// graph-tool -- a general graph modification and manipulation thingy
//
// Copyright (C) 2006-2021 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/>.

#include "graph_python_interface.hh"
#include "graph.hh"
#include "graph_filtering.hh"

#include <boost/python.hpp>

#include "graph_rewiring.hh"

using namespace graph_tool;
using namespace boost;


class PythonFuncWrap
{
public:
    PythonFuncWrap(boost::python::object o): _o(o) {}

    typedef pair<size_t, size_t> deg_t;

    double operator()(deg_t deg1, deg_t deg2)
        const
    {
        boost::python::object ret = _o(boost::python::make_tuple(deg1.first, deg1.second),
                                       boost::python::make_tuple(deg2.first, deg2.second));
        return boost::python::extract<double>(ret);
    }

    template <class Type>
    double operator()(const Type& deg1, const Type& deg2) const
    {
        boost::python::object ret = _o(boost::python::object(deg1), boost::python::object(deg2));
        return boost::python::extract<double>(ret);
    }

    template <class ProbMap>
    void get_probs(ProbMap& probs) const
    {
        typedef typename ProbMap::key_type::first_type block_t;
        if (PyObject_HasAttrString(_o.ptr(), "__getitem__"))
        {
            int N = boost::python::len(_o);
            for (int i = 0; i < N; ++i)
            {
                block_t ks = boost::python::extract<block_t>(_o[i][0])();
                block_t kt = boost::python::extract<block_t>(_o[i][1])();
                double p = boost::python::extract<double>(_o[i][2])();
                if (std::isnan(p) || std::isinf(p) || p <= 0)
                    continue;
                probs[make_pair(ks, kt)] += p;
            }
        }
    }

private:
    boost::python::object _o;
};

struct graph_rewire_block
{
    graph_rewire_block(bool traditional, bool micro) :
        traditional(traditional), micro(micro) {}
    bool traditional;
    bool micro;

    template <class Graph, class EdgeIndexMap, class CorrProb, class PinMap,
              class BlockProp>
    void operator()(Graph& g, EdgeIndexMap edge_index, CorrProb corr_prob,
                    PinMap pin, pair<bool, bool> rest, bool configuration,
                    BlockProp block_prop, pair<size_t, bool> iter_sweep,
                    std::tuple<bool, bool, bool> cache_verbose, size_t& pcount,
                    rng_t& rng) const
    {
        if (traditional)
        {
            if (micro)
                graph_rewire<MicroTradBlockRewireStrategy>()
                    (g, edge_index, corr_prob, pin, rest.first, rest.second,
                     configuration, iter_sweep, cache_verbose, pcount, rng,
                     PropertyBlock<BlockProp>(block_prop));
            else
                graph_rewire<CanTradBlockRewireStrategy>()
                    (g, edge_index, corr_prob, pin, rest.first, rest.second,
                     configuration, iter_sweep, cache_verbose, pcount, rng,
                     PropertyBlock<BlockProp>(block_prop));
        }
        else
        {
            graph_rewire<ProbabilisticRewireStrategy>()
                (g, edge_index, corr_prob, pin, rest.first, rest.second,
                 configuration, iter_sweep, cache_verbose, pcount, rng,
                 PropertyBlock<BlockProp>(block_prop));
        }
    }
};


struct graph_rewire_correlated
{
    template <class Graph, class EdgeIndexMap, class CorrProb, class PinMap,
              class BlockProp>
    void operator()(Graph& g, EdgeIndexMap edge_index, CorrProb corr_prob,
                    PinMap pin, bool self_loops, bool parallel_edges,
                    bool configuration, pair<size_t, bool> iter_sweep,
                    std::tuple<bool, bool, bool> cache_verbose, size_t& pcount,
                    rng_t& rng, BlockProp block_prop) const
    {
        graph_rewire<CorrelatedRewireStrategy>()
            (g, edge_index, corr_prob, pin, self_loops, parallel_edges,
             configuration, iter_sweep, cache_verbose, pcount, rng,
             PropertyBlock<BlockProp>(block_prop));
    }
};


size_t random_rewire(GraphInterface& gi, string strat, size_t niter,
                     bool no_sweep, bool self_loops, bool parallel_edges,
                     bool configuration, bool traditional, bool micro,
                     bool persist, boost::python::object corr_prob,
                     boost::any apin, boost::any block, bool cache, rng_t& rng,
                     bool verbose)
{
    PythonFuncWrap corr(corr_prob);
    size_t pcount = 0;

    typedef eprop_map_t<uint8_t>::type emap_t;

    emap_t::unchecked_t pin =
        any_cast<emap_t>(apin).get_unchecked(gi.get_edge_index_range());

    if (strat == "erdos")
    {
        run_action<graph_tool::detail::never_reversed>()
            (gi,
             [&](auto&& graph)
             {
                 return graph_rewire<ErdosRewireStrategy>()(
                     std::forward<decltype(graph)>(graph), gi.get_edge_index(),
                     corr, pin, self_loops, parallel_edges, configuration,
                     make_pair(niter, no_sweep),
                     std::make_tuple(persist, cache, verbose), pcount, rng);
             })();
    }
    else if (strat == "configuration")
    {
        run_action<graph_tool::detail::never_reversed>()
            (gi,
             [&](auto&& graph)
             {
                 return graph_rewire<RandomRewireStrategy>()(
                     std::forward<decltype(graph)>(graph), gi.get_edge_index(),
                     corr, pin, self_loops, parallel_edges, configuration,
                     make_pair(niter, no_sweep),
                     std::make_tuple(persist, cache, verbose), pcount, rng);
             })();
    }
    else if (strat == "constrained-configuration")
    {
        if (block.empty())
        {
            run_action<graph_tool::detail::never_reversed>()
                (gi,
                 [&](auto&& graph)
                 {
                     return graph_rewire<CorrelatedRewireStrategy>()(
                         std::forward<decltype(graph)>(graph),
                         gi.get_edge_index(), corr, pin, self_loops,
                         parallel_edges, configuration,
                         make_pair(niter, no_sweep),
                         std::make_tuple(persist, cache, verbose), pcount, rng);
                 })();
        }
        else
        {
            run_action<graph_tool::detail::never_reversed>()
                (gi,
                 [&](auto&& graph, auto&& a2)
                 {
                     return graph_rewire_correlated()
                         (std::forward<decltype(graph)>(graph),
                          gi.get_edge_index(), corr, pin, self_loops,
                          parallel_edges, configuration,
                          make_pair(niter, no_sweep),
                          std::make_tuple(persist, cache, verbose), pcount, rng,
                          std::forward<decltype(a2)>(a2));
                 },
                 vertex_properties())(block);
        }
    }
    else if (strat == "probabilistic-configuration")
    {
        run_action<>()
            (gi,
             [&](auto&& graph)
             {
                 return graph_rewire<ProbabilisticRewireStrategy>()(
                     std::forward<decltype(graph)>(graph), gi.get_edge_index(),
                     corr, pin, self_loops, parallel_edges, configuration,
                     make_pair(niter, no_sweep),
                     std::make_tuple(persist, cache, verbose), pcount, rng);
             })();
    }
    else if (strat == "blockmodel")
    {
        run_action<>()
            (gi,
             [&](auto&& graph, auto&& a2)
             {
                 return graph_rewire_block(traditional, micro)(
                     std::forward<decltype(graph)>(graph), gi.get_edge_index(),
                     corr, pin, make_pair(self_loops, parallel_edges),
                     configuration, std::forward<decltype(a2)>(a2),
                     make_pair(niter, no_sweep),
                     std::make_tuple(persist, cache, verbose), pcount, rng);
             },
             vertex_properties())(block);
    }
    else
    {
        throw ValueException("invalid random rewire strategy: " + strat);
    }
    return pcount;
}
