/* -*- 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/lp_soplex.h>

#include <soplex/soplex.h>

///\file

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

namespace lemon {

  LpSoplex::LpSoplex() {

    soplex = new soplex::SoPlex;

  }

  LpSoplex::~LpSoplex() {

    delete soplex;

  }

  LpSoplex::LpSoplex(const LpSoplex& 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 LpSoplex::_clear_temporals() {

    _primal_values.clear();

    _dual_values.clear();

  }

  LpSoplex* LpSoplex::_newSolver() const {

    LpSoplex* newlp = new LpSoplex();

    return newlp;

  }

  LpSoplex* LpSoplex::_cloneSolver() const {

    LpSoplex* newlp = new LpSoplex(*this);

    return newlp;

  }

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

  int LpSoplex::_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 LpSoplex::_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 LpSoplex::_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 LpSoplex::_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 LpSoplex::_eraseColId(int i) {

    cols.eraseIndex(i);

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

  }

  void LpSoplex::_eraseRowId(int i) {

    rows.eraseIndex(i);

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

  }

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

    name = _col_names[c];

  }

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

    name = _row_names[r];

  }

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

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

  }

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

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

  }

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

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

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

  }

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

    double value = soplex->lower(i);

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

  }

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

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

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

  }

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

    double value = soplex->upper(i);

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

  }

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

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

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

  }

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

    double res = soplex->lhs(i);

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

  }

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

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

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

  }

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

    double res = soplex->rhs(i);

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

  }

  void LpSoplex::_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 LpSoplex::_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 LpSoplex::_setObjCoeff(int i, Value obj_coef) {

    soplex->changeObj(i, obj_coef);

  }

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

    return soplex->obj(i);

  }

  LpSoplex::SolveExitStatus LpSoplex::_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;

    }

  }

  LpSoplex::Value LpSoplex::_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];

  }

  LpSoplex::Value LpSoplex::_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];

  }

  LpSoplex::Value LpSoplex::_getPrimalValue() const {

    return soplex->objValue();

  }

  LpSoplex::VarStatus LpSoplex::_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();

    }

  }

  LpSoplex::VarStatus LpSoplex::_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();

    }

  }

  LpSoplex::Value LpSoplex::_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];

  }

  LpSoplex::Value LpSoplex::_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];

  }

  LpSoplex::ProblemType LpSoplex::_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;

    }

  }

  LpSoplex::ProblemType LpSoplex::_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 LpSoplex::_setSense(Sense sense) {

    switch (sense) {

    case MIN:

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

      break;

    case MAX:

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

    }

  }

  LpSoplex::Sense LpSoplex::_getSense() const {

    switch (soplex->spxSense()) {

    case soplex::SPxSolver::MAXIMIZE:

      return MAX;

    case soplex::SPxSolver::MINIMIZE:

      return MIN;

    default:

      LEMON_ASSERT(false, "Wrong sense.");

      return LpSoplex::Sense();

    }

  }

  void LpSoplex::_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