// Copyright (c) 2005-2008 Max-Planck-Institute Saarbruecken (Germany).
// 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
// 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)     :  Peter Hachenberger <hachenberger@mpi-sb.mpg.de>

#ifndef CGAL_CD3_EDGE_SORTER_H
#define CGAL_CD3_EDGE_SORTER_H

#include <CGAL/Nef_3/SNC_decorator.h>
#include <CGAL/Nef_3/SNC_point_locator.h>
#include <CGAL/Nef_polyhedron_3.h>
#include <CGAL/Convex_decomposition_3/Insert_vertex_into_edge.h>

#undef CGAL_NEF_DEBUG
#define CGAL_NEF_DEBUG 547
#include <CGAL/Nef_2/debug.h>

namespace CGAL {

template<typename Halfedge_handle, typename Point_comparison>
class Compare_halfedges_in_reflex_edge_sorter
{
public:
	typedef Point_comparison Compare_points;
	Compare_points comp;
	Compare_halfedges_in_reflex_edge_sorter() {}
	bool operator()(Halfedge_handle e0, Halfedge_handle e1) 
	{
		return comp(e0->source()->point(), e1->source()->point());
	}
};

template<typename Point_3,
  typename FTComparison,
  typename SplitTest,
  typename VertexInserter,
  typename Container>
class Generic_edge_sorter
{
	typedef typename Container::iterator Iterator;
	typedef typename Container::value_type Edge_handle;
	typedef typename Container::key_compare EdgeComparison;
	typedef typename EdgeComparison::Compare_points PointComparison;
  
	PointComparison compare_points;
	FTComparison compare_fts;
  
public:
	Generic_edge_sorter() {}

	void operator()(Container& c, SplitTest& st, VertexInserter& vi) 
	{
//		CGAL_NEF_SETDTHREAD(547);
    
		CGAL_assertion_code(
			for(Iterator ti = c.begin(); ti != c.end(); ++ti)
				CGAL_assertion(compare_points((*ti)->source()->point(),
											  (*ti)->twin()->source()->point())));
		CGAL_NEF_TRACEN("edge_sorter " << c.size());
	
//		std::sort(c.begin(), c.end(), Sort_edges());
    
		Iterator esi1,esi2,esi3;
		for(esi1 = c.begin(); esi1 != c.end(); ++esi1)
		{
			CGAL_NEF_TRACEN("1: " << (*esi1)->source()->point() << 
							"->" << (*esi1)->twin()->source()->point());
			esi2 = esi1;
			++esi2;
			CGAL_assertion_code(
				if(esi2!=c.end())
					CGAL_NEF_TRACEN("2: " << (*esi2)->source()->point() << 
									"->" << (*esi2)->twin()->source()->point()););
			while(esi2!=c.end() &&
				  compare_fts((*esi2)->source()->point().x(),
							  (*esi1)->twin()->source()->point().x())) 
			{
				if((*esi1)->source() == (*esi2)->source()) 
				{
					++esi2;
					continue;
				}
				Point_3 ip;
				bool b = st(*esi1, *esi2, ip);
				if(b) 
				{
					CGAL_NEF_TRACEN("ip " << ip);
				
					Edge_handle e = *esi2;
					Edge_handle svf = vi(e, ip);
				
					esi3 = esi2;
					++esi3;
					while(esi3 != c.end() && 
						  compare_points((*esi3)->source()->point(),
										 svf->source()->point()))
						++esi3;
				
					c.insert(esi3, svf);
				}

				++esi2;

				CGAL_assertion_code(
					if(esi2!=c.end())
						CGAL_NEF_TRACEN("y2: " << (*esi2)->source()->point() << 
										"->" << (*esi2)->twin()->source()->point()););
			} // while
		} //while
	} // operator()

};

template<class Kernel, class PointComparison>
class Need_to_split {
  
  typedef typename Kernel::Segment_3 Segment_3;
  typedef typename Kernel::Point_3 Point_3;
  typedef typename Kernel::Plane_3 Plane_3;
  typedef typename Kernel::Vector_3 Vector_3;

  PointComparison compare_points;
 public:
  Need_to_split() {}
  
  template<typename Edge_handle>
  bool operator()(Edge_handle e1, Edge_handle e2, Point_3& ip2) const {
    Segment_3 s1(e1->source()->point(), e1->twin()->source()->point());
    Segment_3 s2(e2->source()->point(), e2->twin()->source()->point());
    return operator()(s1, s2, ip2);
  }
  
  bool operator()(Segment_3 s1, Segment_3 s2, Point_3& ip2) const {
    CGAL_NEF_TRACEN("need_to_split " << s1);
    CGAL_NEF_TRACEN("         " << s2);
    Point_3 ip1;
    Vector_3 vec1(cross_product(s2.to_vector(),Vector_3(1,0,0)));
    Plane_3 pl1(s2.source(), vec1);
    CGAL_NEF_TRACEN("pl1 " << pl1);
    CGAL_assertion(pl1.has_on(s2.source()));
    CGAL_assertion(pl1.has_on(s2.target()));
    CGAL_assertion(pl1.has_on(s2.source()+Vector_3(1,0,0)));
    Object o1 = intersection(pl1,s1);
    if(!assign(ip1,o1))
      return false;
    CGAL_NEF_TRACEN("ip1 " << ip1);
    Vector_3 vec2(cross_product(s1.to_vector(),Vector_3(1,0,0)));
    Plane_3 pl2(s1.source(), vec2);
    CGAL_NEF_TRACEN("pl2 " << pl2);
    CGAL_assertion(pl2.has_on(s1.source()));
    CGAL_assertion(pl2.has_on(s1.target()));
    CGAL_assertion(pl2.has_on(s1.source()+Vector_3(1,0,0)));
    Object o2 = intersection(pl2,s2);
    if(!assign(ip2,o2) || ip2 == s2.source() || ip2 == s2.target())
      return false;
    
    CGAL_NEF_TRACEN("ips " << ip1 << ", " << ip2);
    if(compare_points(ip2, ip1))
      return true;
    return false;
  }
};

template<typename Nef_, typename FTComparison, typename Container>
  class Edge_sorter : public CGAL::Modifier_base<typename Nef_::SNC_and_PL> {
  
  typedef Nef_                                   Nef_polyhedron;
  typedef typename Nef_polyhedron::SNC_and_PL    SNC_and_PL;
  typedef typename Nef_polyhedron::SNC_structure SNC_structure;
  typedef typename Nef_polyhedron::Items         Items;
  typedef typename Nef_polyhedron::Kernel        Kernel;
  typedef CGAL::SNC_decorator<SNC_structure>     Base;
  typedef CGAL::SNC_point_locator<Base>          SNC_point_locator;
  typedef CGAL::SNC_constructor<Items, SNC_structure>   
    SNC_constructor;

  typedef typename SNC_structure::Vertex_handle     Vertex_handle;
  typedef typename SNC_structure::Halfedge_handle   SVertex_handle;
  typedef typename SNC_structure::Halfedge_iterator SVertex_iterator;
  typedef typename SNC_structure::Halfedge_handle   Halfedge_handle;
  typedef typename SNC_structure::SHalfedge_handle  SHalfedge_handle;
  typedef typename SNC_structure::Segment_3 Segment_3;
  typedef typename SNC_structure::Point_3 Point_3;
  typedef typename SNC_structure::Plane_3 Plane_3;
  typedef typename SNC_structure::Vector_3 Vector_3;

  typedef typename Container::iterator Iterator;
  typedef typename Container::const_iterator Const_iterator;
  typedef typename Container::key_compare::Compare_points PointComparison;
  
  typedef typename CGAL::Insert_vertex_into_edge<SNC_structure, SNC_point_locator> InsertVertex;

  typedef typename CGAL::Generic_edge_sorter<
    Point_3, 
    FTComparison, 
    Need_to_split<Kernel, PointComparison>, 
    InsertVertex, 
    Container> GenericEdgeSorter;
    
  Container& c;
  SNC_structure* sncp;
  SNC_point_locator* pl;

 public:
  Edge_sorter(Container& cin) : c(cin) {}

  void operator()(SNC_and_PL& sncpl) {
    sncp = sncpl.sncp;
    pl = sncpl.pl;
    InsertVertex iv(*sncp, *pl);
    GenericEdgeSorter ges;
    Need_to_split<Kernel, PointComparison> nts;
    ges(c, nts, iv); 
  }
  
  bool check() const {
    Const_iterator ci;
    for(ci = c.begin(); ci != c.end(); ++ci) {
      if(compare_points((*ci)->twin()->source()->point(),
      			(*ci)->source()->point())) {
	CGAL_error_msg("wrong orientation");
	return false;
      }
    }
    
    for(ci = c.begin(); ci != c.end(); ++ci) {
      Const_iterator ci2(ci);
      ++ci2;
      if(ci2 == c.end()) break;
      if(compare_points((*ci2)->source()->point(),
			(*ci)->source()->point())) {
	CGAL_error_msg("wrong sorting");
	return false;
      }
    }

    for(ci = c.begin(); ci != c.end(); ++ci) {
      Const_iterator ci2(ci);
      ++ci2;
      while(ci2 != c.end() &&
	    compare_fts((*ci)->twin()->source()->point().x(),
			(*ci2)->source()->point().x())) {
	
	Point_3 ip;
	bool b = need_to_split(Segment_3((*ci)->source()->point(),
				         (*ci)->twin()->source()->point()), 
			       Segment_3((*ci2)->source()->point(),
				         (*ci2)->twin()->source()->point()),ip);	
	if(b) {
	  CGAL_error_msg("vertical dependence");
	  return false;
	}
	++ci2;
      }
    }
    
    return true;
  }
};
  
} //namespace CGAL
#endif //CGAL_CD3_EDGE_SORTER_H
