//=======================================================================
// Copyright 2009 Trustees of Indiana University.
// Authors: Michael Hansen
//
// 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)
//=======================================================================

#include <cmath>
#include <iostream>
#include <fstream>
#include <sstream>
#include <vector>
#include <ctime>

#include <boost/lexical_cast.hpp>
#include <boost/random.hpp>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/filtered_graph.hpp>
#include <boost/graph/graphviz.hpp>
#include <boost/graph/isomorphism.hpp>
#include <boost/graph/iteration_macros.hpp>
#include <boost/graph/random.hpp>
#include <boost/graph/mcgregor_common_subgraphs.hpp>
#include <boost/property_map/shared_array_property_map.hpp>
#include <boost/core/lightweight_test.hpp>

bool was_common_subgraph_found = false, output_graphs = false;
std::vector< std::string > simple_subgraph_list;

// Callback that compares incoming graphs to the supplied common
// subgraph.
template < typename Graph > struct test_callback
{

    test_callback(
        Graph& common_subgraph, const Graph& graph1, const Graph& graph2)
    : m_graph1(graph1), m_graph2(graph2), m_common_subgraph(common_subgraph)
    {
    }

    template < typename CorrespondenceMapFirstToSecond,
        typename CorrespondenceMapSecondToFirst >
    bool operator()(CorrespondenceMapFirstToSecond correspondence_map_1_to_2,
        CorrespondenceMapSecondToFirst correspondence_map_2_to_1,
        typename boost::graph_traits< Graph >::vertices_size_type subgraph_size)
    {

        typedef typename boost::graph_traits< Graph >::vertex_descriptor Vertex;
        typedef typename boost::graph_traits< Graph >::edge_descriptor Edge;
        typedef std::pair< Edge, bool > EdgeInfo;

        typedef
            typename boost::property_map< Graph, boost::vertex_index_t >::type
                VertexIndexMap;
        typedef
            typename boost::property_map< Graph, boost::vertex_name_t >::type
                VertexNameMap;
        typedef typename boost::property_map< Graph, boost::edge_name_t >::type
            EdgeNameMap;

        if (subgraph_size != num_vertices(m_common_subgraph))
        {
            return (true);
        }

        // Fill membership maps for both graphs
        typedef boost::shared_array_property_map< bool, VertexIndexMap >
            MembershipMap;

        MembershipMap membership_map1(
            num_vertices(m_graph1), get(boost::vertex_index, m_graph1));

        MembershipMap membership_map2(
            num_vertices(m_graph2), get(boost::vertex_index, m_graph2));

        boost::fill_membership_map< Graph >(
            m_graph1, correspondence_map_1_to_2, membership_map1);
        boost::fill_membership_map< Graph >(
            m_graph2, correspondence_map_2_to_1, membership_map2);

        // Generate filtered graphs using membership maps
        typedef typename boost::membership_filtered_graph_traits< Graph,
            MembershipMap >::graph_type MembershipFilteredGraph;

        MembershipFilteredGraph subgraph1
            = boost::make_membership_filtered_graph(m_graph1, membership_map1);

        MembershipFilteredGraph subgraph2
            = boost::make_membership_filtered_graph(m_graph2, membership_map2);

        VertexIndexMap vindex_map1 = get(boost::vertex_index, subgraph1);
        VertexIndexMap vindex_map2 = get(boost::vertex_index, subgraph2);

        VertexNameMap vname_map_common
            = get(boost::vertex_name, m_common_subgraph);
        VertexNameMap vname_map1 = get(boost::vertex_name, subgraph1);
        VertexNameMap vname_map2 = get(boost::vertex_name, subgraph2);

        EdgeNameMap ename_map_common = get(boost::edge_name, m_common_subgraph);
        EdgeNameMap ename_map1 = get(boost::edge_name, subgraph1);
        EdgeNameMap ename_map2 = get(boost::edge_name, subgraph2);

        // Verify that subgraph1 matches the supplied common subgraph
        BGL_FORALL_VERTICES_T(vertex1, subgraph1, MembershipFilteredGraph)
        {

            Vertex vertex_common
                = vertex(get(vindex_map1, vertex1), m_common_subgraph);

            // Match vertex names
            if (get(vname_map_common, vertex_common)
                != get(vname_map1, vertex1))
            {

                // Keep looking
                return (true);
            }

            BGL_FORALL_VERTICES_T(vertex1_2, subgraph1, MembershipFilteredGraph)
            {

                Vertex vertex_common2
                    = vertex(get(vindex_map1, vertex1_2), m_common_subgraph);
                EdgeInfo edge_common
                    = edge(vertex_common, vertex_common2, m_common_subgraph);
                EdgeInfo edge1 = edge(vertex1, vertex1_2, subgraph1);

                if ((edge_common.second != edge1.second)
                    || ((edge_common.second && edge1.second)
                        && (get(ename_map_common, edge_common.first)
                            != get(ename_map1, edge1.first))))
                {

                    // Keep looking
                    return (true);
                }
            }

        } // BGL_FORALL_VERTICES_T (subgraph1)

        // Verify that subgraph2 matches the supplied common subgraph
        BGL_FORALL_VERTICES_T(vertex2, subgraph2, MembershipFilteredGraph)
        {

            Vertex vertex_common
                = vertex(get(vindex_map2, vertex2), m_common_subgraph);

            // Match vertex names
            if (get(vname_map_common, vertex_common)
                != get(vname_map2, vertex2))
            {

                // Keep looking
                return (true);
            }

            BGL_FORALL_VERTICES_T(vertex2_2, subgraph2, MembershipFilteredGraph)
            {

                Vertex vertex_common2
                    = vertex(get(vindex_map2, vertex2_2), m_common_subgraph);
                EdgeInfo edge_common
                    = edge(vertex_common, vertex_common2, m_common_subgraph);
                EdgeInfo edge2 = edge(vertex2, vertex2_2, subgraph2);

                if ((edge_common.second != edge2.second)
                    || ((edge_common.second && edge2.second)
                        && (get(ename_map_common, edge_common.first)
                            != get(ename_map2, edge2.first))))
                {

                    // Keep looking
                    return (true);
                }
            }

        } // BGL_FORALL_VERTICES_T (subgraph2)

        // Check isomorphism just to be thorough
        if (verify_isomorphism(subgraph1, subgraph2, correspondence_map_1_to_2))
        {

            was_common_subgraph_found = true;

            if (output_graphs)
            {

                std::fstream file_subgraph(
                    "found_common_subgraph.dot", std::fstream::out);
                write_graphviz(file_subgraph, subgraph1,
                    make_label_writer(get(boost::vertex_name, m_graph1)),
                    make_label_writer(get(boost::edge_name, m_graph1)));
            }

            // Stop iterating
            return (false);
        }

        // Keep looking
        return (true);
    }

private:
    const Graph &m_graph1, m_graph2;
    Graph& m_common_subgraph;
};

template < typename Graph > struct simple_callback
{

    simple_callback(const Graph& graph1) : m_graph1(graph1) {}

    template < typename CorrespondenceMapFirstToSecond,
        typename CorrespondenceMapSecondToFirst >
    bool operator()(CorrespondenceMapFirstToSecond correspondence_map_1_to_2,
        CorrespondenceMapSecondToFirst /*correspondence_map_2_to_1*/,
        typename boost::graph_traits<
            Graph >::vertices_size_type /*subgraph_size*/)
    {

        typedef typename boost::graph_traits< Graph >::vertex_descriptor Vertex;

        std::stringstream subgraph_string;

        BGL_FORALL_VERTICES_T(vertex1, m_graph1, Graph)
        {

            Vertex vertex2 = get(correspondence_map_1_to_2, vertex1);

            if (vertex2 != boost::graph_traits< Graph >::null_vertex())
            {
                subgraph_string << vertex1 << "," << vertex2 << " ";
            }
        }

        simple_subgraph_list.push_back(subgraph_string.str());

        return (true);
    }

private:
    const Graph& m_graph1;
};

template < typename Graph, typename RandomNumberGenerator,
    typename VertexNameMap, typename EdgeNameMap >
void add_random_vertices(Graph& graph, RandomNumberGenerator& generator,
    int vertices_to_create, int max_edges_per_vertex, VertexNameMap vname_map,
    EdgeNameMap ename_map)
{

    typedef typename boost::graph_traits< Graph >::vertex_descriptor Vertex;
    typedef std::vector< Vertex > VertexList;

    VertexList new_vertices;

    for (int v_index = 0; v_index < vertices_to_create; ++v_index)
    {

        Vertex new_vertex = add_vertex(graph);
        put(vname_map, new_vertex, generator());
        new_vertices.push_back(new_vertex);
    }

    // Add edges for every new vertex. Care is taken to avoid parallel
    // edges.
    for (typename VertexList::const_iterator v_iter = new_vertices.begin();
         v_iter != new_vertices.end(); ++v_iter)
    {

        Vertex source_vertex = *v_iter;
        int edges_for_vertex
            = (std::min)((int)(generator() % max_edges_per_vertex) + 1,
                (int)num_vertices(graph));

        while (edges_for_vertex > 0)
        {

            Vertex target_vertex = random_vertex(graph, generator);

            if (source_vertex == target_vertex)
            {
                continue;
            }

            BGL_FORALL_OUTEDGES_T(source_vertex, edge, graph, Graph)
            {
                if (target(edge, graph) == target_vertex)
                {
                    continue;
                }
            }

            put(ename_map, add_edge(source_vertex, target_vertex, graph).first,
                generator());

            edges_for_vertex--;
        }
    }
}

bool has_subgraph_string(std::string set_string)
{
    return (std::find(simple_subgraph_list.begin(), simple_subgraph_list.end(),
                set_string)
        != simple_subgraph_list.end());
}

int main(int argc, char* argv[])
{
    int vertices_to_create = 10;
    int max_edges_per_vertex = 2;
    std::size_t random_seed = std::time(0);

    if (argc > 1)
    {
        vertices_to_create = boost::lexical_cast< int >(argv[1]);
    }

    if (argc > 2)
    {
        max_edges_per_vertex = boost::lexical_cast< int >(argv[2]);
    }

    if (argc > 3)
    {
        output_graphs = boost::lexical_cast< bool >(argv[3]);
    }

    if (argc > 4)
    {
        random_seed = boost::lexical_cast< std::size_t >(argv[4]);
    }

    boost::minstd_rand generator(random_seed);

    // Using a vecS graph here so that we don't have to mess around with
    // a vertex index map; it will be implicit.
    typedef boost::adjacency_list< boost::listS, boost::vecS, boost::directedS,
        boost::property< boost::vertex_name_t, unsigned int,
            boost::property< boost::vertex_index_t, unsigned int > >,
        boost::property< boost::edge_name_t, unsigned int > >
        Graph;

    typedef boost::property_map< Graph, boost::vertex_name_t >::type
        VertexNameMap;
    typedef boost::property_map< Graph, boost::edge_name_t >::type EdgeNameMap;

    // Generate a random common subgraph and then add random vertices
    // and edges to the two parent graphs.
    Graph common_subgraph, graph1, graph2;

    VertexNameMap vname_map_common = get(boost::vertex_name, common_subgraph);
    VertexNameMap vname_map1 = get(boost::vertex_name, graph1);
    VertexNameMap vname_map2 = get(boost::vertex_name, graph2);

    EdgeNameMap ename_map_common = get(boost::edge_name, common_subgraph);
    EdgeNameMap ename_map1 = get(boost::edge_name, graph1);
    EdgeNameMap ename_map2 = get(boost::edge_name, graph2);

    for (int vindex = 0; vindex < vertices_to_create; ++vindex)
    {
        put(vname_map_common, add_vertex(common_subgraph), generator());
    }

    BGL_FORALL_VERTICES(source_vertex, common_subgraph, Graph)
    {

        BGL_FORALL_VERTICES(target_vertex, common_subgraph, Graph)
        {

            if (source_vertex != target_vertex)
            {
                put(ename_map_common,
                    add_edge(source_vertex, target_vertex, common_subgraph)
                        .first,
                    generator());
            }
        }
    }

    boost::randomize_property< boost::vertex_name_t >(
        common_subgraph, generator);
    boost::randomize_property< boost::edge_name_t >(common_subgraph, generator);

    boost::copy_graph(common_subgraph, graph1);
    boost::copy_graph(common_subgraph, graph2);

    // Randomly add vertices and edges to graph1 and graph2.
    add_random_vertices(graph1, generator, vertices_to_create,
        max_edges_per_vertex, vname_map1, ename_map1);

    add_random_vertices(graph2, generator, vertices_to_create,
        max_edges_per_vertex, vname_map2, ename_map2);

    if (output_graphs)
    {

        std::fstream file_graph1("graph1.dot", std::fstream::out),
            file_graph2("graph2.dot", std::fstream::out),
            file_common_subgraph(
                "expected_common_subgraph.dot", std::fstream::out);

        write_graphviz(file_graph1, graph1, make_label_writer(vname_map1),
            make_label_writer(ename_map1));

        write_graphviz(file_graph2, graph2, make_label_writer(vname_map2),
            make_label_writer(ename_map2));

        write_graphviz(file_common_subgraph, common_subgraph,
            make_label_writer(get(boost::vertex_name, common_subgraph)),
            make_label_writer(get(boost::edge_name, common_subgraph)));
    }

    std::cout << "Searching for common subgraph of size "
              << num_vertices(common_subgraph) << std::endl;

    test_callback< Graph > user_callback(common_subgraph, graph1, graph2);

    boost::mcgregor_common_subgraphs(graph1, graph2, true, user_callback,
        boost::edges_equivalent(
            boost::make_property_map_equivalent(ename_map1, ename_map2))
            .vertices_equivalent(
                boost::make_property_map_equivalent(vname_map1, vname_map2)));

    BOOST_TEST(was_common_subgraph_found);

    // Test maximum and unique variants on known graphs
    Graph graph_simple1, graph_simple2;
    simple_callback< Graph > user_callback_simple(graph_simple1);

    VertexNameMap vname_map_simple1 = get(boost::vertex_name, graph_simple1);
    VertexNameMap vname_map_simple2 = get(boost::vertex_name, graph_simple2);

    put(vname_map_simple1, add_vertex(graph_simple1), 1);
    put(vname_map_simple1, add_vertex(graph_simple1), 2);
    put(vname_map_simple1, add_vertex(graph_simple1), 3);

    add_edge(0, 1, graph_simple1);
    add_edge(0, 2, graph_simple1);
    add_edge(1, 2, graph_simple1);

    put(vname_map_simple2, add_vertex(graph_simple2), 1);
    put(vname_map_simple2, add_vertex(graph_simple2), 2);
    put(vname_map_simple2, add_vertex(graph_simple2), 3);
    put(vname_map_simple2, add_vertex(graph_simple2), 4);

    add_edge(0, 1, graph_simple2);
    add_edge(0, 2, graph_simple2);
    add_edge(1, 2, graph_simple2);
    add_edge(1, 3, graph_simple2);

    // Unique subgraphs
    std::cout << "Searching for unique subgraphs" << std::endl;
    boost::mcgregor_common_subgraphs_unique(graph_simple1, graph_simple2, true,
        user_callback_simple,
        boost::vertices_equivalent(boost::make_property_map_equivalent(
            vname_map_simple1, vname_map_simple2)));

    BOOST_TEST(has_subgraph_string("0,0 1,1 "));
    BOOST_TEST(has_subgraph_string("0,0 1,1 2,2 "));
    BOOST_TEST(has_subgraph_string("0,0 2,2 "));
    BOOST_TEST(has_subgraph_string("1,1 2,2 "));

    if (output_graphs)
    {
        std::copy(simple_subgraph_list.begin(), simple_subgraph_list.end(),
            std::ostream_iterator< std::string >(std::cout, "\n"));

        std::cout << std::endl;
    }

    simple_subgraph_list.clear();

    // Maximum subgraphs
    std::cout << "Searching for maximum subgraphs" << std::endl;
    boost::mcgregor_common_subgraphs_maximum(graph_simple1, graph_simple2, true,
        user_callback_simple,
        boost::vertices_equivalent(boost::make_property_map_equivalent(
            vname_map_simple1, vname_map_simple2)));

    BOOST_TEST(has_subgraph_string("0,0 1,1 2,2 "));

    if (output_graphs)
    {
        std::copy(simple_subgraph_list.begin(), simple_subgraph_list.end(),
            std::ostream_iterator< std::string >(std::cout, "\n"));

        std::cout << std::endl;
    }

    simple_subgraph_list.clear();

    // Maximum, unique subgraphs
    std::cout << "Searching for maximum unique subgraphs" << std::endl;
    boost::mcgregor_common_subgraphs_maximum_unique(graph_simple1,
        graph_simple2, true, user_callback_simple,
        boost::vertices_equivalent(boost::make_property_map_equivalent(
            vname_map_simple1, vname_map_simple2)));

    BOOST_TEST(simple_subgraph_list.size() == 1);
    BOOST_TEST(has_subgraph_string("0,0 1,1 2,2 "));

    if (output_graphs)
    {
        std::copy(simple_subgraph_list.begin(), simple_subgraph_list.end(),
            std::ostream_iterator< std::string >(std::cout, "\n"));

        std::cout << std::endl;
    }

    return boost::report_errors();
}