange>
bool write_GOCAD(const char* fname, const PointRange& points, const PolygonRange& polygons)
{
  return write_GOCAD(fname, points, polygons, parameters::all_default());
}

template <typename PointRange,
          typename PolygonRange,
          typename CGAL_BGL_NP_TEMPLATE_PARAMETERS>
bool write_GOCAD(const std::string& fname,
                 const PointRange& points,
                 const PolygonRange& polygons,
                 const CGAL_BGL_NP_CLASS& np)
{
  std::ofstream os(fname.c_str());
  return IO::internal::write_GOCAD(os, fname.c_str(), points, polygons, np);
}

template <typename PointRange, typename PolygonRange>
bool write_GOCAD(const std::string& fname, const PointRange& points, const PolygonRange& polygons)
{
  return write_GOCAD(fname, points, polygons, parameters::all_default());
}

} // namespace CGAL

#endif // CGAL_IO_GOCAD_H