// Copyright (c) 2012, 2020 Tel-Aviv University (Israel).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org).
//
// $URL: https://github.com/CGAL/cgal/blob/v6.1/Arrangement_on_surface_2/demo/Arrangement_on_surface_2/Conic_reader.h $
// $Id: demo/Arrangement_on_surface_2/Conic_reader.h b26b07a1242 $
// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-Commercial
//
// Author(s): Alex Tsui <alextsui05@gmail.com>
//            Ahmed Essam <theartful.ae@gmail.com>

#ifndef CGAL_CONIC_READER_H
#define CGAL_CONIC_READER_H

#include <iostream>
#include <fstream>
#include <string>

template <typename Traits>
class Conic_reader {
private:
  const Traits& m_traits;

public:
  typedef typename Traits::Curve_2              Curve_2;
  typedef typename Traits::X_monotone_curve_2   X_monotone_curve_2;
  typedef typename Traits::Point_2              Point_2;

  typedef typename Traits::Rational             Rational;
  typedef typename Traits::Algebraic            Algebraic;
  typedef typename Traits::Rat_point_2          Rat_point_2;
  typedef typename Traits::Rat_segment_2        Rat_segment_2;
  typedef typename Traits::Rat_circle_2         Rat_circle_2;

  // Cnstruct from traits.
  Conic_reader(const Traits& traits) : m_traits(traits) {}

  //
  template <class OutputIterator>
  int read_data(std::ifstream& inp, OutputIterator curves_out,
                CGAL::Bbox_2& bbox)
  {

    Curve_2 cv;
    char dummy[256];

    if (!inp.is_open()) {
      std::cerr << "Input stream is not open!" << std::endl;
      return -1;
    }
    int count;
    inp >> count;
    inp.getline(dummy, sizeof(dummy));
    for (int i = 0; i < count; i++) {
      if (read_curve(inp, cv)) {
        ++curves_out = cv;
        CGAL::Bbox_2 curve_bbox = m_traits.construct_bbox_2_object()(cv);
        if (i == 0) bbox = curve_bbox;
        else bbox = bbox + curve_bbox;
      }
    }
    return 0;
  }

  /*! */
  bool read_curve(std::ifstream& is, Curve_2& cv) {
    auto ctr_cv = m_traits.construct_curve_2_object();

    // Read a line from the input file.
    char one_line[128];

    skip_comments (is, one_line);
    std::istringstream str_line (one_line);

    // Read the arc type and act accordingly.
    char type;

    str_line >> type;

    if (type == 's' || type == 'S') {
      // Construct a line segment. The line should have the format:
      //   s <x1> <y1> <x2> <y2>
      // where (x1, y1), (x2, y2) are the endpoints of a segment.
      Rational x1, y1, x2, y2;
      std::string buf;

      //str_line >> x1 >> y1 >> x2 >> y2;
      str_line >> buf;
      x1 = Algebraic( buf ).BigRatValue();
      str_line >> buf;
      y1 = Algebraic( buf ).BigRatValue();
      str_line >> buf;
      x2 = Algebraic( buf ).BigRatValue();
      str_line >> buf;
      y2 = Algebraic( buf ).BigRatValue();

      Rat_point_2 p1(x1, y1), p2(x2, y2);
      Rat_segment_2 seg(p1, p2);

      cv = ctr_cv(seg);
    }
    else if (type == 'c' || type == 'C') {
      // Construct a full circle. The line should have the format:
      //   c <x0> <y0> <R_sq>
      // where (x0, y0) is the center of the circle and R_sq is its squared
      // radius.
      Rational x0, y0, R_sq;

      str_line >> x0 >> y0 >> R_sq;

      Rat_point_2 p0(x0, y0);
      Rat_circle_2 circ(p0, R_sq);

      cv = ctr_cv(circ);
    }
    else if (type == 't' || type == 'T') {
      // Construct a circular arc. The line should have the format:
      //   t <x1> <y1> <x2> <y2> <x3> <y3>
      // where (x1, y1), (x2, y2) and (x3, y3) define the arc.
      Rational x1, y1, x2, y2, x3, y3;

      str_line >> x1 >> y1 >> x2 >> y2 >> x3 >> y3;

      Rat_point_2 p1(x1, y1), p2(x2, y2), p3(x3, y3);

      cv = ctr_cv(p1, p2, p3);
    }
    else if (type == 'f' || type == 'F') {
      // Construct a full conic curve. The line should have the format:
      //   c <r> <s> <t> <u> <v> <w>
      // where r, s, t, u, v, w define the conic equation.
      Rational    r, s, t, u, v, w;

      str_line >> r >> s >> t >> u >> v >> w;

      cv = ctr_cv(r, s, t, u, v, w);
    }
    else if (type == 'a' || type == 'A') {
      // Construct a conic arc. The line should have the format:
      //   c <r> <s> <t> <u> <v> <w> <orient> <x1> <y1> <x2> <y2>
      // where r, s, t, u, v, w define the conic equation, while (x1, y1)
      // and (x2, y2) are the arc's endpoints.
      Rational    r, s, t, u, v, w;

      str_line >> r >> s >> t >> u >> v >> w;

      // Read the orientation.
      int i_orient;
      CGAL::Orientation orient;

      str_line >> i_orient;
      if (i_orient > 0) orient = CGAL::COUNTERCLOCKWISE;
      else if (i_orient < 0) orient = CGAL::CLOCKWISE;
      else orient = CGAL::COLLINEAR;

      // Read the end points of the arc and create it.
      // Notice we read the coordinates as strings, then we convert them to
      // the Algebraic type, as we do not want to initialize Algebraic from
      // a double.
      char    num[50];
      Algebraic    x1, y1, x2, y2;

      str_line >> num;
      x1 = Algebraic(num);
      str_line >> num;
      y1 = Algebraic(num);

      str_line >> num;
      x2 = Algebraic(num);
      str_line >> num;
      y2 = Algebraic(num);

      Point_2 ps (x1, y1);
      Point_2 pt (x2, y2);

      cv = ctr_cv(r, s, t, u, v, w, orient, ps ,pt);
    }
    else if (type == 'q' || type == 'Q') {
      // Construct a circular arc. The line should have the format:
      //   t <x1> <y1> <x2> <y2> <x3> <y3> <x4> <y4> <x5> <y5>
      // where (x1, y1), (x2, y2), (x3, y3), (x4, y4) and (x5, y5) define the
      // arc.
      Rational    x1, y1, x2, y2, x3, y3, x4, y4, x5, y5;

      str_line >> x1 >> y1 >> x2 >> y2 >> x3 >> y3 >> x4 >> y4 >> x5 >> y5;

      Rat_point_2   p1(x1, y1), p2(x2, y2), p3(x3, y3), p4(x4, y4), p5(x5, y5);

      cv = ctr_cv(p1, p2, p3, p4, p5);
    }
    else if(type == 'e' || type == 'E') {
      // Construct a full ellipse. The line should have the format:
      // e <r1_1> <r2_1>  <x0_1> <y0_1>      // raddi and center of ellipse

      int x0, y0, r1, r2;
      Rational sqr_r1, sqr_r2;
      Rational R, S, T, U, V, W;

      str_line >> r1 >> r2 >> x0 >> y0;

      sqr_r1 = Rational (r1*r1);
      sqr_r2 = Rational (r2*r2);
      R = sqr_r2;
      S = sqr_r1;
      T = 0;
      U = -2 * sqr_r2 * x0;
      V = -2 * sqr_r1 * y0;
      W = sqr_r2*x0*x0 + sqr_r1*y0*y0 - sqr_r1*sqr_r2;

      cv = ctr_cv(R, S, T, U, V, W);
    }
    else {
      std::cerr << "Illegal conic type specification: " << type << "."
                << std::endl;
      return false;
    }

    return true;
  }

  /*! */
  void skip_comments(std::ifstream& is, char* one_line) {
    while (!is.eof()) {
      is.getline(one_line, 128);
      if (one_line[0] != '#') break;
    }
  }

  // should probably change class name since it reads and writes
  template <typename InputIterator>
  int write_data(std::ofstream& ofs, InputIterator begin_, InputIterator end_) {
    ofs << std::distance(begin_, end_) << std::endl;
    for (auto it = begin_; it != end_; ++it) {
      if (it->is_full_conic()) {
        ofs << "F ";
        ofs << it->r() << " ";
        ofs << it->s() << " ";
        ofs << it->t() << " ";
        ofs << it->u() << " ";
        ofs << it->v() << " ";
        ofs << it->w() << " ";
        ofs << std::endl;
      }
      else if (it->orientation() == CGAL::COLLINEAR) {
        ofs << "S ";
        ofs << it->source() << " ";
        ofs << it->target() << " ";
        ofs << std::endl;
      }
      else {
        ofs << "A ";
        ofs << it->r() << " ";
        ofs << it->s() << " ";
        ofs << it->t() << " ";
        ofs << it->u() << " ";
        ofs << it->v() << " ";
        ofs << it->w() << " ";
        if (it->orientation() == CGAL::COUNTERCLOCKWISE) ofs << "1 ";
        else if (it->orientation() == CGAL::CLOCKWISE) ofs << "-1 ";
        else ofs << "0 ";
        ofs << it->source() << " ";
        ofs << it->target() << " ";
        ofs << std::endl;
      }
    }
    return 0;
  }
};

#endif
