// graph-tool -- a general graph modification and manipulation thingy
//
// Copyright (C) 2006-2022 Tiago de Paula Peixoto <tiago@skewed.de>
//
// This program is free software; you can redistribute it and/or modify it under
// the terms of the GNU Lesser 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 Lesser General Public License for more
// details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.

#ifndef GRAPH_CORR_HIST_HH
#define GRAPH_CORR_HIST_HH

#include "graph_correlations.hh"

namespace graph_tool
{
using namespace std;
using namespace boost;

// retrieves the generalized vertex-vertex correlation histogram
template <class GetDegreePair>
struct get_correlation_histogram
{
    get_correlation_histogram(python::object& hist,
                              const std::array<vector<long double>,2>& bins,
                              python::object& ret_bins)
        : _hist(hist), _bins(bins), _ret_bins(ret_bins) {}

    template <class Graph, class DegreeSelector1, class DegreeSelector2,
              class WeightMap>
    void operator()(Graph& g, DegreeSelector1 deg1, DegreeSelector2 deg2,
                    WeightMap weight) const
    {
        GetDegreePair put_point;

        typedef typename DegreeSelector1::value_type type1;
        typedef typename DegreeSelector2::value_type type2;

        typedef typename graph_tool::detail::
            select_float_and_larger::apply<type1,type2>::type
            val_type;
        typedef typename property_traits<WeightMap>::value_type count_type;
        typedef Histogram<val_type, count_type, 2> hist_t;

        std::array<vector<val_type>,2> bins;
        for (size_t i = 0; i < bins.size(); ++i)
            clean_bins(_bins[i], bins[i]);

        hist_t hist(bins);
        {
            SharedHistogram<hist_t> s_hist(hist);

            #pragma omp parallel if (num_vertices(g) > OPENMP_MIN_THRESH) \
                firstprivate(s_hist)
            parallel_vertex_loop_no_spawn
                (g,
                 [&](auto v)
                 {
                     put_point(v, deg1, deg2, g, weight, s_hist);
                 });
        }

        bins = hist.get_bins();
        python::list ret_bins;
        ret_bins.append(wrap_vector_owned(bins[0]));
        ret_bins.append(wrap_vector_owned(bins[1]));
        _ret_bins = ret_bins;
        _hist = wrap_multi_array_owned(hist.get_array());
    }
    python::object& _hist;
    const std::array<vector<long double>,2>& _bins;
    python::object& _ret_bins;
};

} // graph_tool namespace

#endif
