// Copyright (c) 1999
// 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/Point_set_2/include/CGAL/range_search_delaunay_2.h $
// $Id: include/CGAL/range_search_delaunay_2.h 50cfbde3b84 $
// SPDX-License-Identifier: GPL-3.0-or-later OR LicenseRef-Commercial
//
//
// Author(s)     : Matthias Baesken

#ifndef CGAL_RANGE_SEARCH_DELAUNAY_2_H
#define CGAL_RANGE_SEARCH_DELAUNAY_2_H

#include <CGAL/license/Point_set_2.h>


#include <CGAL/basic.h>
#include <CGAL/Unique_hash_map.h>
#include <CGAL/Delaunay_triangulation_2.h>
#include <CGAL/nearest_neighbor_delaunay_2.h>
#include <list>
#include <queue>
#include <map>
#include <stack>
#include <cmath>

namespace CGAL {

// was
// std::map<typename Dt::Vertex *,int, std::less<typename Dt::Vertex *> >

template<class Dt,class Circle,class OutputIterator,class MAP_TYPE>
void dfs(const Dt& delau,
         MAP_TYPE& mark,
         typename Dt::Vertex_handle v,
         const Circle& C,
         OutputIterator res,
         bool first_vertex)
{
    typedef typename Dt::Geom_traits               Gt;
    typedef typename Dt::Vertex_circulator         Vertex_circulator;
    typedef typename Dt::Vertex_handle             Vertex_handle;
    typedef typename Gt::Bounded_side_2            Bounded_side_2;

    Bounded_side_2  test;

    if (! first_vertex) *res = v;

    //mark_vertex v
    mark[v] = true;

    // get incident vertices of v ...
    Vertex_circulator vc = delau.incident_vertices(v);
    Vertex_circulator start =vc;

    Vertex_handle act;

    // go through the vertices ...
    do {
       act = vc;

       if (! delau.is_infinite(act)) {
         // test, if act is marked ...
         bool is_marked = mark[act];

         if ((! is_marked) && !( test(C,act->point()) == ON_UNBOUNDED_SIDE) )
           dfs(delau, mark, act, C, res, false);
       }
       vc++;
    } while (vc != start);
}


// second dfs uses test - predicate function object ...

template<class Dt,class Circle,class OutputIterator,class MAP_TYPE,class Pred>
bool dfs(const Dt& delau,
         MAP_TYPE& mark,
         typename Dt::Vertex_handle v,
         const Circle& C,
         OutputIterator res,
         bool first_vertex,
         bool return_if_predicate_succeded,
         Pred& pred)
{
    typedef typename Dt::Geom_traits               Gt;
    typedef typename Dt::Vertex_circulator         Vertex_circulator;
    typedef typename Dt::Vertex_handle             Vertex_handle;
    typedef typename Gt::Bounded_side_2            Bounded_side_2;

    Bounded_side_2  test;

    if (! first_vertex) {
      if (pred(v->point())) {
         *res = v;

         if (return_if_predicate_succeded) return true;
      }
    }

    //mark_vertex v
    mark[v] = true;

    // get incident vertices of v ...
    Vertex_circulator vc = delau.incident_vertices(v);
    Vertex_circulator start =vc;

    Vertex_handle act;

    // go through the vertices ...
    do {
       act = vc;

       if (! delau.is_infinite(act)) {
         // test, if act is marked ...
         bool is_marked = mark[act];

         if ((! is_marked) && !( test(C,act->point()) == ON_UNBOUNDED_SIDE) )
           if (dfs(delau, mark, act, C, res, false, return_if_predicate_succeded, pred)) return true;
       }
       vc++;
    } while (vc != start);

    return false;
}


template<class Dt,class Circle,class OutputIterator,class MAP_TYPE,class Pred>
void dfs_using_predicate(const Dt& delau,
         MAP_TYPE& mark,
         typename Dt::Vertex_handle v,
         const Circle& C,
         OutputIterator res,
         bool first_vertex,
         bool return_if_predicate_succeded,
         Pred& pred)
{
  bool val = dfs(delau, mark, v, C, res, first_vertex, return_if_predicate_succeded, pred);
  pred.set_result(val);
}

// circular range search ...


template<class Dt, class Circle, class OutputIterator>
OutputIterator range_search(Dt& delau,
                            const Circle& C,
                            OutputIterator res)
{
  typedef typename Dt::Geom_traits                    Gt;
  typedef typename Dt::Point                          Point;
  typedef typename Dt::Vertex_handle                  Vertex_handle;
  typedef typename Dt::Vertex_iterator                Vertex_iterator;
  typedef typename Gt::Bounded_side_2                 Bounded_side_2;
  typedef typename Gt::Construct_center_2             Construct_center_2;

  Bounded_side_2  test;

  if (delau.number_of_vertices() == 0) return res;
  if (delau.number_of_vertices() == 1)
  {
       // get the one vertex ...
       Vertex_iterator vit = delau.finite_vertices_begin();
       Point p = vit->point();

       if (! (test(C, p) == ON_UNBOUNDED_SIDE)){
        *res= vit; res++;
       }
       return res;
   }

   // normal case ...
   Point p = Construct_center_2()(C);
   Vertex_handle v = lookup(delau, p);
   bool new_v = false;

   // we have to insert the center ...
   if ( v == nullptr )
   {
       new_v = true;
       v = delau.insert(p);
   }

   //std::map<Vertex*,int, std::less<Vertex*> > mark;
   Unique_hash_map<Vertex_handle, bool> mark;

   dfs(delau,mark,v,C,res,new_v);

   if (new_v)
   {
     delau.remove(v);
   }

   return res;
}



// triangular range search ...
// Note that the function only works correctly with exact constructions
// because it computes the circumcenter of the points a, b, and c
// and then performs a range query with this circle.
// When vertices of the triangulation are on the circle the outcome
// is not deterministic.
// A solution would be to not construct a circle, but to use the
// function CGAL::side_of_bounded_circle

template<class Dt, class OutputIterator>
OutputIterator range_search(Dt& delau,
                            const typename Dt::Point& a,
                            const typename Dt::Point& b,
                            const typename Dt::Point& c,
                            OutputIterator res)
{
  typedef typename Dt::Geom_traits                    Gt;
  typedef typename Dt::Point                          Point;
  typedef typename Gt::Circle_2                       Circle;
  typedef typename Dt::Vertex_handle                  Vertex_handle;
  typedef typename Gt::Orientation_2                  Orientation_2;
  typedef typename Gt::Construct_circle_2             Construct_circle_2;

  Orientation_2 test_ori;

  int orient = (int)(test_ori(a,b,c));
  Circle C = Construct_circle_2()(a,b,c);
  std::list<Vertex_handle> L;
  range_search(delau, C, std::back_inserter(L));

  typename std::list<Vertex_handle>::const_iterator it = L.begin();

  for(;it != L.end();it++)
  { Point p = (*it)->point();
    if ( ((int)(test_ori(a,b,p))) == - orient ||
         ((int)(test_ori(b,c,p))) == - orient ||
         ((int)(test_ori(c,a,p))) == - orient ) { }
    else { *res = *it; res++; }
  }
  return res;
}


// rectangular range search ....

template<class Dt,class OutputIterator>
OutputIterator range_search(Dt& delau,
                            const typename Dt::Point& a1,
                            const typename Dt::Point& b1,
                            const typename Dt::Point& c1,
                            const typename Dt::Point& d1,
                            OutputIterator res)
// a1 upper left, b1 lower left , c1 lower right
{
  typedef typename Dt::Geom_traits                    Gt;
  typedef typename Dt::Point                          Point;
  typedef typename Gt::Circle_2                       Circle;
  typedef typename Dt::Vertex_handle                  Vertex_handle;
  typedef typename Gt::Orientation_2                  Orientation_2;
  typedef typename Gt::Construct_circle_2             Construct_circle_2;

  Point a=a1,b=b1,c=c1,d=d1;

  if (Orientation_2()(a,b,c) == RIGHT_TURN)
  { Point tmp = b;
    b = d;
    d = tmp;
  }

  Circle C = Construct_circle_2()(a,b,c);

  std::list<Vertex_handle> L;
  range_search(delau, C, std::back_inserter(L));
  typename std::list<Vertex_handle>::const_iterator it = L.begin();

  for(;it != L.end();it++)
  { Point p = (*it)->point();
    if ( Orientation_2()(a,b,p) == RIGHT_TURN || Orientation_2()(b,c,p) == RIGHT_TURN ||
         Orientation_2()(c,d,p) == RIGHT_TURN || Orientation_2()(d,a,p) == RIGHT_TURN )  { }
    else { *res = *it; res++; }
  }
  return res;
}


// ------------------------------------------------------------------------------------------------
// new range search variants using test function object ...

// circular range search ...


template<class Dt, class Circle, class OutputIterator,class Pred>
OutputIterator range_search(Dt& delau,
                            const Circle& C,
                            OutputIterator res,
                            Pred& pred,
                            bool return_if_succeded)
{
  typedef typename Dt::Geom_traits                    Gt;
  typedef typename Dt::Point                          Point;
  typedef typename Dt::Vertex_handle                  Vertex_handle;
  typedef typename Dt::Vertex_iterator                Vertex_iterator;
  typedef typename Gt::Bounded_side_2                 Bounded_side_2;
  typedef typename Gt::Construct_center_2             Construct_center_2;

  Bounded_side_2  test;

  if (delau.number_of_vertices() == 0) return res;
  if (delau.number_of_vertices() == 1)
  {
       // get the one vertex ...
       Vertex_iterator vit = delau.finite_vertices_begin();
       Point p = vit->point();

       if (! (test(C, p) == ON_UNBOUNDED_SIDE)){
        *res= vit; res++;
       }

       bool val = pred(p);
       pred.set_result(val);

       return res;
   }

   // normal case ...
   Point p = Construct_center_2()(C);
   Vertex_handle v = lookup(delau, p);
   bool new_v = false;

   // we have to insert the center ...
   if ( v == nullptr )
   {
       new_v = true;
       v = delau.insert(p);
   }

   //std::map<Vertex*,int, std::less<Vertex*> > mark;
   Unique_hash_map<Vertex_handle, bool> mark;

   dfs_using_predicate(delau,mark,v,C,res,new_v, return_if_succeded, pred);

   if (new_v)
   {
     delau.remove(v);
   }

   return res;
}


// triangular range search ...

template<class Dt, class OutputIterator,class Pred>
OutputIterator range_search(Dt& delau,
                            const typename Dt::Point& a,
                            const typename Dt::Point& b,
                            const typename Dt::Point& c,
                            OutputIterator res,
                            Pred& pred,
                            bool return_if_succeded)
{
  typedef typename Dt::Geom_traits                    Gt;
  typedef typename Dt::Point                          Point;
  typedef typename Gt::Circle_2                       Circle;
  typedef typename Dt::Vertex_handle                  Vertex_handle;
  typedef typename Gt::Orientation_2                  Orientation_2;
  typedef typename Gt::Construct_circle_2             Construct_circle_2;

  Orientation_2 test_ori;

  int orient = (int)(test_ori(a,b,c));
  Circle C = Construct_circle_2()(a,b,c);
  std::list<Vertex_handle> L;

  range_search(delau, C, std::back_inserter(L), pred, return_if_succeded);
  if (return_if_succeded) return res;

  typename std::list<Vertex_handle>::const_iterator it = L.begin();

  for(;it != L.end();it++)
  { Point p = (*it)->point();
    if ( ((int)(test_ori(a,b,p))) == - orient ||
         ((int)(test_ori(b,c,p))) == - orient ||
         ((int)(test_ori(c,a,p))) == - orient ) { }
    else { *res = *it; res++; }
  }
  return res;
}


// rectangular range search ....

template<class Dt,class OutputIterator,class Pred>
OutputIterator range_search(Dt& delau,
                            const typename Dt::Point& a1,
                            const typename Dt::Point& b1,
                            const typename Dt::Point& c1,
                            const typename Dt::Point& d1,
                            OutputIterator res,
                            Pred& pred,
                            bool return_if_succeded)
// a1 upper left, b1 lower left , c1 lower right
{
  typedef typename Dt::Geom_traits                    Gt;
  typedef typename Dt::Point                          Point;
  typedef typename Gt::Circle_2                       Circle;
  typedef typename Dt::Vertex_handle                  Vertex_handle;
  typedef typename Gt::Orientation_2                  Orientation_2;
  typedef typename Gt::Construct_circle_2             Construct_circle_2;

  Point a=a1,b=b1,c=c1,d=d1;

  if (Orientation_2()(a,b,c) == RIGHT_TURN)
  { Point tmp = b;
    b = d;
    d = tmp;
  }

  Circle C = Construct_circle_2()(a,b,c);

  std::list<Vertex_handle> L;

  range_search(delau, C, std::back_inserter(L), pred, return_if_succeded);
  if (return_if_succeded) return res;


  typename std::list<Vertex_handle>::const_iterator it = L.begin();

  for(;it != L.end();it++)
  { Point p = (*it)->point();
    if ( Orientation_2()(a,b,p) == RIGHT_TURN || Orientation_2()(b,c,p) == RIGHT_TURN ||
         Orientation_2()(c,d,p) == RIGHT_TURN || Orientation_2()(d,a,p) == RIGHT_TURN )  { }
    else { *res = *it; res++; }
  }
  return res;
}



} //namespace CGAL

#endif

