bool debugUpdatedBasic(const UpdateInfo& selected, ArithVar updated){
  if(selected.describesPivot() &&  updated == selected.leaving()){
    return selected.foundConflict();
  }else{
    return true;
  }
}

WitnessImprovement FCSimplexDecisionProcedure::primalImproveError(ArithVar errorVar){
  bool useBlands = degeneratePivotsInARow() >= s_maxDegeneratePivotsBeforeBlandsOnLeaving;
  UpdateInfo selected = selectUpdateForPrimal (errorVar, useBlands);
  Assert(!selected.uninitialized());
  WitnessImprovement w = selected.getWitness(useBlands);
  Assert(debugCheckWitness(selected, w, useBlands));

  updateAndSignal(selected, w);
  logPivot(w);
  return w;
}

void PassiveUpdateNotifier::versionInfoArrived(const UpdateInfo &info)
{
    if( info.version().isEmpty() ||
            Helper::stringVersionToInt(info.version())
            >= Helper::currentVersionToInt() )
    {
        qDebug() << "Client is on latest version!";
        setDownloadState(UpToDate);
    } else {
        setDownloadState(UpdateOnlyAvailableThroughSystem);
    }
}

void PassiveUpdateNotifier::versionInfoArrived(const UpdateInfo &info)
{
    qint64 currentVer = Helper::currentVersionToInt();
    qint64 remoteVer = Helper::stringVersionToInt(info.version());

    if (info.version().isEmpty() || currentVer >= remoteVer) {
        qCInfo(lcUpdater) << "Client is on latest version!";
        setDownloadState(UpToDate);
    } else {
        setDownloadState(UpdateOnlyAvailableThroughSystem);
    }
}

bool FCSimplexDecisionProcedure::debugCheckWitness(const UpdateInfo& inf, WitnessImprovement w, bool useBlands){
  if(inf.getWitness(useBlands) == w){
    switch(w){
    case ConflictFound: return inf.foundConflict();
    case ErrorDropped: return inf.errorsChange() < 0;
    case FocusImproved: return inf.focusDirection() > 0;
    case FocusShrank: return false; // This is not a valid output
    case Degenerate: return false; // This is not a valid output
    case BlandsDegenerate: return useBlands;
    case HeuristicDegenerate: return !useBlands;
    case AntiProductive: return false;
    }
  }
  return false;
}

void UpdateChecker::checkUpdate() {
    QString applicationName = ApplicationManager::getInstance()->getApplicationName().remove(" ");

    /**
     * dokumentacja dla http://agila.bluebraces.com/service/checkUpdate/$appName/$versionCode
     *
     * @param $appName dozwolone wartości "AgilaFaktury", "AgilaS3" (bez spacji!)
     * @param $versionCode - aktualny numer wersji kodu
     * @return 'NONE' - niewłaściwa liczba argumentów
     * @return 'INCORRECT_APP_NAME' - niewłasciwa nazwa aplikacji
     * @return '{"newVersionCode":2,"newVersionName":"1.2","downloadLink":...}' - odpowiedz JSON
     */

    QStringList args; // kolejność ma znaczenie!
    args << applicationName << QVariant(ApplicationInfo::getVersionCode()).toString();

    HttpRequester *requester = new HttpRequester();
    try {
        QString response = requester->sendAgilaServiceRequest("checkUpdate", args);
        delete requester;

        if(response == "NONE") {
            emit noUpdateAvailable();
        }
        else if(response == "INCORRECT_APP_NAME") {
            //  "Błąd wywołania requestu! Błąd: 102";
        }
        else if(response.startsWith("{"))
        {
           // jest dostępna aktualizacja

            JsonObject *jObject = new JsonObject(response);

            UpdateInfo updateInfo;
            updateInfo.setNewVersionCode(jObject->getInt("newVersionCode"));
            updateInfo.setNewVersionName(jObject->getString("newVersionName"));
            updateInfo.setDownloadLink(jObject->getString("downloadLink"));
            delete jObject;

            emit updateAvailable(updateInfo);
        }

    } catch(NoHttpResponseException *e) {

        delete requester;
    }
}

void NSISUpdater::showDialog(const UpdateInfo &info)
{
    // if the version tag is set, there is a newer version.
    QDialog *msgBox = new QDialog;
    msgBox->setAttribute(Qt::WA_DeleteOnClose);

    QIcon infoIcon = msgBox->style()->standardIcon(QStyle::SP_MessageBoxInformation, 0, 0);
    int iconSize = msgBox->style()->pixelMetric(QStyle::PM_MessageBoxIconSize, 0, 0);

    msgBox->setWindowIcon(infoIcon);

    QVBoxLayout *layout = new QVBoxLayout(msgBox);
    QHBoxLayout *hlayout = new QHBoxLayout;
    layout->addLayout(hlayout);

    msgBox->setWindowTitle(tr("New Version Available"));

    QLabel *ico = new QLabel;
    ico->setFixedSize(iconSize, iconSize);
    ico->setPixmap(infoIcon.pixmap(iconSize));
    QLabel *lbl = new QLabel;
    QString txt = tr("<p>A new version of the %1 Client is available.</p>"
                     "<p><b>%2</b> is available for download. The installed version is %3.</p>")
                      .arg(Utility::escape(Theme::instance()->appNameGUI()),
                          Utility::escape(info.versionString()), Utility::escape(clientVersion()));

    lbl->setText(txt);
    lbl->setTextFormat(Qt::RichText);
    lbl->setWordWrap(true);

    hlayout->addWidget(ico);
    hlayout->addWidget(lbl);

    QDialogButtonBox *bb = new QDialogButtonBox;
    bb->setWindowFlags(bb->windowFlags() & ~Qt::WindowContextHelpButtonHint);
    QPushButton *skip = bb->addButton(tr("Skip this version"), QDialogButtonBox::ResetRole);
    QPushButton *reject = bb->addButton(tr("Skip this time"), QDialogButtonBox::AcceptRole);
    QPushButton *getupdate = bb->addButton(tr("Get update"), QDialogButtonBox::AcceptRole);

    connect(skip, &QAbstractButton::clicked, msgBox, &QDialog::reject);
    connect(reject, &QAbstractButton::clicked, msgBox, &QDialog::reject);
    connect(getupdate, &QAbstractButton::clicked, msgBox, &QDialog::accept);

    connect(skip, &QAbstractButton::clicked, this, &NSISUpdater::slotSetSeenVersion);
    connect(getupdate, SIGNAL(clicked()), SLOT(slotOpenUpdateUrl()));

    layout->addWidget(bb);

    msgBox->open();
}

WitnessImprovement FCSimplexDecisionProcedure::selectFocusImproving() {
  Assert(d_focusErrorVar != ARITHVAR_SENTINEL);
  Assert(d_focusSize >= 2);

  LinearEqualityModule::UpdatePreferenceFunction upf =
    &LinearEqualityModule::preferWitness<true>;

  LinearEqualityModule::VarPreferenceFunction bpf =
    &LinearEqualityModule::minRowLength;

  UpdateInfo selected = selectPrimalUpdate(d_focusErrorVar, upf, bpf);

  if(selected.uninitialized()){
    Debug("selectFocusImproving") << "focus is optimum, but we don't have sat/conflict yet" << endl;

    return focusDownToLastHalf();
  }
  Assert(!selected.uninitialized());
  WitnessImprovement w = selected.getWitness(false);
  Assert(debugCheckWitness(selected, w, false));

  if(degenerate(w)){
    Debug("selectFocusImproving") << "only degenerate" << endl;
    if(d_prevWitnessImprovement == HeuristicDegenerate &&
       d_witnessImprovementInARow >= s_focusThreshold){
      Debug("selectFocusImproving") << "focus down been degenerate too long" << endl;
      return focusDownToLastHalf();
    }else{
      Debug("selectFocusImproving") << "taking degenerate" << endl;
    }
  }
  Debug("selectFocusImproving") << "selectFocusImproving did this " << selected << endl;

  updateAndSignal(selected, w);
  logPivot(w);
  return w;
}

void FCSimplexDecisionProcedure::updateAndSignal(const UpdateInfo& selected, WitnessImprovement w){
  ArithVar nonbasic = selected.nonbasic();

  static bool verbose = false;

  Debug("updateAndSignal") << "updateAndSignal " << selected << endl;

  stringstream ss;
  if(verbose){
    d_errorSet.debugPrint(ss);
    if(selected.describesPivot()){
      ArithVar leaving = selected.leaving();
      ss << "leaving " << leaving
         << " " << d_tableau.basicRowLength(leaving)
         << " " << d_linEq.debugBasicAtBoundCount(leaving)
         << endl;
    }
    if(degenerate(w) && selected.describesPivot()){
      ArithVar leaving = selected.leaving();
      Message()
        << "degenerate " << leaving
        << ", atBounds " << d_linEq.basicsAtBounds(selected)
        << ", len " << d_tableau.basicRowLength(leaving)
        << ", bc " << d_linEq.debugBasicAtBoundCount(leaving)
        << endl;
    }
  }

  if(selected.describesPivot()){
    ConstraintP limiting = selected.limiting();
    ArithVar basic = limiting->getVariable();
    Assert(d_linEq.basicIsTracked(basic));
    d_linEq.pivotAndUpdate(basic, nonbasic, limiting->getValue());
  }else{
    Assert(!selected.unbounded() || selected.errorsChange() < 0);

    DeltaRational newAssignment =
      d_variables.getAssignment(nonbasic) + selected.nonbasicDelta();

    d_linEq.updateTracked(nonbasic, newAssignment);
  }
  d_pivots++;

  increaseLeavingCount(nonbasic);

  vector< pair<ArithVar, int> > focusChanges;
  while(d_errorSet.moreSignals()){
    ArithVar updated = d_errorSet.topSignal();
    int prevFocusSgn = d_errorSet.popSignal();

    if(d_tableau.isBasic(updated)){
      Assert(!d_variables.assignmentIsConsistent(updated) == d_errorSet.inError(updated));
      if(Debug.isOn("updateAndSignal")){debugPrintSignal(updated);}
      if(!d_variables.assignmentIsConsistent(updated)){
        if(checkBasicForConflict(updated)){
          reportConflict(updated);
          Assert(debugUpdatedBasic(selected, updated));
        }
      }
    }else{
      Debug("updateAndSignal") << "updated nonbasic " << updated << endl;
    }
    int currFocusSgn = d_errorSet.focusSgn(updated);
    if(currFocusSgn != prevFocusSgn){
      int change = currFocusSgn - prevFocusSgn;
      focusChanges.push_back(make_pair(updated, change));
    }
  }

  if(verbose){
    Message() << "conflict variable " << selected << endl;
    Message() << ss.str();
  }
  if(Debug.isOn("error")){ d_errorSet.debugPrint(Debug("error")); }

  Assert(debugSelectedErrorDropped(selected, d_errorSize, d_errorSet.errorSize()));

  adjustFocusAndError(selected, focusChanges);
}

bool debugSelectedErrorDropped(const UpdateInfo& selected, int32_t prevErrorSize, int32_t currErrorSize){
  int diff = currErrorSize - prevErrorSize;
  return selected.foundConflict() || diff == selected.errorsChange();
}

UpdateInfo FCSimplexDecisionProcedure::selectPrimalUpdate(ArithVar basic, LinearEqualityModule::UpdatePreferenceFunction upf, LinearEqualityModule::VarPreferenceFunction bpf) {
  UpdateInfo selected;

  static int instance = 0 ;
  ++instance;

  Debug("arith::selectPrimalUpdate")
    << "selectPrimalUpdate " << instance << endl
    << basic << " " << d_tableau.basicRowLength(basic)
    << " " << d_linEq.debugBasicAtBoundCount(basic) << endl;

  static const int s_maxCandidatesAfterImprove = 3;
  bool isFocus = basic == d_focusErrorVar;
  Assert(isFocus || d_errorSet.inError(basic));
  int basicDir =  isFocus? 1 : d_errorSet.getSgn(basic);
  bool dualLike = !isFocus && d_focusSize > 1;

  if(!isFocus){
    loadFocusSigns();
  }

  decreasePenalties();

  typedef std::vector<Cand> CandVector;
  CandVector candidates;

  for(Tableau::RowIterator ri = d_tableau.basicRowIterator(basic); !ri.atEnd(); ++ri){
    const Tableau::Entry& e = *ri;
    ArithVar curr = e.getColVar();
    if(curr == basic){ continue; }

    int sgn = e.getCoefficient().sgn();
    int curr_movement = basicDir * sgn;

    bool candidate =
      (curr_movement > 0 && d_variables.cmpAssignmentUpperBound(curr) < 0) ||
      (curr_movement < 0 && d_variables.cmpAssignmentLowerBound(curr) > 0);

    Debug("arith::selectPrimalUpdate")
      << "storing " << basic
      << " " << curr
      << " " << candidate
      << " " << e.getCoefficient()
      << " " << curr_movement
      << " " << focusCoefficient(curr) << endl;

    if(!candidate) { continue; }

    if(!isFocus){
      const Rational& focusC = focusCoefficient(curr);
      Assert(dualLike || !focusC.isZero());
      if(dualLike && curr_movement != focusC.sgn()){
        Debug("arith::selectPrimalUpdate") << "sgn disagreement " << curr << endl;
        d_sgnDisagreements.push_back(curr);
        continue;
      }else{
        candidates.push_back(Cand(curr, penalty(curr), curr_movement, &focusC));
      }
    }else{
      candidates.push_back(Cand(curr, penalty(curr), curr_movement, &e.getCoefficient()));
    }
  }

  CompPenaltyColLength colCmp(&d_linEq);
  CandVector::iterator i = candidates.begin();
  CandVector::iterator end = candidates.end();
  std::make_heap(i, end, colCmp);

  bool checkEverything = d_pivots == 0;

  int candidatesAfterFocusImprove = 0;
  while(i != end && (checkEverything || candidatesAfterFocusImprove <= s_maxCandidatesAfterImprove)){
    std::pop_heap(i, end, colCmp);
    --end;
    Cand& cand = (*end);
    ArithVar curr = cand.d_nb;
    const Rational& coeff = *cand.d_coeff;

    LinearEqualityModule::UpdatePreferenceFunction leavingPrefFunc = selectLeavingFunction(curr);
    UpdateInfo currProposal = d_linEq.speculativeUpdate(curr, coeff, leavingPrefFunc);

    Debug("arith::selectPrimalUpdate")
      << "selected " << selected << endl
      << "currProp " << currProposal << endl
      << "coeff " << coeff << endl;

    Assert(!currProposal.uninitialized());

    if(candidatesAfterFocusImprove > 0){
      candidatesAfterFocusImprove++;
    }

    if(selected.uninitialized() || (d_linEq.*upf)(selected, currProposal)){

      selected = currProposal;
      WitnessImprovement w = selected.getWitness(false);
      Debug("arith::selectPrimalUpdate") << "selected " << w << endl;
      setPenalty(curr, w);
      if(improvement(w)){
        bool exitEarly;
//.........这里部分代码省略.........

/**
\todo document this function
*/
QDomElement GCF::UpdateInfo::toDomElement(QDomDocument doc, bool forThisSystem) const
{
    QDomElement updateE = doc.createElement("Update");

    QDomElement nameE = doc.createElement("Name");
    nameE.appendChild( doc.createTextNode(d->name) );
    updateE.appendChild(nameE);

    QDomElement titleE = doc.createElement("Title");
    titleE.appendChild( doc.createTextNode(d->title) );
    updateE.appendChild(titleE);

    QDomElement sourceE = doc.createElement("Source");
    sourceE.appendChild( doc.createTextNode(d->source) );
    updateE.appendChild(sourceE);

    QDomElement iconE = doc.createElement("Icon");
    iconE.appendChild( doc.createTextNode(d->iconUrl.toString()) );
    updateE.appendChild(iconE);

    QDomElement typeE = doc.createElement("Type");
    typeE.appendChild( doc.createTextNode(d->type) );
    updateE.appendChild(typeE);

    QDomElement forceInstallE = doc.createElement("ForceInstall");
    forceInstallE.appendChild( doc.createTextNode( QVariant(d->forceInstall).toString() ) );
    updateE.appendChild(forceInstallE);

    QDomElement descE = doc.createElement("Description");
    descE.appendChild( doc.createCDATASection(d->description) );
    updateE.appendChild(descE);

    QDomElement releaseE = doc.createElement("Release");
    releaseE.appendChild( doc.createTextNode(d->release.toString()) );
    updateE.appendChild(releaseE);

    QDomElement versionE = doc.createElement("Version");
    versionE.appendChild( doc.createTextNode(d->version) );
    updateE.appendChild(versionE);

    QList<UpdateFileInfo> ufiList;
    if( forThisSystem )
    {
        UpdateFileInfo fileInfo = updateFileForThisSystem();
        ufiList.append(fileInfo);
    }
    else
        ufiList = d->updateFiles;

    for(int j=0; j<ufiList.count(); j++)
    {
        UpdateFileInfo ufi = ufiList[j];
        QDomElement updateFileE = doc.createElement("UpdateFile");
        updateE.appendChild(updateFileE);

        updateFileE.setAttribute("OS", ufi.OS);
        updateFileE.setAttribute("Arch", ufi.Arch);
        updateFileE.appendChild( doc.createTextNode(ufi.UpdateFileURL.toString()) );
    }

    const QList<UpdateInfo>& deps = d->dependencies;
    for(int j=0; j<deps.count(); j++)
    {
        UpdateInfo dep = deps[j];
        QString depStr = QString("%1 [%2]").arg( dep.name() ).arg( dep.version() );

        QDomElement dependsOnE = doc.createElement("DependsOn");
        dependsOnE.appendChild( doc.createTextNode(depStr) );
        updateE.appendChild(dependsOnE);
    }

    return updateE;
}