// Copyright (c) 2003-2008  INRIA Sophia-Antipolis (France).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org).
//
// $URL: https://github.com/CGAL/cgal/blob/v6.2/Circular_kernel_2/include/CGAL/IO/Dxf_reader_doubles.h $
// $Id: include/CGAL/IO/Dxf_reader_doubles.h cac3e9d75e2 $
// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-Commercial
//
// Author(s)     : Monique Teillaud, Sylvain Pion, Andreas Fabri

// Partially supported by the IST Programme of the EU as a Shared-cost
// RTD (FET Open) Project under Contract No  IST-2000-26473
// (ECG - Effective Computational Geometry for Curves and Surfaces)
// and a STREP (FET Open) Project under Contract No  IST-006413
// (ACS -- Algorithms for Complex Shapes)

// Descriptions of the file format can be found at
// https://images.autodesk.com/adsk/files/autocad_2012_pdf_dxf-reference_enu.pdf

#ifndef CGAL_IO_DXF_READER_DOUBLES_H
#define CGAL_IO_DXF_READER_DOUBLES_H

#include <CGAL/license/Circular_kernel_2.h>


#include <CGAL/basic.h>
#include <iostream>
#include <string>
#include <list>
#include <map>
#include <CGAL/array.h>

namespace CGAL {


class Dxf_reader_doubles {

public:
  typedef double       FT;
  typedef std::array<double, 3>  Triplet;
  typedef Triplet Point_2_and_bulge;
  typedef Triplet Circle_2;


  typedef std::list<Triplet > Polygon;
  typedef std::list<Polygon> Polygons;
  typedef std::list<Circle_2> Circles;

private:


  void
  header(std::istream& is)
  {
    int n;
    double xmin, ymin;
    double xmax, ymax;
    is >> n;
    CGAL_assertion(n == 9);
    char c;
    is >> c;
    CGAL_assertion(c == '$');
    std::string str;
    is >> str;
    if(str == std::string("EXTMIN")){
      is >> n;
      CGAL_assertion(n == 10);
    is >> xmin;
    is >> n;
    CGAL_assertion(n == 20);
    is >> ymin;
    }
    is >> n;
    CGAL_assertion(n == 9);
    is >> c;
    CGAL_assertion(c == '$');
    is >> str;
    if(str == "EXTMAX"){
      is >> n;
      CGAL_assertion(n == 10);
      is >> xmax;
      is >> n;
      CGAL_assertion(n == 20);
      is >> ymax;
    }
  }


  void
  skip_header(std::istream& is)
  {
    int n;
    is >> n;
    CGAL_assertion(n == 0);
    std::string str;
    is >> str;
    CGAL_assertion(str == "SECTION");
    is >> n;
    CGAL_assertion(n == 2);
    is >> str;
    if(str == "HEADER"){
      header(is);
    }
    is >> n;
    CGAL_assertion(n == 0);
    is >> str;
    CGAL_assertion(str == "ENDSEC");
  }



  void
  read_circle(std::istream& is, Circle_2& circ)
  {
    int n;
    double cx, cy, r;
    std::string str;
    is >> n;
    CGAL_assertion(n == 8);
    is >> n;
    CGAL_assertion(n == 0);

  is >> n;
  CGAL_assertion(n == 10);
  is >> IO::iformat(cx);
  is >> n;
  CGAL_assertion(n == 20);
  is >> IO::iformat(cy);
  is >> n;
  CGAL_assertion(n == 40);
  is >> IO::iformat(r);
  FT sqr_ft(r*r);
  circ = CGAL::make_array(cx,cy,sqr_ft);
}


void
read_polygon(std::istream& is, Polygon& poly)
{
  int n;
  double x, y, len;
  std::string str;

  do {
    is >> n;
    if(n != 0){
      int m;
      is >> m;
    }
  } while(n != 0);

  do {
    is >> str;
    if(str == "VERTEX"){
      is >> n;
      CGAL_assertion(n == 8);
      is >> n;
      CGAL_assertion(n == 0);
      is >> n;
      CGAL_assertion(n == 10);
      is >> IO::iformat(x);
      is >> n;
      CGAL_assertion(n == 20);
      is >> IO::iformat(y);
      is >> n;
      len = 0;
      if(n == 42){
        is >> len;
      } else {
        CGAL_assertion(n == 0);
      }
      poly.push_back(CGAL::make_array(x,y, len));
    }

  } while (str != "SEQEND");
  is >> n;
  CGAL_assertion(n == 8);
  is >> n;
  CGAL_assertion(n == 0);


}


void
read_entities(std::istream& is, Polygons& polys, Circles& circles)
{
  int n;
  std::string str;
  is >> n;
  CGAL_assertion(n == 0);
  is >> str;
  CGAL_assertion(str == "SECTION");
  is >> n;
  is >> str;
  CGAL_assertion(str == "ENTITIES");
  do {
    is >> n;
    CGAL_assertion(n == 0);
    is >> str;
    if(str == "POLYLINE"){
      Polygon p;
      polys.push_back(p);
      read_polygon(is, polys.back());
    } else if(str == "CIRCLE"){
      Circle_2 c;
      read_circle(is,c);
      circles.push_back(c);
    } else if(str == "ENDSEC"){

    } else {
      CGAL_error_msg( "unknown entity" );
    }
  } while(str != "ENDSEC");
  is >> n;
  CGAL_assertion(n == 0);
  is >> str;
  CGAL_assertion(str == "EOF");
}



public:

void operator()(std::istream& is, Polygons& polygons, Circles& circles)
{
  skip_header(is);
  read_entities(is, polygons, circles);
}

};

} //namespace CGAL

#endif // CGAL_IO_DXF_READER_DOUBLES_H
