//=======================================================================

// Copyright 1997, 1998, 1999, 2000 University of Notre Dame.

// Authors: Andrew Lumsdaine, Lie-Quan Lee, Jeremy G. Siek

//

// Distributed under the Boost Software License, Version 1.0. (See

// accompanying file LICENSE_1_0.txt or copy at

// http://www.boost.org/LICENSE_1_0.txt)

//=======================================================================

//

// Revision History:

//   01 April 2001: Modified to use new <boost/limits.hpp> header. (JMaddock)

//

#ifndef BOOST_GRAPH_GRAPH_SEARCH_VISITORS_HPP

#define BOOST_GRAPH_GRAPH_SEARCH_VISITORS_HPP

#include <iosfwd>

#include <boost/config.hpp>

#include <boost/property_map.hpp>

#include <boost/graph/graph_traits.hpp>

#include <boost/limits.hpp>

#include <boost/graph/detail/is_same.hpp>

namespace boost {

  // This is a bit more convenient than std::numeric_limits because

  // you don't have to explicitly provide type T.

  template <class T>

  inline T numeric_limits_max(T) { return (std::numeric_limits<T>::max)(); }

  //========================================================================

  // Event Tags

  namespace detail {

    // For partial specialization workaround

    enum event_visitor_enum

    { on_no_event_num,

      on_initialize_vertex_num, on_start_vertex_num,

      on_discover_vertex_num, on_finish_vertex_num, on_examine_vertex_num,

      on_examine_edge_num, on_tree_edge_num, on_non_tree_edge_num,

      on_gray_target_num, on_black_target_num,

      on_forward_or_cross_edge_num, on_back_edge_num,

      on_edge_relaxed_num, on_edge_not_relaxed_num,

      on_edge_minimized_num, on_edge_not_minimized_num

    };

    template<typename Event, typename Visitor>

    struct functor_to_visitor : Visitor

    {

      typedef Event event_filter;

      functor_to_visitor(const Visitor& visitor) : Visitor(visitor) {}

    };

  } // namespace detail

  struct on_no_event { enum { num = detail::on_no_event_num }; };

  struct on_initialize_vertex {

    enum { num = detail::on_initialize_vertex_num }; };

  struct on_start_vertex { enum { num = detail::on_start_vertex_num }; };

  struct on_discover_vertex { enum { num = detail::on_discover_vertex_num }; };

  struct on_examine_vertex { enum { num = detail::on_examine_vertex_num }; };

  struct on_finish_vertex { enum { num = detail::on_finish_vertex_num }; };

  struct on_examine_edge { enum { num = detail::on_examine_edge_num }; };

  struct on_tree_edge { enum { num = detail::on_tree_edge_num }; };

  struct on_non_tree_edge { enum { num = detail::on_non_tree_edge_num }; };

  struct on_gray_target { enum { num = detail::on_gray_target_num }; };

  struct on_black_target { enum { num = detail::on_black_target_num }; };

  struct on_forward_or_cross_edge {

    enum { num = detail::on_forward_or_cross_edge_num }; };

  struct on_back_edge { enum { num = detail::on_back_edge_num }; };

  struct on_edge_relaxed { enum { num = detail::on_edge_relaxed_num }; };

  struct on_edge_not_relaxed {

    enum { num = detail::on_edge_not_relaxed_num }; };

  struct on_edge_minimized { enum { num = detail::on_edge_minimized_num }; };

  struct on_edge_not_minimized {

    enum { num = detail::on_edge_not_minimized_num }; };

  struct true_tag { enum { num = true }; };

  struct false_tag { enum { num = false }; };

  //========================================================================

  // base_visitor and null_visitor

  // needed for MSVC workaround

  template <class Visitor>

  struct base_visitor {

    typedef on_no_event event_filter;

    template <class T, class Graph>

    void operator()(T, Graph&) { }

  };

  struct null_visitor : public base_visitor<null_visitor> {

    typedef on_no_event event_filter;

    template <class T, class Graph>

    void operator()(T, Graph&) { }

  };

  //========================================================================

  // The invoke_visitors() function

  namespace detail {

    template <class Visitor, class T, class Graph>

    inline void

    invoke_dispatch(Visitor& v, T x, Graph& g, true_tag) {

       v(x, g);

    }

    template <class Visitor, class T, class Graph>

    inline void

    invoke_dispatch(Visitor&, T, Graph&, false_tag) { }

  } // namespace detail

  template <class Visitor, class Rest, class T, class Graph, class Tag>

  inline void

  invoke_visitors(std::pair<Visitor, Rest>& vlist, T x, Graph& g, Tag tag) {

    typedef typename Visitor::event_filter Category;

    typedef typename graph_detail::is_same<Category, Tag>::is_same_tag

      IsSameTag;

    detail::invoke_dispatch(vlist.first, x, g, IsSameTag());

    invoke_visitors(vlist.second, x, g, tag);

  }

#if defined(BOOST_MSVC) && BOOST_MSVC <= 1300

  template <class Visitor, class T, class Graph, class Tag>

  inline void

  invoke_visitors(base_visitor<Visitor>& vis, T x, Graph& g, Tag) {

    typedef typename Visitor::event_filter Category;

    typedef typename graph_detail::is_same<Category, Tag>::is_same_tag

      IsSameTag;

    Visitor& v = static_cast<Visitor&>(vis);

    detail::invoke_dispatch(v, x, g, IsSameTag());

  }

#else

  template <class Visitor, class T, class Graph, class Tag>

  inline void

  invoke_visitors(Visitor& v, T x, Graph& g, Tag) {

    typedef typename Visitor::event_filter Category;

    typedef typename graph_detail::is_same<Category, Tag>::is_same_tag

      IsSameTag;

    detail::invoke_dispatch(v, x, g, IsSameTag());

  }

#endif

  //========================================================================

  // predecessor_recorder

  template <class PredecessorMap, class Tag>

  struct predecessor_recorder

    : public base_visitor<predecessor_recorder<PredecessorMap, Tag> >

  {

    typedef Tag event_filter;

    predecessor_recorder(PredecessorMap pa) : m_predecessor(pa) { }

    template <class Edge, class Graph>

    void operator()(Edge e, const Graph& g) {

      put(m_predecessor, target(e, g), source(e, g));

    }

    PredecessorMap m_predecessor;

  };

  template <class PredecessorMap, class Tag>

  predecessor_recorder<PredecessorMap, Tag>

  record_predecessors(PredecessorMap pa, Tag) {

    return predecessor_recorder<PredecessorMap, Tag> (pa);

  }

  //========================================================================

  // edge_predecessor_recorder

  template <class PredEdgeMap, class Tag>

  struct edge_predecessor_recorder

    : public base_visitor<edge_predecessor_recorder<PredEdgeMap, Tag> >

  {

    typedef Tag event_filter;

    edge_predecessor_recorder(PredEdgeMap pa) : m_predecessor(pa) { }

    template <class Edge, class Graph>

    void operator()(Edge e, const Graph& g) {

      put(m_predecessor, target(e, g), e);

    }

    PredEdgeMap m_predecessor;

  };

  template <class PredEdgeMap, class Tag>

  edge_predecessor_recorder<PredEdgeMap, Tag>

  record_edge_predecessors(PredEdgeMap pa, Tag) {

    return edge_predecessor_recorder<PredEdgeMap, Tag> (pa);

  }

  //========================================================================

  // distance_recorder

  template <class DistanceMap, class Tag>

  struct distance_recorder

    : public base_visitor<distance_recorder<DistanceMap, Tag> >

  {

    typedef Tag event_filter;

    distance_recorder(DistanceMap pa) : m_distance(pa) { }

    template <class Edge, class Graph>

    void operator()(Edge e, const Graph& g) {

      typename graph_traits<Graph>::vertex_descriptor

        u = source(e, g), v = target(e, g);

      put(m_distance, v, get(m_distance, u) + 1);

    }

    DistanceMap m_distance;

  };

  template <class DistanceMap, class Tag>

  distance_recorder<DistanceMap, Tag>

  record_distances(DistanceMap pa, Tag) {

    return distance_recorder<DistanceMap, Tag> (pa);

  }

  //========================================================================

  // time_stamper

  template <class TimeMap, class TimeT, class Tag>

  struct time_stamper

    : public base_visitor<time_stamper<TimeMap, TimeT, Tag> >

  {

    typedef Tag event_filter;

    time_stamper(TimeMap pa, TimeT& t) : m_time_pa(pa), m_time(t) { }

    template <class Vertex, class Graph>

    void operator()(Vertex u, const Graph&) {

      put(m_time_pa, u, ++m_time);

    }

    TimeMap m_time_pa;

    TimeT& m_time;

  };

  template <class TimeMap, class TimeT, class Tag>

  time_stamper<TimeMap, TimeT, Tag>

  stamp_times(TimeMap pa, TimeT& time_counter, Tag) {

    return time_stamper<TimeMap, TimeT, Tag>(pa, time_counter);

  }

  //========================================================================

  // property_writer

  template <class PA, class OutputIterator, class Tag>

  struct property_writer

    : public base_visitor<property_writer<PA, OutputIterator, Tag> >

  {

    typedef Tag event_filter;

    property_writer(PA pa, OutputIterator out) : m_pa(pa), m_out(out) { }

    template <class T, class Graph>

    void operator()(T x, Graph&) { *m_out++ = get(m_pa, x); }

    PA m_pa;

    OutputIterator m_out;

  };

  template <class PA, class OutputIterator, class Tag>

  property_writer<PA, OutputIterator, Tag>

  write_property(PA pa, OutputIterator out, Tag) {

    return property_writer<PA, OutputIterator, Tag>(pa, out);

  }

#define BOOST_GRAPH_EVENT_STUB(Event,Kind)                                 \

    typedef ::boost::Event Event##_type;                                   \

    template<typename Visitor>                                             \

    Kind##_visitor<std::pair<detail::functor_to_visitor<Event##_type,      \

                                                     Visitor>, Visitors> > \

    do_##Event(Visitor visitor)                                            \

    {                                                                      \

      typedef std::pair<detail::functor_to_visitor<Event##_type, Visitor>, \

                        Visitors> visitor_list;                            \

      typedef Kind##_visitor<visitor_list> result_type;                    \

      return result_type(visitor_list(visitor, m_vis));                    \

    }

} /* namespace boost */

#endif