/*    This file is part of the Gudhi Library. The Gudhi library
 *    (Geometric Understanding in Higher Dimensions) is a generic C++
 *    library for computational topology.
 *
 *    Author(s):       David Salinas
 *
 *    Copyright (C) 2014 Inria
 *
 *    This program is free software: 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.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#ifndef SKELETON_BLOCKER_SKELETON_BLOCKER_COMPLEX_VISITOR_H_
#define SKELETON_BLOCKER_SKELETON_BLOCKER_COMPLEX_VISITOR_H_

#include <gudhi/Skeleton_blocker/Skeleton_blocker_simplex.h>

namespace Gudhi {

namespace skeleton_blocker {
// TODO(DS): to be constified

/**
 *@class Skeleton_blocker_complex_visitor
 *@brief Interface for a visitor of a simplicial complex.
 */
template<typename Vertex_handle>
class Skeleton_blocker_complex_visitor {
 public:
  virtual ~Skeleton_blocker_complex_visitor() { }

  virtual void on_add_vertex(Vertex_handle) = 0;
  virtual void on_remove_vertex(Vertex_handle) = 0;

  virtual void on_add_edge_without_blockers(Vertex_handle a, Vertex_handle b) = 0;
  virtual void on_remove_edge(Vertex_handle a, Vertex_handle b) = 0;

  /**
   * @brief Called when an edge changes, during the contraction of
   * an edge
   */
  virtual void on_changed_edge(Vertex_handle a, Vertex_handle b) = 0;

  /**
   * @brief Called when performing an edge contraction when
   * an edge bx is replaced by an edge ax (not already present).
   * Precisely, this methods is called this way in contract_edge :
   * add_edge_without_blockers(a,x)
   * on_swaped_edge(a,b,x)
   * remove_edge(b,x)
   */
  virtual void on_swaped_edge(Vertex_handle a, Vertex_handle b,
                              Vertex_handle x) = 0;
  virtual void on_add_blocker(
                              const Skeleton_blocker_simplex<Vertex_handle>&) = 0;
  virtual void on_delete_blocker(
                                 const Skeleton_blocker_simplex<Vertex_handle>*) = 0;
};

/**
 *@class Dummy_complex_visitor
 *@brief A dummy visitor of a simplicial complex that does nothing
 *
 */
template<typename Vertex_handle>
class Dummy_complex_visitor : public Skeleton_blocker_complex_visitor<
Vertex_handle> {
 public:
  void on_add_vertex(Vertex_handle) { }

  void on_remove_vertex(Vertex_handle) { }

  void on_add_edge_without_blockers(Vertex_handle a, Vertex_handle b) { }

  void on_remove_edge(Vertex_handle a, Vertex_handle b) { }

  void on_changed_edge(Vertex_handle a, Vertex_handle b) { }

  void on_swaped_edge(Vertex_handle a, Vertex_handle b, Vertex_handle x) { }

  void on_add_blocker(const Skeleton_blocker_simplex<Vertex_handle>&) { }

  void on_delete_blocker(const Skeleton_blocker_simplex<Vertex_handle>*) { }
};

/**
 *@class Print_complex_visitor
 *@brief A visitor that prints the visit information.
 *
 */
template<typename Vertex_handle>
class Print_complex_visitor : public Skeleton_blocker_complex_visitor<
Vertex_handle> {
 public:
  void on_add_vertex(Vertex_handle v) {
    std::cerr << "on_add_vertex:" << v << std::endl;
  }

  void on_remove_vertex(Vertex_handle v) {
    std::cerr << "on_remove_vertex:" << v << std::endl;
  }

  void on_add_edge_without_blockers(Vertex_handle a, Vertex_handle b) {
    std::cerr << "on_add_edge_without_blockers:" << a << "," << b << std::endl;
  }

  void on_remove_edge(Vertex_handle a, Vertex_handle b) {
    std::cerr << "on_remove_edge:" << a << "," << b << std::endl;
  }

  void on_changed_edge(Vertex_handle a, Vertex_handle b) {
    std::cerr << "on_changed_edge:" << a << "," << b << std::endl;
  }

  void on_swaped_edge(Vertex_handle a, Vertex_handle b, Vertex_handle x) {
    std::cerr << "on_swaped_edge:" << a << "," << b << "," << x << std::endl;
  }

  void on_add_blocker(const Skeleton_blocker_simplex<Vertex_handle>& b) {
    std::cerr << "on_add_blocker:" << b << std::endl;
  }

  void on_delete_blocker(const Skeleton_blocker_simplex<Vertex_handle>* b) {
    std::cerr << "on_delete_blocker:" << b << std::endl;
  }
};

}  // namespace skeleton_blocker

namespace skbl = skeleton_blocker;

}  // namespace Gudhi

#endif  // SKELETON_BLOCKER_SKELETON_BLOCKER_COMPLEX_VISITOR_H_