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

  *

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

  *

  * Copyright (C) 2003-2010

  * 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.

  *

  */

 #ifndef LEMON_GLPK_H

 #define LEMON_GLPK_H

 ///\file

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

 ///\ingroup lp_group

 #include <lemon/lp_base.h>

 namespace lemon {

   namespace _solver_bits {

     class VoidPtr {

     private:

       void *_ptr;

     public:

       VoidPtr() : _ptr(0) {}

       template <typename T>

       VoidPtr(T* ptr) : _ptr(reinterpret_cast<void*>(ptr)) {}

       template <typename T>

       VoidPtr& operator=(T* ptr) {

         _ptr = reinterpret_cast<void*>(ptr);

         return *this;

       }

       template <typename T>

       operator T*() const { return reinterpret_cast<T*>(_ptr); }

     };

   }

   /// \brief Base interface for the GLPK LP and MIP solver

   ///

   /// This class implements the common interface of the GLPK LP and MIP solver.

   /// \ingroup lp_group

   class GlpkBase : virtual public LpBase {

   protected:

     _solver_bits::VoidPtr lp;

     GlpkBase();

     GlpkBase(const GlpkBase&);

     virtual ~GlpkBase();

   protected:

     virtual int _addCol();

     virtual int _addRow();

     virtual int _addRow(Value l, ExprIterator b, ExprIterator e, Value u);

     virtual void _eraseCol(int i);

     virtual void _eraseRow(int i);

     virtual void _eraseColId(int i);

     virtual void _eraseRowId(int i);

     virtual void _getColName(int col, std::string& name) const;

     virtual void _setColName(int col, const std::string& name);

     virtual int _colByName(const std::string& name) const;

     virtual void _getRowName(int row, std::string& name) const;

     virtual void _setRowName(int row, const std::string& name);

     virtual int _rowByName(const std::string& name) const;

     virtual void _setRowCoeffs(int i, ExprIterator b, ExprIterator e);

     virtual void _getRowCoeffs(int i, InsertIterator b) const;

     virtual void _setColCoeffs(int i, ExprIterator b, ExprIterator e);

     virtual void _getColCoeffs(int i, InsertIterator b) const;

     virtual void _setCoeff(int row, int col, Value value);

     virtual Value _getCoeff(int row, int col) const;

     virtual void _setColLowerBound(int i, Value value);

     virtual Value _getColLowerBound(int i) const;

     virtual void _setColUpperBound(int i, Value value);

     virtual Value _getColUpperBound(int i) const;

     virtual void _setRowLowerBound(int i, Value value);

     virtual Value _getRowLowerBound(int i) const;

     virtual void _setRowUpperBound(int i, Value value);

     virtual Value _getRowUpperBound(int i) const;

     virtual void _setObjCoeffs(ExprIterator b, ExprIterator e);

     virtual void _getObjCoeffs(InsertIterator b) const;

     virtual void _setObjCoeff(int i, Value obj_coef);

     virtual Value _getObjCoeff(int i) const;

     virtual void _setSense(Sense);

     virtual Sense _getSense() const;

     virtual void _clear();

     virtual void _messageLevel(MessageLevel level);

     virtual void _write(std::string file, std::string format) const;

   private:

     static void freeEnv();

     struct FreeEnvHelper {

       ~FreeEnvHelper() {

         freeEnv();

       }

     };

     static FreeEnvHelper freeEnvHelper;

   protected:

     int _message_level;

   public:

     ///Pointer to the underlying GLPK data structure.

     _solver_bits::VoidPtr lpx() {return lp;}

     ///Const pointer to the underlying GLPK data structure.

     _solver_bits::VoidPtr lpx() const {return lp;}

     ///Returns the constraint identifier understood by GLPK.

     int lpxRow(Row r) const { return rows(id(r)); }

     ///Returns the variable identifier understood by GLPK.

     int lpxCol(Col c) const { return cols(id(c)); }

 #ifdef DOXYGEN

     /// Write the problem or the solution to a file in the given format

     /// This function writes the problem or the solution

     /// to a file in the given format.

     /// Trying to write in an unsupported format will trigger

     /// \ref UnsupportedFormatError.

     /// \param file The file path

     /// \param format The output file format.

     /// Supportted formats are "MPS" and "LP".

     void write(std::string file, std::string format = "MPS") const {}

 #endif

   };

   /// \brief Interface for the GLPK LP solver

   ///

   /// This class implements an interface for the GLPK LP solver.

   ///\ingroup lp_group

   class GlpkLp : public LpSolver, public GlpkBase {

   public:

     ///\e

     GlpkLp();

     ///\e

     GlpkLp(const GlpkLp&);

     ///\e

     virtual GlpkLp* cloneSolver() const;

     ///\e

     virtual GlpkLp* newSolver() const;

   private:

     mutable std::vector<double> _primal_ray;

     mutable std::vector<double> _dual_ray;

     void _clear_temporals();

   protected:

     virtual const char* _solverName() const;

     virtual SolveExitStatus _solve();

     virtual Value _getPrimal(int i) const;

     virtual Value _getDual(int i) const;

     virtual Value _getPrimalValue() const;

     virtual VarStatus _getColStatus(int i) const;

     virtual VarStatus _getRowStatus(int i) const;

     virtual Value _getPrimalRay(int i) const;

     virtual Value _getDualRay(int i) const;

     virtual ProblemType _getPrimalType() const;

     virtual ProblemType _getDualType() const;

   public:

     ///Solve with primal simplex

     SolveExitStatus solvePrimal();

     ///Solve with dual simplex

     SolveExitStatus solveDual();

   private:

     bool _presolve;

   public:

     ///Turns on or off the presolver

     ///Turns on (\c b is \c true) or off (\c b is \c false) the presolver

     ///

     ///The presolver is off by default.

     void presolver(bool presolve);

   };

   /// \brief Interface for the GLPK MIP solver

   ///

   /// This class implements an interface for the GLPK MIP solver.

   ///\ingroup lp_group

   class GlpkMip : public MipSolver, public GlpkBase {

   public:

     ///\e

     GlpkMip();

     ///\e

     GlpkMip(const GlpkMip&);

     virtual GlpkMip* cloneSolver() const;

     virtual GlpkMip* newSolver() const;

   protected:

     virtual const char* _solverName() const;

     virtual ColTypes _getColType(int col) const;

     virtual void _setColType(int col, ColTypes col_type);

     virtual SolveExitStatus _solve();

     virtual ProblemType _getType() const;

     virtual Value _getSol(int i) const;

     virtual Value _getSolValue() const;

   };

 } //END OF NAMESPACE LEMON

 #endif //LEMON_GLPK_H