// Copyright (c) 1999-2009   INRIA Sophia-Antipolis (France).
// All rights reserved.
//
// This file is part of CGAL (www.cgal.org); you may redistribute it under
// the terms of the Q Public License version 1.0.
// See the file LICENSE.QPL distributed with CGAL.
//
// Licensees holding a valid commercial license may use this file in
// accordance with the commercial license agreement provided with the software.
//
// This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
// WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
//
// $URL: svn+ssh://scm.gforge.inria.fr/svn/cgal/branches/CGAL-3.5-branch/Periodic_3_triangulation_3/include/CGAL/Periodic_3_triangulation_ds_cell_base_3.h $
// $Id: Periodic_3_triangulation_ds_cell_base_3.h 50088 2009-06-26 08:25:50Z mcaroli $
// 
//
// Author(s)     : Monique Teillaud <Monique.Teillaud@sophia.inria.fr>
//                 Sylvain Pion <Sylvain.Pion@sophia.inria.fr>
//                 Nico Kruithof <Nico.Kruithof@sophia.inria.fr>
//                 Manuel Caroli <Manuel.Caroli@sophia.inria.fr>

// cell of a triangulation of any dimension <=3

#ifndef CGAL_PERIODIC_3_TRIANGULATION_DS_CELL_BASE_3_H
#define CGAL_PERIODIC_3_TRIANGULATION_DS_CELL_BASE_3_H

#include <CGAL/basic.h>
#include <CGAL/triangulation_assertions.h>
#include <CGAL/Dummy_tds_3.h>


#define _off0() (off&7)
#define _off1() ((off>>3)&7)
#define _off2() ((off>>6)&7)
#define _off3() ((off>>9)&7)

#define set_off0(i) off = ((off&4088) | (i));
#define set_off1(i) off = ((off&4039) | ((i)<<3));
#define set_off2(i) off = ((off&3647) | ((i)<<6));
#define set_off3(i) off = ((off&511 ) | ((i)<<9));


CGAL_BEGIN_NAMESPACE

template < typename TDS = void >
class Periodic_3_triangulation_ds_cell_base_3
{
public:
  typedef TDS                          Triangulation_data_structure;
  typedef typename TDS::Vertex_handle  Vertex_handle;
  typedef typename TDS::Cell_handle    Cell_handle;
  typedef typename TDS::Vertex         Vertex;
  typedef typename TDS::Cell           Cell;

  template <typename TDS2>
  struct Rebind_TDS {
    typedef Periodic_3_triangulation_ds_cell_base_3<TDS2> Other;
  };

  Periodic_3_triangulation_ds_cell_base_3() : _in_conflict_flag(0),
      _additional_flag(0), off(0) {
    set_vertices();
    set_neighbors();
  }

  Periodic_3_triangulation_ds_cell_base_3(
      const Vertex_handle& v0, const Vertex_handle& v1,
      const Vertex_handle& v2, const Vertex_handle& v3) :
      _in_conflict_flag(0), _additional_flag(0), off(0) {
    set_vertices(v0, v1, v2, v3);
    set_neighbors();
  }

  Periodic_3_triangulation_ds_cell_base_3(
      const Vertex_handle& v0, const Vertex_handle& v1,
      const Vertex_handle& v2, const Vertex_handle& v3,
      const Cell_handle&   n0, const Cell_handle&   n1,
      const Cell_handle&   n2, const Cell_handle&   n3) :
      _in_conflict_flag(0), _additional_flag(0), off(0) {
    set_vertices(v0, v1, v2, v3);
    set_neighbors(n0, n1, n2, n3);
  }

  // ACCESS FUNCTIONS

  const Vertex_handle& vertex(int i) const
  {
    CGAL_triangulation_precondition( i >= 0 && i <= 3 );
    return V[i];
  }

  bool has_vertex(const Vertex_handle& v) const
  {
    return (V[0] == v) || (V[1] == v) || (V[2]== v) || (V[3]== v);
  }

  bool has_vertex(const Vertex_handle& v, int & i) const
    {
      if (v == V[0]) { i = 0; return true; }
      if (v == V[1]) { i = 1; return true; }
      if (v == V[2]) { i = 2; return true; }
      if (v == V[3]) { i = 3; return true; }
      return false;
    }

//   bool has_vertex(const Vertex_handle& v, const unsigned &offset, int & i) const
//     {
//       if ((v == V[0]) && (offset == _off0())) { i = 0; return true; }
//       if ((v == V[1]) && (offset == _off1())) { i = 1; return true; }
//       if ((v == V[2]) && (offset == _off2())) { i = 2; return true; }
//       if ((v == V[3]) && (offset == _off3())) { i = 3; return true; }
//       return false;
//     }

  int index(const Vertex_handle& v) const
  {
    if (v == V[0]) { return 0; }
    if (v == V[1]) { return 1; }
    if (v == V[2]) { return 2; }
    CGAL_triangulation_assertion( v == V[3] );
    return 3;
  }

  const Cell_handle& neighbor(int i) const
  {
    CGAL_triangulation_precondition( i >= 0 && i <= 3);
    return N[i];
  }

  bool has_neighbor(const Cell_handle& n) const
  {
    return (N[0] == n) || (N[1] == n) || (N[2] == n) || (N[3] == n);
  }

  bool has_neighbor(const Cell_handle& n, int & i) const
  {
    if(n == N[0]){ i = 0; return true; }
    if(n == N[1]){ i = 1; return true; }
    if(n == N[2]){ i = 2; return true; }
    if(n == N[3]){ i = 3; return true; }
    return false;
  }

  int index(const Cell_handle& n) const
  {
    if (n == N[0]) return 0;
    if (n == N[1]) return 1;
    if (n == N[2]) return 2;
    CGAL_triangulation_assertion( n == N[3] );
    return 3;
  }

  int offset(int i) const
  {
    CGAL_triangulation_precondition( i >= 0 && i <= 3 );
    return ((off>>3*i)&7);
  }

  // SETTING

  void set_vertex(int i, const Vertex_handle& v)
  {
    CGAL_triangulation_precondition( i >= 0 && i <= 3);
    V[i] = v;
  }

  void set_neighbor(int i, const Cell_handle& n)
  {
    CGAL_triangulation_precondition( i >= 0 && i <= 3);
    N[i] = n;
  }

  void set_vertices()
  {
    V[0] = V[1] = V[2] = V[3] = Vertex_handle();
  }

  void set_vertices(const Vertex_handle& v0, const Vertex_handle& v1,
                    const Vertex_handle& v2, const Vertex_handle& v3)
  {
    V[0] = v0;
    V[1] = v1;
    V[2] = v2;
    V[3] = v3;
  }

  void set_neighbors()
  {
    N[0] = N[1] = N[2] = N[3] = Cell_handle();
  }

  void set_neighbors(const Cell_handle& n0, const Cell_handle& n1,
                     const Cell_handle& n2, const Cell_handle& n3)
  {
    N[0] = n0;
    N[1] = n1;
    N[2] = n2;
    N[3] = n3;
  }

  void set_offsets(int o0,int o1,int o2,int o3) {
    off = 0;
    int off0[3] = {(o0>>2)&1,(o0>>1)&1,(o0&1)};
    int off1[3] = {(o1>>2)&1,(o1>>1)&1,(o1&1)};
    int off2[3] = {(o2>>2)&1,(o2>>1)&1,(o2&1)};
    int off3[3] = {(o3>>2)&1,(o3>>1)&1,(o3&1)};
    for (int i=0; i<3; i++) {
      set_off0( (_off0()<<1) + off0[i]);
      set_off1( (_off1()<<1) + off1[i]);
      set_off2( (_off2()<<1) + off2[i]);
      set_off3( (_off3()<<1) + off3[i]);
    }
  }
 
  // CHECKING

  // the following trivial is_valid allows
  // the user of derived cell base classes
  // to add their own purpose checking

  bool is_valid(bool, int) const
  { return true; }

#ifndef CGAL_NO_DEPRECATED_CODE
  // Obsolete, kept for backward compatibility.
  // This should emit a warning.
  int mirror_index(int i) const
  {
      bool WARNING_THIS_FUNCTION_IS_OBSOLETE;
      CGAL_triangulation_precondition ( i>=0 && i<4 );
      Cell_handle ni = neighbor(i);
      if (&*ni->neighbor(0) == this) return 0;
      if (&*ni->neighbor(1) == this) return 1;
      if (&*ni->neighbor(2) == this) return 2;
      CGAL_triangulation_assertion(&*ni->neighbor(3) == this);
      return 3;
  }

  // Obsolete as above.
  Vertex_handle mirror_vertex(int i) const
  {
      bool WARNING_THIS_FUNCTION_IS_OBSOLETE;
      return neighbor(i)->vertex(mirror_index(i));
  }
#endif

  // For use by Compact_container.
  void * for_compact_container() const { return N[0].for_compact_container(); }
  void * & for_compact_container()     { return N[0].for_compact_container(); }

  // Conflict flag access functions.
  // This should become a property map or something at some point.
  void set_in_conflict_flag(unsigned char f) {
    CGAL_triangulation_assertion(f < 4);
    _in_conflict_flag = f;
  }
  unsigned char get_in_conflict_flag() const {
    return _in_conflict_flag;
  }

  // TODO: Get rid of this flag! Used in convert_to_1_cover.
  // Either use the conflict flag or a std::map.
  void set_additional_flag(unsigned char f) {
    CGAL_triangulation_assertion(f < 4);
    _additional_flag = f;
  }
  unsigned char get_additional_flag() const {
    return _additional_flag;
  }
  
private:
  Cell_handle   N[4];
  Vertex_handle V[4];
  unsigned char _in_conflict_flag:2;
  unsigned char _additional_flag:2;
  // 3 respective bits are the offset in x,y and z
  // right to left: bit[0]-bit[2]: vertex(0),
  // bit[3]-bit[5]: vertex(1), bit[6]-bit[8]: vertex(2),
  // and bit[9]-bit[12]: vertex(3)
  // Thus the underlying data type needs to have at least 12 bit,
  // which is true for uint.
  unsigned int off;
};

template < class TDS >
inline
std::istream&
operator>>(std::istream &is, Periodic_3_triangulation_ds_cell_base_3<TDS> &)
  // non combinatorial information. Default = nothing
{
  return is;
}

template < class TDS >
inline
std::ostream&
operator<<(std::ostream &os,
    const Periodic_3_triangulation_ds_cell_base_3<TDS> &)
  // non combinatorial information. Default = nothing
{
  return os;
}

// Specialization for void.
template <>
class Periodic_3_triangulation_ds_cell_base_3<void>
{
public:
  typedef Dummy_tds_3                   Triangulation_data_structure;
  typedef Triangulation_data_structure::Vertex_handle   Vertex_handle;
  typedef Triangulation_data_structure::Cell_handle     Cell_handle;
  template <typename TDS2>
  struct Rebind_TDS {
    typedef Periodic_3_triangulation_ds_cell_base_3<TDS2> Other;
  };
};

CGAL_END_NAMESPACE

#endif // CGAL_PERIODIC_3_TRIANGULATION_DS_CELL_BASE_3_H
