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

  *

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

  *

  * Copyright (C) 2003-2008

  * 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/soplex.h>

 #include <soplex/soplex.h>

 ///\file

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

 namespace lemon {

   SoplexLp::SoplexLp() {

     soplex = new soplex::SoPlex;

   }

   SoplexLp::~SoplexLp() {

     delete soplex;

   }

   SoplexLp::SoplexLp(const SoplexLp& lp) {

     rows = lp.rows;

     cols = lp.cols;

     soplex = new soplex::SoPlex;

     (*static_cast<soplex::SPxLP*>(soplex)) = *(lp.soplex);

     _col_names = lp._col_names;

     _col_names_ref = lp._col_names_ref;

     _row_names = lp._row_names;

     _row_names_ref = lp._row_names_ref;

   }

   void SoplexLp::_clear_temporals() {

     _primal_values.clear();

     _dual_values.clear();

   }

   SoplexLp* SoplexLp::_newSolver() const {

     SoplexLp* newlp = new SoplexLp();

     return newlp;

   }

   SoplexLp* SoplexLp::_cloneSolver() const {

     SoplexLp* newlp = new SoplexLp(*this);

     return newlp;

   }

   const char* SoplexLp::_solverName() const { return "SoplexLp"; }

   int SoplexLp::_addCol() {

     soplex::LPCol c;

     c.setLower(-soplex::infinity);

     c.setUpper(soplex::infinity);

     soplex->addCol(c);

     _col_names.push_back(std::string());

     return soplex->nCols() - 1;

   }

   int SoplexLp::_addRow() {

     soplex::LPRow r;

     r.setLhs(-soplex::infinity);

     r.setRhs(soplex::infinity);

     soplex->addRow(r);

     _row_names.push_back(std::string());

     return soplex->nRows() - 1;

   }

   void SoplexLp::_eraseCol(int i) {

     soplex->removeCol(i);

     _col_names_ref.erase(_col_names[i]);

     _col_names[i] = _col_names.back();

     _col_names_ref[_col_names.back()] = i;

     _col_names.pop_back();

   }

   void SoplexLp::_eraseRow(int i) {

     soplex->removeRow(i);

     _row_names_ref.erase(_row_names[i]);

     _row_names[i] = _row_names.back();

     _row_names_ref[_row_names.back()] = i;

     _row_names.pop_back();

   }

   void SoplexLp::_eraseColId(int i) {

     cols.eraseIndex(i);

     cols.relocateIndex(i, cols.maxIndex());

   }

   void SoplexLp::_eraseRowId(int i) {

     rows.eraseIndex(i);

     rows.relocateIndex(i, rows.maxIndex());

   }

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

     name = _col_names[c];

   }

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

     _col_names_ref.erase(_col_names[c]);

     _col_names[c] = name;

     if (!name.empty()) {

       _col_names_ref.insert(std::make_pair(name, c));

     }

   }

   int SoplexLp::_colByName(const std::string& name) const {

     std::map<std::string, int>::const_iterator it =

       _col_names_ref.find(name);

     if (it != _col_names_ref.end()) {

       return it->second;

     } else {

       return -1;

     }

   }

   void SoplexLp::_getRowName(int r, std::string &name) const {

     name = _row_names[r];

   }

   void SoplexLp::_setRowName(int r, const std::string &name) {

     _row_names_ref.erase(_row_names[r]);

     _row_names[r] = name;

     if (!name.empty()) {

       _row_names_ref.insert(std::make_pair(name, r));

     }

   }

   int SoplexLp::_rowByName(const std::string& name) const {

     std::map<std::string, int>::const_iterator it =

       _row_names_ref.find(name);

     if (it != _row_names_ref.end()) {

       return it->second;

     } else {

       return -1;

     }

   }

   void SoplexLp::_setRowCoeffs(int i, ExprIterator b, ExprIterator e) {

     for (int j = 0; j < soplex->nCols(); ++j) {

       soplex->changeElement(i, j, 0.0);

     }

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

       soplex->changeElement(i, it->first, it->second);

     }

   }

   void SoplexLp::_getRowCoeffs(int i, InsertIterator b) const {

     const soplex::SVector& vec = soplex->rowVector(i);

     for (int k = 0; k < vec.size(); ++k) {

       *b = std::make_pair(vec.index(k), vec.value(k));

       ++b;

     }

   }

   void SoplexLp::_setColCoeffs(int j, ExprIterator b, ExprIterator e) {

     for (int i = 0; i < soplex->nRows(); ++i) {

       soplex->changeElement(i, j, 0.0);

     }

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

       soplex->changeElement(it->first, j, it->second);

     }

   }

   void SoplexLp::_getColCoeffs(int i, InsertIterator b) const {

     const soplex::SVector& vec = soplex->colVector(i);

     for (int k = 0; k < vec.size(); ++k) {

       *b = std::make_pair(vec.index(k), vec.value(k));

       ++b;

     }

   }

   void SoplexLp::_setCoeff(int i, int j, Value value) {

     soplex->changeElement(i, j, value);

   }

   SoplexLp::Value SoplexLp::_getCoeff(int i, int j) const {

     return soplex->rowVector(i)[j];

   }

   void SoplexLp::_setColLowerBound(int i, Value value) {

     LEMON_ASSERT(value != INF, "Invalid bound");

     soplex->changeLower(i, value != -INF ? value : -soplex::infinity);

   }

   SoplexLp::Value SoplexLp::_getColLowerBound(int i) const {

     double value = soplex->lower(i);

     return value != -soplex::infinity ? value : -INF;

   }

   void SoplexLp::_setColUpperBound(int i, Value value) {

     LEMON_ASSERT(value != -INF, "Invalid bound");

     soplex->changeUpper(i, value != INF ? value : soplex::infinity);

   }

   SoplexLp::Value SoplexLp::_getColUpperBound(int i) const {

     double value = soplex->upper(i);

     return value != soplex::infinity ? value : INF;

   }

   void SoplexLp::_setRowLowerBound(int i, Value lb) {

     LEMON_ASSERT(lb != INF, "Invalid bound");

     soplex->changeRange(i, lb != -INF ? lb : -soplex::infinity, soplex->rhs(i));

   }

   SoplexLp::Value SoplexLp::_getRowLowerBound(int i) const {

     double res = soplex->lhs(i);

     return res == -soplex::infinity ? -INF : res;

   }

   void SoplexLp::_setRowUpperBound(int i, Value ub) {

     LEMON_ASSERT(ub != -INF, "Invalid bound");

     soplex->changeRange(i, soplex->lhs(i), ub != INF ? ub : soplex::infinity);

   }

   SoplexLp::Value SoplexLp::_getRowUpperBound(int i) const {

     double res = soplex->rhs(i);

     return res == soplex::infinity ? INF : res;

   }

   void SoplexLp::_setObjCoeffs(ExprIterator b, ExprIterator e) {

     for (int j = 0; j < soplex->nCols(); ++j) {

       soplex->changeObj(j, 0.0);

     }

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

       soplex->changeObj(it->first, it->second);

     }

   }

   void SoplexLp::_getObjCoeffs(InsertIterator b) const {

     for (int j = 0; j < soplex->nCols(); ++j) {

       Value coef = soplex->obj(j);

       if (coef != 0.0) {

         *b = std::make_pair(j, coef);

         ++b;

       }

     }

   }

   void SoplexLp::_setObjCoeff(int i, Value obj_coef) {

     soplex->changeObj(i, obj_coef);

   }

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

     return soplex->obj(i);

   }

   SoplexLp::SolveExitStatus SoplexLp::_solve() {

     _clear_temporals();

     soplex::SPxSolver::Status status = soplex->solve();

     switch (status) {

     case soplex::SPxSolver::OPTIMAL:

     case soplex::SPxSolver::INFEASIBLE:

     case soplex::SPxSolver::UNBOUNDED:

       return SOLVED;

     default:

       return UNSOLVED;

     }

   }

   SoplexLp::Value SoplexLp::_getPrimal(int i) const {

     if (_primal_values.empty()) {

       _primal_values.resize(soplex->nCols());

       soplex::Vector pv(_primal_values.size(), &_primal_values.front());

       soplex->getPrimal(pv);

     }

     return _primal_values[i];

   }

   SoplexLp::Value SoplexLp::_getDual(int i) const {

     if (_dual_values.empty()) {

       _dual_values.resize(soplex->nRows());

       soplex::Vector dv(_dual_values.size(), &_dual_values.front());

       soplex->getDual(dv);

     }

     return _dual_values[i];

   }

   SoplexLp::Value SoplexLp::_getPrimalValue() const {

     return soplex->objValue();

   }

   SoplexLp::VarStatus SoplexLp::_getColStatus(int i) const {

     switch (soplex->getBasisColStatus(i)) {

     case soplex::SPxSolver::BASIC:

       return BASIC;

     case soplex::SPxSolver::ON_UPPER:

       return UPPER;

     case soplex::SPxSolver::ON_LOWER:

       return LOWER;

     case soplex::SPxSolver::FIXED:

       return FIXED;

     case soplex::SPxSolver::ZERO:

       return FREE;

     default:

       LEMON_ASSERT(false, "Wrong column status");

       return VarStatus();

     }

   }

   SoplexLp::VarStatus SoplexLp::_getRowStatus(int i) const {

     switch (soplex->getBasisRowStatus(i)) {

     case soplex::SPxSolver::BASIC:

       return BASIC;

     case soplex::SPxSolver::ON_UPPER:

       return UPPER;

     case soplex::SPxSolver::ON_LOWER:

       return LOWER;

     case soplex::SPxSolver::FIXED:

       return FIXED;

     case soplex::SPxSolver::ZERO:

       return FREE;

     default:

       LEMON_ASSERT(false, "Wrong row status");

       return VarStatus();

     }

   }

   SoplexLp::Value SoplexLp::_getPrimalRay(int i) const {

     if (_primal_ray.empty()) {

       _primal_ray.resize(soplex->nCols());

       soplex::Vector pv(_primal_ray.size(), &_primal_ray.front());

       soplex->getDualfarkas(pv);

     }

     return _primal_ray[i];

   }

   SoplexLp::Value SoplexLp::_getDualRay(int i) const {

     if (_dual_ray.empty()) {

       _dual_ray.resize(soplex->nRows());

       soplex::Vector dv(_dual_ray.size(), &_dual_ray.front());

       soplex->getDualfarkas(dv);

     }

     return _dual_ray[i];

   }

   SoplexLp::ProblemType SoplexLp::_getPrimalType() const {

     switch (soplex->status()) {

     case soplex::SPxSolver::OPTIMAL:

       return OPTIMAL;

     case soplex::SPxSolver::UNBOUNDED:

       return UNBOUNDED;

     case soplex::SPxSolver::INFEASIBLE:

       return INFEASIBLE;

     default:

       return UNDEFINED;

     }

   }

   SoplexLp::ProblemType SoplexLp::_getDualType() const {

     switch (soplex->status()) {

     case soplex::SPxSolver::OPTIMAL:

       return OPTIMAL;

     case soplex::SPxSolver::UNBOUNDED:

       return UNBOUNDED;

     case soplex::SPxSolver::INFEASIBLE:

       return INFEASIBLE;

     default:

       return UNDEFINED;

     }

   }

   void SoplexLp::_setSense(Sense sense) {

     switch (sense) {

     case MIN:

       soplex->changeSense(soplex::SPxSolver::MINIMIZE);

       break;

     case MAX:

       soplex->changeSense(soplex::SPxSolver::MAXIMIZE);

     }

   }

   SoplexLp::Sense SoplexLp::_getSense() const {

     switch (soplex->spxSense()) {

     case soplex::SPxSolver::MAXIMIZE:

       return MAX;

     case soplex::SPxSolver::MINIMIZE:

       return MIN;

     default:

       LEMON_ASSERT(false, "Wrong sense.");

       return SoplexLp::Sense();

     }

   }

   void SoplexLp::_clear() {

     soplex->clear();

     _col_names.clear();

     _col_names_ref.clear();

     _row_names.clear();

     _row_names_ref.clear();

     cols.clear();

     rows.clear();

     _clear_temporals();

   }

 } //namespace lemon