//  (C) Copyright Jeremy Siek 2004
//  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 <set>

#include <boost/test/minimal.hpp>

#include <boost/graph/subgraph.hpp>
#include <boost/graph/adjacency_list.hpp>
#include <boost/graph/random.hpp>
#include "graph_test.hpp"
#include <boost/graph/iteration_macros.hpp>
#include <boost/random/mersenne_twister.hpp>

#include "test_graph.hpp"

// UNDER CONSTRUCTION


// This is a helper function to recusively compare two subgraphs,
// including the index for every local edges and their children.
template<typename subgraph_t>
void sub_cmp(subgraph_t const &g1, subgraph_t const &g2)
{
    BOOST_CHECK(g1.is_root() == g2.is_root());
    BOOST_CHECK(num_vertices(g1) == num_vertices(g2));
    BOOST_CHECK(num_edges(g1) == num_edges(g2));
    typename subgraph_t::edge_iterator e1_i, e1_i_end, e2_i, e2_i_end;
    boost::tie(e1_i, e1_i_end) = edges(g1);
    boost::tie(e2_i, e2_i_end) = edges(g2);
    for(; e1_i != e1_i_end; ++e1_i, ++e2_i)
    {
        BOOST_CHECK(get(boost::edge_index, g1, *e1_i)
                    == get(boost::edge_index, g2, *e2_i));
    }
    typename subgraph_t::const_children_iterator g1_i, g1_i_end, g2_i, g2_i_end;
    boost::tie(g1_i, g1_i_end) = g1.children();
    boost::tie(g2_i, g2_i_end) = g2.children();
    for(; g1_i != g1_i_end && g2_i != g2_i_end; ++g1_i, ++g2_i)
    {
        sub_cmp(*g1_i, *g2_i);
    }
    BOOST_CHECK(g1_i == g1_i_end && g2_i == g2_i_end);
}

int test_main(int, char*[])
{
  using namespace boost;
  typedef adjacency_list<vecS, vecS, bidirectionalS,
    property<vertex_color_t, int>,
    property<edge_index_t, std::size_t, property<edge_weight_t, int> >
  > graph_t;
  typedef subgraph<graph_t> subgraph_t;
  typedef graph_traits<subgraph_t>::vertex_descriptor vertex_t;

  mt19937 gen;
  for (int t = 0; t < 100; t += 5) {
    subgraph_t g;
    int N = t + 2;
    std::vector<vertex_t> vertex_set;
    std::vector< std::pair<vertex_t, vertex_t> > edge_set;
    generate_random_graph(g, N, N * 2, gen,
                          std::back_inserter(vertex_set),
                          std::back_inserter(edge_set));

    graph_test< subgraph_t > gt;

    gt.test_incidence_graph(vertex_set, edge_set, g);
    gt.test_bidirectional_graph(vertex_set, edge_set, g);
    gt.test_adjacency_graph(vertex_set, edge_set, g);
    gt.test_vertex_list_graph(vertex_set, g);
    gt.test_edge_list_graph(vertex_set, edge_set, g);
    gt.test_adjacency_matrix(vertex_set, edge_set, g);

    std::vector<vertex_t> sub_vertex_set;
    std::vector<vertex_t> sub_global_map;
    std::vector<vertex_t> global_sub_map(num_vertices(g));
    std::vector< std::pair<vertex_t, vertex_t> > sub_edge_set;

    subgraph_t& g_s = g.create_subgraph();

    const std::set<vertex_t>::size_type Nsub = N/2;

    // Collect a set of random vertices to put in the subgraph
    std::set<vertex_t> verts;
    while (verts.size() < Nsub)
      verts.insert(random_vertex(g, gen));

    for (std::set<vertex_t>::iterator it = verts.begin();
        it != verts.end(); ++it) {
      vertex_t v_global = *it;
      vertex_t v = add_vertex(v_global, g_s);
      sub_vertex_set.push_back(v);
      sub_global_map.push_back(v_global);
      global_sub_map[v_global] = v;
    }

    // compute induced edges
    BGL_FORALL_EDGES(e, g, subgraph_t)
      if (container_contains(sub_global_map, source(e, g))
          && container_contains(sub_global_map, target(e, g)))
        sub_edge_set.push_back(std::make_pair(global_sub_map[source(e, g)],
                                              global_sub_map[target(e, g)]));

    gt.test_incidence_graph(sub_vertex_set, sub_edge_set, g_s);
    gt.test_bidirectional_graph(sub_vertex_set, sub_edge_set, g_s);
    gt.test_adjacency_graph(sub_vertex_set, sub_edge_set, g_s);
    gt.test_vertex_list_graph(sub_vertex_set, g_s);
    gt.test_edge_list_graph(sub_vertex_set, sub_edge_set, g_s);
    gt.test_adjacency_matrix(sub_vertex_set, sub_edge_set, g_s);

    if (num_vertices(g_s) == 0)
      return 0;
    std::vector<int> weights;
    for (unsigned i = 0; i < num_vertices(g_s); ++i)
    weights.push_back(i*2);
    gt.test_vertex_property_graph(weights, vertex_color_t(), g_s);

    // A regression test: the copy constructor of subgraph did not
    // copy one of the members, so local_edge->global_edge mapping
    // was broken.
    {
        subgraph_t g;
        graph_t::vertex_descriptor v1, v2;
        v1 = add_vertex(g);
        v2 = add_vertex(g);
        add_edge(v1, v2, g);

        subgraph_t sub = g.create_subgraph(vertices(g).first, vertices(g).second);

        graph_t::edge_iterator ei, ee;
        for (boost::tie(ei, ee) = edges(sub); ei != ee; ++ei) {
            // This used to segfault.
            get(edge_weight, sub, *ei);
        }
    }

    // This block generates a complete graph with 8 vertices,
    // and puts the first and last four of the vertices into two children.
    // Do these again to the children, so there are 4 grandchildren with 2 vertices for each.
    // Use the copy constructor to generate a copy and compare with the original one.
    {
        subgraph_t g1;

        for(size_t i = 0; i < 8; i ++)
        {
            add_vertex(g1);
        }
        subgraph_t::vertex_iterator vi_start, vi, vi_end, vj_start, vj, vj_end;
        for(tie(vi, vi_end) = vertices(g1); vi != vi_end; ++vi)
        {
            for(tie(vj, vj_end) = vertices(g1); vj != vj_end; ++vj)
            {
                if(*vi != *vj)
                {
                    add_edge(*vi, *vj, g1);
                }
            }
        }
        tie(vi_start, vi_end) = vertices(g1);
        vi = vi_start;
        for(size_t i = 0; i < 4; i++)
        {
            ++vi;
        }
        g1.create_subgraph(vi_start, vi);
        g1.create_subgraph(++vi, vi_end);
        subgraph_t::children_iterator gi1, gi2;
        gi2 = g1.children().first;
        gi1 = gi2++;
        tie(vi_start, vi_end) = vertices(*gi1);
        vi = vi_start;
        tie(vj_start, vj_end) = vertices(*gi2);
        vj = vj_start;
        for(size_t i = 0; i < 2; i++)
        {
          ++vi;
          ++vj;
        }
        (*gi1).create_subgraph(vi_start, vi);
        (*gi1).create_subgraph(++vi, vi_end);
        (*gi2).create_subgraph(vj_start, vj);
        (*gi2).create_subgraph(++vj, vj_end);
        subgraph_t g2(g1);
        sub_cmp(g1, g2);
    }

    // Bootstrap the test_graph framework.
    // TODO: Subgraph is fundamentally broken for property types.
    // TODO: Under construction.
    {
        using namespace boost;
        typedef property<edge_index_t, size_t, EdgeBundle> EdgeProp;
        typedef adjacency_list<vecS, vecS, directedS, VertexBundle, EdgeProp> BaseGraph;
        typedef subgraph<BaseGraph> Graph;
        typedef graph_traits<Graph>::vertex_descriptor Vertex;
        Graph g;
        Vertex v = add_vertex(g);

        typedef property_map<Graph, int VertexBundle::*>::type BundleMap;
        BundleMap map = get(&VertexBundle::value, g);
        get(map, v);
//         put(map, v, 5);
//         BOOST_ASSERT(get(map, v) == 5);

//         test_graph(g);
        return 0;
    }
  }
  return 0;
}