// Copyright (c) 2000,2001  
// Utrecht University (The Netherlands),
// ETH Zurich (Switzerland),
// INRIA Sophia-Antipolis (France),
// Max-Planck-Institute Saarbruecken (Germany),
// and Tel-Aviv University (Israel).  All rights reserved. 
//
// This file is part of CGAL (www.cgal.org); you can redistribute it and/or
// modify it under the terms of the GNU Lesser General Public License as
// published by the Free Software Foundation; either version 3 of the License,
// or (at your option) any later version.
//
// 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.
//
// $URL$
// $Id$
//
// Author(s)     : Michael Seel

#ifndef CGAL_TUPLE_D_H
#define CGAL_TUPLE_D_H

#include <CGAL/basic.h>
#include <CGAL/Handle_for.h>
#include <CGAL/Quotient.h>
#include <CGAL/Kernel_d/Cartesian_const_iterator_d.h>
#include <sstream>

namespace CGAL {
#define PointCd PointCd2
#define PointHd PointHd2

template <typename NT, typename LA> class PointHd;
template <typename NT, typename LA> class VectorHd;
template <typename NT, typename LA> class DirectionHd;
template <typename NT, typename LA> class HyperplaneHd;
template <typename NT, typename LA> class Aff_transformationHd;
template <typename FT, typename LA> class PointCd;
template <typename NT, typename LA> class VectorCd;
template <typename FT, typename LA> class DirectionCd;
template <typename FT, typename LA> class HyperplaneCd;
template <typename NT, typename LA> class Aff_transformationCd;


class MatchHelper {};

template <typename NT, typename LA>
class Tuple_d  {
  typedef Tuple_d<NT,LA> Self;
  typedef typename LA::Vector Vector;
  Vector v;
public:
  typedef typename Vector::const_iterator const_iterator;

  typedef Cartesian_const_iterator_d<const_iterator> Cartesian_const_iterator;

  struct Homogeneous_const_iterator {
    typedef Homogeneous_const_iterator self;
    typedef std::random_access_iterator_tag iterator_category;
    typedef NT                              value_type;
    typedef std::ptrdiff_t                  difference_type;
    typedef const value_type*               pointer;
    typedef const value_type&               reference;

  Homogeneous_const_iterator() : _it(0), _w(0) {}
  Homogeneous_const_iterator(const_iterator it, const_iterator w = 0) 
    : _it(it), _w(w) {}
    
  value_type operator*() const 
  { if (_it == _w) return value_type(1); else return *_it; }

  self& operator++() { ++_it; return *this; }
  self  operator++(int) { self tmp = *this; ++_it; return tmp; }
  self& operator--() { --_it; return *this; }
  self  operator--(int) { self tmp = *this; --_it; return tmp; }

  self& operator+=(difference_type i) { _it+=i; return *this; }
  self& operator-=(difference_type i) { _it-=i; return *this; }
  self operator+(difference_type i) const 
  { self tmp=*this; return tmp += i; }
  self operator-(difference_type i) const 
  { self tmp=*this; return tmp -= i; }

  difference_type operator-(self x) const { return _it-x._it; }
  value_type operator[](difference_type i) const { return *(*this + i); }

  bool operator==(const self& x) const { return _it==x._it; }
  bool operator!=(const self& x) const { return ! (*this==x); }
  bool operator<(self x) const { return (x - *this) > 0; }

  private:
    const_iterator _it, _w;  
  }; // Homogeneous_const_iterator


  Tuple_d(int d) : v(d) {}
  Tuple_d(const NT& a, const NT& b) : v(2)
  { v[0]=a; v[1]=b; }
  Tuple_d(const NT& a, const NT& b, const NT& c, const MatchHelper&) : v(3)
  { v[0]=a; v[1]=b; v[2]=c; }
  Tuple_d(const NT& a, const NT& b, const NT& c, const NT& d) : v(4)
  { v[0]=a; v[1]=b; v[2]=c; v[3]=d; }

  template <typename I>
  Tuple_d(int d, I& start, I end) : v(d) 
  { int i(0); 
    while ( i < d && start != end ) v[i++] = *start++; 
  } 
  /* this constructor returns the final position of start 
     to offer access to a possible common denominator as
     part of the tuple range */

  template <typename I>
  Tuple_d(int d, I start, I end, NT D) : v(d) 
  { int i(0); 
    while ( i < d && start != end ) v[i++] = *start++; 
    v[d-1] = D; 
  }

  int size() const { return v.dimension(); }
  const_iterator begin() const { return v.begin(); }
  const_iterator last() const { return v.end()-1; }
  const_iterator end() const { return v.end(); }
  const_iterator beyondend() const { return v.end()+1; }


  void invert()
  { for (int i=0; i<size(); ++i) v[i]=-v[i]; }
  void invert(int d)
  { for (int i=0; i<d; ++i) v[i]=-v[i]; }

  void print(std::ostream& out, const char*) const;
  void read(std::istream& in);
  void homogeneous_add(const Self* a, const Self* b)
  { int d = a->size()-1;
    if ( d < 0 ) return;
    CGAL_assertion_msg((d == b->size()-1),"dimensions disagree."); 
    CGAL_assertion_msg((d == size()-1),"dimensions disagree."); 
    NT aw = a->v[d], bw = b->v[d]; 
    for (int i = 0; i < d; ++i) { 
      v[i] = a->v[i]*bw + b->v[i]*aw; 
    }
    v[d] = aw*bw; 
  }

  void homogeneous_sub(const Self* a, const Self* b)
  { int d = a->size()-1; 
    if ( d < 0 ) return;
    CGAL_assertion_msg((d == b->size()-1),"dimensions disagree."); 
    CGAL_assertion_msg((d == size()-1),"dimensions disagree."); 
    NT aw = a->v[d], bw = b->v[d]; 
    for (int i = 0; i < d; ++i) { 
      v[i] = a->v[i]*bw - b->v[i]*aw; 
    }
    v[d] = aw*bw; 
  }

  void cartesian_add(const Self* a, const Self* b)
  { v = a->v + b->v; }
  void cartesian_sub(const Self* a, const Self* b)
  { v = a->v - b->v; }

  friend class PointHd<NT,LA>;
  friend class VectorHd<NT,LA>;
  friend class DirectionHd<NT,LA>;
  friend class HyperplaneHd<NT,LA>;
  friend class PointCd<NT,LA>;
  friend class VectorCd<NT,LA>;
  friend class DirectionCd<NT,LA>;
  friend class HyperplaneCd<NT,LA>;
  
}; // Tuple_d


template <class NT, class LA> 
class Compare_homogeneously
{ 
public:
Comparison_result operator()(
  const typename LA::Vector& v1, const typename LA::Vector& v2)
{ 
  CGAL_assertion_msg((v1.dimension() == v2.dimension()),
    "Compare_homogeneously: dimensions disagree.");
  NT aw = v1[v1.dimension()-1]; 
  NT bw = v2[v2.dimension()-1]; 
  CGAL_assertion(aw>0 && bw>0);
  for (int i = 0; i < v1.dimension()-1; i++ ) { 
    NT aibw = v1[i]*bw; 
    NT biaw = v2[i]*aw; 
    Comparison_result S = (aibw<biaw ? SMALLER : 
                          (biaw<aibw ? LARGER : EQUAL));
    if (S != EQUAL) return S;
  }
  return EQUAL; 
}
}; // Compare_homogeneously

template <class NT, class LA> 
class Compare_componentwise
{ public:
Comparison_result operator()(
  const typename LA::Vector& v1, const typename LA::Vector& v2)
{ 
  CGAL_assertion_msg((v1.dimension() == v2.dimension()),
  "Compare_coefficientwise: dimensions disagree.");
  for (int i = 0; i < v1.dimension(); i++ ) { 
    Comparison_result S = (v1[i]<v2[i] ? SMALLER : 
                          (v2[i]<v1[i] ? LARGER : EQUAL));
    if (S != EQUAL) return S;
  }
  return EQUAL;
}
}; // Compare_coefficientwise


template <typename NT, typename LA>
void Tuple_d<NT,LA>::print(std::ostream& os, const char* l) const
{ int i;
  switch( get_mode(os) ) {
    case CGAL::IO::ASCII :
      os << size() << " ";
      for (i = 0; i < size(); ++i) 
        os << v[i] << " ";
      break;
    case CGAL::IO::BINARY :
      CGAL::write(os, size()); 
      for (i = 0; i < size(); ++i) 
        CGAL::write(os, v[i]);
      break;
    default :
      os << l << "(" << size() << ", ";
      for (i = 0; i < size(); ++i) {
        os << v[i]; if (i!=size()-1) os<<", "; else os<<")";
      }
  }
}


template <typename NT, typename LA>
void Tuple_d<NT,LA>::read(std::istream& is)
{ int i = 0, d;
  switch( get_mode(is) ) {
    case CGAL::IO::ASCII :
      is >> d; v = Vector(d);
      while (i < d && is >> v[i] ) ++i; 
      break;
    case CGAL::IO::BINARY :
      CGAL::read(is, d); v = Vector(d);
      while (i < d) { CGAL::read(is, v[i]); ++i; } break;
    default:
    CGAL_error_msg("\nStream must be in ascii or binary mode\n"); 
  }
}

template <class ForwardIterator>
void tuple_dim_check(ForwardIterator first, ForwardIterator last, 
                     const char* file, int line, const char* op)
{ if (first==last) return;
  int d = first->dimension(); ++first;
  for (; first!=last; ++first) 
    if (first->dimension() != d) {
      std::ostringstream os;
      os << "Tuple Dimension Error " << 
            "File " << file << "Line " << line << "Operation " << op << '\0';
      CGAL_error_msg(os.str().c_str()); 
    }
}

#define TUPLE_DIM_CHECK(i1,i2,op) tuple_dim_check(i1,i2,__FILE__,__LINE__,#op)

template <class InputIterator, class OutputIterator>
int copy_and_count(InputIterator first, InputIterator last,
                   OutputIterator result) 
{ int n=0;
  while (first != last) { ++n; *result++ = *first++; }
  return n;
}

#undef PointCd
#undef PointHd
} //namespace CGAL
#endif //CGAL_TUPLE_D_H
