// -*- c++ -*-

#ifndef LEMON_MIN_COST_GEN_FLOW_H

#define LEMON_MIN_COST_GEN_FLOW_H

#include <iostream>

//#include <fstream>

#include <lemon/smart_graph.h>

#include <lemon/list_graph.h>

//#include <lemon/dimacs.h>

//#include <lemon/time_measure.h>

//#include <graph_wrapper.h>

#include <lemon/preflow.h>

//#include <augmenting_flow.h>

//#include <preflow_res.h>

#include <../merge_node_graph_wrapper.h>

#include <lemon/../work/marci/lp/lp_solver_wrapper.h>

namespace lemon {

  template<typename Edge, typename EdgeIndexMap> 

  class PrimalMap {

  protected:

    LPSolverWrapper* lp;

    EdgeIndexMap* edge_index_map;

  public:

    PrimalMap(LPSolverWrapper& _lp, EdgeIndexMap& _edge_index_map) : 

      lp(&_lp), edge_index_map(&_edge_index_map) { }

    double operator[](Edge e) const { 

      return lp->getPrimal((*edge_index_map)[e]);

    }

  };

  // excess: rho-delta

  template <typename Graph, typename Num,

	    typename Excess=typename Graph::template NodeMap<Num>, 

	    typename LCapMap=typename Graph::template EdgeMap<Num>,

	    typename CapMap=typename Graph::template EdgeMap<Num>,

            typename FlowMap=typename Graph::template EdgeMap<Num>,

	    typename CostMap=typename Graph::template EdgeMap<Num> >

  class MinCostGenFlow {

  protected:

    const Graph& g;

    const Excess& excess;

    const LCapMap& lcapacity;

    const CapMap& capacity;

    FlowMap& flow;

    const CostMap& cost;

  public:

    MinCostGenFlow(const Graph& _g, const Excess& _excess, 

		   const LCapMap& _lcapacity, const CapMap& _capacity, 

		   FlowMap& _flow, 

		   const CostMap& _cost) :

      g(_g), excess(_excess), lcapacity(_lcapacity),

      capacity(_capacity), flow(_flow), cost(_cost) { }

    bool feasible() {

      //      std::cout << "making new vertices..." << std::endl; 

      typedef ListGraph Graph2;

      Graph2 g2;

      typedef MergeEdgeGraphWrapper<const Graph, Graph2> GW;

      //      std::cout << "merging..." << std::endl; 

      GW gw(g, g2);

      typename GW::Node s(INVALID, g2.addNode(), true);

      typename GW::Node t(INVALID, g2.addNode(), true);

      typedef SmartGraph Graph3;

      //      std::cout << "making extender graph..." << std::endl; 

      typedef NewEdgeSetGraphWrapper2<GW, Graph3> GWW;

//       {

// 	checkConcept<StaticGraph, GWW>();   

//       }

      GWW gww(gw);

      typedef AugmentingGraphWrapper<GW, GWW> GWWW;

      GWWW gwww(gw, gww);

      //      std::cout << "making new edges..." << std::endl; 

      typename GWWW::template EdgeMap<Num> translated_cap(gwww);

      for (typename GW::EdgeIt e(gw); e!=INVALID; ++e)

      translated_cap.set(typename GWWW::Edge(e,INVALID,false), 

			 capacity[e]-lcapacity[e]);

      Num expected=0;

      //      std::cout << "making new edges 2..." << std::endl; 

      for (typename Graph::NodeIt n(g); n!=INVALID; ++n) {

	Num a=0;

	for (typename Graph::InEdgeIt e(g, n); e!=INVALID; ++e)

	  a+=lcapacity[e];

	for (typename Graph::OutEdgeIt e(g, n); e!=INVALID; ++e) 

	  a-=lcapacity[e];

	if (excess[n]>a) {

	  typename GWW::Edge e=

	    gww.addEdge(typename GW::Node(n,INVALID,false), t);

	  translated_cap.set(typename GWWW::Edge(INVALID, e, true), 

			     excess[n]-a);

	}

	if (excess[n]<a) {

	  typename GWW::Edge e=

	    gww.addEdge(s, typename GW::Node(n,INVALID,false));

	  translated_cap.set(typename GWWW::Edge(INVALID, e, true), 

			     a-excess[n]);

	  expected+=a-excess[n];

	}

      }

      //      std::cout << "preflow..." << std::endl; 

      typename GWWW::template EdgeMap<Num> translated_flow(gwww, 0);

      Preflow<GWWW, Num> preflow(gwww, s, t, 

				 translated_cap, translated_flow);

      preflow.run();

      //      std::cout << "fv: " << preflow.flowValue() << std::endl; 

      //      std::cout << "expected: " << expected << std::endl; 

      for (typename Graph::EdgeIt e(g); e!=INVALID; ++e) {

	typename GW::Edge ew(e, INVALID, false);

	typename GWWW::Edge ewww(ew, INVALID, false);

	flow.set(e, translated_flow[ewww]+lcapacity[e]);

      }

      return (expected>=preflow.flowValue());

    }

    void run() {

      LPSolverWrapper lp;

      lp.setMinimize();

      typedef LPSolverWrapper::ColIt ColIt;

      typedef LPSolverWrapper::RowIt RowIt;

      typedef typename Graph::template EdgeMap<ColIt> EdgeIndexMap;

      EdgeIndexMap edge_index_map(g);

      PrimalMap<typename Graph::Edge, EdgeIndexMap> lp_flow(lp, edge_index_map);

      for (typename Graph::EdgeIt e(g); e!=INVALID; ++e) {

	ColIt col_it=lp.addCol();

	edge_index_map.set(e, col_it);

	if (lcapacity[e]==capacity[e])

	  lp.setColBounds(col_it, LPX_FX, lcapacity[e], capacity[e]);

	else 

	  lp.setColBounds(col_it, LPX_DB, lcapacity[e], capacity[e]);

	lp.setObjCoef(col_it, cost[e]);

      }

      for (typename Graph::NodeIt n(g); n!=INVALID; ++n) {

	typename Graph::template EdgeMap<Num> coeffs(g, 0);

	for (typename Graph::InEdgeIt e(g, n); e!=INVALID; ++e)

	coeffs.set(e, coeffs[e]+1);

	for (typename Graph::OutEdgeIt e(g, n); e!=INVALID; ++e) 

	coeffs.set(e, coeffs[e]-1);

	RowIt row_it=lp.addRow();

	typename std::vector< std::pair<ColIt, double> > row;

	//std::cout << "node:" <<g.id(n)<<std::endl;

	for (typename Graph::EdgeIt e(g); e!=INVALID; ++e) {

	  if (coeffs[e]!=0) {

	    //std::cout << " edge:" <<g.id(e)<<" "<<coeffs[e];

	    row.push_back(std::make_pair(edge_index_map[e], coeffs[e]));

	  }

	}

	//std::cout << std::endl;

	lp.setRowCoeffs(row_it, row.begin(), row.end());

	lp.setRowBounds(row_it, LPX_FX, 0.0, 0.0);

      }

      lp.solveSimplex();

      //std::cout << lp.colNum() << std::endl;

      //std::cout << lp.rowNum() << std::endl;

      //std::cout << "flow value: "<< lp.getObjVal() << std::endl;

      for (typename Graph::EdgeIt e(g); e!=INVALID; ++e) 

      flow.set(e, lp_flow[e]);

    }

  };

} // namespace lemon

#endif //LEMON_MIN_COST_GEN_FLOW_H