// Copyright (c) 1997-2002  Max-Planck-Institute Saarbruecken (Germany).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org).
//
// $URL: https://github.com/CGAL/cgal/blob/v6.0.1/Nef_3/include/CGAL/Nef_3/SNC_indexed_items.h $
// $Id: include/CGAL/Nef_3/SNC_indexed_items.h 50cfbde3b84 $
// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-Commercial
//
//
// Author(s)     :     Peter Hachenberger  <hachenberger@mpi-sb.mpg.de>

#ifndef CGAL_NEF_SNC_INDEXED_ITEMS_H
#define CGAL_NEF_SNC_INDEXED_ITEMS_H

#include <CGAL/license/Nef_3.h>

#include <CGAL/Nef_3/Vertex.h>
#include <CGAL/Nef_3/Halfedge.h>
#include <CGAL/Nef_3/Halffacet.h>
#include <CGAL/Nef_3/Volume.h>
#include <CGAL/Nef_3/SHalfedge.h>
#include <CGAL/Nef_3/SHalfloop.h>
#include <CGAL/Nef_3/SFace.h>

#include <atomic>

#undef CGAL_NEF_DEBUG
#define CGAL_NEF_DEBUG 83
#include <CGAL/Nef_2/debug.h>

namespace CGAL {

class Index_generator {

 public:
  static int get_unique_index()
  {
    // initialized with 0
    // https://en.cppreference.com/w/cpp/language/zero_initialization
#ifdef CGAL_NO_ATOMIC
    static int unique;
#else
    static std::atomic<int> unique;
#endif
    return unique++;
  }
};

class SNC_indexed_items {
 public:
  template <class Refs> class Vertex :    public Vertex_base<Refs> {};
  template <class Refs> class Volume :    public Volume_base<Refs> {};
  template <class Refs> class SFace :     public SFace_base<Refs> {};

  template <class Refs> class Halffacet : public Halffacet_base<Refs> {
    typedef Halffacet_base<Refs>    Base;
    typedef typename Refs::SHalfedge_around_facet_const_circulator
      SHalfedge_around_facet_const_circulator;
    typedef typename Refs::SHalfedge_const_handle
      SHalfedge_const_handle;
    typedef typename Refs::SHalfloop_const_handle
      SHalfloop_const_handle;
    typedef typename Refs::Halffacet_cycle_const_iterator
      Halffacet_cycle_const_iterator;
    typedef typename Refs::Plane_3  Plane_3;
    typedef typename Refs::Mark     Mark;

  public:
    Halffacet() : Base() {}
    Halffacet(const Plane_3& h, Mark m) : Base(h, m) {}

    bool is_valid( bool verb = false, int level = 0) const {
      bool valid = Base::is_valid(verb, level);

      Halffacet_cycle_const_iterator
        fci(this->facet_cycles_begin());
      if(!fci.is_shalfedge()) return false;
      SHalfedge_const_handle set(fci);
      int index = set->get_index();
      for(; fci != this->facet_cycles_end(); ++fci) {
        if(fci.is_shalfedge()) {
          SHalfedge_const_handle se(fci);
          SHalfedge_around_facet_const_circulator
            sfc(se), send(sfc);
          do {
            valid = valid && sfc->get_index() == index;
            ++sfc;
          } while(sfc != send);
        } else if(fci.is_shalfloop()) {
          SHalfloop_const_handle sl(fci);
          valid = valid && sl->get_index() == index;
        } else
          return false;
      }
      return valid;
    }
  };

  template <class Refs> class SHalfloop : public SHalfloop_base<Refs> {
    typedef SHalfloop_base<Refs>                    Base;
    typedef typename Refs::Halffacet_const_handle Halffacet_const_handle;
    int index;
    Halffacet_const_handle ifacet;
    bool init_ifacet;
  public:
    SHalfloop() : Base(), index(0), init_ifacet(false) {}
    SHalfloop(const SHalfloop<Refs>& sl)
      : Base(sl), index(0),
      ifacet(sl.ifacet), init_ifacet(sl.init_ifacet) {}
    SHalfloop<Refs>& operator=(const SHalfloop<Refs>& sl) {
      (Base&) *this = (Base) sl;
      index = sl.index;
      ifacet = sl.ifacet;
      init_ifacet = sl.init_ifacet;
      return *this;
    }
    int new_index()
    { index = Index_generator::get_unique_index(); return index; }
    void set_index(int idx)
    { index = idx; }
    int get_index() const { return index; }
    Halffacet_const_handle get_index_facet() const {
      if(init_ifacet)
        return ifacet;
      return this->facet();
    }
    void set_index_facet(Halffacet_const_handle f) {
      ifacet = f;
      init_ifacet = true;
    }
  };

  template <class Refs> class SHalfedge : public SHalfedge_base<Refs> {
    typedef SHalfedge_base<Refs>                    Base;
    typedef typename Refs::Halffacet_const_handle Halffacet_const_handle;
    int index;
    int index2;
    Halffacet_const_handle ifacet;
    bool init_ifacet;
  public:
    SHalfedge() : Base(), index(0), index2(0), init_ifacet(false) {}
    SHalfedge(const SHalfedge<Refs>& se)
      : Base(se), index(se.index), index2(se.index2),
      ifacet(se.ifacet), init_ifacet(se.init_ifacet) {}
    SHalfedge<Refs>& operator=(const SHalfedge<Refs>& se) {
      (Base&) *this = (Base) se;
      index = se.index;
      index2 = se.index2;
      ifacet = se.ifacet;
      init_ifacet = se.init_ifacet;
      return *this;
    }
    int new_index()
    { index = index2 = Index_generator::get_unique_index(); return index; }
    void set_index(int idx)
    { index = index2 = idx; }
    int get_index() const {
      return index;
    }
    void set_forward_index(int idx)  { index  = idx;}
    void set_backward_index(int idx) { index2 = idx;}
    int get_forward_index() { return index;  }
    int get_backward_index() { return index2; }
    int get_smaller_index() { return index < index2 ? index : index2; }
    Halffacet_const_handle get_index_facet() const {
      if(init_ifacet)
        return ifacet;
      return this->facet();
    }
    void set_index_facet(Halffacet_const_handle f) {
      ifacet = f;
      init_ifacet = true;
    }
  };

  template <class Refs> class SVertex :   public Halfedge_base<Refs> {
    typedef Halfedge_base<Refs>          Base;
    typedef typename Refs::Mark          Mark;
    int index;
  public:
    SVertex() : Base(), index(0) {}
    SVertex(Mark m) : Base(m), index(0) {}
    SVertex(const SVertex<Refs>& sv) : Base(sv) { index = sv.index; }
    SVertex<Refs>& operator=(const SVertex<Refs>& sv) {
      (Base&) *this = (Base) sv;
      index = sv.index;
      return *this;
    }
    int new_index()
    { index = Index_generator::get_unique_index(); return index; }
    void set_index(int idx)
    { index = idx; }
    int get_index() const { return index; }
  };
};

} //namespace CGAL
#endif // CGAL_NEF_SNC_INDEXED_ITEMS_H

