text: // Copyright (c) 2011-2014 The Bitcoin developers
  // Copyright (c) 2014-2015 The Dash developers
  //Copyright (c) 2015-2020 The PIVX developers
  //Copyright (c) 2020 The remita developers
  // Distributed under the MIT/X11 software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include "walletmodel.h"
  
  #include "addresstablemodel.h"
  #include "guiconstants.h"
  #include "optionsmodel.h"
  #include "recentrequeststablemodel.h"
  #include "transactiontablemodel.h"
  
  #include "base58.h"
  #include "db.h"
  #include "keystore.h"
  #include "main.h"
  #include "spork.h"
  #include "sync.h"
  #include "guiinterface.h"
  #include "wallet/wallet.h"
  #include "wallet/walletdb.h" // for BackupWallet
  #include <stdint.h>
  #include <iostream>
  
  #include <QDebug>
  #include <QSet>
  #include <QTimer>
  
  
  WalletModel::WalletModel(CWallet* wallet, OptionsModel* optionsModel, QObject* parent) : QObject(parent), wallet(wallet), optionsModel(optionsModel), addressTableModel(0),
                                                                                           transactionTableModel(0),
                                                                                           recentRequestsTableModel(0),
                                                                                           cachedBalance(0), cachedUnconfirmedBalance(0), cachedImmatureBalance(0),
                                                                                           cachedEncryptionStatus(Unencrypted),
                                                                                           cachedNumBlocks(0)
  {
      fHaveWatchOnly = wallet->HaveWatchOnly();
      fForceCheckBalanceChanged = false;
  
      addressTableModel = new AddressTableModel(wallet, this);
      transactionTableModel = new TransactionTableModel(wallet, this);
      recentRequestsTableModel = new RecentRequestsTableModel(wallet, this);
  
      // This timer will be fired repeatedly to update the balance
      pollTimer = new QTimer(this);
      connect(pollTimer, &QTimer::timeout, this, &WalletModel::pollBalanceChanged);
      pollTimer->start(MODEL_UPDATE_DELAY);
  
      subscribeToCoreSignals();
  }
  
  WalletModel::~WalletModel()
  {
      unsubscribeFromCoreSignals();
  }
  
  bool WalletModel::isTestNetwork() const
  {
      return Params().NetworkID() == CBaseChainParams::TESTNET;
  }
  
  bool WalletModel::isRegTestNetwork() const
  {
      return Params().IsRegTestNet();
  }
  
  bool WalletModel::isColdStakingNetworkelyEnabled() const
  {
      return sporkManager.IsSporkActive(SPORK_17_COLDSTAKING_ENFORCEMENT);
  }
  
  bool WalletModel::isStakingStatusActive() const
  {
      return wallet->pStakerStatus->IsActive();
  }
  
  bool WalletModel::isHDEnabled() const
  {
      return wallet->IsHDEnabled();
  }
  
  bool WalletModel::upgradeWallet(std::string& upgradeError)
  {
      // This action must be performed in a separate thread and not the main one.
      LOCK2(cs_main, wallet->cs_wallet);
  
      // Get version
      int prev_version = wallet->GetVersion();
      // Upgrade wallet's version
      wallet->SetMinVersion(FEATURE_LATEST);
      wallet->SetMaxVersion(FEATURE_LATEST);
  
      // Upgrade to HD
      return wallet->Upgrade(upgradeError, prev_version);
  }
  
  CAmount WalletModel::getBalance(const CCoinControl* coinControl, bool fIncludeDelegated) const
  {
      if (coinControl) {
          CAmount nBalance = 0;
          std::vector<COutput> vCoins;
          wallet->AvailableCoins(&vCoins, coinControl, fIncludeDelegated);
          for (const COutput& out : vCoins)
              if (out.fSpendable)
                  nBalance += out.tx->vout[out.i].nValue;
  
          return nBalance;
      }
  
      return wallet->GetBalance(fIncludeDelegated);
  }
  
  CAmount WalletModel::getMinColdStakingAmount() const
  {
      return MIN_COLDSTAKING_AMOUNT;
  }
  
  CAmount WalletModel::getUnconfirmedBalance() const
  {
      return wallet->GetUnconfirmedBalance();
  }
  
  CAmount WalletModel::getImmatureBalance() const
  {
      return wallet->GetImmatureBalance();
  }
  
  CAmount WalletModel::getLockedBalance() const
  {
      return wallet->GetLockedCoins();
  }
  
  bool WalletModel::haveWatchOnly() const
  {
      return fHaveWatchOnly;
  }
  
  CAmount WalletModel::getWatchBalance() const
  {
      return wallet->GetWatchOnlyBalance();
  }
  
  CAmount WalletModel::getWatchUnconfirmedBalance() const
  {
      return wallet->GetUnconfirmedWatchOnlyBalance();
  }
  
  CAmount WalletModel::getWatchImmatureBalance() const
  {
      return wallet->GetImmatureWatchOnlyBalance();
  }
  
  CAmount WalletModel::getDelegatedBalance() const
  {
      return wallet->GetDelegatedBalance();
  }
  
  CAmount WalletModel::getColdStakedBalance() const
  {
      return wallet->GetColdStakingBalance();
  }
  
  bool WalletModel::isColdStaking() const
  {
      // TODO: Complete me..
      return false;
  }
  
  void WalletModel::updateStatus()
  {
      EncryptionStatus newEncryptionStatus = getEncryptionStatus();
  
      if (cachedEncryptionStatus != newEncryptionStatus)
          Q_EMIT encryptionStatusChanged(newEncryptionStatus);
  }
  
  bool WalletModel::isWalletUnlocked() const
  {
      EncryptionStatus status = getEncryptionStatus();
      return (status == Unencrypted || status == Unlocked);
  }
  
  bool WalletModel::isWalletLocked(bool fFullUnlocked) const
  {
      EncryptionStatus status = getEncryptionStatus();
      return (status == Locked || (!fFullUnlocked && status == UnlockedForStaking));
  }
  
  bool IsImportingOrReindexing()
  {
      return fImporting || fReindex;
  }
  
  void WalletModel::pollBalanceChanged()
  {
      // Wait a little bit more when the wallet is reindexing and/or importing, no need to lock cs_main so often.
      if (IsImportingOrReindexing()) {
          static uint8_t waitLonger = 0;
          waitLonger++;
          if (waitLonger < 10) // 10 seconds
              return;
          waitLonger = 0;
      }
  
      // Get required locks upfront. This avoids the GUI from getting stuck on
      // periodical polls if the core is holding the locks for a longer time -
      // for example, during a wallet rescan.
      TRY_LOCK(cs_main, lockMain);
      if (!lockMain)
          return;
      TRY_LOCK(wallet->cs_wallet, lockWallet);
      if (!lockWallet)
          return;
  
      int chainHeight = chainActive.Height();
      if (fForceCheckBalanceChanged || chainHeight != cachedNumBlocks) {
          fForceCheckBalanceChanged = false;
  
          // Balance and number of transactions might have changed
          cachedNumBlocks = chainHeight;
  
          checkBalanceChanged();
          if (transactionTableModel) {
              transactionTableModel->updateConfirmations();
          }
  
          // Address in receive tab may have been used
          Q_EMIT notifyReceiveAddressChanged();
      }
  }
  
  void WalletModel::emitBalanceChanged()
  {
      // TODO: Improve all of this..
      // Force update of UI elements even when no values have changed
      Q_EMIT balanceChanged(cachedBalance, cachedUnconfirmedBalance, cachedImmatureBalance,
                          cachedWatchOnlyBalance, cachedWatchUnconfBalance, cachedWatchImmatureBalance,
                          cachedDelegatedBalance, cachedColdStakedBalance);
  }
  
  void WalletModel::checkBalanceChanged()
  {
      CAmount newBalance = getBalance();
      CAmount newUnconfirmedBalance = getUnconfirmedBalance();
      CAmount newImmatureBalance = getImmatureBalance();
      CAmount newWatchOnlyBalance = 0;
      CAmount newWatchUnconfBalance = 0;
      CAmount newWatchImmatureBalance = 0;
      // Cold staking
      CAmount newColdStakedBalance =  getColdStakedBalance();
      CAmount newDelegatedBalance = getDelegatedBalance();
  
  
      if (haveWatchOnly()) {
          newWatchOnlyBalance = getWatchBalance();
          newWatchUnconfBalance = getWatchUnconfirmedBalance();
          newWatchImmatureBalance = getWatchImmatureBalance();
      }
  
      if (cachedBalance != newBalance || cachedUnconfirmedBalance != newUnconfirmedBalance || cachedImmatureBalance != newImmatureBalance ||
          cachedWatchOnlyBalance != newWatchOnlyBalance || cachedWatchUnconfBalance != newWatchUnconfBalance || cachedWatchImmatureBalance != newWatchImmatureBalance ||
          cachedTxLocks != nCompleteTXLocks || cachedDelegatedBalance != newDelegatedBalance || cachedColdStakedBalance != newColdStakedBalance) {
          cachedBalance = newBalance;
          cachedUnconfirmedBalance = newUnconfirmedBalance;
          cachedImmatureBalance = newImmatureBalance;
          cachedTxLocks = nCompleteTXLocks;
          cachedWatchOnlyBalance = newWatchOnlyBalance;
          cachedWatchUnconfBalance = newWatchUnconfBalance;
          cachedWatchImmatureBalance = newWatchImmatureBalance;
          cachedColdStakedBalance = newColdStakedBalance;
          cachedDelegatedBalance = newDelegatedBalance;
          Q_EMIT balanceChanged(newBalance, newUnconfirmedBalance, newImmatureBalance,
                              newWatchOnlyBalance, newWatchUnconfBalance, newWatchImmatureBalance,
                              newDelegatedBalance, newColdStakedBalance);
      }
  }
  
  void WalletModel::setWalletDefaultFee(CAmount fee)
  {
      payTxFee = CFeeRate(fee);
  }
  
  bool WalletModel::hasWalletCustomFee()
  {
      if (!optionsModel) return false;
      return optionsModel->data(optionsModel->index(OptionsModel::fUseCustomFee), Qt::EditRole).toBool();
  }
  
  bool WalletModel::getWalletCustomFee(CAmount& nFeeRet)
  {
      nFeeRet = static_cast<CAmount>(optionsModel->data(optionsModel->index(OptionsModel::nCustomFee), Qt::EditRole).toLongLong());
      return hasWalletCustomFee();
  }
  
  void WalletModel::setWalletCustomFee(bool fUseCustomFee, const CAmount& nFee)
  {
      if (!optionsModel) return;
      optionsModel->setData(optionsModel->index(OptionsModel::fUseCustomFee), fUseCustomFee);
      // do not update custom fee value when fUseCustomFee is set to false
      if (fUseCustomFee) {
          optionsModel->setData(optionsModel->index(OptionsModel::nCustomFee), static_cast<qlonglong>(nFee));
      }
  }
  
  void WalletModel::updateTransaction()
  {
      // Balance and number of transactions might have changed
      fForceCheckBalanceChanged = true;
  }
  
  void WalletModel::updateAddressBook(const QString& address, const QString& label, bool isMine, const QString& purpose, int status)
  {
      try {
          if (addressTableModel)
              addressTableModel->updateEntry(address, label, isMine, purpose, status);
      } catch (...) {
          std::cout << "Exception updateAddressBook" << std::endl;
      }
  }
  
  void WalletModel::updateWatchOnlyFlag(bool fHaveWatchonly)
  {
      fHaveWatchOnly = fHaveWatchonly;
      Q_EMIT notifyWatchonlyChanged(fHaveWatchonly);
  }
  
  bool WalletModel::validateAddress(const QString& address)
  {
      // Only regular base58 addresses accepted here
      return IsValidDestinationString(address.toStdString(), false);
  }
  
  bool WalletModel::validateAddress(const QString& address, bool fStaking)
  {
      return IsValidDestinationString(address.toStdString(), fStaking);
  }
  
  bool WalletModel::updateAddressBookLabels(const CTxDestination& dest, const std::string& strName, const std::string& strPurpose)
  {
      LOCK(wallet->cs_wallet);
  
      std::map<CTxDestination, AddressBook::CAddressBookData>::iterator mi = wallet->mapAddressBook.find(dest);
  
      // Check if we have a new address or an updated label
      if (mi == wallet->mapAddressBook.end()) {
          return wallet->SetAddressBook(dest, strName, strPurpose);
      } else if (mi->second.name != strName) {
          return wallet->SetAddressBook(dest, strName, ""); // "" means don't change purpose
      }
      return false;
  }
  
  WalletModel::SendCoinsReturn WalletModel::prepareTransaction(WalletModelTransaction& transaction, const CCoinControl* coinControl, bool fIncludeDelegations)
  {
      CAmount total = 0;
      QList<SendCoinsRecipient> recipients = transaction.getRecipients();
      std::vector<std::pair<CScript, CAmount> > vecSend;
  
      if (recipients.empty()) {
          return OK;
      }
  
      if (isStakingOnlyUnlocked()) {
          return StakingOnlyUnlocked;
      }
  
      QSet<QString> setAddress; // Used to detect duplicates
      int nAddresses = 0;
  
      // Pre-check input data for validity
      Q_FOREACH (const SendCoinsRecipient& rcp, recipients) {
          if (rcp.paymentRequest.IsInitialized()) { // PaymentRequest...
              CAmount subtotal = 0;
              const payments::PaymentDetails& details = rcp.paymentRequest.getDetails();
              for (int i = 0; i < details.outputs_size(); i++) {
                  const payments::Output& out = details.outputs(i);
                  if (out.amount() <= 0) continue;
                  subtotal += out.amount();
                  const unsigned char* scriptStr = (const unsigned char*)out.script().data();
                  CScript scriptPubKey(scriptStr, scriptStr + out.script().size());
                  vecSend.push_back(std::pair<CScript, CAmount>(scriptPubKey, out.amount()));
              }
              if (subtotal <= 0) {
                  return InvalidAmount;
              }
              total += subtotal;
          } else { // User-entered remita address / amount:
              if (!validateAddress(rcp.address, rcp.isP2CS)) {
                  return InvalidAddress;
              }
              if (rcp.amount <= 0) {
                  return InvalidAmount;
              }
              setAddress.insert(rcp.address);
              ++nAddresses;
  
              CScript scriptPubKey;
              CTxDestination out = DecodeDestination(rcp.address.toStdString());
  
              if (rcp.isP2CS) {
                  Destination ownerAdd;
                  if (rcp.ownerAddress.isEmpty()) {
                      // Create new internal owner address
                      if (!getNewAddress(ownerAdd).result)
                          return CannotCreateInternalAddress;
                  } else {
                      ownerAdd = Destination(DecodeDestination(rcp.ownerAddress.toStdString()), false);
                  }
  
                  const CKeyID* stakerId = boost::get<CKeyID>(&out);
                  const CKeyID* ownerId = boost::get<CKeyID>(&ownerAdd.dest);
                  if (!stakerId || !ownerId) {
                      return InvalidAddress;
                  }
  
                  scriptPubKey = GetScriptForStakeDelegation(*stakerId, *ownerId);
              } else {
                  // Regular P2PK or P2PKH
                  scriptPubKey = GetScriptForDestination(out);
              }
              vecSend.push_back(std::pair<CScript, CAmount>(scriptPubKey, rcp.amount));
  
              total += rcp.amount;
          }
      }
      if (setAddress.size() != nAddresses) {
          return DuplicateAddress;
      }
  
      CAmount nBalance = getBalance(coinControl, fIncludeDelegations);
  
      if (total > nBalance) {
          return AmountExceedsBalance;
      }
  
      {
          LOCK2(cs_main, wallet->cs_wallet);
  
          transaction.newPossibleKeyChange(wallet);
          CAmount nFeeRequired = 0;
          std::string strFailReason;
  
          CWalletTx* newTx = transaction.getTransaction();
          CReserveKey* keyChange = transaction.getPossibleKeyChange();
  
  
          if (recipients[0].useSwiftTX && total > sporkManager.GetSporkValue(SPORK_5_MAX_VALUE) * COIN) {
              Q_EMIT message(tr("Send Coins"), tr("SwiftX doesn't support sending values that high yet. Transactions are currently limited to %1 %2.").arg(sporkManager.GetSporkValue(SPORK_5_MAX_VALUE)).arg(CURRENCY_UNIT.c_str()),
                  CClientUIInterface::MSG_ERROR);
              return TransactionCreationFailed;
          }
  
          bool fCreated = wallet->CreateTransaction(vecSend,
                                                    *newTx,
                                                    *keyChange,
                                                    nFeeRequired,
                                                    strFailReason,
                                                    coinControl,
                                                    recipients[0].inputType,
                                                    recipients[0].useSwiftTX,
                                                    0,
                                                    fIncludeDelegations);
          transaction.setTransactionFee(nFeeRequired);
  
          if (recipients[0].useSwiftTX && newTx->GetValueOut() > sporkManager.GetSporkValue(SPORK_5_MAX_VALUE) * COIN) {
              Q_EMIT message(tr("Send Coins"), tr("SwiftX doesn't support sending values that high yet. Transactions are currently limited to %1 %2.").arg(sporkManager.GetSporkValue(SPORK_5_MAX_VALUE)).arg(CURRENCY_UNIT.c_str()),
                  CClientUIInterface::MSG_ERROR);
              return TransactionCreationFailed;
          }
  
          if (!fCreated) {
              if ((total + nFeeRequired) > nBalance) {
                  return SendCoinsReturn(AmountWithFeeExceedsBalance);
              }
  
              Q_EMIT message(tr("Send Coins"), tr("Transaction creation failed!\n%1").arg(
                      strFailReason == "Transaction too large" ?
                              tr("The size of the transaction is too big.\nSelect fewer inputs with coin control.") :
                              QString::fromStdString(strFailReason)),
                      CClientUIInterface::MSG_ERROR);
              return TransactionCreationFailed;
          }
  
          // reject insane fee
          if (nFeeRequired > ::minRelayTxFee.GetFee(transaction.getTransactionSize()) * 10000)
              return InsaneFee;
      }
  
      return SendCoinsReturn(OK);
  }
  
  WalletModel::SendCoinsReturn WalletModel::sendCoins(WalletModelTransaction& transaction)
  {
      QByteArray transaction_array; /* store serialized transaction */
  
      if (isStakingOnlyUnlocked()) {
          return StakingOnlyUnlocked;
      }
  
      bool fColdStakingActive = sporkManager.IsSporkActive(SPORK_17_COLDSTAKING_ENFORCEMENT);
  
      // Double check tx before do anything
      CValidationState state;
      if (!CheckTransaction(*transaction.getTransaction(), state, fColdStakingActive)) {
          return TransactionCommitFailed;
      }
  
      {
          LOCK2(cs_main, wallet->cs_wallet);
          CWalletTx* newTx = transaction.getTransaction();
          QList<SendCoinsRecipient> recipients = transaction.getRecipients();
  
          // Store PaymentRequests in wtx.vOrderForm in wallet.
          Q_FOREACH (const SendCoinsRecipient& rcp, recipients) {
              if (rcp.paymentRequest.IsInitialized()) {
                  std::string key("PaymentRequest");
                  std::string value;
                  rcp.paymentRequest.SerializeToString(&value);
                  newTx->vOrderForm.push_back(std::make_pair(key, value));
              } else if (!rcp.message.isEmpty()) // Message from normal remita:URI (remita:XyZ...?message=example)
              {
                  newTx->vOrderForm.push_back(std::make_pair("Message", rcp.message.toStdString()));
              }
          }
  
          CReserveKey* keyChange = transaction.getPossibleKeyChange();
          if (!wallet->CommitTransaction(*newTx, *keyChange, (recipients[0].useSwiftTX) ? NetMsgType::IX : NetMsgType::TX))
              return TransactionCommitFailed;
  
          CTransaction* t = (CTransaction*)newTx;
          CDataStream ssTx(SER_NETWORK, PROTOCOL_VERSION);
          ssTx << *t;
          transaction_array.append(&(ssTx[0]), ssTx.size());
      }
  
      // Add addresses / update labels that we've sent to to the address book,
      // and emit coinsSent signal for each recipient
      Q_FOREACH (const SendCoinsRecipient& rcp, transaction.getRecipients()) {
          // Don't touch the address book when we have a payment request
          if (!rcp.paymentRequest.IsInitialized()) {
              CBitcoinAddress address = CBitcoinAddress(rcp.address.toStdString());
              std::string purpose = address.IsStakingAddress() ? AddressBook::AddressBookPurpose::COLD_STAKING_SEND : AddressBook::AddressBookPurpose::SEND;
              std::string strLabel = rcp.label.toStdString();
              updateAddressBookLabels(address.Get(), strLabel, purpose);
          }
          Q_EMIT coinsSent(wallet, rcp, transaction_array);
      }
      checkBalanceChanged(); // update balance immediately, otherwise there could be a short noticeable delay until pollBalanceChanged hits
  
      return SendCoinsReturn(OK);
  }
  
  const CWalletTx* WalletModel::getTx(uint256 id)
  {
      return wallet->GetWalletTx(id);
  }
  
  OptionsModel* WalletModel::getOptionsModel()
  {
      return optionsModel;
  }
  
  AddressTableModel* WalletModel::getAddressTableModel()
  {
      return addressTableModel;
  }
  
  TransactionTableModel* WalletModel::getTransactionTableModel()
  {
      return transactionTableModel;
  }
  
  RecentRequestsTableModel* WalletModel::getRecentRequestsTableModel()
  {
      return recentRequestsTableModel;
  }
  
  WalletModel::EncryptionStatus WalletModel::getEncryptionStatus() const
  {
      if (!wallet->IsCrypted()) {
          return Unencrypted;
      } else if (wallet->fWalletUnlockStaking) {
          return UnlockedForStaking;
      } else if (wallet->IsLocked()) {
          return Locked;
      } else {
          return Unlocked;
      }
  
  }
  
  bool WalletModel::setWalletEncrypted(bool encrypted, const SecureString& passphrase)
  {
      if (encrypted) {
          // Encrypt
          return wallet->EncryptWallet(passphrase);
      } else {
          // Decrypt -- TODO; not supported yet
          return false;
      }
  }
  
  bool WalletModel::setWalletLocked(bool locked, const SecureString& passPhrase, bool stakingOnly)
  {
      if (locked) {
          // Lock
          wallet->fWalletUnlockStaking = false;
          return wallet->Lock();
      } else {
          // Unlock
          return wallet->Unlock(passPhrase, stakingOnly);
      }
  }
  
  bool WalletModel::lockForStakingOnly(const SecureString& passPhrase)
  {
      if (!wallet->IsLocked()) {
          wallet->fWalletUnlockStaking = true;
          return true;
      } else {
          setWalletLocked(false, passPhrase, true);
      }
      return false;
  }
  
  bool WalletModel::isStakingOnlyUnlocked()
  {
      return wallet->fWalletUnlockStaking;
  }
  
  bool WalletModel::changePassphrase(const SecureString& oldPass, const SecureString& newPass)
  {
      bool retval;
      {
          LOCK(wallet->cs_wallet);
          wallet->Lock(); // Make sure wallet is locked before attempting pass change
          retval = wallet->ChangeWalletPassphrase(oldPass, newPass);
      }
      return retval;
  }
  
  bool WalletModel::backupWallet(const QString& filename)
  {
      //attempt regular backup
      if (!BackupWallet(*wallet, filename.toLocal8Bit().data())) {
          return error("ERROR: Failed to backup wallet!");
      }
  
      return true;
  }
  
  
  // Handlers for core signals
  static void NotifyKeyStoreStatusChanged(WalletModel* walletmodel, CCryptoKeyStore* wallet)
  {
      qDebug() << "NotifyKeyStoreStatusChanged";
      QMetaObject::invokeMethod(walletmodel, "updateStatus", Qt::QueuedConnection);
  }
  
  static void NotifyAddressBookChanged(WalletModel* walletmodel, CWallet* wallet, const CTxDestination& address, const std::string& label, bool isMine, const std::string& purpose, ChangeType status)
  {
      QString strAddress = QString::fromStdString(pwalletMain->ParseIntoAddress(address, purpose).ToString());
      QString strLabel = QString::fromStdString(label);
      QString strPurpose = QString::fromStdString(purpose);
  
      qDebug() << "NotifyAddressBookChanged : " + strAddress + " " + strLabel + " isMine=" + QString::number(isMine) + " purpose=" + strPurpose + " status=" + QString::number(status);
      QMetaObject::invokeMethod(walletmodel, "updateAddressBook", Qt::QueuedConnection,
          Q_ARG(QString, strAddress),
          Q_ARG(QString, strLabel),
          Q_ARG(bool, isMine),
          Q_ARG(QString, strPurpose),
          Q_ARG(int, status));
  }
  
  // queue notifications to show a non freezing progress dialog e.g. for rescan
  static bool fQueueNotifications = false;
  static std::vector<std::pair<uint256, ChangeType> > vQueueNotifications;
  static void NotifyTransactionChanged(WalletModel* walletmodel, CWallet* wallet, const uint256& hash, ChangeType status)
  {
      if (fQueueNotifications) {
          vQueueNotifications.push_back(std::make_pair(hash, status));
          return;
      }
  
      QString strHash = QString::fromStdString(hash.GetHex());
  
      qDebug() << "NotifyTransactionChanged : " + strHash + " status= " + QString::number(status);
      QMetaObject::invokeMethod(walletmodel, "updateTransaction", Qt::QueuedConnection /*,
                                Q_ARG(QString, strHash),
                                Q_ARG(int, status)*/);
  }
  
  static void ShowProgress(WalletModel* walletmodel, const std::string& title, int nProgress)
  {
      // emits signal "showProgress"
      QMetaObject::invokeMethod(walletmodel, "showProgress", Qt::QueuedConnection,
          Q_ARG(QString, QString::fromStdString(title)),
          Q_ARG(int, nProgress));
  }
  
  static void NotifyWatchonlyChanged(WalletModel* walletmodel, bool fHaveWatchonly)
  {
      QMetaObject::invokeMethod(walletmodel, "updateWatchOnlyFlag", Qt::QueuedConnection,
          Q_ARG(bool, fHaveWatchonly));
  }
  
  static void NotifyWalletBacked(WalletModel* model, const bool& fSuccess, const std::string& filename)
  {
      std::string message;
      std::string title = "Backup ";
      CClientUIInterface::MessageBoxFlags method;
  
      if (fSuccess) {
          message = "The wallet data was successfully saved to ";
          title += "Successful: ";
          method = CClientUIInterface::MessageBoxFlags::MSG_INFORMATION;
      } else {
          message = "There was an error trying to save the wallet data to ";
          title += "Failed: ";
          method = CClientUIInterface::MessageBoxFlags::MSG_ERROR;
      }
  
      message += _(filename.data());
  
      QMetaObject::invokeMethod(model, "message", Qt::QueuedConnection,
                                Q_ARG(QString, QString::fromStdString(title)),
                                Q_ARG(QString, QString::fromStdString(message)),
                                Q_ARG(unsigned int, (unsigned int)method));
  }
  
  void WalletModel::subscribeToCoreSignals()
  {
      // Connect signals to wallet
      wallet->NotifyStatusChanged.connect(boost::bind(&NotifyKeyStoreStatusChanged, this, _1));
      wallet->NotifyAddressBookChanged.connect(boost::bind(NotifyAddressBookChanged, this, _1, _2, _3, _4, _5, _6));
      wallet->NotifyTransactionChanged.connect(boost::bind(NotifyTransactionChanged, this, _1, _2, _3));
      wallet->ShowProgress.connect(boost::bind(ShowProgress, this, _1, _2));
      wallet->NotifyWatchonlyChanged.connect(boost::bind(NotifyWatchonlyChanged, this, _1));
      wallet->NotifyWalletBacked.connect(boost::bind(NotifyWalletBacked, this, _1, _2));
  }
  
  void WalletModel::unsubscribeFromCoreSignals()
  {
      // Disconnect signals from wallet
      wallet->NotifyStatusChanged.disconnect(boost::bind(&NotifyKeyStoreStatusChanged, this, _1));
      wallet->NotifyAddressBookChanged.disconnect(boost::bind(NotifyAddressBookChanged, this, _1, _2, _3, _4, _5, _6));
      wallet->NotifyTransactionChanged.disconnect(boost::bind(NotifyTransactionChanged, this, _1, _2, _3));
      wallet->ShowProgress.disconnect(boost::bind(ShowProgress, this, _1, _2));
      wallet->NotifyWatchonlyChanged.disconnect(boost::bind(NotifyWatchonlyChanged, this, _1));
      wallet->NotifyWalletBacked.disconnect(boost::bind(NotifyWalletBacked, this, _1, _2));
  }
  
  // WalletModel::UnlockContext implementation
  WalletModel::UnlockContext WalletModel::requestUnlock()
  {
      const WalletModel::EncryptionStatus status_before = getEncryptionStatus();
      if (status_before == Locked || status_before == UnlockedForStaking)
      {
          // Request UI to unlock wallet
          Q_EMIT requireUnlock();
      }
      // If wallet is still locked, unlock was failed or cancelled, mark context as invalid
      bool valid = isWalletUnlocked();
  
      return UnlockContext(this, valid, status_before);
  }
  
  WalletModel::UnlockContext::UnlockContext(WalletModel *_wallet, bool _valid, const WalletModel::EncryptionStatus& status_before):
          wallet(_wallet),
          valid(_valid),
          was_status(status_before),
          relock(status_before == Locked || status_before == UnlockedForStaking)
  {
  }
  
  WalletModel::UnlockContext::~UnlockContext()
  {
      if (valid && relock && wallet) {
          if (was_status == Locked) wallet->setWalletLocked(true);
          else if (was_status == UnlockedForStaking) wallet->lockForStakingOnly();
          wallet->updateStatus();
      }
  }
  
  void WalletModel::UnlockContext::CopyFrom(UnlockContext&& rhs)
  {
      // Transfer context; old object no longer relocks wallet
      *this = rhs;
      rhs.relock = false;
  }
  
  bool WalletModel::getPubKey(const CKeyID& address, CPubKey& vchPubKeyOut) const
  {
      return wallet->GetPubKey(address, vchPubKeyOut);
  }
  
  int64_t WalletModel::getCreationTime() const {
      return wallet->nTimeFirstKey;
  }
  
  int64_t WalletModel::getKeyCreationTime(const CPubKey& key)
  {
      return pwalletMain->GetKeyCreationTime(key);
  }
  
  int64_t WalletModel::getKeyCreationTime(const CTxDestination& address)
  {
      if (this->isMine(address)) {
          return pwalletMain->GetKeyCreationTime(address);
      }
      return 0;
  }
  
  PairResult WalletModel::getNewAddress(Destination& ret, std::string label) const
  {
      CTxDestination dest;
      PairResult res = wallet->getNewAddress(dest, label);
      if (res.result) ret = Destination(dest, false);
      return res;
  }
  
  PairResult WalletModel::getNewStakingAddress(Destination& ret,std::string label) const
  {
      CTxDestination dest;
      PairResult res = wallet->getNewStakingAddress(dest, label);
      if (res.result) ret = Destination(dest, true);
      return res;
  }
  
  bool WalletModel::whitelistAddressFromColdStaking(const QString &addressStr)
  {
      return updateAddressBookPurpose(addressStr, AddressBook::AddressBookPurpose::DELEGATOR);
  }
  
  bool WalletModel::blacklistAddressFromColdStaking(const QString &addressStr)
  {
      return updateAddressBookPurpose(addressStr, AddressBook::AddressBookPurpose::DELEGABLE);
  }
  
  bool WalletModel::updateAddressBookPurpose(const QString &addressStr, const std::string& purpose)
  {
      CBitcoinAddress address(addressStr.toStdString());
      if (address.IsStakingAddress())
          return error("Invalid Remita Coin address, cold staking address");
      CKeyID keyID;
      if (!getKeyId(address, keyID))
          return false;
      return pwalletMain->SetAddressBook(keyID, getLabelForAddress(address), purpose);
  }
  
  bool WalletModel::getKeyId(const CBitcoinAddress& address, CKeyID& keyID)
  {
      if (!address.IsValid())
          return error("Invalid Remita Coin address");
  
      if (!address.GetKeyID(keyID))
          return error("Unable to get KeyID from Remita Coin address");
  
      return true;
  }
  
  std::string WalletModel::getLabelForAddress(const CBitcoinAddress& address)
  {
      std::string label = "";
      {
          LOCK(wallet->cs_wallet);
          std::map<CTxDestination, AddressBook::CAddressBookData>::iterator mi = wallet->mapAddressBook.find(address.Get());
          if (mi != wallet->mapAddressBook.end()) {
              label = mi->second.name;
          }
      }
      return label;
  }
  
  // returns a list of COutputs from COutPoints
  void WalletModel::getOutputs(const std::vector<COutPoint>& vOutpoints, std::vector<COutput>& vOutputs)
  {
      LOCK2(cs_main, wallet->cs_wallet);
      for (const COutPoint& outpoint : vOutpoints) {
          if (!wallet->mapWallet.count(outpoint.hash)) continue;
          bool fConflicted;
          const int nDepth = wallet->mapWallet[outpoint.hash].GetDepthAndMempool(fConflicted);
          if (nDepth < 0 || fConflicted) continue;
          COutput out(&wallet->mapWallet[outpoint.hash], outpoint.n, nDepth, true);
          vOutputs.push_back(out);
      }
  }
  
  // returns a COutPoint of Collateral Amount if found
  bool WalletModel::getMNCollateralCandidate(COutPoint& outPoint)
  {
      std::vector<COutput> vCoins;
      wallet->AvailableCoins(&vCoins, nullptr, false, false, ONLY_10000);
      for (const COutput& out : vCoins) {
          // skip locked collaterals
          if (!isLockedCoin(out.tx->GetHash(), out.i)) {
              outPoint = COutPoint(out.tx->GetHash(), out.i);
              return true;
          }
      }
      return false;
  }
  
  bool WalletModel::isSpent(const COutPoint& outpoint) const
  {
      LOCK2(cs_main, wallet->cs_wallet);
      return wallet->IsSpent(outpoint.hash, outpoint.n);
  }
  
  // AvailableCoins + LockedCoins grouped by wallet address (put change in one group with wallet address)
  void WalletModel::listCoins(std::map<QString, std::vector<COutput> >& mapCoins) const
  {
      std::vector<COutput> vCoins;
      wallet->AvailableCoins(&vCoins);
  
      LOCK2(cs_main, wallet->cs_wallet); // ListLockedCoins, mapWallet
      std::vector<COutPoint> vLockedCoins;
      wallet->ListLockedCoins(vLockedCoins);
  
      // add locked coins
      for (const COutPoint& outpoint : vLockedCoins) {
          if (!wallet->mapWallet.count(outpoint.hash)) continue;
          bool fConflicted;
          int nDepth = wallet->mapWallet[outpoint.hash].GetDepthAndMempool(fConflicted);
          if (nDepth < 0 || fConflicted) continue;
          COutput out(&wallet->mapWallet[outpoint.hash], outpoint.n, nDepth, true);
          if (outpoint.n < out.tx->vout.size() &&
                  (wallet->IsMine(out.tx->vout[outpoint.n]) & ISMINE_SPENDABLE_ALL) != ISMINE_NO)
              vCoins.push_back(out);
      }
  
      for (const COutput& out : vCoins) {
          COutput cout = out;
  
          while (wallet->IsChange(cout.tx->vout[cout.i]) && cout.tx->vin.size() > 0 && wallet->IsMine(cout.tx->vin[0])) {
              if (!wallet->mapWallet.count(cout.tx->vin[0].prevout.hash)) break;
              cout = COutput(&wallet->mapWallet[cout.tx->vin[0].prevout.hash], cout.tx->vin[0].prevout.n, 0, true);
          }
  
          CTxDestination address;
          if (!out.fSpendable || !ExtractDestination(cout.tx->vout[cout.i].scriptPubKey, address))
              continue;
          mapCoins[QString::fromStdString(CBitcoinAddress(address).ToString())].push_back(out);
      }
  }
  
  bool WalletModel::isLockedCoin(uint256 hash, unsigned int n) const
  {
      LOCK2(cs_main, wallet->cs_wallet);
      return wallet->IsLockedCoin(hash, n);
  }
  
  void WalletModel::lockCoin(COutPoint& output)
  {
      LOCK2(cs_main, wallet->cs_wallet);
      wallet->LockCoin(output);
  }
  
  void WalletModel::unlockCoin(COutPoint& output)
  {
      LOCK2(cs_main, wallet->cs_wallet);
      wallet->UnlockCoin(output);
  }
  
  void WalletModel::listLockedCoins(std::vector<COutPoint>& vOutpts)
  {
      LOCK2(cs_main, wallet->cs_wallet);
      wallet->ListLockedCoins(vOutpts);
  }
  
  void WalletModel::loadReceiveRequests(std::vector<std::string>& vReceiveRequests)
  {
      LOCK(wallet->cs_wallet);
      for (const PAIRTYPE(CTxDestination, AddressBook::CAddressBookData) & item : wallet->mapAddressBook)
          for (const PAIRTYPE(std::string, std::string) & item2 : item.second.destdata)
              if (item2.first.size() > 2 && item2.first.substr(0, 2) == "rr") // receive request
                  vReceiveRequests.push_back(item2.second);
  }
  
  bool WalletModel::saveReceiveRequest(const std::string& sAddress, const int64_t nId, const std::string& sRequest)
  {
      CTxDestination dest = DecodeDestination(sAddress);
  
      std::stringstream ss;
      ss << nId;
      std::string key = "rr" + ss.str(); // "rr" prefix = "receive request" in destdata
  
      LOCK(wallet->cs_wallet);
      if (sRequest.empty())
          return wallet->EraseDestData(dest, key);
      else
          return wallet->AddDestData(dest, key, sRequest);
  }
  
  bool WalletModel::isMine(const CTxDestination& address)
  {
      return IsMine(*wallet, address);
  }
  
  bool WalletModel::isMine(const QString& addressStr)
  {
      CBitcoinAddress address(addressStr.toStdString());
      return IsMine(*wallet, address.Get());
  }
  
  bool WalletModel::isUsed(CBitcoinAddress address)
  {
      return wallet->IsUsed(address);
  }
  