text: // Copyright (c) 2011-2013 The Bitcoin developers
  // Copyright (c) 2017-2018 The PIVX developers
  // Copyright (c) 2017-2018 The Franc developers
  // Distributed under the MIT/X11 software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include "peertablemodel.h"
  
  #include "clientmodel.h"
  #include "guiconstants.h"
  #include "guiutil.h"
  
  #include "net.h"
  #include "sync.h"
  
  #include <QDebug>
  #include <QList>
  #include <QTimer>
  
  bool NodeLessThan::operator()(const CNodeCombinedStats& left, const CNodeCombinedStats& right) const
  {
      const CNodeStats* pLeft = &(left.nodeStats);
      const CNodeStats* pRight = &(right.nodeStats);
  
      if (order == Qt::DescendingOrder)
          std::swap(pLeft, pRight);
  
      switch (column) {
      case PeerTableModel::Address:
          return pLeft->addrName.compare(pRight->addrName) < 0;
      case PeerTableModel::Subversion:
          return pLeft->cleanSubVer.compare(pRight->cleanSubVer) < 0;
      case PeerTableModel::Ping:
          return pLeft->dPingTime < pRight->dPingTime;
      }
  
      return false;
  }
  
  // private implementation
  class PeerTablePriv
  {
  public:
      /** Local cache of peer information */
      QList<CNodeCombinedStats> cachedNodeStats;
      /** Column to sort nodes by */
      int sortColumn;
      /** Order (ascending or descending) to sort nodes by */
      Qt::SortOrder sortOrder;
      /** Index of rows by node ID */
      std::map<NodeId, int> mapNodeRows;
  
      /** Pull a full list of peers from vNodes into our cache */
      void refreshPeers()
      {
          {
              TRY_LOCK(cs_vNodes, lockNodes);
              if (!lockNodes) {
                  // skip the refresh if we can't immediately get the lock
                  return;
              }
              cachedNodeStats.clear();
              cachedNodeStats.reserve(vNodes.size());
              foreach (CNode* pnode, vNodes) {
                  CNodeCombinedStats stats;
                  stats.nodeStateStats.nMisbehavior = 0;
                  stats.nodeStateStats.nSyncHeight = -1;
                  stats.nodeStateStats.nCommonHeight = -1;
                  stats.fNodeStateStatsAvailable = false;
                  pnode->copyStats(stats.nodeStats);
                  cachedNodeStats.append(stats);
              }
          }
  
          // Try to retrieve the CNodeStateStats for each node.
          {
              TRY_LOCK(cs_main, lockMain);
              if (lockMain) {
                  BOOST_FOREACH (CNodeCombinedStats& stats, cachedNodeStats)
                      stats.fNodeStateStatsAvailable = GetNodeStateStats(stats.nodeStats.nodeid, stats.nodeStateStats);
              }
          }
  
          if (sortColumn >= 0)
              // sort cacheNodeStats (use stable sort to prevent rows jumping around unneceesarily)
              qStableSort(cachedNodeStats.begin(), cachedNodeStats.end(), NodeLessThan(sortColumn, sortOrder));
  
          // build index map
          mapNodeRows.clear();
          int row = 0;
          foreach (const CNodeCombinedStats& stats, cachedNodeStats)
              mapNodeRows.insert(std::pair<NodeId, int>(stats.nodeStats.nodeid, row++));
      }
  
      int size()
      {
          return cachedNodeStats.size();
      }
  
      CNodeCombinedStats* index(int idx)
      {
          if (idx >= 0 && idx < cachedNodeStats.size()) {
              return &cachedNodeStats[idx];
          } else {
              return 0;
          }
      }
  };
  
  PeerTableModel::PeerTableModel(ClientModel* parent) : QAbstractTableModel(parent),
                                                        clientModel(parent),
                                                        timer(0)
  {
      columns << tr("Address/Hostname") << tr("Version") << tr("Ping Time");
      priv = new PeerTablePriv();
      // default to unsorted
      priv->sortColumn = -1;
  
      // set up timer for auto refresh
      timer = new QTimer();
      connect(timer, SIGNAL(timeout()), SLOT(refresh()));
      timer->setInterval(MODEL_UPDATE_DELAY);
  
      // load initial data
      refresh();
  }
  
  void PeerTableModel::startAutoRefresh()
  {
      timer->start();
  }
  
  void PeerTableModel::stopAutoRefresh()
  {
      timer->stop();
  }
  
  int PeerTableModel::rowCount(const QModelIndex& parent) const
  {
      Q_UNUSED(parent);
      return priv->size();
  }
  
  int PeerTableModel::columnCount(const QModelIndex& parent) const
  {
      Q_UNUSED(parent);
      return columns.length();
      ;
  }
  
  QVariant PeerTableModel::data(const QModelIndex& index, int role) const
  {
      if (!index.isValid())
          return QVariant();
  
      CNodeCombinedStats* rec = static_cast<CNodeCombinedStats*>(index.internalPointer());
  
      if (role == Qt::DisplayRole) {
          switch (index.column()) {
          case Address:
              return QString::fromStdString(rec->nodeStats.addrName);
          case Subversion:
              return QString::fromStdString(rec->nodeStats.cleanSubVer);
          case Ping:
              return GUIUtil::formatPingTime(rec->nodeStats.dPingTime);
          }
      } else if (role == Qt::TextAlignmentRole) {
          if (index.column() == Ping)
              return (int)(Qt::AlignRight | Qt::AlignVCenter);
      }
  
      return QVariant();
  }
  
  QVariant PeerTableModel::headerData(int section, Qt::Orientation orientation, int role) const
  {
      if (orientation == Qt::Horizontal) {
          if (role == Qt::DisplayRole && section < columns.size()) {
              return columns[section];
          }
      }
      return QVariant();
  }
  
  Qt::ItemFlags PeerTableModel::flags(const QModelIndex& index) const
  {
      if (!index.isValid())
          return 0;
  
      Qt::ItemFlags retval = Qt::ItemIsSelectable | Qt::ItemIsEnabled;
      return retval;
  }
  
  QModelIndex PeerTableModel::index(int row, int column, const QModelIndex& parent) const
  {
      Q_UNUSED(parent);
      CNodeCombinedStats* data = priv->index(row);
  
      if (data) {
          return createIndex(row, column, data);
      } else {
          return QModelIndex();
      }
  }
  
  const CNodeCombinedStats* PeerTableModel::getNodeStats(int idx)
  {
      return priv->index(idx);
  }
  
  void PeerTableModel::refresh()
  {
      emit layoutAboutToBeChanged();
      priv->refreshPeers();
      emit layoutChanged();
  }
  
  int PeerTableModel::getRowByNodeId(NodeId nodeid)
  {
      std::map<NodeId, int>::iterator it = priv->mapNodeRows.find(nodeid);
      if (it == priv->mapNodeRows.end())
          return -1;
  
      return it->second;
  }
  
  void PeerTableModel::sort(int column, Qt::SortOrder order)
  {
      priv->sortColumn = column;
      priv->sortOrder = order;
      refresh();
  }
  