// Copyright (c) 2006,2007,2009,2010,2011 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
// 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)     : Ron Wein   <wein@post.tau.ac.il>
//                 (based on old version by Eyal Flato)
//                 Efi Fogel  <efif@post.tau.ac.il>

#ifndef CGAL_ARR_NAIVE_POINT_LOCATION_FUNCTIONS_H
#define CGAL_ARR_NAIVE_POINT_LOCATION_FUNCTIONS_H

/*! \file
 * Member-function definitions for the Arr_naive_point_location<Arrangement>
 * class.
 */

namespace CGAL {

//-----------------------------------------------------------------------------
// Locate the arrangement feature containing the given point.
//
template <class Arrangement>
typename Arr_naive_point_location<Arrangement>::Result_type
Arr_naive_point_location<Arrangement>::locate(const Point_2& p) const
{
  // Go over the arrangement vertices and check whether one of them equals
  // the query point.
  typename Traits_adaptor_2::Equal_2   equal = geom_traits->equal_2_object();
  typename Arrangement_2::Vertex_const_iterator  vit;
  Vertex_const_handle                            vh;

  for (vit = p_arr->vertices_begin(); vit != p_arr->vertices_end(); ++vit) {
    vh = vit;
    if (equal(p, vh->point()))
      return make_result(vh);
  }

  // Go over arrangement halfedges and check whether one of them contains
  // the query point in its interior.
  typename Traits_adaptor_2::Is_in_x_range_2    is_in_x_range = 
    geom_traits->is_in_x_range_2_object();
  typename Traits_adaptor_2::Compare_y_at_x_2   compare_y_at_x = 
    geom_traits->compare_y_at_x_2_object();
  typename Arrangement_2::Edge_const_iterator   eit;
  Halfedge_const_handle                         hh;

  for (eit = p_arr->edges_begin(); eit != p_arr->edges_end(); ++eit) {
    hh = eit;

    if (is_in_x_range(hh->curve(), p) && compare_y_at_x(p, hh->curve()) == EQUAL)
      return make_result(hh);
  }

  // Go over all faces an locate the innermost one that contains the query
  // point in its interior.
  typename Arrangement_2::Face_const_iterator   fit;
  Face_const_handle                             fh;
  Face_const_handle                             f_inner;
  const Face_const_handle                       invalid_f;
  
  for (fit = p_arr->faces_begin(); fit != p_arr->faces_end(); ++fit) {
    fh = fit;
  
    if (top_traits->is_in_face(&(*fh), p, NULL)) {
      // The current face contains p in its interior.
      if (f_inner == invalid_f ||
          f_inner->is_unbounded() ||
          f_inner->number_of_outer_ccbs() == 0)
      {
        // This is the first face that contains p we encounter:
        f_inner = fh;
      }
      else if (! fh->is_unbounded() && fh->number_of_outer_ccbs() > 0)
      {
        // As we have already some other containing face, one face must be
        // contained inside the other. Two check that, we select a
        // representative vertex of inner_f and check whether it is contained
        // in our current face.

        // This is a workaround for MSVC. For some reason the compiler barfs
        // when the iterator is not saved in a variable and only then the
        // source() of its value_type is accessed.
        typename Arrangement_2::Outer_ccb_const_iterator it =
          fh->outer_ccbs_begin();
        Vertex_const_handle  v = (*it)->source();

        if (top_traits->is_in_face(&(*f_inner), v->point(), NULL))
          f_inner = fh;
      }
    }
  }

  // Return the innermost face.
  CGAL_assertion(f_inner != invalid_f);
  return make_result(f_inner);
}

} //namespace CGAL

#endif
