//=======================================================================
// Copyright 2001 Jeremy G. Siek, Andrew Lumsdaine, Lie-Quan Lee, 
//
// This file is part of the Boost Graph Library
//
// You should have received a copy of the License Agreement for the
// Boost Graph Library along with the software; see the file LICENSE.
// If not, contact Office of Research, Indiana University,
// Bloomington, IN 47405.
//
// Permission to modify the code and to distribute the code is
// granted, provided the text of this NOTICE is retained, a notice if
// the code was modified is included with the above COPYRIGHT NOTICE
// and with the COPYRIGHT NOTICE in the LICENSE file, and that the
// LICENSE file is distributed with the modified code.
//
// LICENSOR MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR IMPLIED.
// By way of example, but not limitation, Licensor MAKES NO
// REPRESENTATIONS OR WARRANTIES OF MERCHANTABILITY OR FITNESS FOR ANY
// PARTICULAR PURPOSE OR THAT THE USE OF THE LICENSED SOFTWARE COMPONENTS
// OR DOCUMENTATION WILL NOT INFRINGE ANY PATENTS, COPYRIGHTS, TRADEMARKS
// OR OTHER RIGHTS.
//=======================================================================
#include <boost/config.hpp>
#include <iostream>
#include <fstream>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/depth_first_search.hpp>
#include <boost/graph/graphviz.hpp>
#include <boost/graph/copy.hpp>

int
main(int argc, char *argv[])
{
  if (argc < 3) {
    std::cerr << "usage: reachable-loop-head.exe <in-file> <out-file>"
      << std::endl;
    return -1;
  }
  using namespace boost;
  GraphvizDigraph g;
  read_graphviz(argv[1], g);
  graph_traits < GraphvizDigraph >::vertex_descriptor loop_head = 1;
  typedef color_traits < default_color_type > Color;

  std::vector < default_color_type >
    reachable_from_head(num_vertices(g), Color::white());
  depth_first_visit(g, loop_head, default_dfs_visitor(),
                    make_iterator_property_map(reachable_from_head.begin(),
                                               get(vertex_index, g)));


  graph_traits < GraphvizDigraph >::vertex_iterator i, i_end;
  for (tie(i, i_end) = vertices(g); i != i_end; ++i)
    if (reachable_from_head[*i] != Color::white()) {
      get(vertex_attribute, g)[*i]["color"] = "gray";
      get(vertex_attribute, g)[*i]["style"] = "filled";
    }

  get_property(g, graph_graph_attribute)["size"] = "3,3";
  get_property(g, graph_graph_attribute)["ratio"] = "fill";
  get_property(g, graph_vertex_attribute)["shape"] = "box";

  std::ofstream loops_out(argv[2]);
  write_graphviz(loops_out, g,
                 make_vertex_attributes_writer(g),
                 make_edge_attributes_writer(g),
                 make_graph_attributes_writer(g));


  return EXIT_SUCCESS;
}