text: // Copyright (c) 2011-2017 The Bitcoin Core developers
  // Distributed under the MIT software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include <qt/recentrequeststablemodel.h>
  
  #include <qt/libercoinunits.h>
  #include <qt/guiutil.h>
  #include <qt/optionsmodel.h>
  
  #include <clientversion.h>
  #include <streams.h>
  
  
  RecentRequestsTableModel::RecentRequestsTableModel(CWallet *wallet, WalletModel *parent) :
      QAbstractTableModel(parent), walletModel(parent)
  {
      Q_UNUSED(wallet);
      nReceiveRequestsMaxId = 0;
  
      // Load entries from wallet
      std::vector<std::string> vReceiveRequests;
      parent->loadReceiveRequests(vReceiveRequests);
      for (const std::string& request : vReceiveRequests)
          addNewRequest(request);
  
      /* These columns must match the indices in the ColumnIndex enumeration */
      columns << tr("Date") << tr("Label") << tr("Message") << getAmountTitle();
  
      connect(walletModel->getOptionsModel(), SIGNAL(displayUnitChanged(int)), this, SLOT(updateDisplayUnit()));
  }
  
  RecentRequestsTableModel::~RecentRequestsTableModel()
  {
      /* Intentionally left empty */
  }
  
  int RecentRequestsTableModel::rowCount(const QModelIndex &parent) const
  {
      Q_UNUSED(parent);
  
      return list.length();
  }
  
  int RecentRequestsTableModel::columnCount(const QModelIndex &parent) const
  {
      Q_UNUSED(parent);
  
      return columns.length();
  }
  
  QVariant RecentRequestsTableModel::data(const QModelIndex &index, int role) const
  {
      if(!index.isValid() || index.row() >= list.length())
          return QVariant();
  
      if(role == Qt::DisplayRole || role == Qt::EditRole)
      {
          const RecentRequestEntry *rec = &list[index.row()];
          switch(index.column())
          {
          case Date:
              return GUIUtil::dateTimeStr(rec->date);
          case Label:
              if(rec->recipient.label.isEmpty() && role == Qt::DisplayRole)
              {
                  return tr("(no label)");
              }
              else
              {
                  return rec->recipient.label;
              }
          case Message:
              if(rec->recipient.message.isEmpty() && role == Qt::DisplayRole)
              {
                  return tr("(no message)");
              }
              else
              {
                  return rec->recipient.message;
              }
          case Amount:
              if (rec->recipient.amount == 0 && role == Qt::DisplayRole)
                  return tr("(no amount requested)");
              else if (role == Qt::EditRole)
                  return BitcoinUnits::format(walletModel->getOptionsModel()->getDisplayUnit(), rec->recipient.amount, false, BitcoinUnits::separatorNever);
              else
                  return BitcoinUnits::format(walletModel->getOptionsModel()->getDisplayUnit(), rec->recipient.amount);
          }
      }
      else if (role == Qt::TextAlignmentRole)
      {
          if (index.column() == Amount)
              return (int)(Qt::AlignRight|Qt::AlignVCenter);
      }
      return QVariant();
  }
  
  bool RecentRequestsTableModel::setData(const QModelIndex &index, const QVariant &value, int role)
  {
      return true;
  }
  
  QVariant RecentRequestsTableModel::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();
  }
  
  /** Updates the column title to "Amount (DisplayUnit)" and emits headerDataChanged() signal for table headers to react. */
  void RecentRequestsTableModel::updateAmountColumnTitle()
  {
      columns[Amount] = getAmountTitle();
      Q_EMIT headerDataChanged(Qt::Horizontal,Amount,Amount);
  }
  
  /** Gets title for amount column including current display unit if optionsModel reference available. */
  QString RecentRequestsTableModel::getAmountTitle()
  {
      return (this->walletModel->getOptionsModel() != nullptr) ? tr("Requested") + " ("+BitcoinUnits::shortName(this->walletModel->getOptionsModel()->getDisplayUnit()) + ")" : "";
  }
  
  QModelIndex RecentRequestsTableModel::index(int row, int column, const QModelIndex &parent) const
  {
      Q_UNUSED(parent);
  
      return createIndex(row, column);
  }
  
  bool RecentRequestsTableModel::removeRows(int row, int count, const QModelIndex &parent)
  {
      Q_UNUSED(parent);
  
      if(count > 0 && row >= 0 && (row+count) <= list.size())
      {
          const RecentRequestEntry *rec;
          for (int i = 0; i < count; ++i)
          {
              rec = &list[row+i];
              if (!walletModel->saveReceiveRequest(rec->recipient.address.toStdString(), rec->id, ""))
                  return false;
          }
  
          beginRemoveRows(parent, row, row + count - 1);
          list.erase(list.begin() + row, list.begin() + row + count);
          endRemoveRows();
          return true;
      } else {
          return false;
      }
  }
  
  Qt::ItemFlags RecentRequestsTableModel::flags(const QModelIndex &index) const
  {
      return Qt::ItemIsSelectable | Qt::ItemIsEnabled;
  }
  
  // called when adding a request from the GUI
  void RecentRequestsTableModel::addNewRequest(const SendCoinsRecipient &recipient)
  {
      RecentRequestEntry newEntry;
      newEntry.id = ++nReceiveRequestsMaxId;
      newEntry.date = QDateTime::currentDateTime();
      newEntry.recipient = recipient;
  
      CDataStream ss(SER_DISK, CLIENT_VERSION);
      ss << newEntry;
  
      if (!walletModel->saveReceiveRequest(recipient.address.toStdString(), newEntry.id, ss.str()))
          return;
  
      addNewRequest(newEntry);
  }
  
  // called from ctor when loading from wallet
  void RecentRequestsTableModel::addNewRequest(const std::string &recipient)
  {
      std::vector<char> data(recipient.begin(), recipient.end());
      CDataStream ss(data, SER_DISK, CLIENT_VERSION);
  
      RecentRequestEntry entry;
      ss >> entry;
  
      if (entry.id == 0) // should not happen
          return;
  
      if (entry.id > nReceiveRequestsMaxId)
          nReceiveRequestsMaxId = entry.id;
  
      addNewRequest(entry);
  }
  
  // actually add to table in GUI
  void RecentRequestsTableModel::addNewRequest(RecentRequestEntry &recipient)
  {
      beginInsertRows(QModelIndex(), 0, 0);
      list.prepend(recipient);
      endInsertRows();
  }
  
  void RecentRequestsTableModel::sort(int column, Qt::SortOrder order)
  {
      qSort(list.begin(), list.end(), RecentRequestEntryLessThan(column, order));
      Q_EMIT dataChanged(index(0, 0, QModelIndex()), index(list.size() - 1, NUMBER_OF_COLUMNS - 1, QModelIndex()));
  }
  
  void RecentRequestsTableModel::updateDisplayUnit()
  {
      updateAmountColumnTitle();
  }
  
  bool RecentRequestEntryLessThan::operator()(RecentRequestEntry &left, RecentRequestEntry &right) const
  {
      RecentRequestEntry *pLeft = &left;
      RecentRequestEntry *pRight = &right;
      if (order == Qt::DescendingOrder)
          std::swap(pLeft, pRight);
  
      switch(column)
      {
      case RecentRequestsTableModel::Date:
          return pLeft->date.toTime_t() < pRight->date.toTime_t();
      case RecentRequestsTableModel::Label:
          return pLeft->recipient.label < pRight->recipient.label;
      case RecentRequestsTableModel::Message:
          return pLeft->recipient.message < pRight->recipient.message;
      case RecentRequestsTableModel::Amount:
          return pLeft->recipient.amount < pRight->recipient.amount;
      default:
          return pLeft->id < pRight->id;
      }
  }
  