/* -*- mode: C++; indent-tabs-mode: nil; -*-

 *

 * This file is a part of LEMON, a generic C++ optimization library.

 *

 * Copyright (C) 2003-2009

 * Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

 * (Egervary Research Group on Combinatorial Optimization, EGRES).

 *

 * Permission to use, modify and distribute this software is granted

 * provided that this copyright notice appears in all copies. For

 * precise terms see the accompanying LICENSE file.

 *

 * This software is provided "AS IS" with no warranty of any kind,

 * express or implied, and with no claim as to its suitability for any

 * purpose.

 *

 */

///\ingroup tools

///\file

///\brief DIMACS problem solver.

///

/// This program solves various problems given in DIMACS format.

///

/// See

/// \code

///   dimacs-solver --help

/// \endcode

/// for more info on usage.

#include <iostream>

#include <fstream>

#include <cstring>

#include <lemon/smart_graph.h>

#include <lemon/dimacs.h>

#include <lemon/lgf_writer.h>

#include <lemon/time_measure.h>

#include <lemon/arg_parser.h>

#include <lemon/error.h>

#include <lemon/dijkstra.h>

#include <lemon/preflow.h>

#include <lemon/matching.h>

#include <lemon/network_simplex.h>

using namespace lemon;

typedef SmartDigraph Digraph;

DIGRAPH_TYPEDEFS(Digraph);

typedef SmartGraph Graph;

template<class Value>

void solve_sp(ArgParser &ap, std::istream &is, std::ostream &,

              DimacsDescriptor &desc)

{

  bool report = !ap.given("q");

  Digraph g;

  Node s;

  Digraph::ArcMap<Value> len(g);

  Timer t;

  t.restart();

  readDimacsSp(is, g, len, s, desc);

  if(report) std::cerr << "Read the file: " << t << '\n';

  t.restart();

  Dijkstra<Digraph, Digraph::ArcMap<Value> > dij(g,len);

  if(report) std::cerr << "Setup Dijkstra class: " << t << '\n';

  t.restart();

  dij.run(s);

  if(report) std::cerr << "Run Dijkstra: " << t << '\n';

}

template<class Value>

void solve_max(ArgParser &ap, std::istream &is, std::ostream &,

               Value infty, DimacsDescriptor &desc)

{

  bool report = !ap.given("q");

  Digraph g;

  Node s,t;

  Digraph::ArcMap<Value> cap(g);

  Timer ti;

  ti.restart();

  readDimacsMax(is, g, cap, s, t, infty, desc);

  if(report) std::cerr << "Read the file: " << ti << '\n';

  ti.restart();

  Preflow<Digraph, Digraph::ArcMap<Value> > pre(g,cap,s,t);

  if(report) std::cerr << "Setup Preflow class: " << ti << '\n';

  ti.restart();

  pre.run();

  if(report) std::cerr << "Run Preflow: " << ti << '\n';

  if(report) std::cerr << "\nMax flow value: " << pre.flowValue() << '\n';  

}

template<class Value>

void solve_min(ArgParser &ap, std::istream &is, std::ostream &,

               Value infty, DimacsDescriptor &desc)

{

  bool report = !ap.given("q");

  Digraph g;

  Digraph::ArcMap<Value> lower(g), cap(g), cost(g);

  Digraph::NodeMap<Value> sup(g);

  Timer ti;

  ti.restart();

  readDimacsMin(is, g, lower, cap, cost, sup, infty, desc);

  ti.stop();

  Value sum_sup = 0;

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

    sum_sup += sup[n];

  }

  if (report) {

    std::cerr << "Sum of supply values: " << sum_sup << "\n";

    if (sum_sup <= 0)

      std::cerr << "GEQ supply contraints are used for NetworkSimplex\n\n";

    else

      std::cerr << "LEQ supply contraints are used for NetworkSimplex\n\n";

  }

  if (report) std::cerr << "Read the file: " << ti << '\n';

  ti.restart();

  NetworkSimplex<Digraph, Value> ns(g);

  ns.lowerMap(lower).capacityMap(cap).costMap(cost).supplyMap(sup);

  if (sum_sup > 0) ns.problemType(ns.LEQ);

  if (report) std::cerr << "Setup NetworkSimplex class: " << ti << '\n';

  ti.restart();

  bool res = ns.run();

  if (report) {

    std::cerr << "Run NetworkSimplex: " << ti << "\n\n";

    std::cerr << "Feasible flow: " << (res ? "found" : "not found") << '\n';

    if (res) std::cerr << "Min flow cost: " << ns.totalCost() << '\n';

  }

}

void solve_mat(ArgParser &ap, std::istream &is, std::ostream &,

              DimacsDescriptor &desc)

{

  bool report = !ap.given("q");

  Graph g;

  Timer ti;

  ti.restart();

  readDimacsMat(is, g, desc);

  if(report) std::cerr << "Read the file: " << ti << '\n';

  ti.restart();

  MaxMatching<Graph> mat(g);

  if(report) std::cerr << "Setup MaxMatching class: " << ti << '\n';

  ti.restart();

  mat.run();

  if(report) std::cerr << "Run MaxMatching: " << ti << '\n';

  if(report) std::cerr << "\nCardinality of max matching: "

                       << mat.matchingSize() << '\n';  

}

template<class Value>

void solve(ArgParser &ap, std::istream &is, std::ostream &os,

           DimacsDescriptor &desc)

{

  std::stringstream iss(static_cast<std::string>(ap["infcap"]));

  Value infty;

  iss >> infty;

  if(iss.fail())

    {

      std::cerr << "Cannot interpret '"

                << static_cast<std::string>(ap["infcap"]) << "' as infinite"

                << std::endl;

      exit(1);

    }

  switch(desc.type)

    {

    case DimacsDescriptor::MIN:

      solve_min<Value>(ap,is,os,infty,desc);

      break;

    case DimacsDescriptor::MAX:

      solve_max<Value>(ap,is,os,infty,desc);

      break;

    case DimacsDescriptor::SP:

      solve_sp<Value>(ap,is,os,desc);

      break;

    case DimacsDescriptor::MAT:

      solve_mat(ap,is,os,desc);

      break;

    default:

      break;

    }

}

int main(int argc, const char *argv[]) {

  typedef SmartDigraph Digraph;

  typedef Digraph::Arc Arc;

  std::string inputName;

  std::string outputName;

  ArgParser ap(argc, argv);

  ap.other("[INFILE [OUTFILE]]",

           "If either the INFILE or OUTFILE file is missing the standard\n"

           "     input/output will be used instead.")

    .boolOption("q", "Do not print any report")

    .boolOption("int","Use 'int' for capacities, costs etc. (default)")

    .optionGroup("datatype","int")

#ifdef HAVE_LONG_LONG

    .boolOption("long","Use 'long long' for capacities, costs etc.")

    .optionGroup("datatype","long")

#endif

    .boolOption("double","Use 'double' for capacities, costs etc.")

    .optionGroup("datatype","double")

    .boolOption("ldouble","Use 'long double' for capacities, costs etc.")

    .optionGroup("datatype","ldouble")

    .onlyOneGroup("datatype")

    .stringOption("infcap","Value used for 'very high' capacities","0")

    .run();

  std::ifstream input;

  std::ofstream output;

  switch(ap.files().size())

    {

    case 2:

      output.open(ap.files()[1].c_str());

      if (!output) {

        throw IoError("Cannot open the file for writing", ap.files()[1]);

      }

    case 1:

      input.open(ap.files()[0].c_str());

      if (!input) {

        throw IoError("File cannot be found", ap.files()[0]);

      }

    case 0:

      break;

    default:

      std::cerr << ap.commandName() << ": too many arguments\n";

      return 1;

    }

  std::istream& is = (ap.files().size()<1 ? std::cin : input);

  std::ostream& os = (ap.files().size()<2 ? std::cout : output);

  DimacsDescriptor desc = dimacsType(is);

  if(!ap.given("q"))

    {

      std::cout << "Problem type: ";

      switch(desc.type)

        {

        case DimacsDescriptor::MIN:

          std::cout << "min";

          break;

        case DimacsDescriptor::MAX:

          std::cout << "max";

          break;

        case DimacsDescriptor::SP:

          std::cout << "sp";

        case DimacsDescriptor::MAT:

          std::cout << "mat";

          break;

        default:

          exit(1);

          break;

        }

      std::cout << "\nNum of nodes: " << desc.nodeNum;

      std::cout << "\nNum of arcs:  " << desc.edgeNum;

      std::cout << "\n\n";

    }

  if(ap.given("double"))

    solve<double>(ap,is,os,desc);

  else if(ap.given("ldouble"))

    solve<long double>(ap,is,os,desc);

#ifdef HAVE_LONG_LONG

  else if(ap.given("long"))

    solve<long long>(ap,is,os,desc);

#endif

  else solve<int>(ap,is,os,desc);

  return 0;

}