/* -*- C++ -*-

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

 *

 * Copyright (C) 2005 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.

 *

 */

#include <iostream>

#include<lemon/lp_cplex.h>

///\file

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

namespace lemon {

  LpCplex::LpCplex() : LpSolverBase() {

    //    env = CPXopenCPLEXdevelop(&status);     

    env = CPXopenCPLEX(&status);     

    lp = CPXcreateprob(env, &status, "LP problem");

  }

  LpCplex::~LpCplex() {

    CPXfreeprob(env,&lp); 

    CPXcloseCPLEX(&env); 

  }

  LpSolverBase &LpCplex::_newLp() 

  {

    //The first approach opens a new environment

    LpCplex* newlp=new LpCplex();

    return *newlp;

  }

  LpSolverBase &LpCplex::_copyLp() {

    //The first approach opens a new environment

    LpCplex* newlp=new LpCplex();

    //The routine CPXcloneprob can be used to create a new CPLEX problem 

    //object and copy all the problem data from an existing problem 

    //object to it. Solution and starting information is not copied.

    newlp->lp = CPXcloneprob (env, lp, &status);

    return *newlp;

  }

  int LpCplex::_addCol()

  {

    int i = CPXgetnumcols (env, lp);

    Value lb[1],ub[1];

    lb[0]=-INF;//-CPX_INFBOUND;

    ub[0]=INF;//CPX_INFBOUND;

    status = CPXnewcols (env, lp, 1, NULL, lb, ub, NULL, NULL);

    return i;

  }

  int LpCplex::_addRow() 

  {

    //We want a row that is not constrained

    char sense[1];

    sense[0]='L';//<= constraint

    Value rhs[1];

    rhs[0]=INF;

    int i = CPXgetnumrows (env, lp);

    status = CPXnewrows (env, lp, 1, rhs, sense, NULL, NULL);

    return i;

  }

  void LpCplex::_eraseCol(int i) {

    CPXdelcols (env, lp, i, i);

  }

  void LpCplex::_eraseRow(int i) {

    CPXdelrows (env, lp, i, i);

  }

  ///\warning Data at index 0 is ignored in the arrays.

  void LpCplex::_setRowCoeffs(int i, 

			      int length,

			      int  const * indices, 

			      Value  const * values )

  {

    int rowlist[length+1];

    int* p=rowlist;

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

      rowlist[k]=i;

    }

    status = CPXchgcoeflist(env, lp, 

			    length, 

			    p+1, 

			    const_cast<int * >(indices+1), 

			    const_cast<Value * >(values+1));

  }

  void LpCplex::_setColCoeffs(int i, 

			      int length,

			      int  const * indices, 

			      Value  const * values)

  {

    int collist[length+1];

    int* p=collist;

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

      collist[k]=i;

    }

    status = CPXchgcoeflist(env, lp, 

			    length, 

			    const_cast<int * >(indices+1), 

			    p+1, 

			    const_cast<Value * >(values+1));

  }

  void LpCplex::_setCoeff(int row, int col, Value value) 

  {

    CPXchgcoef (env, lp, row, col, value);

  }

  void LpCplex::_setColLowerBound(int i, Value value)

  {

    int indices[1];

    indices[0]=i;

    char lu[1];

    lu[0]='L';

    Value bd[1];

    bd[0]=value;

    status = CPXchgbds (env, lp, 1, indices, lu, bd);

  }

  void LpCplex::_setColUpperBound(int i, Value value)

  {

    int indices[1];

    indices[0]=i;

    char lu[1];

    lu[0]='U';

    Value bd[1];

    bd[0]=value;

    status = CPXchgbds (env, lp, 1, indices, lu, bd);

  }

  //This will be easier to implement

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

  {

    //Bad parameter

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

      //FIXME error

    }

    int cnt=1;

    int indices[1];

    indices[0]=i;

    char sense[1];

    if (lb==-INF){

      sense[0]='L';

      CPXchgsense (env, lp, cnt, indices, sense);

      CPXchgcoef (env, lp, i, -1, ub);

    }

    else{

      if (ub==INF){

	sense[0]='G';

	CPXchgsense (env, lp, cnt, indices, sense);

	CPXchgcoef (env, lp, i, -1, lb);

      }

      else{

	if (lb == ub){

	  sense[0]='E';

	  CPXchgsense (env, lp, cnt, indices, sense);

	  CPXchgcoef (env, lp, i, -1, lb);

	}

	else{

	  sense[0]='R';

	  CPXchgsense (env, lp, cnt, indices, sense);

	  CPXchgcoef (env, lp, i, -1, lb);

	  CPXchgcoef (env, lp, i, -2, ub-lb);	  

	}

      }

    }

  }

//   void LpCplex::_setRowLowerBound(int i, Value value)

//   {

//     //Not implemented, obsolete

//   }

//   void LpCplex::_setRowUpperBound(int i, Value value)

//   {

//     //Not implemented, obsolete

// //     //TODO Ezt kell meg megirni

// //     //type of the problem

// //     char sense[1];

// //     status = CPXgetsense (env, lp, sense, i, i);

// //     Value rhs[1];

// //     status = CPXgetrhs (env, lp, rhs, i, i);

// //     switch (sense[0]) {

// //     case 'L'://<= constraint

// //       break;

// //     case 'E'://= constraint

// //       break;

// //     case 'G'://>= constraint

// //       break;

// //     case 'R'://ranged constraint

// //       break;

// //     default: ;

// //       //FIXME error

// //     }

// //     status = CPXchgcoef (env, lp, i, -2, value_rng);

//   }

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

  {

    CPXchgcoef (env, lp, -1, i, obj_coef);

  }

  void LpCplex::_clearObj()

  {

    for (int i=0;i< CPXgetnumcols (env, lp);++i){

      CPXchgcoef (env, lp, -1, i, 0);

    }

  }

  // The routine returns zero unless an error occurred during the

  // optimization. Examples of errors include exhausting available

  // memory (CPXERR_NO_MEMORY) or encountering invalid data in the

  // CPLEX problem object (CPXERR_NO_PROBLEM). Exceeding a

  // user-specified CPLEX limit, or proving the model infeasible or

  // unbounded, are not considered errors. Note that a zero return

  // value does not necessarily mean that a solution exists. Use query

  // routines CPXsolninfo, CPXgetstat, and CPXsolution to obtain

  // further information about the status of the optimization.

  LpCplex::SolveExitStatus LpCplex::_solve()

  {

    //CPX_PARAM_LPMETHOD 

    status = CPXlpopt (env, lp);

    if (status == 0){

      //We want to exclude some cases

      switch (CPXgetstat (env, lp)){

      case CPX_OBJ_LIM:

      case CPX_IT_LIM_FEAS:

      case CPX_IT_LIM_INFEAS:               

      case CPX_TIME_LIM_FEAS:

      case CPX_TIME_LIM_INFEAS:

	return UNSOLVED;

      default:

	return SOLVED; 

      }

    }

    else{

      return UNSOLVED;

    }

  }

  LpCplex::Value LpCplex::_getPrimal(int i)

  {

    Value x;

    CPXgetx (env, lp, &x, i, i);

    return x;

  }

  LpCplex::Value LpCplex::_getPrimalValue()

  {

    Value objval;

    //method = CPXgetmethod (env, lp);

    status = CPXgetobjval (env, lp, &objval);

    return objval;

  }

//7.5-os cplex statusai (Vigyazat: a 9.0-asei masok!)

// This table lists the statuses, returned by the CPXgetstat() routine, for solutions to LP problems or mixed integer problems. If no solution exists, the return value is zero.

// For Simplex, Barrier  

// 1  	CPX_OPTIMAL  

// 	 Optimal solution found  

// 2  	CPX_INFEASIBLE  

// 	 Problem infeasible  

// 3    CPX_UNBOUNDED  

// 	 Problem unbounded  

// 4  	CPX_OBJ_LIM  

// 	 Objective limit exceeded in Phase II  

// 5  	CPX_IT_LIM_FEAS  

// 	 Iteration limit exceeded in Phase II  

// 6  	CPX_IT_LIM_INFEAS  

// 	 Iteration limit exceeded in Phase I  

// 7  	CPX_TIME_LIM_FEAS  

// 	 Time limit exceeded in Phase II  

// 8  	CPX_TIME_LIM_INFEAS  

// 	 Time limit exceeded in Phase I  

// 9  	CPX_NUM_BEST_FEAS  

// 	 Problem non-optimal, singularities in Phase II  

// 10 	CPX_NUM_BEST_INFEAS  

// 	 Problem non-optimal, singularities in Phase I  

// 11 	CPX_OPTIMAL_INFEAS  

// 	 Optimal solution found, unscaled infeasibilities  

// 12 	CPX_ABORT_FEAS  

// 	 Aborted in Phase II  

// 13 	CPX_ABORT_INFEAS  

// 	 Aborted in Phase I  

// 14  	CPX_ABORT_DUAL_INFEAS  

// 	 Aborted in barrier, dual infeasible  

// 15  	CPX_ABORT_PRIM_INFEAS  

// 	 Aborted in barrier, primal infeasible  

// 16  	CPX_ABORT_PRIM_DUAL_INFEAS  

// 	 Aborted in barrier, primal and dual infeasible  

// 17  	CPX_ABORT_PRIM_DUAL_FEAS  

// 	 Aborted in barrier, primal and dual feasible  

// 18  	CPX_ABORT_CROSSOVER  

// 	 Aborted in crossover  

// 19  	CPX_INForUNBD  

// 	 Infeasible or unbounded  

// 20   CPX_PIVOT

//       User pivot used

//

//     Ezeket hova tegyem:

// ??case CPX_ABORT_DUAL_INFEAS           

// ??case CPX_ABORT_CROSSOVER             

// ??case CPX_INForUNBD                   

// ??case CPX_PIVOT                       

  LpCplex::SolutionStatus LpCplex::_getPrimalStatus()

  {

    int stat = CPXgetstat (env, lp);

    switch (stat) {

    case 0:

      return UNDEFINED; //Undefined

    case CPX_OPTIMAL://Optimal

      return OPTIMAL;

    case CPX_UNBOUNDED://Unbounded

      return INFINITE;

    case CPX_INFEASIBLE://Infeasible 

 //    case CPX_IT_LIM_INFEAS:

//     case CPX_TIME_LIM_INFEAS:

//     case CPX_NUM_BEST_INFEAS:             

//     case CPX_OPTIMAL_INFEAS:              

//     case CPX_ABORT_INFEAS:                

//     case CPX_ABORT_PRIM_INFEAS:           

//     case CPX_ABORT_PRIM_DUAL_INFEAS:      

      return INFEASIBLE;

//     case CPX_OBJ_LIM:                    

//     case CPX_IT_LIM_FEAS:             

//     case CPX_TIME_LIM_FEAS:                

//     case CPX_NUM_BEST_FEAS:                

//     case CPX_ABORT_FEAS:                  

//     case CPX_ABORT_PRIM_DUAL_FEAS:        

//       return FEASIBLE;

    default:

      return UNDEFINED; //Everything else comes here

      //FIXME error

    }

  }

//9.0-as cplex verzio statusai

// CPX_STAT_ABORT_DUAL_OBJ_LIM

// CPX_STAT_ABORT_IT_LIM

// CPX_STAT_ABORT_OBJ_LIM

// CPX_STAT_ABORT_PRIM_OBJ_LIM

// CPX_STAT_ABORT_TIME_LIM

// CPX_STAT_ABORT_USER

// CPX_STAT_FEASIBLE_RELAXED

// CPX_STAT_INFEASIBLE

// CPX_STAT_INForUNBD

// CPX_STAT_NUM_BEST

// CPX_STAT_OPTIMAL

// CPX_STAT_OPTIMAL_FACE_UNBOUNDED

// CPX_STAT_OPTIMAL_INFEAS

// CPX_STAT_OPTIMAL_RELAXED

// CPX_STAT_UNBOUNDED

  LpCplex::SolutionStatus LpCplex::_getDualStatus()

  {

    int stat = CPXgetstat (env, lp);

    switch (stat) {

    case 0:

      return UNDEFINED; //Undefined

    case CPX_OPTIMAL://Optimal

      return OPTIMAL;

    case CPX_UNBOUNDED:

     return INFEASIBLE;

    default:

      return UNDEFINED; //Everything else comes here

      //FIXME error

    }

  }

  LpCplex::ProblemTypes LpCplex::_getProblemType()

  {

    int stat = CPXgetstat (env, lp);

    switch (stat) {

    case CPX_OPTIMAL://Optimal

	return PRIMAL_DUAL_FEASIBLE;

    case CPX_UNBOUNDED:

 	return PRIMAL_FEASIBLE_DUAL_INFEASIBLE;

// 	return PRIMAL_INFEASIBLE_DUAL_FEASIBLE;

// 	return PRIMAL_DUAL_INFEASIBLE;

//Seems to be that this is all we can say for sure

    default:

	//In all other cases

	return UNKNOWN;

      //FIXME error

    }

  }

  void LpCplex::_setMax()

  {

    CPXchgobjsen (env, lp, CPX_MAX);

   }

  void LpCplex::_setMin()

  {

    CPXchgobjsen (env, lp, CPX_MIN);

   }

} //namespace lemon