/* -*- C++ -*-

 * src/lemon/lp_glpk.cc - Part of LEMON, a generic C++ optimization library

 *

 * Copyright (C) 2005 Egervary Jeno Kombinatorikus Optimalizalasi Kutatocsoport

 * (Egervary Combinatorial Optimization Research Group, 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.

 *

 */

#ifndef LEMON_LP_GLPK_CC

#define LEMON_LP_GLPK_CC

///\file

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

#include <lemon/lp_glpk.h>

namespace lemon {

    /// \e

    int LpGlpk::_addCol() { 

	int i=lpx_add_cols(lp, 1);

	_setColLowerBound(i, -INF);

	_setColUpperBound(i, INF);

	return i;

    }

    /// \e

    int LpGlpk::_addRow() { 

	int i=lpx_add_rows(lp, 1);

	return i;

    }

    void LpGlpk::_setRowCoeffs(int i, 

			       int length,

			       const int   * indices, 

			       const Value   * values )

    {

      lpx_set_mat_row(lp, i, length,

		      const_cast<int * >(indices) ,

		      const_cast<Value * >(values));

    }

    void LpGlpk::_setColCoeffs(int i, 

			       int length,

			       const int   * indices, 

			       const Value   * values)

    {

      lpx_set_mat_col(lp, i, length,

		      const_cast<int * >(indices),

		      const_cast<Value * >(values));

    }

    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

	}

      }

    }

    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

	}

      }

    }

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

    {

      if (lo==INF) {

	//FIXME error

      }

      int b=lpx_get_row_type(lp, i);

      double up=lpx_get_row_ub(lp, i);	

      if (lo==-INF) {

	switch (b) {

	case LPX_FR:

	case LPX_LO:

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

	  break;

	case LPX_UP:

	  break;

	case LPX_DB:

	case LPX_FX:

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

	  break;

	default: ;

	  //FIXME error

	}

      } else {

	switch (b) {

	case LPX_FR:

	case LPX_LO:

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

	  break;

	case LPX_UP:	  

	case LPX_DB:

	case LPX_FX:

	  if (lo==up) 

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

	  else 

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

	  break;

	default: ;

	  //FIXME error

	}

      }

    }

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

  {

    if (up==-INF) {

      //FIXME error

    }

    int b=lpx_get_row_type(lp, i);

    double lo=lpx_get_row_lb(lp, i);

    if (up==INF) {

      switch (b) {

      case LPX_FR:

      case LPX_LO:

	break;

      case LPX_UP:

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

	break;

      case LPX_DB:

      case LPX_FX:

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

	break;

      default: ;

	//FIXME error

      }

    } else {

      switch (b) {

      case LPX_FR:

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

	break;

      case LPX_UP:

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

	break;

      case LPX_LO:

      case LPX_DB:

      case LPX_FX:

	if (lo==up) 

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

	else 

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

	break;

      default: ;

	//FIXME error

      }

    }

  }

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

  {

    lpx_set_obj_coef(lp, i, obj_coef);

  }

  LpGlpk::SolveExitStatus LpGlpk::_solve()

  {

    int i=  lpx_simplex(lp);

    switch (i) {

    case LPX_E_OK: 

      return SOLVED;

      break;

    default:

      return UNSOLVED;

    }

  }

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

  {

    return lpx_get_col_prim(lp,i);

  }

  LpGlpk::Value LpGlpk::_getPrimalValue()

  {

    return lpx_get_obj_val(lp);

  }

  LpGlpk::SolutionStatus LpGlpk::_getPrimalStatus()

  {

    int stat=  lpx_get_status(lp);

    switch (stat) {

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

      return UNDEFINED;

      break;

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

    case LPX_INFEAS://Infeasible 

      return INFEASIBLE;

      break;

    case LPX_UNBND://Unbounded

      return INFINITE;

      break;

    case LPX_FEAS://Feasible

      return FEASIBLE;

      break;

    case LPX_OPT://Feasible

      return OPTIMAL;

      break;

    default:

      return UNDEFINED; //to avoid gcc warning

      //FIXME error

    }

  }

  void LpGlpk::_setMax()

  {

      lpx_set_obj_dir(lp, LPX_MAX);

   }

  void LpGlpk::_setMin()

  {

      lpx_set_obj_dir(lp, LPX_MIN);

   }

} //END OF NAMESPACE LEMON

#endif //LEMON_LP_GLPK_CC