//! \file examples/Arrangement_2/ex_edge_manipulation.cpp
// Using the edge-manipulation functions.

#include <CGAL/basic.h>

#ifdef CGAL_USE_GMP
  #include <CGAL/Gmpz.h>
  typedef CGAL::Gmpz                                    Number_type;
#else
  #include <CGAL/MP_Float.h>
  typedef CGAL::MP_Float                                Number_type;
#endif

#include <CGAL/Cartesian.h>
#include <CGAL/Arr_segment_traits_2.h>
#include <CGAL/Arrangement_2.h>

#include "arr_print.h"

typedef CGAL::Cartesian<Number_type>                  Kernel;
typedef CGAL::Arr_segment_traits_2<Kernel>            Traits_2;
typedef Traits_2::Point_2                             Point_2;
typedef Traits_2::X_monotone_curve_2                  Segment_2;
typedef CGAL::Arrangement_2<Traits_2>                 Arrangement_2;
typedef Arrangement_2::Vertex_handle                  Vertex_handle;
typedef Arrangement_2::Halfedge_handle                Halfedge_handle;

int main ()
{
  // Step (a) - construct a triangular face.
  Arrangement_2   arr;

  Segment_2       s1 (Point_2 (667, 1000), Point_2 (4000, 5000));
  Segment_2       s2 (Point_2 (4000, 0), Point_2 (4000, 5000));
  Segment_2       s3 (Point_2 (667, 1000), Point_2 (4000, 0));

  Halfedge_handle e1 = arr.insert_in_face_interior (s1, arr.unbounded_face());
  Vertex_handle   v1 = e1->source();
  Vertex_handle   v2 = e1->target();
  Halfedge_handle e2 = arr.insert_from_right_vertex (s2, v2);
  Vertex_handle   v3 = e2->target();
  Halfedge_handle e3 = arr.insert_at_vertices (s3, v3, v1);

  // Step (b) - create additional two faces inside the triangle.
  Point_2         p1 (4000, 3666), p2 (4000, 1000);
  Segment_2       s4 (Point_2 (4000, 5000), p1);
  Segment_2       s5 (p1, p2);
  Segment_2       s6 (Point_2 (4000, 0), p2);

  Halfedge_handle e4 = arr.split_edge (e2, s4,
                                       Segment_2 (Point_2 (4000, 0), p1));
  Vertex_handle   w1 = e4->target();
  Halfedge_handle e5 = arr.split_edge (e4->next(), s5, s6);
  Vertex_handle   w2 = e5->target();
  Halfedge_handle e6 = e5->next();

  Segment_2       s7 (p1, Point_2 (3000, 2666));
  Segment_2       s8 (p2, Point_2 (3000, 1333));
  Segment_2       s9 (Point_2 (3000, 2666), Point_2 (2000, 1666));
  Segment_2       s10 (Point_2 (3000, 1333), Point_2 (2000, 1666));
  Segment_2       s11 (Point_2 (3000, 1333), Point_2 (3000, 2666));

  Halfedge_handle e7 = arr.insert_from_right_vertex (s7, w1);
  Vertex_handle   v4 = e7->target();
  Halfedge_handle e8 = arr.insert_from_right_vertex (s8, w2);
  Vertex_handle   v5 = e8->target();
  Vertex_handle   v6 = arr.insert_in_face_interior (Point_2 (2000, 1666),
                                                    e8->face());

  arr.insert_at_vertices (s9, v4, v6);
  arr.insert_at_vertices (s10, v5, v6);
  arr.insert_at_vertices (s11, v4, v5);

  // Step (c) - remove and merge faces to form a single hole in the traingle.
  arr.remove_edge (e7);
  arr.remove_edge (e8);

  e5 = arr.merge_edge (e5, e6, Segment_2 (e5->source()->point(),
                                          e6->target()->point()));
  e2 = arr.merge_edge (e4, e5, s2);

  print_arrangement (arr);
  return (0);
}