/* -*- C++ -*-

 *

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

 *

 * Copyright (C) 2003-2006

 * 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.

 *

 */

///\file

///\brief Implementation of the LEMON-GLPK lp solver interface.

#include <lemon/lp_glpk.h>

//#include <iostream>

namespace lemon {

  LpGlpk::LpGlpk() : Parent() {

    rows = _lp_bits::LpId(1);

    cols = _lp_bits::LpId(1);

    lp = lpx_create_prob();

    lpx_create_index(lp);

    ///\todo control function for this:

    lpx_set_int_parm(lp, LPX_K_DUAL, 1);

    messageLevel(0);

  }

  LpGlpk::LpGlpk(const LpGlpk &glp) : Parent() {

    rows = _lp_bits::LpId(1);

    cols = _lp_bits::LpId(1);

    lp = lpx_create_prob();

    lpx_create_index(lp);

    ///\todo control function for this:

    lpx_set_int_parm(lp, LPX_K_DUAL, 1);

    messageLevel(0);

    //Coefficient matrix, row bounds

    lpx_add_rows(lp, lpx_get_num_rows(glp.lp));

    lpx_add_cols(lp, lpx_get_num_cols(glp.lp));

    int len;

    int ind[1+lpx_get_num_cols(glp.lp)];

    Value val[1+lpx_get_num_cols(glp.lp)];

    for (int i=1;i<=lpx_get_num_rows(glp.lp);++i)

      {

	len=lpx_get_mat_row(glp.lp,i,ind,val);

	lpx_set_mat_row(lp, i,len,ind,val);

	lpx_set_row_bnds(lp,i,lpx_get_row_type(glp.lp,i),

			 lpx_get_row_lb(glp.lp,i),lpx_get_row_ub(glp.lp,i));

      }

    //Objective function, coloumn bounds

    lpx_set_obj_dir(lp, lpx_get_obj_dir(glp.lp));

    //Objectif function's constant term treated separately

    lpx_set_obj_coef(lp,0,lpx_get_obj_coef(glp.lp,0));

    for (int i=1;i<=lpx_get_num_cols(glp.lp);++i)

      {

	lpx_set_obj_coef(lp,i,lpx_get_obj_coef(glp.lp,i));

	lpx_set_col_bnds(lp,i,lpx_get_col_type(glp.lp,i),

			 lpx_get_col_lb(glp.lp,i),lpx_get_col_ub(glp.lp,i));

      }

  }

  LpGlpk::~LpGlpk() {

    lpx_delete_prob(lp);

  }

  int LpGlpk::_addCol() { 

    int i=lpx_add_cols(lp, 1);

    _setColLowerBound(i, -INF);

    _setColUpperBound(i, INF);

    return i;

  }

  ///\e

  LpSolverBase &LpGlpk::_newLp()

  {

    LpGlpk* newlp=new LpGlpk;

    return *newlp;

  }

  ///\e

  LpSolverBase &LpGlpk::_copyLp()

  {

    LpGlpk* newlp=new LpGlpk(*this);

    return *newlp;

  }

  int LpGlpk::_addRow() { 

    int i=lpx_add_rows(lp, 1);

    return i;

  }

  void LpGlpk::_eraseCol(int i) {

    int ca[2];

    ca[1]=i;

    lpx_del_cols(lp, 1, ca);

  }

  void LpGlpk::_eraseRow(int i) {

    int ra[2];

    ra[1]=i;

    lpx_del_rows(lp, 1, ra);

  }

  void LpGlpk::_getColName(int c, std::string & name) const

  {

    char *n = lpx_get_col_name(lp,c);

    name = n?n:"";

  }

  void LpGlpk::_setColName(int c, const std::string & name)

  {

    lpx_set_col_name(lp,c,const_cast<char*>(name.c_str()));

  }

  int LpGlpk::_colByName(const std::string& name) const

  {

    int k = lpx_find_col(lp, const_cast<char*>(name.c_str()));

    return k > 0 ? k : -1; 

  }

  void LpGlpk::_setRowCoeffs(int i, ConstRowIterator b, ConstRowIterator e) 

  {

    std::vector<int> indices;

    std::vector<Value> values;

    indices.push_back(0);

    values.push_back(0);

    for(ConstRowIterator it=b; it!=e; ++it) {

      indices.push_back(it->first);

      values.push_back(it->second);

    }

    lpx_set_mat_row(lp, i, values.size() - 1, &indices[0], &values[0]);

  }

  void LpGlpk::_getRowCoeffs(int ix, RowIterator b) const

  {

    int length = lpx_get_mat_row(lp, ix, 0, 0);

    std::vector<int> indices(length + 1);

    std::vector<Value> values(length + 1);

    lpx_get_mat_row(lp, ix, &indices[0], &values[0]);

    for (int i = 1; i <= length; ++i) {

      *b = std::make_pair(indices[i], values[i]);

      ++b;

    }

  }

  void LpGlpk::_setColCoeffs(int ix, ConstColIterator b, ConstColIterator e) {

    std::vector<int> indices;

    std::vector<Value> values;

    indices.push_back(0);

    values.push_back(0);

    for(ConstColIterator it=b; it!=e; ++it) {

      indices.push_back(it->first);

      values.push_back(it->second);

    }

    lpx_set_mat_col(lp, ix, values.size() - 1, &indices[0], &values[0]);

  }

  void LpGlpk::_getColCoeffs(int ix, ColIterator b) const

  {

    int length = lpx_get_mat_col(lp, ix, 0, 0);

    std::vector<int> indices(length + 1);

    std::vector<Value> values(length + 1);

    lpx_get_mat_col(lp, ix, &indices[0], &values[0]);

    for (int i = 1; i <= length; ++i) {

      *b = std::make_pair(indices[i], values[i]);

      ++b;

    }

  }

  void LpGlpk::_setCoeff(int ix, int jx, Value value) 

  {

    if (lpx_get_num_cols(lp) < lpx_get_num_rows(lp)) {

      int length=lpx_get_mat_row(lp, ix, 0, 0);

      std::vector<int> indices(length + 2);

      std::vector<Value> values(length + 2);

      lpx_get_mat_row(lp, ix, &indices[0], &values[0]);

      //The following code does not suppose that the elements of the

      //array indices are sorted

      bool found=false;

      for (int i = 1; i <= length; ++i) {

        if (indices[i]==jx){

          found=true;

          values[i]=value;

          break;

        }

      }

      if (!found){

        ++length;

        indices[length]=jx;

        values[length]=value;

      }

      lpx_set_mat_row(lp, ix, length, &indices[0], &values[0]);

    } else {

      int length=lpx_get_mat_col(lp, jx, 0, 0);

      std::vector<int> indices(length + 2);

      std::vector<Value> values(length + 2);

      lpx_get_mat_col(lp, jx, &indices[0], &values[0]);

      //The following code does not suppose that the elements of the

      //array indices are sorted

      bool found=false;

      for (int i = 1; i <= length; ++i) {

        if (indices[i]==jx){

          found=true;

          values[i]=value;

          break;

        }

      }

      if (!found){

        ++length;

        indices[length]=ix;

        values[length]=value;

      }

      lpx_set_mat_col(lp, jx, length, &indices[0], &values[0]);

    }

  }

  LpGlpk::Value LpGlpk::_getCoeff(int ix, int jx) const

  {

    int length=lpx_get_mat_row(lp, ix, 0, 0);

    std::vector<int> indices(length + 1);

    std::vector<Value> values(length + 1);

    lpx_get_mat_row(lp, ix, &indices[0], &values[0]);

    //The following code does not suppose that the elements of the

    //array indices are sorted

    for (int i = 1; i <= length; ++i) {

      if (indices[i]==jx){

	return values[i];

      }

    }

    return 0;

  }

  void LpGlpk::_setColLowerBound(int i, Value lo)

  {

    if (lo==INF) {

      //FIXME error

    }

    int b=lpx_get_col_type(lp, i);

    double up=lpx_get_col_ub(lp, i);	

    if (lo==-INF) {

      switch (b) {

      case LPX_FR:

      case LPX_LO:

	lpx_set_col_bnds(lp, i, LPX_FR, lo, up);

	break;

      case LPX_UP:

	break;

      case LPX_DB:

      case LPX_FX:

	lpx_set_col_bnds(lp, i, LPX_UP, lo, up);

	break;

      default: ;

	//FIXME error

      }

    } else {

      switch (b) {

      case LPX_FR:

      case LPX_LO:

	lpx_set_col_bnds(lp, i, LPX_LO, lo, up);

	break;

      case LPX_UP:	  

      case LPX_DB:

      case LPX_FX:

	if (lo==up) 

	  lpx_set_col_bnds(lp, i, LPX_FX, lo, up);

	else 

	  lpx_set_col_bnds(lp, i, LPX_DB, lo, up);

	break;

      default: ;

	//FIXME error

      }

    }

  }

  LpGlpk::Value LpGlpk::_getColLowerBound(int i) const

  {

    int b=lpx_get_col_type(lp, i);

      switch (b) {

      case LPX_LO:

      case LPX_DB:

      case LPX_FX:

	return lpx_get_col_lb(lp, i);	

      default: ;

	return -INF;

      }

  }

  void LpGlpk::_setColUpperBound(int i, Value up)

  {

    if (up==-INF) {

      //FIXME error

    }

    int b=lpx_get_col_type(lp, i);

    double lo=lpx_get_col_lb(lp, i);

    if (up==INF) {

      switch (b) {

      case LPX_FR:

      case LPX_LO:

	break;

      case LPX_UP:

	lpx_set_col_bnds(lp, i, LPX_FR, lo, up);

	break;

      case LPX_DB:

      case LPX_FX:

	lpx_set_col_bnds(lp, i, LPX_LO, lo, up);

	break;

      default: ;

	//FIXME error

      }

    } else {

      switch (b) {

      case LPX_FR:

	lpx_set_col_bnds(lp, i, LPX_UP, lo, up);

	break;

      case LPX_UP:

	lpx_set_col_bnds(lp, i, LPX_UP, lo, up);

	break;

      case LPX_LO:

      case LPX_DB:

      case LPX_FX:

	if (lo==up) 

	  lpx_set_col_bnds(lp, i, LPX_FX, lo, up);

	else 

	  lpx_set_col_bnds(lp, i, LPX_DB, lo, up);

	break;

      default: ;

	//FIXME error

      }

    }

  }

  LpGlpk::Value LpGlpk::_getColUpperBound(int i) const

  {

    int b=lpx_get_col_type(lp, i);

      switch (b) {

      case LPX_UP:

      case LPX_DB:

      case LPX_FX:

	return lpx_get_col_ub(lp, i);	

      default: ;

	return INF;

      }

  }

  void LpGlpk::_setRowBounds(int i, Value lb, Value ub)

  {

    //Bad parameter

    if (lb==INF || ub==-INF) {

      //FIXME error

    }

    if (lb == -INF){

      if (ub == INF){

	lpx_set_row_bnds(lp, i, LPX_FR, lb, ub);

      }

      else{

	lpx_set_row_bnds(lp, i, LPX_UP, lb, ub);

      }

    }

    else{

      if (ub==INF){

	lpx_set_row_bnds(lp, i, LPX_LO, lb, ub);

      }

      else{

	if (lb == ub){

	  lpx_set_row_bnds(lp, i, LPX_FX, lb, ub);

	}

	else{

	  lpx_set_row_bnds(lp, i, LPX_DB, lb, ub);

	}

      }

    }

  }

  void LpGlpk::_getRowBounds(int i, Value &lb, Value &ub) const

  {

    int b=lpx_get_row_type(lp, i);

    switch (b) {

    case LPX_FR:

    case LPX_UP:

      lb = -INF;

	break;

    default: 

      lb=lpx_get_row_lb(lp, i);

    }

    switch (b) {

    case LPX_FR:

    case LPX_LO:

      ub = INF;

	break;

    default: 

      ub=lpx_get_row_ub(lp, i);

    }

  }

  void LpGlpk::_setObjCoeff(int i, Value obj_coef)

  {

    //i=0 means the constant term (shift)

    lpx_set_obj_coef(lp, i, obj_coef);

  }

  LpGlpk::Value LpGlpk::_getObjCoeff(int i) const {

    //i=0 means the constant term (shift)

    return lpx_get_obj_coef(lp, i);

  }

  void LpGlpk::_clearObj()

  {

    for (int i=0;i<=lpx_get_num_cols(lp);++i){

      lpx_set_obj_coef(lp, i, 0);

    }

  }

  LpGlpk::SolveExitStatus LpGlpk::_solve()

  {

    // A way to check the problem to be solved

    //lpx_write_cpxlp(lp,"naittvan.cpx");    

    lpx_std_basis(lp);

    int i =  lpx_simplex(lp);

    switch (i) {

    case LPX_E_OK: 

      return SOLVED;

    default:

      return UNSOLVED;

    }

  }

  LpGlpk::Value LpGlpk::_getPrimal(int i) const

  {

    return lpx_get_col_prim(lp,i);

  }

  LpGlpk::Value LpGlpk::_getDual(int i) const

  {

    return lpx_get_row_dual(lp,i);

  }

  LpGlpk::Value LpGlpk::_getPrimalValue() const

  {

    return lpx_get_obj_val(lp);

  }

  bool LpGlpk::_isBasicCol(int i) const

  {

    return (lpx_get_col_stat(lp, i)==LPX_BS);

  }

  LpGlpk::SolutionStatus LpGlpk::_getPrimalStatus() const

  {

    int stat=  lpx_get_status(lp);

    switch (stat) {

    case LPX_UNDEF://Undefined (no solve has been run yet)

      return UNDEFINED;

    case LPX_NOFEAS://There is no feasible solution (primal, I guess)

    case LPX_INFEAS://Infeasible 

      return INFEASIBLE;

    case LPX_UNBND://Unbounded

      return INFINITE;

    case LPX_FEAS://Feasible

      return FEASIBLE;

    case LPX_OPT://Feasible

      return OPTIMAL;

    default:

      return UNDEFINED; //to avoid gcc warning

      //FIXME error

    }

  }

  LpGlpk::SolutionStatus LpGlpk::_getDualStatus() const

  {

    switch (lpx_get_dual_stat(lp)) {

    case LPX_D_UNDEF://Undefined (no solve has been run yet)

      return UNDEFINED;

    case LPX_D_NOFEAS://There is no dual feasible solution 

//    case LPX_D_INFEAS://Infeasible 

      return INFEASIBLE;

    case LPX_D_FEAS://Feasible    

      switch (lpx_get_status(lp)) {

      case LPX_NOFEAS:

	return INFINITE;

      case LPX_OPT:

	return OPTIMAL;

      default:

	return FEASIBLE;

      }

    default:

      return UNDEFINED; //to avoid gcc warning

      //FIXME error

    }

  }

  LpGlpk::ProblemTypes LpGlpk::_getProblemType() const

  {

      //int stat=  lpx_get_status(lp);

    int statp=  lpx_get_prim_stat(lp);

    int statd=  lpx_get_dual_stat(lp);

    if (statp==LPX_P_FEAS && statd==LPX_D_FEAS)

	return PRIMAL_DUAL_FEASIBLE;

    if (statp==LPX_P_FEAS && statd==LPX_D_NOFEAS)

	return PRIMAL_FEASIBLE_DUAL_INFEASIBLE;

    if (statp==LPX_P_NOFEAS && statd==LPX_D_FEAS)

	return PRIMAL_INFEASIBLE_DUAL_FEASIBLE;

    if (statp==LPX_P_NOFEAS && statd==LPX_D_NOFEAS)

	return PRIMAL_DUAL_INFEASIBLE;

    //In all other cases

    return UNKNOWN;

  }

  void LpGlpk::_setMax()

  {

    lpx_set_obj_dir(lp, LPX_MAX);

  }

  void LpGlpk::_setMin()

  {

    lpx_set_obj_dir(lp, LPX_MIN);

  }

  bool LpGlpk::_isMax() const

  {

    return (lpx_get_obj_dir(lp)==LPX_MAX);

  }

  void LpGlpk::messageLevel(int m)

  {

    lpx_set_int_parm(lp, LPX_K_MSGLEV, m);

  }

  void LpGlpk::presolver(bool b)

  {

    lpx_set_int_parm(lp, LPX_K_PRESOL, b);

  }

} //END OF NAMESPACE LEMON