//=======================================================================
// Copyright 2013 University of Warsaw.
// Authors: Piotr Wygocki 
//
// 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)
//=======================================================================
#ifndef BOOST_GRAPH_FIND_FLOW_COST_HPP
#define BOOST_GRAPH_FIND_FLOW_COST_HPP

#include <boost/graph/iteration_macros.hpp>

namespace boost {

template<class Graph, class Capacity, class ResidualCapacity, class Weight>
typename property_traits<typename property_map < Graph, edge_capacity_t >::type>::value_type
find_flow_cost(const Graph & g, Capacity capacity, ResidualCapacity residual_capacity, Weight weight) {
    typedef typename property_traits<typename property_map<Graph, edge_weight_t>::const_type>::value_type Cost;

    Cost cost = 0;
    BGL_FORALL_EDGES_T(e, g, Graph) {
        if(get(capacity, e) > Cost(0)) {
            cost +=  (get(capacity, e) - get(residual_capacity, e)) * get(weight, e);
        } 
    }
    return cost;
}

template <class Graph, class P, class T, class R> 
typename property_traits<typename property_map < Graph, edge_capacity_t >::type>::value_type
find_flow_cost(const Graph & g,
               const bgl_named_params<P, T, R>& params) {
    return find_flow_cost(g,
           choose_const_pmap(get_param(params, edge_capacity), g, edge_capacity),
           choose_const_pmap(get_param(params, edge_residual_capacity), 
                       g, edge_residual_capacity),
           choose_const_pmap(get_param(params, edge_weight), g, edge_weight));
}

template <class Graph>
typename property_traits<typename property_map < Graph, edge_capacity_t >::type>::value_type
find_flow_cost(const Graph &g) {
    bgl_named_params<int, buffer_param_t> params(0);
    return find_flow_cost(g, params);
}


} //boost

#endif /* BOOST_GRAPH_FIND_FLOW_COST_HPP */