/* -*- 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.
 *
 */

#include<iostream>
#include<lemon/lp_soplex.h>

#include <soplex/soplex.h>


///\file
///\brief Implementation of the LEMON-SOPLEX lp solver interface.
namespace lemon {
  
  LpSoplex::LpSoplex() : LpSolverBase() {
    soplex = new soplex::SoPlex;
  }
  
  LpSoplex::~LpSoplex() {
    delete soplex;
  }
  
  LpSolverBase &LpSoplex::_newLp() {
    LpSoplex* newlp = new LpSoplex();
    return *newlp;
  }

  LpSolverBase &LpSoplex::_copyLp() {
    LpSoplex* newlp = new LpSoplex();
    ((soplex::SPxLP&)*(newlp->soplex)) = *soplex;
    return *newlp;
  }

  int LpSoplex::_addCol() {
    soplex::LPCol col;
    soplex->addCol(col);

    colNames.push_back(std::string());
    primal.push_back(0.0);

    return soplex->nCols() - 1;
  }

  int LpSoplex::_addRow() {
    soplex::LPRow row;
    soplex->addRow(row);

    dual.push_back(0.0);

    return soplex->nRows() - 1;
  }


  void LpSoplex::_eraseCol(int i) {
    soplex->removeCol(i);
    primal[i] = primal.back();
    primal.pop_back();
  }
  
  void LpSoplex::_eraseRow(int i) {
    soplex->removeRow(i);
    dual[i] = dual.back();
    dual.pop_back();
  }
  
  void LpSoplex::_getColName(int col, std::string &name) {
    name = colNames[col]; 
  }
  
  void LpSoplex::_setColName(int col, const std::string &name) {
    colNames[col] = name; 
  }
  

  void LpSoplex::_setRowCoeffs(int i, LpRowIterator b, LpRowIterator e) {
    for (int j = 0; j < soplex->nCols(); ++j) {
      soplex->changeElement(i, j, 0.0);
    }
    for(LpRowIterator it = b; it != e; ++it) {
      soplex->changeElement(i, it->first, it->second);
    }
  }
  
  void LpSoplex::_setColCoeffs(int j, LpColIterator b, LpColIterator e) {
    for (int i = 0; i < soplex->nRows(); ++i) {
      soplex->changeElement(i, j, 0.0);
    }
    for(LpColIterator it = b; it != e; ++it) {
      soplex->changeElement(it->first, j, it->second);
    }
  }
  
  void LpSoplex::_setCoeff(int row, int col, Value value) {
    soplex->changeElement(row, col, value);
  }

  void LpSoplex::_setColLowerBound(int i, Value value) {
    soplex->changeLower(i, value); 
  }
  
  void LpSoplex::_setColUpperBound(int i, Value value) {
    soplex->changeUpper(i, value); 
  }

  void LpSoplex::_setRowBounds(int i, Value lb, Value ub) {
    soplex->changeRange(i, lb, ub);
  }

  void LpSoplex::_setObjCoeff(int i, Value obj_coef) {
    soplex->changeObj(i, obj_coef);
  }

  void LpSoplex::_clearObj() {
    for (int i = 0; i < soplex->nCols(); ++i) {
      soplex->changeObj(i, 0.0);
    }
  }

  LpSoplex::SolveExitStatus LpSoplex::_solve() {
    soplex::SPxSolver::Status status = soplex->solve();

    soplex::Vector pv(primal.size(), &primal[0]);
    soplex->getPrimal(pv);

    soplex::Vector dv(dual.size(), &dual[0]);
    soplex->getDual(dv);

    switch (status) {
    case soplex::SPxSolver::OPTIMAL:
    case soplex::SPxSolver::INFEASIBLE:
    case soplex::SPxSolver::UNBOUNDED:
      return SOLVED;
    default:
      return UNSOLVED;
    }
  }

  LpSoplex::Value LpSoplex::_getPrimal(int i) {
    return primal[i];
  }

  LpSoplex::Value LpSoplex::_getDual(int i) {
    return dual[i];
  }
  
  LpSoplex::Value LpSoplex::_getPrimalValue() {
    return soplex->objValue();
  }

  bool LpSoplex::_isBasicCol(int i) {
    return soplex->getBasisColStatus(i) == soplex::SPxSolver::BASIC;
  }  

  LpSoplex::SolutionStatus LpSoplex::_getPrimalStatus() {
    switch (soplex->status()) {
    case soplex::SPxSolver::OPTIMAL:
      return OPTIMAL;
    case soplex::SPxSolver::UNBOUNDED:
      return INFINITE;
    case soplex::SPxSolver::INFEASIBLE:
      return INFEASIBLE;
    default:
      return UNDEFINED;
    }
  }

  LpSoplex::SolutionStatus LpSoplex::_getDualStatus() {
    switch (0) {
    case 0:
      return UNDEFINED;
      return OPTIMAL;
      return INFEASIBLE;
      return UNDEFINED;
    }
  }

  LpSoplex::ProblemTypes LpSoplex::_getProblemType() {
    switch (0) {
    case 0:
      return PRIMAL_DUAL_FEASIBLE;
      return PRIMAL_FEASIBLE_DUAL_INFEASIBLE;
      return UNKNOWN;
    }
  }

  void LpSoplex::_setMax() {
    soplex->changeSense(soplex::SPxSolver::MAXIMIZE);
  }
  void LpSoplex::_setMin() {
    soplex->changeSense(soplex::SPxSolver::MINIMIZE);
  }
  
} //namespace lemon