text: // Copyright (c) 2009-2010 Satoshi Nakamoto
  // Copyright (c) 2009-2016 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 "wallet/wallet.h"
  
  #include "base58.h"
  #include "checkpoints.h"
  #include "chain.h"
  #include "wallet/coincontrol.h"
  #include "consensus/consensus.h"
  #include "consensus/validation.h"
  #include "fs.h"
  #include "init.h"
  #include "key.h"
  #include "keystore.h"
  #include "validation.h"
  #include "net.h"
  #include "policy/fees.h"
  #include "policy/policy.h"
  #include "policy/rbf.h"
  #include "primitives/block.h"
  #include "primitives/transaction.h"
  #include "script/script.h"
  #include "script/sign.h"
  #include "scheduler.h"
  #include "timedata.h"
  #include "txmempool.h"
  #include "util.h"
  #include "ui_interface.h"
  #include "utilmoneystr.h"
  
  #include <assert.h>
  
  #include <boost/algorithm/string/replace.hpp>
  #include <boost/thread.hpp>
  
  std::vector<CWalletRef> vpwallets;
  /** Transaction fee set by the user */
  CFeeRate payTxFee(DEFAULT_TRANSACTION_FEE);
  unsigned int nTxConfirmTarget = DEFAULT_TX_CONFIRM_TARGET;
  bool bSpendZeroConfChange = DEFAULT_SPEND_ZEROCONF_CHANGE;
  bool fWalletRbf = DEFAULT_WALLET_RBF;
  
  const char * DEFAULT_WALLET_DAT = "wallet.dat";
  const uint32_t BIP32_HARDENED_KEY_LIMIT = 0x80000000;
  
  /**
   * Fees smaller than this (in liu) are considered zero fee (for transaction creation)
   * Override with -mintxfee
   */
  CFeeRate CWallet::minTxFee = CFeeRate(DEFAULT_TRANSACTION_MINFEE);
  /**
   * If fee estimation does not have enough data to provide estimates, use this fee instead.
   * Has no effect if not using fee estimation
   * Override with -fallbackfee
   */
  CFeeRate CWallet::fallbackFee = CFeeRate(DEFAULT_FALLBACK_FEE);
  
  CFeeRate CWallet::m_discard_rate = CFeeRate(DEFAULT_DISCARD_FEE);
  
  const uint256 CMerkleTx::ABANDON_HASH(uint256S("0000000000000000000000000000000000000000000000000000000000000001"));
  
  /** @defgroup mapWallet
   *
   * @{
   */
  
  struct CompareValueOnly
  {
      bool operator()(const CInputCoin& t1,
                      const CInputCoin& t2) const
      {
          return t1.txout.nValue < t2.txout.nValue;
      }
  };
  
  std::string COutput::ToString() const
  {
      return strprintf("COutput(%s, %d, %d) [%s]", tx->GetHash().ToString(), i, nDepth, FormatMoney(tx->tx->vout[i].nValue));
  }
  
  class CAffectedKeysVisitor : public boost::static_visitor<void> {
  private:
      const CKeyStore &keystore;
      std::vector<CKeyID> &vKeys;
  
  public:
      CAffectedKeysVisitor(const CKeyStore &keystoreIn, std::vector<CKeyID> &vKeysIn) : keystore(keystoreIn), vKeys(vKeysIn) {}
  
      void Process(const CScript &script) {
          txnouttype type;
          std::vector<CTxDestination> vDest;
          int nRequired;
          if (ExtractDestinations(script, type, vDest, nRequired)) {
              for (const CTxDestination &dest : vDest)
                  boost::apply_visitor(*this, dest);
          }
      }
  
      void operator()(const CKeyID &keyId) {
          if (keystore.HaveKey(keyId))
              vKeys.push_back(keyId);
      }
  
      void operator()(const CScriptID &scriptId) {
          CScript script;
          if (keystore.GetCScript(scriptId, script))
              Process(script);
      }
  
      void operator()(const CNoDestination &none) {}
  };
  
  const CWalletTx* CWallet::GetWalletTx(const uint256& hash) const
  {
      LOCK(cs_wallet);
      std::map<uint256, CWalletTx>::const_iterator it = mapWallet.find(hash);
      if (it == mapWallet.end())
          return nullptr;
      return &(it->second);
  }
  
  CPubKey CWallet::GenerateNewKey(CWalletDB &walletdb, bool internal)
  {
      AssertLockHeld(cs_wallet); // mapKeyMetadata
      bool fCompressed = CanSupportFeature(FEATURE_COMPRPUBKEY); // default to compressed public keys if we want 0.6.0 wallets
  
      CKey secret;
  
      // Create new metadata
      int64_t nCreationTime = GetTime();
      CKeyMetadata metadata(nCreationTime);
  
      // use HD key derivation if HD was enabled during wallet creation
      if (IsHDEnabled()) {
          DeriveNewChildKey(walletdb, metadata, secret, (CanSupportFeature(FEATURE_HD_SPLIT) ? internal : false));
      } else {
          secret.MakeNewKey(fCompressed);
      }
  
      // Compressed public keys were introduced in version 0.6.0
      if (fCompressed) {
          SetMinVersion(FEATURE_COMPRPUBKEY);
      }
  
      CPubKey pubkey = secret.GetPubKey();
      assert(secret.VerifyPubKey(pubkey));
  
      mapKeyMetadata[pubkey.GetID()] = metadata;
      UpdateTimeFirstKey(nCreationTime);
  
      if (!AddKeyPubKeyWithDB(walletdb, secret, pubkey)) {
          throw std::runtime_error(std::string(__func__) + ": AddKey failed");
      }
      return pubkey;
  }
  
  void CWallet::DeriveNewChildKey(CWalletDB &walletdb, CKeyMetadata& metadata, CKey& secret, bool internal)
  {
      // for now we use a fixed keypath scheme of m/0'/0'/k
      CKey key;                      //master key seed (256bit)
      CExtKey masterKey;             //hd master key
      CExtKey accountKey;            //key at m/0'
      CExtKey chainChildKey;         //key at m/0'/0' (external) or m/0'/1' (internal)
      CExtKey childKey;              //key at m/0'/0'/<n>'
  
      // try to get the master key
      if (!GetKey(hdChain.masterKeyID, key))
          throw std::runtime_error(std::string(__func__) + ": Master key not found");
  
      masterKey.SetMaster(key.begin(), key.size());
  
      // derive m/0'
      // use hardened derivation (child keys >= 0x80000000 are hardened after bip32)
      masterKey.Derive(accountKey, BIP32_HARDENED_KEY_LIMIT);
  
      // derive m/0'/0' (external chain) OR m/0'/1' (internal chain)
      assert(internal ? CanSupportFeature(FEATURE_HD_SPLIT) : true);
      accountKey.Derive(chainChildKey, BIP32_HARDENED_KEY_LIMIT+(internal ? 1 : 0));
  
      // derive child key at next index, skip keys already known to the wallet
      do {
          // always derive hardened keys
          // childIndex | BIP32_HARDENED_KEY_LIMIT = derive childIndex in hardened child-index-range
          // example: 1 | BIP32_HARDENED_KEY_LIMIT == 0x80000001 == 2147483649
          if (internal) {
              chainChildKey.Derive(childKey, hdChain.nInternalChainCounter | BIP32_HARDENED_KEY_LIMIT);
              metadata.hdKeypath = "m/0'/1'/" + std::to_string(hdChain.nInternalChainCounter) + "'";
              hdChain.nInternalChainCounter++;
          }
          else {
              chainChildKey.Derive(childKey, hdChain.nExternalChainCounter | BIP32_HARDENED_KEY_LIMIT);
              metadata.hdKeypath = "m/0'/0'/" + std::to_string(hdChain.nExternalChainCounter) + "'";
              hdChain.nExternalChainCounter++;
          }
      } while (HaveKey(childKey.key.GetPubKey().GetID()));
      secret = childKey.key;
      metadata.hdMasterKeyID = hdChain.masterKeyID;
      // update the chain model in the database
      if (!walletdb.WriteHDChain(hdChain))
          throw std::runtime_error(std::string(__func__) + ": Writing HD chain model failed");
  }
  
  bool CWallet::AddKeyPubKeyWithDB(CWalletDB &walletdb, const CKey& secret, const CPubKey &pubkey)
  {
      AssertLockHeld(cs_wallet); // mapKeyMetadata
  
      // CCryptoKeyStore has no concept of wallet databases, but calls AddCryptedKey
      // which is overridden below.  To avoid flushes, the database handle is
      // tunneled through to it.
      bool needsDB = !pwalletdbEncryption;
      if (needsDB) {
          pwalletdbEncryption = &walletdb;
      }
      if (!CCryptoKeyStore::AddKeyPubKey(secret, pubkey)) {
          if (needsDB) pwalletdbEncryption = nullptr;
          return false;
      }
      if (needsDB) pwalletdbEncryption = nullptr;
  
      // check if we need to remove from watch-only
      CScript script;
      script = GetScriptForDestination(pubkey.GetID());
      if (HaveWatchOnly(script)) {
          RemoveWatchOnly(script);
      }
      script = GetScriptForRawPubKey(pubkey);
      if (HaveWatchOnly(script)) {
          RemoveWatchOnly(script);
      }
  
      if (!IsCrypted()) {
          return walletdb.WriteKey(pubkey,
                                                   secret.GetPrivKey(),
                                                   mapKeyMetadata[pubkey.GetID()]);
      }
      return true;
  }
  
  bool CWallet::AddKeyPubKey(const CKey& secret, const CPubKey &pubkey)
  {
      CWalletDB walletdb(*dbw);
      return CWallet::AddKeyPubKeyWithDB(walletdb, secret, pubkey);
  }
  
  bool CWallet::AddCryptedKey(const CPubKey &vchPubKey,
                              const std::vector<unsigned char> &vchCryptedSecret)
  {
      if (!CCryptoKeyStore::AddCryptedKey(vchPubKey, vchCryptedSecret))
          return false;
      {
          LOCK(cs_wallet);
          if (pwalletdbEncryption)
              return pwalletdbEncryption->WriteCryptedKey(vchPubKey,
                                                          vchCryptedSecret,
                                                          mapKeyMetadata[vchPubKey.GetID()]);
          else
              return CWalletDB(*dbw).WriteCryptedKey(vchPubKey,
                                                              vchCryptedSecret,
                                                              mapKeyMetadata[vchPubKey.GetID()]);
      }
  }
  
  bool CWallet::LoadKeyMetadata(const CTxDestination& keyID, const CKeyMetadata &meta)
  {
      AssertLockHeld(cs_wallet); // mapKeyMetadata
      UpdateTimeFirstKey(meta.nCreateTime);
      mapKeyMetadata[keyID] = meta;
      return true;
  }
  
  bool CWallet::LoadCryptedKey(const CPubKey &vchPubKey, const std::vector<unsigned char> &vchCryptedSecret)
  {
      return CCryptoKeyStore::AddCryptedKey(vchPubKey, vchCryptedSecret);
  }
  
  /**
   * Update wallet first key creation time. This should be called whenever keys
   * are added to the wallet, with the oldest key creation time.
   */
  void CWallet::UpdateTimeFirstKey(int64_t nCreateTime)
  {
      AssertLockHeld(cs_wallet);
      if (nCreateTime <= 1) {
          // Cannot determine birthday information, so set the wallet birthday to
          // the beginning of time.
          nTimeFirstKey = 1;
      } else if (!nTimeFirstKey || nCreateTime < nTimeFirstKey) {
          nTimeFirstKey = nCreateTime;
      }
  }
  
  bool CWallet::AddCScript(const CScript& redeemScript)
  {
      if (!CCryptoKeyStore::AddCScript(redeemScript))
          return false;
      return CWalletDB(*dbw).WriteCScript(Hash160(redeemScript), redeemScript);
  }
  
  bool CWallet::LoadCScript(const CScript& redeemScript)
  {
      /* A sanity check was added in pull #3843 to avoid adding redeemScripts
       * that never can be redeemed. However, old wallets may still contain
       * these. Do not add them to the wallet and warn. */
      if (redeemScript.size() > MAX_SCRIPT_ELEMENT_SIZE)
      {
          std::string strAddr = CFabcoinAddress(CScriptID(redeemScript)).ToString();
          LogPrintf("%s: Warning: This wallet contains a redeemScript of size %i which exceeds maximum size %i thus can never be redeemed. Do not use address %s.\n",
              __func__, redeemScript.size(), MAX_SCRIPT_ELEMENT_SIZE, strAddr);
          return true;
      }
  
      return CCryptoKeyStore::AddCScript(redeemScript);
  }
  
  bool CWallet::AddWatchOnly(const CScript& dest)
  {
      if (!CCryptoKeyStore::AddWatchOnly(dest))
          return false;
      const CKeyMetadata& meta = mapKeyMetadata[CScriptID(dest)];
      UpdateTimeFirstKey(meta.nCreateTime);
      NotifyWatchonlyChanged(true);
      return CWalletDB(*dbw).WriteWatchOnly(dest, meta);
  }
  
  bool CWallet::AddWatchOnly(const CScript& dest, int64_t nCreateTime)
  {
      mapKeyMetadata[CScriptID(dest)].nCreateTime = nCreateTime;
      return AddWatchOnly(dest);
  }
  
  bool CWallet::RemoveWatchOnly(const CScript &dest)
  {
      AssertLockHeld(cs_wallet);
      if (!CCryptoKeyStore::RemoveWatchOnly(dest))
          return false;
      if (!HaveWatchOnly())
          NotifyWatchonlyChanged(false);
      if (!CWalletDB(*dbw).EraseWatchOnly(dest))
          return false;
  
      return true;
  }
  
  bool CWallet::LoadWatchOnly(const CScript &dest)
  {
      return CCryptoKeyStore::AddWatchOnly(dest);
  }
  
  bool CWallet::Unlock(const SecureString& strWalletPassphrase)
  {
      CCrypter crypter;
      CKeyingMaterial _vMasterKey;
  
      {
          LOCK(cs_wallet);
          for (const MasterKeyMap::value_type& pMasterKey : mapMasterKeys)
          {
              if(!crypter.SetKeyFromPassphrase(strWalletPassphrase, pMasterKey.second.vchSalt, pMasterKey.second.nDeriveIterations, pMasterKey.second.nDerivationMethod))
                  return false;
              if (!crypter.Decrypt(pMasterKey.second.vchCryptedKey, _vMasterKey))
                  continue; // try another master key
              if (CCryptoKeyStore::Unlock(_vMasterKey))
                  return true;
          }
      }
      return false;
  }
  
  bool CWallet::ChangeWalletPassphrase(const SecureString& strOldWalletPassphrase, const SecureString& strNewWalletPassphrase)
  {
      bool fWasLocked = IsLocked();
  
      {
          LOCK(cs_wallet);
          Lock();
  
          CCrypter crypter;
          CKeyingMaterial _vMasterKey;
          for (MasterKeyMap::value_type& pMasterKey : mapMasterKeys)
          {
              if(!crypter.SetKeyFromPassphrase(strOldWalletPassphrase, pMasterKey.second.vchSalt, pMasterKey.second.nDeriveIterations, pMasterKey.second.nDerivationMethod))
                  return false;
              if (!crypter.Decrypt(pMasterKey.second.vchCryptedKey, _vMasterKey))
                  return false;
              if (CCryptoKeyStore::Unlock(_vMasterKey))
              {
                  int64_t nStartTime = GetTimeMillis();
                  crypter.SetKeyFromPassphrase(strNewWalletPassphrase, pMasterKey.second.vchSalt, pMasterKey.second.nDeriveIterations, pMasterKey.second.nDerivationMethod);
                  pMasterKey.second.nDeriveIterations = pMasterKey.second.nDeriveIterations * (100 / ((double)(GetTimeMillis() - nStartTime)));
  
                  nStartTime = GetTimeMillis();
                  crypter.SetKeyFromPassphrase(strNewWalletPassphrase, pMasterKey.second.vchSalt, pMasterKey.second.nDeriveIterations, pMasterKey.second.nDerivationMethod);
                  pMasterKey.second.nDeriveIterations = (pMasterKey.second.nDeriveIterations + pMasterKey.second.nDeriveIterations * 100 / ((double)(GetTimeMillis() - nStartTime))) / 2;
  
                  if (pMasterKey.second.nDeriveIterations < 25000)
                      pMasterKey.second.nDeriveIterations = 25000;
  
                  LogPrintf("Wallet passphrase changed to an nDeriveIterations of %i\n", pMasterKey.second.nDeriveIterations);
  
                  if (!crypter.SetKeyFromPassphrase(strNewWalletPassphrase, pMasterKey.second.vchSalt, pMasterKey.second.nDeriveIterations, pMasterKey.second.nDerivationMethod))
                      return false;
                  if (!crypter.Encrypt(_vMasterKey, pMasterKey.second.vchCryptedKey))
                      return false;
                  CWalletDB(*dbw).WriteMasterKey(pMasterKey.first, pMasterKey.second);
                  if (fWasLocked)
                      Lock();
                  return true;
              }
          }
      }
  
      return false;
  }
  
  void CWallet::SetBestChain(const CBlockLocator& loc)
  {
      CWalletDB walletdb(*dbw);
      walletdb.WriteBestBlock(loc);
  }
  
  bool CWallet::SetMinVersion(enum WalletFeature nVersion, CWalletDB* pwalletdbIn, bool fExplicit)
  {
      LOCK(cs_wallet); // nWalletVersion
      if (nWalletVersion >= nVersion)
          return true;
  
      // when doing an explicit upgrade, if we pass the max version permitted, upgrade all the way
      if (fExplicit && nVersion > nWalletMaxVersion)
              nVersion = FEATURE_LATEST;
  
      nWalletVersion = nVersion;
  
      if (nVersion > nWalletMaxVersion)
          nWalletMaxVersion = nVersion;
  
      {
          CWalletDB* pwalletdb = pwalletdbIn ? pwalletdbIn : new CWalletDB(*dbw);
          if (nWalletVersion > 40000)
              pwalletdb->WriteMinVersion(nWalletVersion);
          if (!pwalletdbIn)
              delete pwalletdb;
      }
  
      return true;
  }
  
  bool CWallet::SetMaxVersion(int nVersion)
  {
      LOCK(cs_wallet); // nWalletVersion, nWalletMaxVersion
      // cannot downgrade below current version
      if (nWalletVersion > nVersion)
          return false;
  
      nWalletMaxVersion = nVersion;
  
      return true;
  }
  
  std::set<uint256> CWallet::GetConflicts(const uint256& txid) const
  {
      std::set<uint256> result;
      AssertLockHeld(cs_wallet);
  
      std::map<uint256, CWalletTx>::const_iterator it = mapWallet.find(txid);
      if (it == mapWallet.end())
          return result;
      const CWalletTx& wtx = it->second;
  
      std::pair<TxSpends::const_iterator, TxSpends::const_iterator> range;
  
      for (const CTxIn& txin : wtx.tx->vin)
      {
          if (mapTxSpends.count(txin.prevout) <= 1)
              continue;  // No conflict if zero or one spends
          range = mapTxSpends.equal_range(txin.prevout);
          for (TxSpends::const_iterator _it = range.first; _it != range.second; ++_it)
              result.insert(_it->second);
      }
      return result;
  }
  
  bool CWallet::HasWalletSpend(const uint256& txid) const
  {
      AssertLockHeld(cs_wallet);
      auto iter = mapTxSpends.lower_bound(COutPoint(txid, 0));
      return (iter != mapTxSpends.end() && iter->first.hash == txid);
  }
  
  void CWallet::Flush(bool shutdown)
  {
      dbw->Flush(shutdown);
  }
  
  bool CWallet::Verify()
  {
      if (gArgs.GetBoolArg("-disablewallet", DEFAULT_DISABLE_WALLET))
          return true;
  
      uiInterface.InitMessage(_("Verifying wallet(s)..."));
  
      // Keep track of each wallet absolute path to detect duplicates.
      std::set<fs::path> wallet_paths;
  
      for (const std::string& walletFile : gArgs.GetArgs("-wallet")) {
          if (boost::filesystem::path(walletFile).filename() != walletFile) {
              return InitError(strprintf(_("Error loading wallet %s. -wallet parameter must only specify a filename (not a path)."), walletFile));
          }
  
          if (SanitizeString(walletFile, SAFE_CHARS_FILENAME) != walletFile) {
              return InitError(strprintf(_("Error loading wallet %s. Invalid characters in -wallet filename."), walletFile));
          }
  
          fs::path wallet_path = fs::absolute(walletFile, GetDataDir());
  
          if (fs::exists(wallet_path) && (!fs::is_regular_file(wallet_path) || fs::is_symlink(wallet_path))) {
              return InitError(strprintf(_("Error loading wallet %s. -wallet filename must be a regular file."), walletFile));
          }
  
          if (!wallet_paths.insert(wallet_path).second) {
              return InitError(strprintf(_("Error loading wallet %s. Duplicate -wallet filename specified."), walletFile));
          }
  
          std::string strError;
          if (!CWalletDB::VerifyEnvironment(walletFile, GetDataDir().string(), strError)) {
              return InitError(strError);
          }
  
          if (gArgs.GetBoolArg("-salvagewallet", false)) {
              // Recover readable keypairs:
              CWallet dummyWallet;
              std::string backup_filename;
              if (!CWalletDB::Recover(walletFile, (void *)&dummyWallet, CWalletDB::RecoverKeysOnlyFilter, backup_filename)) {
                  return false;
              }
          }
  
          std::string strWarning;
          bool dbV = CWalletDB::VerifyDatabaseFile(walletFile, GetDataDir().string(), strWarning, strError);
          if (!strWarning.empty()) {
              InitWarning(strWarning);
          }
          if (!dbV) {
              InitError(strError);
              return false;
          }
      }
  
      return true;
  }
  
  void CWallet::SyncMetaData(std::pair<TxSpends::iterator, TxSpends::iterator> range)
  {
      // We want all the wallet transactions in range to have the same metadata as
      // the oldest (smallest nOrderPos).
      // So: find smallest nOrderPos:
  
      int nMinOrderPos = std::numeric_limits<int>::max();
      const CWalletTx* copyFrom = nullptr;
      for (TxSpends::iterator it = range.first; it != range.second; ++it)
      {
          const uint256& hash = it->second;
          int n = mapWallet[hash].nOrderPos;
          if (n < nMinOrderPos)
          {
              nMinOrderPos = n;
              copyFrom = &mapWallet[hash];
          }
      }
      // Now copy data from copyFrom to rest:
      for (TxSpends::iterator it = range.first; it != range.second; ++it)
      {
          const uint256& hash = it->second;
          CWalletTx* copyTo = &mapWallet[hash];
          if (copyFrom == copyTo) continue;
          if (!copyFrom->IsEquivalentTo(*copyTo)) continue;
          copyTo->mapValue = copyFrom->mapValue;
          copyTo->vOrderForm = copyFrom->vOrderForm;
          // fTimeReceivedIsTxTime not copied on purpose
          // nTimeReceived not copied on purpose
          copyTo->nTimeSmart = copyFrom->nTimeSmart;
          copyTo->fFromMe = copyFrom->fFromMe;
          copyTo->strFromAccount = copyFrom->strFromAccount;
          // nOrderPos not copied on purpose
          // cached members not copied on purpose
      }
  }
  
  /**
   * Outpoint is spent if any non-conflicted transaction
   * spends it:
   */
  bool CWallet::IsSpent(const uint256& hash, unsigned int n) const
  {
      const COutPoint outpoint(hash, n);
      std::pair<TxSpends::const_iterator, TxSpends::const_iterator> range;
      range = mapTxSpends.equal_range(outpoint);
  
      for (TxSpends::const_iterator it = range.first; it != range.second; ++it)
      {
          const uint256& wtxid = it->second;
          std::map<uint256, CWalletTx>::const_iterator mit = mapWallet.find(wtxid);
          if (mit != mapWallet.end()) {
              int depth = mit->second.GetDepthInMainChain();
              if (depth > 0  || (depth == 0 && !mit->second.isAbandoned()))
                  return true; // Spent
          }
      }
      return false;
  }
  
  void CWallet::AddToSpends(const COutPoint& outpoint, const uint256& wtxid)
  {
      mapTxSpends.insert(std::make_pair(outpoint, wtxid));
  
      std::pair<TxSpends::iterator, TxSpends::iterator> range;
      range = mapTxSpends.equal_range(outpoint);
      SyncMetaData(range);
  }
  
  
  void CWallet::AddToSpends(const uint256& wtxid)
  {
      assert(mapWallet.count(wtxid));
      CWalletTx& thisTx = mapWallet[wtxid];
      if (thisTx.IsCoinBase()) // Coinbases don't spend anything!
          return;
  
      for (const CTxIn& txin : thisTx.tx->vin)
          AddToSpends(txin.prevout, wtxid);
  }
  
  bool CWallet::EncryptWallet(const SecureString& strWalletPassphrase)
  {
      if (IsCrypted())
          return false;
  
      CKeyingMaterial _vMasterKey;
  
      _vMasterKey.resize(WALLET_CRYPTO_KEY_SIZE);
      GetStrongRandBytes(&_vMasterKey[0], WALLET_CRYPTO_KEY_SIZE);
  
      CMasterKey kMasterKey;
  
      kMasterKey.vchSalt.resize(WALLET_CRYPTO_SALT_SIZE);
      GetStrongRandBytes(&kMasterKey.vchSalt[0], WALLET_CRYPTO_SALT_SIZE);
  
      CCrypter crypter;
      int64_t nStartTime = GetTimeMillis();
      crypter.SetKeyFromPassphrase(strWalletPassphrase, kMasterKey.vchSalt, 25000, kMasterKey.nDerivationMethod);
      kMasterKey.nDeriveIterations = 2500000 / ((double)(GetTimeMillis() - nStartTime));
  
      nStartTime = GetTimeMillis();
      crypter.SetKeyFromPassphrase(strWalletPassphrase, kMasterKey.vchSalt, kMasterKey.nDeriveIterations, kMasterKey.nDerivationMethod);
      kMasterKey.nDeriveIterations = (kMasterKey.nDeriveIterations + kMasterKey.nDeriveIterations * 100 / ((double)(GetTimeMillis() - nStartTime))) / 2;
  
      if (kMasterKey.nDeriveIterations < 25000)
          kMasterKey.nDeriveIterations = 25000;
  
      LogPrintf("Encrypting Wallet with an nDeriveIterations of %i\n", kMasterKey.nDeriveIterations);
  
      if (!crypter.SetKeyFromPassphrase(strWalletPassphrase, kMasterKey.vchSalt, kMasterKey.nDeriveIterations, kMasterKey.nDerivationMethod))
          return false;
      if (!crypter.Encrypt(_vMasterKey, kMasterKey.vchCryptedKey))
          return false;
  
      {
          LOCK(cs_wallet);
          mapMasterKeys[++nMasterKeyMaxID] = kMasterKey;
          assert(!pwalletdbEncryption);
          pwalletdbEncryption = new CWalletDB(*dbw);
          if (!pwalletdbEncryption->TxnBegin()) {
              delete pwalletdbEncryption;
              pwalletdbEncryption = nullptr;
              return false;
          }
          pwalletdbEncryption->WriteMasterKey(nMasterKeyMaxID, kMasterKey);
  
          if (!EncryptKeys(_vMasterKey))
          {
              pwalletdbEncryption->TxnAbort();
              delete pwalletdbEncryption;
              // We now probably have half of our keys encrypted in memory, and half not...
              // die and let the user reload the unencrypted wallet.
              assert(false);
          }
  
          // Encryption was introduced in version 0.4.0
          SetMinVersion(FEATURE_WALLETCRYPT, pwalletdbEncryption, true);
  
          if (!pwalletdbEncryption->TxnCommit()) {
              delete pwalletdbEncryption;
              // We now have keys encrypted in memory, but not on disk...
              // die to avoid confusion and let the user reload the unencrypted wallet.
              assert(false);
          }
  
          delete pwalletdbEncryption;
          pwalletdbEncryption = nullptr;
  
          Lock();
          Unlock(strWalletPassphrase);
  
          // if we are using HD, replace the HD master key (seed) with a new one
          if (IsHDEnabled()) {
              if (!SetHDMasterKey(GenerateNewHDMasterKey())) {
                  return false;
              }
          }
  
          NewKeyPool();
          Lock();
  
          // Need to completely rewrite the wallet file; if we don't, bdb might keep
          // bits of the unencrypted private key in slack space in the database file.
          dbw->Rewrite();
  
      }
      NotifyStatusChanged(this);
  
      return true;
  }
  
  DBErrors CWallet::ReorderTransactions()
  {
      LOCK(cs_wallet);
      CWalletDB walletdb(*dbw);
  
      // Old wallets didn't have any defined order for transactions
      // Probably a bad idea to change the output of this
  
      // First: get all CWalletTx and CAccountingEntry into a sorted-by-time multimap.
      typedef std::pair<CWalletTx*, CAccountingEntry*> TxPair;
      typedef std::multimap<int64_t, TxPair > TxItems;
      TxItems txByTime;
  
      for (std::map<uint256, CWalletTx>::iterator it = mapWallet.begin(); it != mapWallet.end(); ++it)
      {
          CWalletTx* wtx = &((*it).second);
          txByTime.insert(std::make_pair(wtx->nTimeReceived, TxPair(wtx, (CAccountingEntry*)0)));
      }
      std::list<CAccountingEntry> acentries;
      walletdb.ListAccountCreditDebit("", acentries);
      for (CAccountingEntry& entry : acentries)
      {
          txByTime.insert(std::make_pair(entry.nTime, TxPair((CWalletTx*)0, &entry)));
      }
  
      nOrderPosNext = 0;
      std::vector<int64_t> nOrderPosOffsets;
      for (TxItems::iterator it = txByTime.begin(); it != txByTime.end(); ++it)
      {
          CWalletTx *const pwtx = (*it).second.first;
          CAccountingEntry *const pacentry = (*it).second.second;
          int64_t& nOrderPos = (pwtx != 0) ? pwtx->nOrderPos : pacentry->nOrderPos;
  
          if (nOrderPos == -1)
          {
              nOrderPos = nOrderPosNext++;
              nOrderPosOffsets.push_back(nOrderPos);
  
              if (pwtx)
              {
                  if (!walletdb.WriteTx(*pwtx))
                      return DB_LOAD_FAIL;
              }
              else
                  if (!walletdb.WriteAccountingEntry(pacentry->nEntryNo, *pacentry))
                      return DB_LOAD_FAIL;
          }
          else
          {
              int64_t nOrderPosOff = 0;
              for (const int64_t& nOffsetStart : nOrderPosOffsets)
              {
                  if (nOrderPos >= nOffsetStart)
                      ++nOrderPosOff;
              }
              nOrderPos += nOrderPosOff;
              nOrderPosNext = std::max(nOrderPosNext, nOrderPos + 1);
  
              if (!nOrderPosOff)
                  continue;
  
              // Since we're changing the order, write it back
              if (pwtx)
              {
                  if (!walletdb.WriteTx(*pwtx))
                      return DB_LOAD_FAIL;
              }
              else
                  if (!walletdb.WriteAccountingEntry(pacentry->nEntryNo, *pacentry))
                      return DB_LOAD_FAIL;
          }
      }
      walletdb.WriteOrderPosNext(nOrderPosNext);
  
      return DB_LOAD_OK;
  }
  
  int64_t CWallet::IncOrderPosNext(CWalletDB *pwalletdb)
  {
      AssertLockHeld(cs_wallet); // nOrderPosNext
      int64_t nRet = nOrderPosNext++;
      if (pwalletdb) {
          pwalletdb->WriteOrderPosNext(nOrderPosNext);
      } else {
          CWalletDB(*dbw).WriteOrderPosNext(nOrderPosNext);
      }
      return nRet;
  }
  
  bool CWallet::AccountMove(std::string strFrom, std::string strTo, CAmount nAmount, std::string strComment)
  {
      CWalletDB walletdb(*dbw);
      if (!walletdb.TxnBegin())
          return false;
  
      int64_t nNow = GetAdjustedTime();
  
      // Debit
      CAccountingEntry debit;
      debit.nOrderPos = IncOrderPosNext(&walletdb);
      debit.strAccount = strFrom;
      debit.nCreditDebit = -nAmount;
      debit.nTime = nNow;
      debit.strOtherAccount = strTo;
      debit.strComment = strComment;
      AddAccountingEntry(debit, &walletdb);
  
      // Credit
      CAccountingEntry credit;
      credit.nOrderPos = IncOrderPosNext(&walletdb);
      credit.strAccount = strTo;
      credit.nCreditDebit = nAmount;
      credit.nTime = nNow;
      credit.strOtherAccount = strFrom;
      credit.strComment = strComment;
      AddAccountingEntry(credit, &walletdb);
  
      if (!walletdb.TxnCommit())
          return false;
  
      return true;
  }
  
  bool CWallet::GetAccountPubkey(CPubKey &pubKey, std::string strAccount, bool bForceNew)
  {
      CWalletDB walletdb(*dbw);
  
      CAccount account;
      walletdb.ReadAccount(strAccount, account);
  
      if (!bForceNew) {
          if (!account.vchPubKey.IsValid())
              bForceNew = true;
          else {
              // Check if the current key has been used
              CScript scriptPubKey = GetScriptForDestination(account.vchPubKey.GetID());
              for (std::map<uint256, CWalletTx>::iterator it = mapWallet.begin();
                   it != mapWallet.end() && account.vchPubKey.IsValid();
                   ++it)
                  for (const CTxOut& txout : (*it).second.tx->vout)
                      if (txout.scriptPubKey == scriptPubKey) {
                          bForceNew = true;
                          break;
                      }
          }
      }
  
      // Generate a new key
      if (bForceNew) {
          if (!GetKeyFromPool(account.vchPubKey, false))
              return false;
  
          SetAddressBook(account.vchPubKey.GetID(), strAccount, "receive");
          walletdb.WriteAccount(strAccount, account);
      }
  
      pubKey = account.vchPubKey;
  
      return true;
  }
  
  void CWallet::MarkDirty()
  {
      {
          LOCK(cs_wallet);
          for (std::pair<const uint256, CWalletTx>& item : mapWallet)
              item.second.MarkDirty();
      }
  }
  
  bool CWallet::MarkReplaced(const uint256& originalHash, const uint256& newHash)
  {
      LOCK(cs_wallet);
  
      auto mi = mapWallet.find(originalHash);
  
      // There is a bug if MarkReplaced is not called on an existing wallet transaction.
      assert(mi != mapWallet.end());
  
      CWalletTx& wtx = (*mi).second;
  
      // Ensure for now that we're not overwriting data
      assert(wtx.mapValue.count("replaced_by_txid") == 0);
  
      wtx.mapValue["replaced_by_txid"] = newHash.ToString();
  
      CWalletDB walletdb(*dbw, "r+");
  
      bool success = true;
      if (!walletdb.WriteTx(wtx)) {
          LogPrintf("%s: Updating walletdb tx %s failed", __func__, wtx.GetHash().ToString());
          success = false;
      }
  
      NotifyTransactionChanged(this, originalHash, CT_UPDATED);
  
      return success;
  }
  
  bool CWallet::AddToWallet(const CWalletTx& wtxIn, bool fFlushOnClose)
  {
      LOCK(cs_wallet);
  
      CWalletDB walletdb(*dbw, "r+", fFlushOnClose);
  
      uint256 hash = wtxIn.GetHash();
  
      // Inserts only if not already there, returns tx inserted or tx found
      std::pair<std::map<uint256, CWalletTx>::iterator, bool> ret = mapWallet.insert(std::make_pair(hash, wtxIn));
      CWalletTx& wtx = (*ret.first).second;
      wtx.BindWallet(this);
      bool fInsertedNew = ret.second;
      if (fInsertedNew)
      {
          wtx.nTimeReceived = GetAdjustedTime();
          wtx.nOrderPos = IncOrderPosNext(&walletdb);
          wtxOrdered.insert(std::make_pair(wtx.nOrderPos, TxPair(&wtx, (CAccountingEntry*)0)));
          wtx.nTimeSmart = ComputeTimeSmart(wtx);
          AddToSpends(hash);
      }
  
      bool fUpdated = false;
      if (!fInsertedNew)
      {
          // Merge
          if (!wtxIn.hashUnset() && wtxIn.hashBlock != wtx.hashBlock)
          {
              wtx.hashBlock = wtxIn.hashBlock;
              fUpdated = true;
          }
          // If no longer abandoned, update
          if (wtxIn.hashBlock.IsNull() && wtx.isAbandoned())
          {
              wtx.hashBlock = wtxIn.hashBlock;
              fUpdated = true;
          }
          if (wtxIn.nIndex != -1 && (wtxIn.nIndex != wtx.nIndex))
          {
              wtx.nIndex = wtxIn.nIndex;
              fUpdated = true;
          }
          if (wtxIn.fFromMe && wtxIn.fFromMe != wtx.fFromMe)
          {
              wtx.fFromMe = wtxIn.fFromMe;
              fUpdated = true;
          }
          // If we have a witness-stripped version of this transaction, and we
          // see a new version with a witness, then we must be upgrading a pre-segwit
          // wallet.  Store the new version of the transaction with the witness,
          // as the stripped-version must be invalid.
          // TODO: Store all versions of the transaction, instead of just one.
          if (wtxIn.tx->HasWitness() && !wtx.tx->HasWitness()) {
              wtx.SetTx(wtxIn.tx);
              fUpdated = true;
          }
      }
  
      //// debug print
      LogPrintf("AddToWallet %s  %s%s\n", wtxIn.GetHash().ToString(), (fInsertedNew ? "new" : ""), (fUpdated ? "update" : ""));
  
      // Write to disk
      if (fInsertedNew || fUpdated)
          if (!walletdb.WriteTx(wtx))
              return false;
  
      // Break debit/credit balance caches:
      wtx.MarkDirty();
  
      // Notify UI of new or updated transaction
      NotifyTransactionChanged(this, hash, fInsertedNew ? CT_NEW : CT_UPDATED);
  
      // notify an external script when a wallet transaction comes in or is updated
      std::string strCmd = gArgs.GetArg("-walletnotify", "");
  
      if ( !strCmd.empty())
      {
          boost::replace_all(strCmd, "%s", wtxIn.GetHash().GetHex());
          boost::thread t(runCommand, strCmd); // thread runs free
      }
  
      return true;
  }
  
  bool CWallet::LoadToWallet(const CWalletTx& wtxIn)
  {
      uint256 hash = wtxIn.GetHash();
  
      mapWallet[hash] = wtxIn;
      CWalletTx& wtx = mapWallet[hash];
      wtx.BindWallet(this);
      wtxOrdered.insert(std::make_pair(wtx.nOrderPos, TxPair(&wtx, (CAccountingEntry*)0)));
      AddToSpends(hash);
      for (const CTxIn& txin : wtx.tx->vin) {
          if (mapWallet.count(txin.prevout.hash)) {
              CWalletTx& prevtx = mapWallet[txin.prevout.hash];
              if (prevtx.nIndex == -1 && !prevtx.hashUnset()) {
                  MarkConflicted(prevtx.hashBlock, wtx.GetHash());
              }
          }
      }
  
      return true;
  }
  
  /**
   * Add a transaction to the wallet, or update it.  pIndex and posInBlock should
   * be set when the transaction was known to be included in a block.  When
   * pIndex == nullptr, then wallet state is not updated in AddToWallet, but
   * notifications happen and cached balances are marked dirty.
   *
   * If fUpdate is true, existing transactions will be updated.
   * TODO: One exception to this is that the abandoned state is cleared under the
   * assumption that any further notification of a transaction that was considered
   * abandoned is an indication that it is not safe to be considered abandoned.
   * Abandoned state should probably be more carefully tracked via different
   * posInBlock signals or by checking mempool presence when necessary.
   */
  bool CWallet::AddToWalletIfInvolvingMe(const CTransactionRef& ptx, const CBlockIndex* pIndex, int posInBlock, bool fUpdate)
  {
      const CTransaction& tx = *ptx;
      {
          AssertLockHeld(cs_wallet);
  
          if (pIndex != nullptr) {
              for (const CTxIn& txin : tx.vin) {
                  std::pair<TxSpends::const_iterator, TxSpends::const_iterator> range = mapTxSpends.equal_range(txin.prevout);
                  while (range.first != range.second) {
                      if (range.first->second != tx.GetHash()) {
                          LogPrintf("Transaction %s (in block %s) conflicts with wallet transaction %s (both spend %s:%i)\n", tx.GetHash().ToString(), pIndex->GetBlockHash().ToString(), range.first->second.ToString(), range.first->first.hash.ToString(), range.first->first.n);
                          MarkConflicted(pIndex->GetBlockHash(), range.first->second);
                      }
                      range.first++;
                  }
              }
          }
  
          bool fExisted = mapWallet.count(tx.GetHash()) != 0;
          if (fExisted && !fUpdate) return false;
          if (fExisted || IsMine(tx) || IsFromMe(tx))
          {
              /* Check if any keys in the wallet keypool that were supposed to be unused
               * have appeared in a new transaction. If so, remove those keys from the keypool.
               * This can happen when restoring an old wallet backup that does not contain
               * the mostly recently created transactions from newer versions of the wallet.
               */
  
              // loop though all outputs
              for (const CTxOut& txout: tx.vout) {
                  // extract addresses and check if they match with an unused keypool key
                  std::vector<CKeyID> vAffected;
                  CAffectedKeysVisitor(*this, vAffected).Process(txout.scriptPubKey);
                  for (const CKeyID &keyid : vAffected) {
                      std::map<CKeyID, int64_t>::const_iterator mi = m_pool_key_to_index.find(keyid);
                      if (mi != m_pool_key_to_index.end()) {
                          LogPrintf("%s: Detected a used keypool key, mark all keypool key up to this key as used\n", __func__);
                          MarkReserveKeysAsUsed(mi->second);
  
                          if (!TopUpKeyPool()) {
                              LogPrintf("%s: Topping up keypool failed (locked wallet)\n", __func__);
                          }
                      }
                  }
              }
  
              CWalletTx wtx(this, ptx);
  
              // Get merkle branch if transaction was found in a block
              if (pIndex != nullptr)
                  wtx.SetMerkleBranch(pIndex, posInBlock);
  
              return AddToWallet(wtx, false);
          }
      }
      return false;
  }
  
  bool CWallet::TransactionCanBeAbandoned(const uint256& hashTx) const
  {
      LOCK2(cs_main, cs_wallet);
      const CWalletTx* wtx = GetWalletTx(hashTx);
      return wtx && !wtx->isAbandoned() && wtx->GetDepthInMainChain() <= 0 && !wtx->InMempool();
  }
  
  bool CWallet::AbandonTransaction(const uint256& hashTx)
  {
      LOCK2(cs_main, cs_wallet);
  
      CWalletDB walletdb(*dbw, "r+");
  
      std::set<uint256> todo;
      std::set<uint256> done;
  
      // Can't mark abandoned if confirmed or in mempool
      assert(mapWallet.count(hashTx));
      CWalletTx& origtx = mapWallet[hashTx];
      if (origtx.GetDepthInMainChain() > 0 || origtx.InMempool()) {
          return false;
      }
  
      todo.insert(hashTx);
  
      while (!todo.empty()) {
          uint256 now = *todo.begin();
          todo.erase(now);
          done.insert(now);
          assert(mapWallet.count(now));
          CWalletTx& wtx = mapWallet[now];
          int currentconfirm = wtx.GetDepthInMainChain();
          // If the orig tx was not in block, none of its spends can be
          assert(currentconfirm <= 0);
          // if (currentconfirm < 0) {Tx and spends are already conflicted, no need to abandon}
          if (currentconfirm == 0 && !wtx.isAbandoned()) {
              // If the orig tx was not in block/mempool, none of its spends can be in mempool
              assert(!wtx.InMempool());
              wtx.nIndex = -1;
              wtx.setAbandoned();
              wtx.MarkDirty();
              walletdb.WriteTx(wtx);
              NotifyTransactionChanged(this, wtx.GetHash(), CT_UPDATED);
              // Iterate over all its outputs, and mark transactions in the wallet that spend them abandoned too
              TxSpends::const_iterator iter = mapTxSpends.lower_bound(COutPoint(hashTx, 0));
              while (iter != mapTxSpends.end() && iter->first.hash == now) {
                  if (!done.count(iter->second)) {
                      todo.insert(iter->second);
                  }
                  iter++;
              }
              // If a transaction changes 'conflicted' state, that changes the balance
              // available of the outputs it spends. So force those to be recomputed
              for (const CTxIn& txin : wtx.tx->vin)
              {
                  if (mapWallet.count(txin.prevout.hash))
                      mapWallet[txin.prevout.hash].MarkDirty();
              }
          }
      }
  
      return true;
  }
  
  void CWallet::MarkConflicted(const uint256& hashBlock, const uint256& hashTx)
  {
      LOCK2(cs_main, cs_wallet);
  
      int conflictconfirms = 0;
      if (mapBlockIndex.count(hashBlock)) {
          CBlockIndex* pindex = mapBlockIndex[hashBlock];
          if (chainActive.Contains(pindex)) {
              conflictconfirms = -(chainActive.Height() - pindex->nHeight + 1);
          }
      }
      // If number of conflict confirms cannot be determined, this means
      // that the block is still unknown or not yet part of the main chain,
      // for example when loading the wallet during a reindex. Do nothing in that
      // case.
      if (conflictconfirms >= 0)
          return;
  
      // Do not flush the wallet here for performance reasons
      CWalletDB walletdb(*dbw, "r+", false);
  
      std::set<uint256> todo;
      std::set<uint256> done;
  
      todo.insert(hashTx);
  
      while (!todo.empty()) {
          uint256 now = *todo.begin();
          todo.erase(now);
          done.insert(now);
          assert(mapWallet.count(now));
          CWalletTx& wtx = mapWallet[now];
          int currentconfirm = wtx.GetDepthInMainChain();
          if (conflictconfirms < currentconfirm) {
              // Block is 'more conflicted' than current confirm; update.
              // Mark transaction as conflicted with this block.
              wtx.nIndex = -1;
              wtx.hashBlock = hashBlock;
              wtx.MarkDirty();
              walletdb.WriteTx(wtx);
              // Iterate over all its outputs, and mark transactions in the wallet that spend them conflicted too
              TxSpends::const_iterator iter = mapTxSpends.lower_bound(COutPoint(now, 0));
              while (iter != mapTxSpends.end() && iter->first.hash == now) {
                   if (!done.count(iter->second)) {
                       todo.insert(iter->second);
                   }
                   iter++;
              }
              // If a transaction changes 'conflicted' state, that changes the balance
              // available of the outputs it spends. So force those to be recomputed
              for (const CTxIn& txin : wtx.tx->vin)
              {
                  if (mapWallet.count(txin.prevout.hash))
                      mapWallet[txin.prevout.hash].MarkDirty();
              }
          }
      }
  }
  
  void CWallet::SyncTransaction(const CTransactionRef& ptx, const CBlockIndex *pindex, int posInBlock) {
      const CTransaction& tx = *ptx;
  
      if (!AddToWalletIfInvolvingMe(ptx, pindex, posInBlock, true))
          return; // Not one of ours
  
      // If a transaction changes 'conflicted' state, that changes the balance
      // available of the outputs it spends. So force those to be
      // recomputed, also:
      for (const CTxIn& txin : tx.vin)
      {
          if (mapWallet.count(txin.prevout.hash))
              mapWallet[txin.prevout.hash].MarkDirty();
      }
  }
  
  void CWallet::TransactionAddedToMempool(const CTransactionRef& ptx) {
      LOCK2(cs_main, cs_wallet);
      SyncTransaction(ptx);
  }
  
  void CWallet::BlockConnected(const std::shared_ptr<const CBlock>& pblock, const CBlockIndex *pindex, const std::vector<CTransactionRef>& vtxConflicted) {
      LOCK2(cs_main, cs_wallet);
      // TODO: Temporarily ensure that mempool removals are notified before
      // connected transactions.  This shouldn't matter, but the abandoned
      // state of transactions in our wallet is currently cleared when we
      // receive another notification and there is a race condition where
      // notification of a connected conflict might cause an outside process
      // to abandon a transaction and then have it inadvertently cleared by
      // the notification that the conflicted transaction was evicted.
  
      for (const CTransactionRef& ptx : vtxConflicted) {
          SyncTransaction(ptx);
      }
      for (size_t i = 0; i < pblock->vtx.size(); i++) {
          SyncTransaction(pblock->vtx[i], pindex, i);
      }
  }
  
  void CWallet::BlockDisconnected(const std::shared_ptr<const CBlock>& pblock) {
      LOCK2(cs_main, cs_wallet);
  
      for (const CTransactionRef& ptx : pblock->vtx) {
          SyncTransaction(ptx);
      }
  }
  
  
  
  isminetype CWallet::IsMine(const CTxIn &txin) const
  {
      {
          LOCK(cs_wallet);
          std::map<uint256, CWalletTx>::const_iterator mi = mapWallet.find(txin.prevout.hash);
          if (mi != mapWallet.end())
          {
              const CWalletTx& prev = (*mi).second;
              if (txin.prevout.n < prev.tx->vout.size())
                  return IsMine(prev.tx->vout[txin.prevout.n]);
          }
      }
      return ISMINE_NO;
  }
  
  // Note that this function doesn't distinguish between a 0-valued input,
  // and a not-"is mine" (according to the filter) input.
  CAmount CWallet::GetDebit(const CTxIn &txin, const isminefilter& filter) const
  {
      {
          LOCK(cs_wallet);
          std::map<uint256, CWalletTx>::const_iterator mi = mapWallet.find(txin.prevout.hash);
          if (mi != mapWallet.end())
          {
              const CWalletTx& prev = (*mi).second;
              if (txin.prevout.n < prev.tx->vout.size())
                  if (IsMine(prev.tx->vout[txin.prevout.n]) & filter)
                      return prev.tx->vout[txin.prevout.n].nValue;
          }
      }
      return 0;
  }
  
  isminetype CWallet::IsMine(const CTxOut& txout) const
  {
      return ::IsMine(*this, txout.scriptPubKey);
  }
  
  CAmount CWallet::GetCredit(const CTxOut& txout, const isminefilter& filter) const
  {
      if (!MoneyRange(txout.nValue))
          throw std::runtime_error(std::string(__func__) + ": value out of range");
      return ((IsMine(txout) & filter) ? txout.nValue : 0);
  }
  
  bool CWallet::IsChange(const CTxOut& txout) const
  {
      // TODO: fix handling of 'change' outputs. The assumption is that any
      // payment to a script that is ours, but is not in the address book
      // is change. That assumption is likely to break when we implement multisignature
      // wallets that return change back into a multi-signature-protected address;
      // a better way of identifying which outputs are 'the send' and which are
      // 'the change' will need to be implemented (maybe extend CWalletTx to remember
      // which output, if any, was change).
      if (::IsMine(*this, txout.scriptPubKey))
      {
          CTxDestination address;
          if (!ExtractDestination(txout.scriptPubKey, address))
              return true;
  
          LOCK(cs_wallet);
          if (!mapAddressBook.count(address))
              return true;
      }
      return false;
  }
  
  CAmount CWallet::GetChange(const CTxOut& txout) const
  {
      if (!MoneyRange(txout.nValue))
          throw std::runtime_error(std::string(__func__) + ": value out of range");
      return (IsChange(txout) ? txout.nValue : 0);
  }
  
  bool CWallet::IsMine(const CTransaction& tx) const
  {
      for (const CTxOut& txout : tx.vout)
          if (IsMine(txout))
              return true;
      return false;
  }
  
  bool CWallet::IsFromMe(const CTransaction& tx) const
  {
      return (GetDebit(tx, ISMINE_ALL) > 0);
  }
  
  CAmount CWallet::GetDebit(const CTransaction& tx, const isminefilter& filter) const
  {
      CAmount nDebit = 0;
      for (const CTxIn& txin : tx.vin)
      {
          nDebit += GetDebit(txin, filter);
          if (!MoneyRange(nDebit))
              throw std::runtime_error(std::string(__func__) + ": value out of range");
      }
      return nDebit;
  }
  
  bool CWallet::IsAllFromMe(const CTransaction& tx, const isminefilter& filter) const
  {
      LOCK(cs_wallet);
  
      for (const CTxIn& txin : tx.vin)
      {
          auto mi = mapWallet.find(txin.prevout.hash);
          if (mi == mapWallet.end())
              return false; // any unknown inputs can't be from us
  
          const CWalletTx& prev = (*mi).second;
  
          if (txin.prevout.n >= prev.tx->vout.size())
              return false; // invalid input!
  
          if (!(IsMine(prev.tx->vout[txin.prevout.n]) & filter))
              return false;
      }
      return true;
  }
  
  CAmount CWallet::GetCredit(const CTransaction& tx, const isminefilter& filter) const
  {
      CAmount nCredit = 0;
      for (const CTxOut& txout : tx.vout)
      {
          nCredit += GetCredit(txout, filter);
          if (!MoneyRange(nCredit))
              throw std::runtime_error(std::string(__func__) + ": value out of range");
      }
      return nCredit;
  }
  
  CAmount CWallet::GetChange(const CTransaction& tx) const
  {
      CAmount nChange = 0;
      for (const CTxOut& txout : tx.vout)
      {
          nChange += GetChange(txout);
          if (!MoneyRange(nChange))
              throw std::runtime_error(std::string(__func__) + ": value out of range");
      }
      return nChange;
  }
  
  CPubKey CWallet::GenerateNewHDMasterKey()
  {
      CKey key;
      key.MakeNewKey(true);
  
      int64_t nCreationTime = GetTime();
      CKeyMetadata metadata(nCreationTime);
  
      // calculate the pubkey
      CPubKey pubkey = key.GetPubKey();
      assert(key.VerifyPubKey(pubkey));
  
      // set the hd keypath to "m" -> Master, refers the masterkeyid to itself
      metadata.hdKeypath     = "m";
      metadata.hdMasterKeyID = pubkey.GetID();
  
      {
          LOCK(cs_wallet);
  
          // mem store the metadata
          mapKeyMetadata[pubkey.GetID()] = metadata;
  
          // write the key&metadata to the database
          if (!AddKeyPubKey(key, pubkey))
              throw std::runtime_error(std::string(__func__) + ": AddKeyPubKey failed");
      }
  
      return pubkey;
  }
  
  bool CWallet::SetHDMasterKey(const CPubKey& pubkey)
  {
      LOCK(cs_wallet);
      // store the keyid (hash160) together with
      // the child index counter in the database
      // as a hdchain object
      CHDChain newHdChain;
      newHdChain.nVersion = CanSupportFeature(FEATURE_HD_SPLIT) ? CHDChain::VERSION_HD_CHAIN_SPLIT : CHDChain::VERSION_HD_BASE;
      newHdChain.masterKeyID = pubkey.GetID();
      SetHDChain(newHdChain, false);
  
      return true;
  }
  
  bool CWallet::SetHDChain(const CHDChain& chain, bool memonly)
  {
      LOCK(cs_wallet);
      if (!memonly && !CWalletDB(*dbw).WriteHDChain(chain))
          throw std::runtime_error(std::string(__func__) + ": writing chain failed");
  
      hdChain = chain;
      return true;
  }
  
  bool CWallet::IsHDEnabled() const
  {
      return !hdChain.masterKeyID.IsNull();
  }
  
  int64_t CWalletTx::GetTxTime() const
  {
      int64_t n = nTimeSmart;
      return n ? n : nTimeReceived;
  }
  
  int CWalletTx::GetRequestCount() const
  {
      // Returns -1 if it wasn't being tracked
      int nRequests = -1;
      {
          LOCK(pwallet->cs_wallet);
          if (IsCoinBase())
          {
              // Generated block
              if (!hashUnset())
              {
                  std::map<uint256, int>::const_iterator mi = pwallet->mapRequestCount.find(hashBlock);
                  if (mi != pwallet->mapRequestCount.end())
                      nRequests = (*mi).second;
              }
          }
          else
          {
              // Did anyone request this transaction?
              std::map<uint256, int>::const_iterator mi = pwallet->mapRequestCount.find(GetHash());
              if (mi != pwallet->mapRequestCount.end())
              {
                  nRequests = (*mi).second;
  
                  // How about the block it's in?
                  if (nRequests == 0 && !hashUnset())
                  {
                      std::map<uint256, int>::const_iterator _mi = pwallet->mapRequestCount.find(hashBlock);
                      if (_mi != pwallet->mapRequestCount.end())
                          nRequests = (*_mi).second;
                      else
                          nRequests = 1; // If it's in someone else's block it must have got out
                  }
              }
          }
      }
      return nRequests;
  }
  
  void CWalletTx::GetAmounts(std::list<COutputEntry>& listReceived,
                             std::list<COutputEntry>& listSent, CAmount& nFee, std::string& strSentAccount, const isminefilter& filter) const
  {
      nFee = 0;
      listReceived.clear();
      listSent.clear();
      strSentAccount = strFromAccount;
  
      // Compute fee:
      CAmount nDebit = GetDebit(filter);
      if (nDebit > 0) // debit>0 means we signed/sent this transaction
      {
          CAmount nValueOut = tx->GetValueOut();
          nFee = nDebit - nValueOut;
      }
  
      // Sent/received.
      for (unsigned int i = 0; i < tx->vout.size(); ++i)
      {
          const CTxOut& txout = tx->vout[i];
          isminetype fIsMine = pwallet->IsMine(txout);
          // Only need to handle txouts if AT LEAST one of these is true:
          //   1) they debit from us (sent)
          //   2) the output is to us (received)
          if (nDebit > 0)
          {
              // Don't report 'change' txouts
              if (pwallet->IsChange(txout))
                  continue;
          }
          else if (!(fIsMine & filter))
              continue;
  
          // In either case, we need to get the destination address
          CTxDestination address;
  
          if (!ExtractDestination(txout.scriptPubKey, address) && !txout.scriptPubKey.IsUnspendable())
          {
              LogPrintf("CWalletTx::GetAmounts: Unknown transaction type found, txid %s\n",
                       this->GetHash().ToString());
              address = CNoDestination();
          }
  
          COutputEntry output = {address, txout.nValue, (int)i};
  
          // If we are debited by the transaction, add the output as a "sent" entry
          if (nDebit > 0)
              listSent.push_back(output);
  
          // If we are receiving the output, add it as a "received" entry
          if (fIsMine & filter)
              listReceived.push_back(output);
      }
  
  }
  
  /**
   * Scan active chain for relevant transactions after importing keys. This should
   * be called whenever new keys are added to the wallet, with the oldest key
   * creation time.
   *
   * @return Earliest timestamp that could be successfully scanned from. Timestamp
   * returned will be higher than startTime if relevant blocks could not be read.
   */
  int64_t CWallet::RescanFromTime(int64_t startTime, bool update)
  {
      AssertLockHeld(cs_main);
      AssertLockHeld(cs_wallet);
  
      // Find starting block. May be null if nCreateTime is greater than the
      // highest blockchain timestamp, in which case there is nothing that needs
      // to be scanned.
      CBlockIndex* const startBlock = chainActive.FindEarliestAtLeast(startTime - TIMESTAMP_WINDOW);
      LogPrintf("%s: Rescanning last %i blocks\n", __func__, startBlock ? chainActive.Height() - startBlock->nHeight + 1 : 0);
  
      if (startBlock) {
          const CBlockIndex* const failedBlock = ScanForWalletTransactions(startBlock, update);
          if (failedBlock) {
              return failedBlock->GetBlockTimeMax() + TIMESTAMP_WINDOW + 1;
          }
      }
      return startTime;
  }
  
  /**
   * Scan the block chain (starting in pindexStart) for transactions
   * from or to us. If fUpdate is true, found transactions that already
   * exist in the wallet will be updated.
   *
   * Returns null if scan was successful. Otherwise, if a complete rescan was not
   * possible (due to pruning or corruption), returns pointer to the most recent
   * block that could not be scanned.
   */
  CBlockIndex* CWallet::ScanForWalletTransactions(CBlockIndex* pindexStart, bool fUpdate)
  {
      int64_t nNow = GetTime();
      const CChainParams& chainParams = Params();
  
      CBlockIndex* pindex = pindexStart;
      CBlockIndex* ret = nullptr;
      {
          LOCK2(cs_main, cs_wallet);
          fAbortRescan = false;
          fScanningWallet = true;
  
          ShowProgress(_("Rescanning..."), 0); // show rescan progress in GUI as dialog or on splashscreen, if -rescan on startup
          double dProgressStart = GuessVerificationProgress(chainParams.TxData(), pindex);
          double dProgressTip = GuessVerificationProgress(chainParams.TxData(), chainActive.Tip());
          while (pindex && !fAbortRescan)
          {
              if (pindex->nHeight % 100 == 0 && dProgressTip - dProgressStart > 0.0)
                  ShowProgress(_("Rescanning..."), std::max(1, std::min(99, (int)((GuessVerificationProgress(chainParams.TxData(), pindex) - dProgressStart) / (dProgressTip - dProgressStart) * 100))));
              if (GetTime() >= nNow + 60) {
                  nNow = GetTime();
                  LogPrintf("Still rescanning. At block %d. Progress=%f\n", pindex->nHeight, GuessVerificationProgress(chainParams.TxData(), pindex));
              }
  
              CBlock block;
              if (ReadBlockFromDisk(block, pindex, Params().GetConsensus())) {
                  for (size_t posInBlock = 0; posInBlock < block.vtx.size(); ++posInBlock) {
                      AddToWalletIfInvolvingMe(block.vtx[posInBlock], pindex, posInBlock, fUpdate);
                  }
              } else {
                  ret = pindex;
              }
              pindex = chainActive.Next(pindex);
          }
          if (pindex && fAbortRescan) {
              LogPrintf("Rescan aborted at block %d. Progress=%f\n", pindex->nHeight, GuessVerificationProgress(chainParams.TxData(), pindex));
          }
          ShowProgress(_("Rescanning..."), 100); // hide progress dialog in GUI
  
          fScanningWallet = false;
      }
      return ret;
  }
  
  void CWallet::ReacceptWalletTransactions()
  {
      // If transactions aren't being broadcasted, don't let them into local mempool either
      if (!fBroadcastTransactions)
          return;
      LOCK2(cs_main, cs_wallet);
      std::map<int64_t, CWalletTx*> mapSorted;
  
      // Sort pending wallet transactions based on their initial wallet insertion order
      for (std::pair<const uint256, CWalletTx>& item : mapWallet)
      {
          const uint256& wtxid = item.first;
          CWalletTx& wtx = item.second;
          assert(wtx.GetHash() == wtxid);
  
          int nDepth = wtx.GetDepthInMainChain();
  
          if (!wtx.IsCoinBase() && (nDepth == 0 && !wtx.isAbandoned())) {
              mapSorted.insert(std::make_pair(wtx.nOrderPos, &wtx));
          }
      }
  
      // Try to add wallet transactions to memory pool
      for (std::pair<const int64_t, CWalletTx*>& item : mapSorted)
      {
          CWalletTx& wtx = *(item.second);
  
          LOCK(mempool.cs);
          CValidationState state;
          wtx.AcceptToMemoryPool(maxTxFee, state);
      }
  }
  
  bool CWalletTx::RelayWalletTransaction(CConnman* connman)
  {
      assert(pwallet->GetBroadcastTransactions());
      if (!IsCoinBase() && !isAbandoned() && GetDepthInMainChain() == 0)
      {
          CValidationState state;
          /* GetDepthInMainChain already catches known conflicts. */
          if (InMempool() || AcceptToMemoryPool(maxTxFee, state)) {
              LogPrintf("Relaying wtx %s\n", GetHash().ToString());
              if (connman) {
                  CInv inv(MSG_TX, GetHash());
                  connman->ForEachNode([&inv](CNode* pnode)
                  {
                      pnode->PushInventory(inv);
                  });
                  return true;
              }
          }
      }
      return false;
  }
  
  std::set<uint256> CWalletTx::GetConflicts() const
  {
      std::set<uint256> result;
      if (pwallet != nullptr)
      {
          uint256 myHash = GetHash();
          result = pwallet->GetConflicts(myHash);
          result.erase(myHash);
      }
      return result;
  }
  
  CAmount CWalletTx::GetDebit(const isminefilter& filter) const
  {
      if (tx->vin.empty())
          return 0;
  
      CAmount debit = 0;
      if(filter & ISMINE_SPENDABLE)
      {
          if (fDebitCached)
              debit += nDebitCached;
          else
          {
              nDebitCached = pwallet->GetDebit(*this, ISMINE_SPENDABLE);
              fDebitCached = true;
              debit += nDebitCached;
          }
      }
      if(filter & ISMINE_WATCH_ONLY)
      {
          if(fWatchDebitCached)
              debit += nWatchDebitCached;
          else
          {
              nWatchDebitCached = pwallet->GetDebit(*this, ISMINE_WATCH_ONLY);
              fWatchDebitCached = true;
              debit += nWatchDebitCached;
          }
      }
      return debit;
  }
  
  CAmount CWalletTx::GetCredit(const isminefilter& filter) const
  {
      // Must wait until coinbase is safely deep enough in the chain before valuing it
      if (IsCoinBase() && GetBlocksToMaturity() > 0)
          return 0;
  
      CAmount credit = 0;
      if (filter & ISMINE_SPENDABLE)
      {
          // GetBalance can assume transactions in mapWallet won't change
          if (fCreditCached)
              credit += nCreditCached;
          else
          {
              nCreditCached = pwallet->GetCredit(*this, ISMINE_SPENDABLE);
              fCreditCached = true;
              credit += nCreditCached;
          }
      }
      if (filter & ISMINE_WATCH_ONLY)
      {
          if (fWatchCreditCached)
              credit += nWatchCreditCached;
          else
          {
              nWatchCreditCached = pwallet->GetCredit(*this, ISMINE_WATCH_ONLY);
              fWatchCreditCached = true;
              credit += nWatchCreditCached;
          }
      }
      return credit;
  }
  
  CAmount CWalletTx::GetImmatureCredit(bool fUseCache) const
  {
      if (IsCoinBase() && GetBlocksToMaturity() > 0 && IsInMainChain())
      {
          if (fUseCache && fImmatureCreditCached)
              return nImmatureCreditCached;
          nImmatureCreditCached = pwallet->GetCredit(*this, ISMINE_SPENDABLE);
          fImmatureCreditCached = true;
          return nImmatureCreditCached;
      }
  
      return 0;
  }
  
  CAmount CWalletTx::GetAvailableCredit(bool fUseCache) const
  {
      if (pwallet == 0)
          return 0;
  
      // Must wait until coinbase is safely deep enough in the chain before valuing it
      if (IsCoinBase() && GetBlocksToMaturity() > 0)
          return 0;
  
      if (fUseCache && fAvailableCreditCached)
          return nAvailableCreditCached;
  
      CAmount nCredit = 0;
      uint256 hashTx = GetHash();
      for (unsigned int i = 0; i < tx->vout.size(); i++)
      {
          if (!pwallet->IsSpent(hashTx, i))
          {
              const CTxOut &txout = tx->vout[i];
              nCredit += pwallet->GetCredit(txout, ISMINE_SPENDABLE);
              if (!MoneyRange(nCredit))
                  throw std::runtime_error(std::string(__func__) + " : value out of range");
          }
      }
  
      nAvailableCreditCached = nCredit;
      fAvailableCreditCached = true;
      return nCredit;
  }
  
  CAmount CWalletTx::GetImmatureWatchOnlyCredit(const bool& fUseCache) const
  {
      if (IsCoinBase() && GetBlocksToMaturity() > 0 && IsInMainChain())
      {
          if (fUseCache && fImmatureWatchCreditCached)
              return nImmatureWatchCreditCached;
          nImmatureWatchCreditCached = pwallet->GetCredit(*this, ISMINE_WATCH_ONLY);
          fImmatureWatchCreditCached = true;
          return nImmatureWatchCreditCached;
      }
  
      return 0;
  }
  
  CAmount CWalletTx::GetAvailableWatchOnlyCredit(const bool& fUseCache) const
  {
      if (pwallet == 0)
          return 0;
  
      // Must wait until coinbase is safely deep enough in the chain before valuing it
      if (IsCoinBase() && GetBlocksToMaturity() > 0)
          return 0;
  
      if (fUseCache && fAvailableWatchCreditCached)
          return nAvailableWatchCreditCached;
  
      CAmount nCredit = 0;
      for (unsigned int i = 0; i < tx->vout.size(); i++)
      {
          if (!pwallet->IsSpent(GetHash(), i))
          {
              const CTxOut &txout = tx->vout[i];
              nCredit += pwallet->GetCredit(txout, ISMINE_WATCH_ONLY);
              if (!MoneyRange(nCredit))
                  throw std::runtime_error(std::string(__func__) + ": value out of range");
          }
      }
  
      nAvailableWatchCreditCached = nCredit;
      fAvailableWatchCreditCached = true;
      return nCredit;
  }
  
  CAmount CWalletTx::GetChange() const
  {
      if (fChangeCached)
          return nChangeCached;
      nChangeCached = pwallet->GetChange(*this);
      fChangeCached = true;
      return nChangeCached;
  }
  
  bool CWalletTx::InMempool() const
  {
      LOCK(mempool.cs);
      return mempool.exists(GetHash());
  }
  
  bool CWalletTx::IsTrusted() const
  {
      // Quick answer in most cases
      if (!CheckFinalTx(*this))
          return false;
      int nDepth = GetDepthInMainChain();
      if (nDepth >= 1)
          return true;
      if (nDepth < 0)
          return false;
      if (!bSpendZeroConfChange || !IsFromMe(ISMINE_ALL)) // using wtx's cached debit
          return false;
  
      // Don't trust unconfirmed transactions from us unless they are in the mempool.
      if (!InMempool())
          return false;
  
      // Trusted if all inputs are from us and are in the mempool:
      for (const CTxIn& txin : tx->vin)
      {
          // Transactions not sent by us: not trusted
          const CWalletTx* parent = pwallet->GetWalletTx(txin.prevout.hash);
          if (parent == nullptr)
              return false;
          const CTxOut& parentOut = parent->tx->vout[txin.prevout.n];
          if (pwallet->IsMine(parentOut) != ISMINE_SPENDABLE)
              return false;
      }
      return true;
  }
  
  bool CWalletTx::IsEquivalentTo(const CWalletTx& _tx) const
  {
          CMutableTransaction tx1 = *this->tx;
          CMutableTransaction tx2 = *_tx.tx;
          for (auto& txin : tx1.vin) txin.scriptSig = CScript();
          for (auto& txin : tx2.vin) txin.scriptSig = CScript();
          return CTransaction(tx1) == CTransaction(tx2);
  }
  
  std::vector<uint256> CWallet::ResendWalletTransactionsBefore(int64_t nTime, CConnman* connman)
  {
      std::vector<uint256> result;
  
      LOCK(cs_wallet);
  
      // Sort them in chronological order
      std::multimap<unsigned int, CWalletTx*> mapSorted;
      for (std::pair<const uint256, CWalletTx>& item : mapWallet)
      {
          CWalletTx& wtx = item.second;
          // Don't rebroadcast if newer than nTime:
          if (wtx.nTimeReceived > nTime)
              continue;
          mapSorted.insert(std::make_pair(wtx.nTimeReceived, &wtx));
      }
      for (std::pair<const unsigned int, CWalletTx*>& item : mapSorted)
      {
          CWalletTx& wtx = *item.second;
          if (wtx.RelayWalletTransaction(connman))
              result.push_back(wtx.GetHash());
      }
      return result;
  }
  
  void CWallet::ResendWalletTransactions(int64_t nBestBlockTime, CConnman* connman)
  {
      // Do this infrequently and randomly to avoid giving away
      // that these are our transactions.
      if (GetTime() < nNextResend || !fBroadcastTransactions)
          return;
      bool fFirst = (nNextResend == 0);
      nNextResend = GetTime() + GetRand(30 * 60);
      if (fFirst)
          return;
  
      // Only do it if there's been a new block since last time
      if (nBestBlockTime < nLastResend)
          return;
      nLastResend = GetTime();
  
      // Rebroadcast unconfirmed txes older than 5 minutes before the last
      // block was found:
      std::vector<uint256> relayed = ResendWalletTransactionsBefore(nBestBlockTime-5*60, connman);
      if (!relayed.empty())
          LogPrintf("%s: rebroadcast %u unconfirmed transactions\n", __func__, relayed.size());
  }
  
  /** @} */ // end of mapWallet
  
  
  
  
  /** @defgroup Actions
   *
   * @{
   */
  
  
  CAmount CWallet::GetBalance() const
  {
      CAmount nTotal = 0;
      {
          LOCK2(cs_main, cs_wallet);
          for (std::map<uint256, CWalletTx>::const_iterator it = mapWallet.begin(); it != mapWallet.end(); ++it)
          {
              const CWalletTx* pcoin = &(*it).second;
              if (pcoin->IsTrusted())
                  nTotal += pcoin->GetAvailableCredit();
          }
      }
  
      return nTotal;
  }
  
  CAmount CWallet::GetUnconfirmedBalance() const
  {
      CAmount nTotal = 0;
      {
          LOCK2(cs_main, cs_wallet);
          for (std::map<uint256, CWalletTx>::const_iterator it = mapWallet.begin(); it != mapWallet.end(); ++it)
          {
              const CWalletTx* pcoin = &(*it).second;
              if (!pcoin->IsTrusted() && pcoin->GetDepthInMainChain() == 0 && pcoin->InMempool())
                  nTotal += pcoin->GetAvailableCredit();
          }
      }
      return nTotal;
  }
  
  CAmount CWallet::GetImmatureBalance() const
  {
      CAmount nTotal = 0;
      {
          LOCK2(cs_main, cs_wallet);
          for (std::map<uint256, CWalletTx>::const_iterator it = mapWallet.begin(); it != mapWallet.end(); ++it)
          {
              const CWalletTx* pcoin = &(*it).second;
              nTotal += pcoin->GetImmatureCredit();
          }
      }
      return nTotal;
  }
  
  CAmount CWallet::GetWatchOnlyBalance() const
  {
      CAmount nTotal = 0;
      {
          LOCK2(cs_main, cs_wallet);
          for (std::map<uint256, CWalletTx>::const_iterator it = mapWallet.begin(); it != mapWallet.end(); ++it)
          {
              const CWalletTx* pcoin = &(*it).second;
              if (pcoin->IsTrusted())
                  nTotal += pcoin->GetAvailableWatchOnlyCredit();
          }
      }
  
      return nTotal;
  }
  
  CAmount CWallet::GetUnconfirmedWatchOnlyBalance() const
  {
      CAmount nTotal = 0;
      {
          LOCK2(cs_main, cs_wallet);
          for (std::map<uint256, CWalletTx>::const_iterator it = mapWallet.begin(); it != mapWallet.end(); ++it)
          {
              const CWalletTx* pcoin = &(*it).second;
              if (!pcoin->IsTrusted() && pcoin->GetDepthInMainChain() == 0 && pcoin->InMempool())
                  nTotal += pcoin->GetAvailableWatchOnlyCredit();
          }
      }
      return nTotal;
  }
  
  CAmount CWallet::GetImmatureWatchOnlyBalance() const
  {
      CAmount nTotal = 0;
      {
          LOCK2(cs_main, cs_wallet);
          for (std::map<uint256, CWalletTx>::const_iterator it = mapWallet.begin(); it != mapWallet.end(); ++it)
          {
              const CWalletTx* pcoin = &(*it).second;
              nTotal += pcoin->GetImmatureWatchOnlyCredit();
          }
      }
      return nTotal;
  }
  
  // Calculate total balance in a different way from GetBalance. The biggest
  // difference is that GetBalance sums up all unspent TxOuts paying to the
  // wallet, while this sums up both spent and unspent TxOuts paying to the
  // wallet, and then subtracts the values of TxIns spending from the wallet. This
  // also has fewer restrictions on which unconfirmed transactions are considered
  // trusted.
  CAmount CWallet::GetLegacyBalance(const isminefilter& filter, int minDepth, const std::string* account) const
  {
      LOCK2(cs_main, cs_wallet);
  
      CAmount balance = 0;
      for (const auto& entry : mapWallet) {
          const CWalletTx& wtx = entry.second;
          const int depth = wtx.GetDepthInMainChain();
          if (depth < 0 || !CheckFinalTx(*wtx.tx) || wtx.GetBlocksToMaturity() > 0) {
              continue;
          }
  
          // Loop through tx outputs and add incoming payments. For outgoing txs,
          // treat change outputs specially, as part of the amount debited.
          CAmount debit = wtx.GetDebit(filter);
          const bool outgoing = debit > 0;
          for (const CTxOut& out : wtx.tx->vout) {
              if (outgoing && IsChange(out)) {
                  debit -= out.nValue;
              } else if (IsMine(out) & filter && depth >= minDepth && (!account || *account == GetAccountName(out.scriptPubKey))) {
                  balance += out.nValue;
              }
          }
  
          // For outgoing txs, subtract amount debited.
          if (outgoing && (!account || *account == wtx.strFromAccount)) {
              balance -= debit;
          }
      }
  
      if (account) {
          balance += CWalletDB(*dbw).GetAccountCreditDebit(*account);
      }
  
      return balance;
  }
  
  CAmount CWallet::GetAvailableBalance(const CCoinControl* coinControl) const
  {
      LOCK2(cs_main, cs_wallet);
  
      CAmount balance = 0;
      std::vector<COutput> vCoins;
      AvailableCoins(vCoins, true, coinControl);
      for (const COutput& out : vCoins) {
          if (out.fSpendable) {
              balance += out.tx->tx->vout[out.i].nValue;
          }
      }
      return balance;
  }
  
  void CWallet::AvailableCoins(std::vector<COutput> &vCoins, bool fOnlySafe, const CCoinControl *coinControl, const CAmount &nMinimumAmount, const CAmount &nMaximumAmount, const CAmount &nMinimumSumAmount, const uint64_t &nMaximumCount, const int &nMinDepth, const int &nMaxDepth) const
  {
      vCoins.clear();
  
      {
          LOCK2(cs_main, cs_wallet);
  
          CAmount nTotal = 0;
  
          for (std::map<uint256, CWalletTx>::const_iterator it = mapWallet.begin(); it != mapWallet.end(); ++it)
          {
              const uint256& wtxid = it->first;
              const CWalletTx* pcoin = &(*it).second;
  
              if (!CheckFinalTx(*pcoin))
                  continue;
  
              if (pcoin->IsCoinBase() && pcoin->GetBlocksToMaturity() > 0)
                  continue;
  
              int nDepth = pcoin->GetDepthInMainChain();
              if (nDepth < 0)
                  continue;
  
              // We should not consider coins which aren't at least in our mempool
              // It's possible for these to be conflicted via ancestors which we may never be able to detect
              if (nDepth == 0 && !pcoin->InMempool())
                  continue;
  
              bool safeTx = pcoin->IsTrusted();
  
              // We should not consider coins from transactions that are replacing
              // other transactions.
              //
              // Example: There is a transaction A which is replaced by bumpfee
              // transaction B. In this case, we want to prevent creation of
              // a transaction B' which spends an output of B.
              //
              // Reason: If transaction A were initially confirmed, transactions B
              // and B' would no longer be valid, so the user would have to create
              // a new transaction C to replace B'. However, in the case of a
              // one-block reorg, transactions B' and C might BOTH be accepted,
              // when the user only wanted one of them. Specifically, there could
              // be a 1-block reorg away from the chain where transactions A and C
              // were accepted to another chain where B, B', and C were all
              // accepted.
              if (nDepth == 0 && pcoin->mapValue.count("replaces_txid")) {
                  safeTx = false;
              }
  
              // Similarly, we should not consider coins from transactions that
              // have been replaced. In the example above, we would want to prevent
              // creation of a transaction A' spending an output of A, because if
              // transaction B were initially confirmed, conflicting with A and
              // A', we wouldn't want to the user to create a transaction D
              // intending to replace A', but potentially resulting in a scenario
              // where A, A', and D could all be accepted (instead of just B and
              // D, or just A and A' like the user would want).
              if (nDepth == 0 && pcoin->mapValue.count("replaced_by_txid")) {
                  safeTx = false;
              }
  
              if (fOnlySafe && !safeTx) {
                  continue;
              }
  
              if (nDepth < nMinDepth || nDepth > nMaxDepth)
                  continue;
  
              for (unsigned int i = 0; i < pcoin->tx->vout.size(); i++) {
                  if (pcoin->tx->vout[i].nValue < nMinimumAmount || pcoin->tx->vout[i].nValue > nMaximumAmount)
                      continue;
  
                  if (coinControl && coinControl->HasSelected() && !coinControl->fAllowOtherInputs && !coinControl->IsSelected(COutPoint((*it).first, i)))
                      continue;
  
                  if (IsLockedCoin((*it).first, i))
                      continue;
  
                  if (IsSpent(wtxid, i))
                      continue;
  
                  isminetype mine = IsMine(pcoin->tx->vout[i]);
  
                  if (mine == ISMINE_NO) {
                      continue;
                  }
  
                  bool fSpendableIn = ((mine & ISMINE_SPENDABLE) != ISMINE_NO) || (coinControl && coinControl->fAllowWatchOnly && (mine & ISMINE_WATCH_SOLVABLE) != ISMINE_NO);
                  bool fSolvableIn = (mine & (ISMINE_SPENDABLE | ISMINE_WATCH_SOLVABLE)) != ISMINE_NO;
  
                  vCoins.push_back(COutput(pcoin, i, nDepth, fSpendableIn, fSolvableIn, safeTx));
  
                  // Checks the sum amount of all UTXO's.
                  if (nMinimumSumAmount != MAX_MONEY) {
                      nTotal += pcoin->tx->vout[i].nValue;
  
                      if (nTotal >= nMinimumSumAmount) {
                          return;
                      }
                  }
  
                  // Checks the maximum number of UTXO's.
                  if (nMaximumCount > 0 && vCoins.size() >= nMaximumCount) {
                      return;
                  }
              }
          }
      }
  }
  
  std::map<CTxDestination, std::vector<COutput>> CWallet::ListCoins() const
  {
      // TODO: Add AssertLockHeld(cs_wallet) here.
      //
      // Because the return value from this function contains pointers to
      // CWalletTx objects, callers to this function really should acquire the
      // cs_wallet lock before calling it. However, the current caller doesn't
      // acquire this lock yet. There was an attempt to add the missing lock in
      // https://github.com/blockchaingate/fabcoin/pull/10340, but that change has been
      // postponed until after https://github.com/blockchaingate/fabcoin/pull/10244 to
      // avoid adding some extra complexity to the Qt code.
  
      std::map<CTxDestination, std::vector<COutput>> result;
  
      std::vector<COutput> availableCoins;
      AvailableCoins(availableCoins);
  
      LOCK2(cs_main, cs_wallet);
      for (auto& coin : availableCoins) {
          CTxDestination address;
          if (coin.fSpendable &&
              ExtractDestination(FindNonChangeParentOutput(*coin.tx->tx, coin.i).scriptPubKey, address)) {
              result[address].emplace_back(std::move(coin));
          }
      }
  
      std::vector<COutPoint> lockedCoins;
      ListLockedCoins(lockedCoins);
      for (const auto& output : lockedCoins) {
          auto it = mapWallet.find(output.hash);
          if (it != mapWallet.end()) {
              int depth = it->second.GetDepthInMainChain();
              if (depth >= 0 && output.n < it->second.tx->vout.size() &&
                  IsMine(it->second.tx->vout[output.n]) == ISMINE_SPENDABLE) {
                  CTxDestination address;
                  if (ExtractDestination(FindNonChangeParentOutput(*it->second.tx, output.n).scriptPubKey, address)) {
                      result[address].emplace_back(
                          &it->second, output.n, depth, true /* spendable */, true /* solvable */, false /* safe */);
                  }
              }
          }
      }
  
      return result;
  }
  
  const CTxOut& CWallet::FindNonChangeParentOutput(const CTransaction& tx, int output) const
  {
      const CTransaction* ptx = &tx;
      int n = output;
      while (IsChange(ptx->vout[n]) && ptx->vin.size() > 0) {
          const COutPoint& prevout = ptx->vin[0].prevout;
          auto it = mapWallet.find(prevout.hash);
          if (it == mapWallet.end() || it->second.tx->vout.size() <= prevout.n ||
              !IsMine(it->second.tx->vout[prevout.n])) {
              break;
          }
          ptx = it->second.tx.get();
          n = prevout.n;
      }
      return ptx->vout[n];
  }
  
  static void ApproximateBestSubset(const std::vector<CInputCoin>& vValue, const CAmount& nTotalLower, const CAmount& nTargetValue,
                                    std::vector<char>& vfBest, CAmount& nBest, int iterations = 1000)
  {
      std::vector<char> vfIncluded;
  
      vfBest.assign(vValue.size(), true);
      nBest = nTotalLower;
  
      FastRandomContext insecure_rand;
  
      for (int nRep = 0; nRep < iterations && nBest != nTargetValue; nRep++)
      {
          vfIncluded.assign(vValue.size(), false);
          CAmount nTotal = 0;
          bool fReachedTarget = false;
          for (int nPass = 0; nPass < 2 && !fReachedTarget; nPass++)
          {
              for (unsigned int i = 0; i < vValue.size(); i++)
              {
                  //The solver here uses a randomized algorithm,
                  //the randomness serves no real security purpose but is just
                  //needed to prevent degenerate behavior and it is important
                  //that the rng is fast. We do not use a constant random sequence,
                  //because there may be some privacy improvement by making
                  //the selection random.
                  if (nPass == 0 ? insecure_rand.randbool() : !vfIncluded[i])
                  {
                      nTotal += vValue[i].txout.nValue;
                      vfIncluded[i] = true;
                      if (nTotal >= nTargetValue)
                      {
                          fReachedTarget = true;
                          if (nTotal < nBest)
                          {
                              nBest = nTotal;
                              vfBest = vfIncluded;
                          }
                          nTotal -= vValue[i].txout.nValue;
                          vfIncluded[i] = false;
                      }
                  }
              }
          }
      }
  }
  
  bool CWallet::SelectCoinsMinConf(const CAmount& nTargetValue, const int nConfMine, const int nConfTheirs, const uint64_t nMaxAncestors, std::vector<COutput> vCoins,
                                   std::set<CInputCoin>& setCoinsRet, CAmount& nValueRet) const
  {
      setCoinsRet.clear();
      nValueRet = 0;
  
      // List of values less than target
      boost::optional<CInputCoin> coinLowestLarger;
      std::vector<CInputCoin> vValue;
      CAmount nTotalLower = 0;
  
      random_shuffle(vCoins.begin(), vCoins.end(), GetRandInt);
  
      for (const COutput &output : vCoins)
      {
          if (!output.fSpendable)
              continue;
  
          const CWalletTx *pcoin = output.tx;
  
          if (output.nDepth < (pcoin->IsFromMe(ISMINE_ALL) ? nConfMine : nConfTheirs))
              continue;
  
          if (!mempool.TransactionWithinChainLimit(pcoin->GetHash(), nMaxAncestors))
              continue;
  
          int i = output.i;
  
          CInputCoin coin = CInputCoin(pcoin, i);
  
          if (coin.txout.nValue == nTargetValue)
          {
              setCoinsRet.insert(coin);
              nValueRet += coin.txout.nValue;
              return true;
          }
          else if (coin.txout.nValue < nTargetValue + MIN_CHANGE)
          {
              vValue.push_back(coin);
              nTotalLower += coin.txout.nValue;
          }
          else if (!coinLowestLarger || coin.txout.nValue < coinLowestLarger->txout.nValue)
          {
              coinLowestLarger = coin;
          }
      }
  
      if (nTotalLower == nTargetValue)
      {
          for (const auto& input : vValue)
          {
              setCoinsRet.insert(input);
              nValueRet += input.txout.nValue;
          }
          return true;
      }
  
      if (nTotalLower < nTargetValue)
      {
          if (!coinLowestLarger)
              return false;
          setCoinsRet.insert(coinLowestLarger.get());
          nValueRet += coinLowestLarger->txout.nValue;
          return true;
      }
  
      // Solve subset sum by stochastic approximation
      std::sort(vValue.begin(), vValue.end(), CompareValueOnly());
      std::reverse(vValue.begin(), vValue.end());
      std::vector<char> vfBest;
      CAmount nBest;
  
      ApproximateBestSubset(vValue, nTotalLower, nTargetValue, vfBest, nBest);
      if (nBest != nTargetValue && nTotalLower >= nTargetValue + MIN_CHANGE)
          ApproximateBestSubset(vValue, nTotalLower, nTargetValue + MIN_CHANGE, vfBest, nBest);
  
      // If we have a bigger coin and (either the stochastic approximation didn't find a good solution,
      //                                   or the next bigger coin is closer), return the bigger coin
      if (coinLowestLarger &&
          ((nBest != nTargetValue && nBest < nTargetValue + MIN_CHANGE) || coinLowestLarger->txout.nValue <= nBest))
      {
          setCoinsRet.insert(coinLowestLarger.get());
          nValueRet += coinLowestLarger->txout.nValue;
      }
      else {
          for (unsigned int i = 0; i < vValue.size(); i++)
              if (vfBest[i])
              {
                  setCoinsRet.insert(vValue[i]);
                  nValueRet += vValue[i].txout.nValue;
              }
  
          if (LogAcceptCategory(BCLog::SELECTCOINS)) {
              LogPrint(BCLog::SELECTCOINS, "SelectCoins() best subset: ");
              for (unsigned int i = 0; i < vValue.size(); i++) {
                  if (vfBest[i]) {
                      LogPrint(BCLog::SELECTCOINS, "%s ", FormatMoney(vValue[i].txout.nValue));
                  }
              }
              LogPrint(BCLog::SELECTCOINS, "total %s\n", FormatMoney(nBest));
          }
      }
  
      return true;
  }
  
  bool CWallet::SelectCoins(const std::vector<COutput>& vAvailableCoins, const CAmount& nTargetValue, std::set<CInputCoin>& setCoinsRet, CAmount& nValueRet, const CCoinControl* coinControl) const
  {
      std::vector<COutput> vCoins(vAvailableCoins);
  
      // coin control -> return all selected outputs (we want all selected to go into the transaction for sure)
      if (coinControl && coinControl->HasSelected() && !coinControl->fAllowOtherInputs)
      {
          for (const COutput& out : vCoins)
          {
              if (!out.fSpendable)
                   continue;
              nValueRet += out.tx->tx->vout[out.i].nValue;
              setCoinsRet.insert(CInputCoin(out.tx, out.i));
          }
          return (nValueRet >= nTargetValue);
      }
  
      // calculate value from preset inputs and store them
      std::set<CInputCoin> setPresetCoins;
      CAmount nValueFromPresetInputs = 0;
  
      std::vector<COutPoint> vPresetInputs;
      if (coinControl)
          coinControl->ListSelected(vPresetInputs);
      for (const COutPoint& outpoint : vPresetInputs)
      {
          std::map<uint256, CWalletTx>::const_iterator it = mapWallet.find(outpoint.hash);
          if (it != mapWallet.end())
          {
              const CWalletTx* pcoin = &it->second;
              // Clearly invalid input, fail
              if (pcoin->tx->vout.size() <= outpoint.n)
                  return false;
              nValueFromPresetInputs += pcoin->tx->vout[outpoint.n].nValue;
              setPresetCoins.insert(CInputCoin(pcoin, outpoint.n));
          } else
              return false; // TODO: Allow non-wallet inputs
      }
  
      // remove preset inputs from vCoins
      for (std::vector<COutput>::iterator it = vCoins.begin(); it != vCoins.end() && coinControl && coinControl->HasSelected();)
      {
          if (setPresetCoins.count(CInputCoin(it->tx, it->i)))
              it = vCoins.erase(it);
          else
              ++it;
      }
  
      size_t nMaxChainLength = std::min(gArgs.GetArg("-limitancestorcount", DEFAULT_ANCESTOR_LIMIT), gArgs.GetArg("-limitdescendantcount", DEFAULT_DESCENDANT_LIMIT));
      bool fRejectLongChains = gArgs.GetBoolArg("-walletrejectlongchains", DEFAULT_WALLET_REJECT_LONG_CHAINS);
  
      bool res = nTargetValue <= nValueFromPresetInputs ||
          SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs, 1, 6, 0, vCoins, setCoinsRet, nValueRet) ||
          SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs, 1, 1, 0, vCoins, setCoinsRet, nValueRet) ||
          (bSpendZeroConfChange && SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs, 0, 1, 2, vCoins, setCoinsRet, nValueRet)) ||
          (bSpendZeroConfChange && SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs, 0, 1, std::min((size_t)4, nMaxChainLength/3), vCoins, setCoinsRet, nValueRet)) ||
          (bSpendZeroConfChange && SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs, 0, 1, nMaxChainLength/2, vCoins, setCoinsRet, nValueRet)) ||
          (bSpendZeroConfChange && SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs, 0, 1, nMaxChainLength, vCoins, setCoinsRet, nValueRet)) ||
          (bSpendZeroConfChange && !fRejectLongChains && SelectCoinsMinConf(nTargetValue - nValueFromPresetInputs, 0, 1, std::numeric_limits<uint64_t>::max(), vCoins, setCoinsRet, nValueRet));
  
      // because SelectCoinsMinConf clears the setCoinsRet, we now add the possible inputs to the coinset
      setCoinsRet.insert(setPresetCoins.begin(), setPresetCoins.end());
  
      // add preset inputs to the total value selected
      nValueRet += nValueFromPresetInputs;
  
      return res;
  }
  
  bool CWallet::SignTransaction(CMutableTransaction &tx)
  {
      AssertLockHeld(cs_wallet); // mapWallet
  
      // sign the new tx
      CTransaction txNewConst(tx);
      int nIn = 0;
      for (const auto& input : tx.vin) {
          std::map<uint256, CWalletTx>::const_iterator mi = mapWallet.find(input.prevout.hash);
          if(mi == mapWallet.end() || input.prevout.n >= mi->second.tx->vout.size()) {
              return false;
          }
          const CScript& scriptPubKey = mi->second.tx->vout[input.prevout.n].scriptPubKey;
          const CAmount& amount = mi->second.tx->vout[input.prevout.n].nValue;
          SignatureData sigdata;
          if (!ProduceSignature(TransactionSignatureCreator(this, &txNewConst, nIn, amount, SIGHASH_ALL), scriptPubKey, sigdata)) {
              return false;
          }
          UpdateTransaction(tx, nIn, sigdata);
          nIn++;
      }
      return true;
  }
  
  bool CWallet::FundTransaction(CMutableTransaction& tx, CAmount& nFeeRet, int& nChangePosInOut, std::string& strFailReason, bool lockUnspents, const std::set<int>& setSubtractFeeFromOutputs, CCoinControl coinControl)
  {
      std::vector<CRecipient> vecSend;
  
      // Turn the txout set into a CRecipient vector
      for (size_t idx = 0; idx < tx.vout.size(); idx++)
      {
          const CTxOut& txOut = tx.vout[idx];
          CRecipient recipient = {txOut.scriptPubKey, txOut.nValue, setSubtractFeeFromOutputs.count(idx) == 1};
          vecSend.push_back(recipient);
      }
  
      coinControl.fAllowOtherInputs = true;
  
      for (const CTxIn& txin : tx.vin)
          coinControl.Select(txin.prevout);
  
      CReserveKey reservekey(this);
      CWalletTx wtx;
      if (!CreateTransaction(vecSend, wtx, reservekey, nFeeRet, nChangePosInOut, strFailReason, coinControl, false)) {
          return false;
      }
  
      if (nChangePosInOut != -1) {
          tx.vout.insert(tx.vout.begin() + nChangePosInOut, wtx.tx->vout[nChangePosInOut]);
          // we dont have the normal Create/Commit cycle, and dont want to risk reusing change,
          // so just remove the key from the keypool here.
          reservekey.KeepKey();
      }
  
      // Copy output sizes from new transaction; they may have had the fee subtracted from them
      for (unsigned int idx = 0; idx < tx.vout.size(); idx++)
          tx.vout[idx].nValue = wtx.tx->vout[idx].nValue;
  
      // Add new txins (keeping original txin scriptSig/order)
      for (const CTxIn& txin : wtx.tx->vin)
      {
          if (!coinControl.IsSelected(txin.prevout))
          {
              tx.vin.push_back(txin);
  
              if (lockUnspents)
              {
                LOCK2(cs_main, cs_wallet);
                LockCoin(txin.prevout);
              }
          }
      }
  
  
      return true;
  }
  
  static CFeeRate GetDiscardRate(const CBlockPolicyEstimator& estimator)
  {
      unsigned int highest_target = estimator.HighestTargetTracked(FeeEstimateHorizon::LONG_HALFLIFE);
      CFeeRate discard_rate = estimator.estimateSmartFee(highest_target, nullptr /* FeeCalculation */, false /* conservative */);
      // Don't let discard_rate be greater than longest possible fee estimate if we get a valid fee estimate
      discard_rate = (discard_rate == CFeeRate(0)) ? CWallet::m_discard_rate : std::min(discard_rate, CWallet::m_discard_rate);
      // Discard rate must be at least dustRelayFee
      discard_rate = std::max(discard_rate, ::dustRelayFee);
      return discard_rate;
  }
  
  bool CWallet::CreateTransaction(const std::vector<CRecipient>& vecSend, CWalletTx& wtxNew, CReserveKey& reservekey, CAmount& nFeeRet,
                                  int& nChangePosInOut, std::string& strFailReason, const CCoinControl& coin_control, bool sign)
  {
      CAmount nValue = 0;
      int nChangePosRequest = nChangePosInOut;
      unsigned int nSubtractFeeFromAmount = 0;
      for (const auto& recipient : vecSend)
      {
          if (nValue < 0 || recipient.nAmount < 0)
          {
              strFailReason = _("Transaction amounts must not be negative");
              return false;
          }
          nValue += recipient.nAmount;
  
          if (recipient.fSubtractFeeFromAmount)
              nSubtractFeeFromAmount++;
      }
      if (vecSend.empty())
      {
          strFailReason = _("Transaction must have at least one recipient");
          return false;
      }
  
      wtxNew.fTimeReceivedIsTxTime = true;
      wtxNew.BindWallet(this);
      CMutableTransaction txNew;
  
      // Discourage fee sniping.
      //
      // For a large miner the value of the transactions in the best block and
      // the mempool can exceed the cost of deliberately attempting to mine two
      // blocks to orphan the current best block. By setting nLockTime such that
      // only the next block can include the transaction, we discourage this
      // practice as the height restricted and limited blocksize gives miners
      // considering fee sniping fewer options for pulling off this attack.
      //
      // A simple way to think about this is from the wallet's point of view we
      // always want the blockchain to move forward. By setting nLockTime this
      // way we're basically making the statement that we only want this
      // transaction to appear in the next block; we don't want to potentially
      // encourage reorgs by allowing transactions to appear at lower heights
      // than the next block in forks of the best chain.
      //
      // Of course, the subsidy is high enough, and transaction volume low
      // enough, that fee sniping isn't a problem yet, but by implementing a fix
      // now we ensure code won't be written that makes assumptions about
      // nLockTime that preclude a fix later.
      txNew.nLockTime = chainActive.Height();
  
      // Secondly occasionally randomly pick a nLockTime even further back, so
      // that transactions that are delayed after signing for whatever reason,
      // e.g. high-latency mix networks and some CoinJoin implementations, have
      // better privacy.
      if (GetRandInt(10) == 0)
          txNew.nLockTime = std::max(0, (int)txNew.nLockTime - GetRandInt(100));
  
      assert(txNew.nLockTime <= (unsigned int)chainActive.Height());
      assert(txNew.nLockTime < LOCKTIME_THRESHOLD);
      FeeCalculation feeCalc;
      CAmount nFeeNeeded;
      unsigned int nBytes;
      {
          std::set<CInputCoin> setCoins;
          LOCK2(cs_main, cs_wallet);
          {
              std::vector<COutput> vAvailableCoins;
              AvailableCoins(vAvailableCoins, true, &coin_control);
  
              // Create change script that will be used if we need change
              // TODO: pass in scriptChange instead of reservekey so
              // change transaction isn't always pay-to-fabcoin-address
              CScript scriptChange;
  
              // coin control: send change to custom address
              if (!boost::get<CNoDestination>(&coin_control.destChange)) {
                  scriptChange = GetScriptForDestination(coin_control.destChange);
              } else { // no coin control: send change to newly generated address
                  // Note: We use a new key here to keep it from being obvious which side is the change.
                  //  The drawback is that by not reusing a previous key, the change may be lost if a
                  //  backup is restored, if the backup doesn't have the new private key for the change.
                  //  If we reused the old key, it would be possible to add code to look for and
                  //  rediscover unknown transactions that were written with keys of ours to recover
                  //  post-backup change.
  
                  // Reserve a new key pair from key pool
                  CPubKey vchPubKey;
                  bool ret;
                  ret = reservekey.GetReservedKey(vchPubKey, true);
                  if (!ret)
                  {
                      strFailReason = _("Keypool ran out, please call keypoolrefill first");
                      return false;
                  }
  
                  scriptChange = GetScriptForDestination(vchPubKey.GetID());
              }
              CTxOut change_prototype_txout(0, scriptChange);
              size_t change_prototype_size = GetSerializeSize(change_prototype_txout, SER_DISK, 0);
  
              CFeeRate discard_rate = GetDiscardRate(::feeEstimator);
              nFeeRet = 0;
              bool pick_new_inputs = true;
              CAmount nValueIn = 0;
              // Start with no fee and loop until there is enough fee
              while (true)
              {
                  nChangePosInOut = nChangePosRequest;
                  txNew.vin.clear();
                  txNew.vout.clear();
                  wtxNew.fFromMe = true;
                  bool fFirst = true;
  
                  CAmount nValueToSelect = nValue;
                  if (nSubtractFeeFromAmount == 0)
                      nValueToSelect += nFeeRet;
                  // vouts to the payees
                  for (const auto& recipient : vecSend)
                  {
                      CTxOut txout(recipient.nAmount, recipient.scriptPubKey);
  
                      if (recipient.fSubtractFeeFromAmount)
                      {
                          txout.nValue -= nFeeRet / nSubtractFeeFromAmount; // Subtract fee equally from each selected recipient
  
                          if (fFirst) // first receiver pays the remainder not divisible by output count
                          {
                              fFirst = false;
                              txout.nValue -= nFeeRet % nSubtractFeeFromAmount;
                          }
                      }
  
                      if (IsDust(txout, ::dustRelayFee))
                      {
                          if (recipient.fSubtractFeeFromAmount && nFeeRet > 0)
                          {
                              if (txout.nValue < 0)
                                  strFailReason = _("The transaction amount is too small to pay the fee");
                              else
                                  strFailReason = _("The transaction amount is too small to send after the fee has been deducted");
                          }
                          else
                              strFailReason = _("Transaction amount too small");
                          return false;
                      }
                      txNew.vout.push_back(txout);
                  }
  
                  // Choose coins to use
                  if (pick_new_inputs) {
                      nValueIn = 0;
                      setCoins.clear();
                      if (!SelectCoins(vAvailableCoins, nValueToSelect, setCoins, nValueIn, &coin_control))
                      {
                          strFailReason = _("Insufficient funds");
                          return false;
                      }
                  }
  
                  const CAmount nChange = nValueIn - nValueToSelect;
  
                  if (nChange > 0)
                  {
                      // Fill a vout to ourself
                      CTxOut newTxOut(nChange, scriptChange);
  
                      // Never create dust outputs; if we would, just
                      // add the dust to the fee.
                      if (IsDust(newTxOut, discard_rate))
                      {
                          nChangePosInOut = -1;
                          nFeeRet += nChange;
                      }
                      else
                      {
                          if (nChangePosInOut == -1)
                          {
                              // Insert change txn at random position:
                              nChangePosInOut = GetRandInt(txNew.vout.size()+1);
                          }
                          else if ((unsigned int)nChangePosInOut > txNew.vout.size())
                          {
                              strFailReason = _("Change index out of range");
                              return false;
                          }
  
                          std::vector<CTxOut>::iterator position = txNew.vout.begin()+nChangePosInOut;
                          txNew.vout.insert(position, newTxOut);
                      }
                  } else {
                      nChangePosInOut = -1;
                  }
  
                  // Fill vin
                  //
                  // Note how the sequence number is set to non-maxint so that
                  // the nLockTime set above actually works.
                  //
                  // BIP125 defines opt-in RBF as any nSequence < maxint-1, so
                  // we use the highest possible value in that range (maxint-2)
                  // to avoid conflicting with other possible uses of nSequence,
                  // and in the spirit of "smallest possible change from prior
                  // behavior."
                  const uint32_t nSequence = coin_control.signalRbf ? MAX_BIP125_RBF_SEQUENCE : (CTxIn::SEQUENCE_FINAL - 1);
                  for (const auto& coin : setCoins)
                      txNew.vin.push_back(CTxIn(coin.outpoint,CScript(),
                                                nSequence));
  
                  // Fill in dummy signatures for fee calculation.
                  if (!DummySignTx(txNew, setCoins)) {
                      strFailReason = _("Signing transaction failed");
                      return false;
                  }
  
                  nBytes = GetVirtualTransactionSize(txNew);
  
                  // Remove scriptSigs to eliminate the fee calculation dummy signatures
                  for (auto& vin : txNew.vin) {
                      vin.scriptSig = CScript();
                      vin.scriptWitness.SetNull();
                  }
  
                  nFeeNeeded = GetMinimumFee(nBytes, coin_control, ::mempool, ::feeEstimator, &feeCalc);
  
                  // If we made it here and we aren't even able to meet the relay fee on the next pass, give up
                  // because we must be at the maximum allowed fee.
                  if (nFeeNeeded < ::minRelayTxFee.GetFee(nBytes))
                  {
                      strFailReason = _("Transaction too large for fee policy");
                      return false;
                  }
  
                  if (nFeeRet >= nFeeNeeded) {
                      // Reduce fee to only the needed amount if possible. This
                      // prevents potential overpayment in fees if the coins
                      // selected to meet nFeeNeeded result in a transaction that
                      // requires less fee than the prior iteration.
  
                      // If we have no change and a big enough excess fee, then
                      // try to construct transaction again only without picking
                      // new inputs. We now know we only need the smaller fee
                      // (because of reduced tx size) and so we should add a
                      // change output. Only try this once.
                      if (nChangePosInOut == -1 && nSubtractFeeFromAmount == 0 && pick_new_inputs) {
                          unsigned int tx_size_with_change = nBytes + change_prototype_size + 2; // Add 2 as a buffer in case increasing # of outputs changes compact size
                          CAmount fee_needed_with_change = GetMinimumFee(tx_size_with_change, coin_control, ::mempool, ::feeEstimator, nullptr);
                          CAmount minimum_value_for_change = GetDustThreshold(change_prototype_txout, discard_rate);
                          if (nFeeRet >= fee_needed_with_change + minimum_value_for_change) {
                              pick_new_inputs = false;
                              nFeeRet = fee_needed_with_change;
                              continue;
                          }
                      }
  
                      // If we have change output already, just increase it
                      if (nFeeRet > nFeeNeeded && nChangePosInOut != -1 && nSubtractFeeFromAmount == 0) {
                          CAmount extraFeePaid = nFeeRet - nFeeNeeded;
                          std::vector<CTxOut>::iterator change_position = txNew.vout.begin()+nChangePosInOut;
                          change_position->nValue += extraFeePaid;
                          nFeeRet -= extraFeePaid;
                      }
                      break; // Done, enough fee included.
                  }
                  else if (!pick_new_inputs) {
                      // This shouldn't happen, we should have had enough excess
                      // fee to pay for the new output and still meet nFeeNeeded
                      // Or we should have just subtracted fee from recipients and
                      // nFeeNeeded should not have changed
                      strFailReason = _("Transaction fee and change calculation failed");
                      return false;
                  }
  
                  // Try to reduce change to include necessary fee
                  if (nChangePosInOut != -1 && nSubtractFeeFromAmount == 0) {
                      CAmount additionalFeeNeeded = nFeeNeeded - nFeeRet;
                      std::vector<CTxOut>::iterator change_position = txNew.vout.begin()+nChangePosInOut;
                      // Only reduce change if remaining amount is still a large enough output.
                      if (change_position->nValue >= MIN_FINAL_CHANGE + additionalFeeNeeded) {
                          change_position->nValue -= additionalFeeNeeded;
                          nFeeRet += additionalFeeNeeded;
                          break; // Done, able to increase fee from change
                      }
                  }
  
                  // If subtracting fee from recipients, we now know what fee we
                  // need to subtract, we have no reason to reselect inputs
                  if (nSubtractFeeFromAmount > 0) {
                      pick_new_inputs = false;
                  }
  
                  // Include more fee and try again.
                  nFeeRet = nFeeNeeded;
                  continue;
              }
          }
  
          if (nChangePosInOut == -1) reservekey.ReturnKey(); // Return any reserved key if we don't have change
  
          if (sign)
          {
              CTransaction txNewConst(txNew);
              int nIn = 0;
              for (const auto& coin : setCoins)
              {
                  const CScript& scriptPubKey = coin.txout.scriptPubKey;
                  SignatureData sigdata;
  
                  if (!ProduceSignature(TransactionSignatureCreator(this, &txNewConst, nIn, coin.txout.nValue, SIGHASH_ALL), scriptPubKey, sigdata))
                  {
                      strFailReason = _("Signing transaction failed");
                      return false;
                  } else {
                      UpdateTransaction(txNew, nIn, sigdata);
                  }
  
                  nIn++;
              }
          }
  
          // Embed the constructed transaction data in wtxNew.
          wtxNew.SetTx(MakeTransactionRef(std::move(txNew)));
  
          // Limit size
          if (GetTransactionWeight(wtxNew) >= MAX_STANDARD_TX_WEIGHT)
          {
              strFailReason = _("Transaction too large");
              return false;
          }
      }
  
      if (gArgs.GetBoolArg("-walletrejectlongchains", DEFAULT_WALLET_REJECT_LONG_CHAINS)) {
          // Lastly, ensure this tx will pass the mempool's chain limits
          LockPoints lp;
          CTxMemPoolEntry entry(wtxNew.tx, 0, 0, 0, false, 0, lp);
          CTxMemPool::setEntries setAncestors;
          size_t nLimitAncestors = gArgs.GetArg("-limitancestorcount", DEFAULT_ANCESTOR_LIMIT);
          size_t nLimitAncestorSize = gArgs.GetArg("-limitancestorsize", DEFAULT_ANCESTOR_SIZE_LIMIT)*1000;
          size_t nLimitDescendants = gArgs.GetArg("-limitdescendantcount", DEFAULT_DESCENDANT_LIMIT);
          size_t nLimitDescendantSize = gArgs.GetArg("-limitdescendantsize", DEFAULT_DESCENDANT_SIZE_LIMIT)*1000;
          std::string errString;
          if (!mempool.CalculateMemPoolAncestors(entry, setAncestors, nLimitAncestors, nLimitAncestorSize, nLimitDescendants, nLimitDescendantSize, errString)) {
              strFailReason = _("Transaction has too long of a mempool chain");
              return false;
          }
      }
  
      LogPrintf("Fee Calculation: Fee:%d Bytes:%u Needed:%d Tgt:%d (requested %d) Reason:\"%s\" Decay %.5f: Estimation: (%g - %g) %.2f%% %.1f/(%.1f %d mem %.1f out) Fail: (%g - %g) %.2f%% %.1f/(%.1f %d mem %.1f out)\n",
                nFeeRet, nBytes, nFeeNeeded, feeCalc.returnedTarget, feeCalc.desiredTarget, StringForFeeReason(feeCalc.reason), feeCalc.est.decay,
                feeCalc.est.pass.start, feeCalc.est.pass.end,
                100 * feeCalc.est.pass.withinTarget / (feeCalc.est.pass.totalConfirmed + feeCalc.est.pass.inMempool + feeCalc.est.pass.leftMempool),
                feeCalc.est.pass.withinTarget, feeCalc.est.pass.totalConfirmed, feeCalc.est.pass.inMempool, feeCalc.est.pass.leftMempool,
                feeCalc.est.fail.start, feeCalc.est.fail.end,
                100 * feeCalc.est.fail.withinTarget / (feeCalc.est.fail.totalConfirmed + feeCalc.est.fail.inMempool + feeCalc.est.fail.leftMempool),
                feeCalc.est.fail.withinTarget, feeCalc.est.fail.totalConfirmed, feeCalc.est.fail.inMempool, feeCalc.est.fail.leftMempool);
      return true;
  }
  
  /**
   * Call after CreateTransaction unless you want to abort
   */
  bool CWallet::CommitTransaction(CWalletTx& wtxNew, CReserveKey& reservekey, CConnman* connman, CValidationState& state)
  {
      {
          LOCK2(cs_main, cs_wallet);
          LogPrintf("CommitTransaction:\n%s", wtxNew.tx->ToString());
          {
              // Take key pair from key pool so it won't be used again
              reservekey.KeepKey();
  
              // Add tx to wallet, because if it has change it's also ours,
              // otherwise just for transaction history.
              AddToWallet(wtxNew);
  
              // Notify that old coins are spent
              for (const CTxIn& txin : wtxNew.tx->vin)
              {
                  CWalletTx &coin = mapWallet[txin.prevout.hash];
                  coin.BindWallet(this);
                  NotifyTransactionChanged(this, coin.GetHash(), CT_UPDATED);
              }
          }
  
          // Track how many getdata requests our transaction gets
          mapRequestCount[wtxNew.GetHash()] = 0;
  
          if (fBroadcastTransactions)
          {
              // Broadcast
              if (!wtxNew.AcceptToMemoryPool(maxTxFee, state)) {
                  LogPrintf("CommitTransaction(): Transaction cannot be broadcast immediately, %s\n", state.GetRejectReason());
                  // TODO: if we expect the failure to be long term or permanent, instead delete wtx from the wallet and return failure.
              } else {
                  wtxNew.RelayWalletTransaction(connman);
              }
          }
      }
      return true;
  }
  
  void CWallet::ListAccountCreditDebit(const std::string& strAccount, std::list<CAccountingEntry>& entries) {
      CWalletDB walletdb(*dbw);
      return walletdb.ListAccountCreditDebit(strAccount, entries);
  }
  
  bool CWallet::AddAccountingEntry(const CAccountingEntry& acentry)
  {
      CWalletDB walletdb(*dbw);
  
      return AddAccountingEntry(acentry, &walletdb);
  }
  
  bool CWallet::AddAccountingEntry(const CAccountingEntry& acentry, CWalletDB *pwalletdb)
  {
      if (!pwalletdb->WriteAccountingEntry(++nAccountingEntryNumber, acentry)) {
          return false;
      }
  
      laccentries.push_back(acentry);
      CAccountingEntry & entry = laccentries.back();
      wtxOrdered.insert(std::make_pair(entry.nOrderPos, TxPair((CWalletTx*)0, &entry)));
  
      return true;
  }
  
  CAmount CWallet::GetRequiredFee(unsigned int nTxBytes)
  {
      return std::max(minTxFee.GetFee(nTxBytes), ::minRelayTxFee.GetFee(nTxBytes));
  }
  
  CAmount CWallet::GetMinimumFee(unsigned int nTxBytes, const CCoinControl& coin_control, const CTxMemPool& pool, const CBlockPolicyEstimator& estimator, FeeCalculation *feeCalc)
  {
      /* User control of how to calculate fee uses the following parameter precedence:
         1. coin_control.m_feerate
         2. coin_control.m_confirm_target
         3. payTxFee (user-set global variable)
         4. nTxConfirmTarget (user-set global variable)
         The first parameter that is set is used.
      */
      CAmount fee_needed;
      if (coin_control.m_feerate) { // 1.
          fee_needed = coin_control.m_feerate->GetFee(nTxBytes);
          if (feeCalc) feeCalc->reason = FeeReason::PAYTXFEE;
          // Allow to override automatic min/max check over coin control instance
          if (coin_control.fOverrideFeeRate) return fee_needed;
      }
      else if (!coin_control.m_confirm_target && ::payTxFee != CFeeRate(0)) { // 3. TODO: remove magic value of 0 for global payTxFee
          fee_needed = ::payTxFee.GetFee(nTxBytes);
          if (feeCalc) feeCalc->reason = FeeReason::PAYTXFEE;
      }
      else { // 2. or 4.
          // We will use smart fee estimation
          unsigned int target = coin_control.m_confirm_target ? *coin_control.m_confirm_target : ::nTxConfirmTarget;
          // By default estimates are economical iff we are signaling opt-in-RBF
          bool conservative_estimate = !coin_control.signalRbf;
          // Allow to override the default fee estimate mode over the CoinControl instance
          if (coin_control.m_fee_mode == FeeEstimateMode::CONSERVATIVE) conservative_estimate = true;
          else if (coin_control.m_fee_mode == FeeEstimateMode::ECONOMICAL) conservative_estimate = false;
  
          fee_needed = estimator.estimateSmartFee(target, feeCalc, conservative_estimate).GetFee(nTxBytes);
          if (fee_needed == 0) {
              // if we don't have enough data for estimateSmartFee, then use fallbackFee
              fee_needed = fallbackFee.GetFee(nTxBytes);
              if (feeCalc) feeCalc->reason = FeeReason::FALLBACK;
          }
          // Obey mempool min fee when using smart fee estimation
          CAmount min_mempool_fee = pool.GetMinFee(gArgs.GetArg("-maxmempool", DEFAULT_MAX_MEMPOOL_SIZE) * 1000000).GetFee(nTxBytes);
          if (fee_needed < min_mempool_fee) {
              fee_needed = min_mempool_fee;
              if (feeCalc) feeCalc->reason = FeeReason::MEMPOOL_MIN;
          }
      }
  
      // prevent user from paying a fee below minRelayTxFee or minTxFee
      CAmount required_fee = GetRequiredFee(nTxBytes);
      if (required_fee > fee_needed) {
          fee_needed = required_fee;
          if (feeCalc) feeCalc->reason = FeeReason::REQUIRED;
      }
      // But always obey the maximum
      if (fee_needed > maxTxFee) {
          fee_needed = maxTxFee;
          if (feeCalc) feeCalc->reason = FeeReason::MAXTXFEE;
      }
      return fee_needed;
  }
  
  
  
  
  DBErrors CWallet::LoadWallet(bool& fFirstRunRet)
  {
      LOCK2(cs_main, cs_wallet);
  
      fFirstRunRet = false;
      DBErrors nLoadWalletRet = CWalletDB(*dbw,"cr+").LoadWallet(this);
      if (nLoadWalletRet == DB_NEED_REWRITE)
      {
          if (dbw->Rewrite("\x04pool"))
          {
              setInternalKeyPool.clear();
              setExternalKeyPool.clear();
              m_pool_key_to_index.clear();
              // Note: can't top-up keypool here, because wallet is locked.
              // User will be prompted to unlock wallet the next operation
              // that requires a new key.
          }
      }
  
      if (nLoadWalletRet != DB_LOAD_OK)
          return nLoadWalletRet;
      fFirstRunRet = !vchDefaultKey.IsValid();
  
      uiInterface.LoadWallet(this);
  
      return DB_LOAD_OK;
  }
  
  DBErrors CWallet::ZapSelectTx(std::vector<uint256>& vHashIn, std::vector<uint256>& vHashOut)
  {
      AssertLockHeld(cs_wallet); // mapWallet
      vchDefaultKey = CPubKey();
      DBErrors nZapSelectTxRet = CWalletDB(*dbw,"cr+").ZapSelectTx(vHashIn, vHashOut);
      for (uint256 hash : vHashOut)
          mapWallet.erase(hash);
  
      if (nZapSelectTxRet == DB_NEED_REWRITE)
      {
          if (dbw->Rewrite("\x04pool"))
          {
              setInternalKeyPool.clear();
              setExternalKeyPool.clear();
              m_pool_key_to_index.clear();
              // Note: can't top-up keypool here, because wallet is locked.
              // User will be prompted to unlock wallet the next operation
              // that requires a new key.
          }
      }
  
      if (nZapSelectTxRet != DB_LOAD_OK)
          return nZapSelectTxRet;
  
      MarkDirty();
  
      return DB_LOAD_OK;
  
  }
  
  DBErrors CWallet::ZapWalletTx(std::vector<CWalletTx>& vWtx)
  {
      vchDefaultKey = CPubKey();
      DBErrors nZapWalletTxRet = CWalletDB(*dbw,"cr+").ZapWalletTx(vWtx);
      if (nZapWalletTxRet == DB_NEED_REWRITE)
      {
          if (dbw->Rewrite("\x04pool"))
          {
              LOCK(cs_wallet);
              setInternalKeyPool.clear();
              setExternalKeyPool.clear();
              m_pool_key_to_index.clear();
              // Note: can't top-up keypool here, because wallet is locked.
              // User will be prompted to unlock wallet the next operation
              // that requires a new key.
          }
      }
  
      if (nZapWalletTxRet != DB_LOAD_OK)
          return nZapWalletTxRet;
  
      return DB_LOAD_OK;
  }
  
  
  bool CWallet::SetAddressBook(const CTxDestination& address, const std::string& strName, const std::string& strPurpose)
  {
      bool fUpdated = false;
      {
          LOCK(cs_wallet); // mapAddressBook
          std::map<CTxDestination, CAddressBookData>::iterator mi = mapAddressBook.find(address);
          fUpdated = mi != mapAddressBook.end();
          mapAddressBook[address].name = strName;
          if (!strPurpose.empty()) /* update purpose only if requested */
              mapAddressBook[address].purpose = strPurpose;
      }
      NotifyAddressBookChanged(this, address, strName, ::IsMine(*this, address) != ISMINE_NO,
                               strPurpose, (fUpdated ? CT_UPDATED : CT_NEW) );
      if (!strPurpose.empty() && !CWalletDB(*dbw).WritePurpose(CFabcoinAddress(address).ToString(), strPurpose))
          return false;
      return CWalletDB(*dbw).WriteName(CFabcoinAddress(address).ToString(), strName);
  }
  
  bool CWallet::DelAddressBook(const CTxDestination& address)
  {
      {
          LOCK(cs_wallet); // mapAddressBook
  
          // Delete destdata tuples associated with address
          std::string strAddress = CFabcoinAddress(address).ToString();
          for (const std::pair<std::string, std::string> &item : mapAddressBook[address].destdata)
          {
              CWalletDB(*dbw).EraseDestData(strAddress, item.first);
          }
          mapAddressBook.erase(address);
      }
  
      NotifyAddressBookChanged(this, address, "", ::IsMine(*this, address) != ISMINE_NO, "", CT_DELETED);
  
      CWalletDB(*dbw).ErasePurpose(CFabcoinAddress(address).ToString());
      return CWalletDB(*dbw).EraseName(CFabcoinAddress(address).ToString());
  }
  
  const std::string& CWallet::GetAccountName(const CScript& scriptPubKey) const
  {
      CTxDestination address;
      if (ExtractDestination(scriptPubKey, address) && !scriptPubKey.IsUnspendable()) {
          auto mi = mapAddressBook.find(address);
          if (mi != mapAddressBook.end()) {
              return mi->second.name;
          }
      }
      // A scriptPubKey that doesn't have an entry in the address book is
      // associated with the default account ("").
      const static std::string DEFAULT_ACCOUNT_NAME;
      return DEFAULT_ACCOUNT_NAME;
  }
  
  bool CWallet::SetDefaultKey(const CPubKey &vchPubKey)
  {
      if (!CWalletDB(*dbw).WriteDefaultKey(vchPubKey))
          return false;
      vchDefaultKey = vchPubKey;
      return true;
  }
  
  /**
   * Mark old keypool keys as used,
   * and generate all new keys
   */
  bool CWallet::NewKeyPool()
  {
      {
          LOCK(cs_wallet);
          CWalletDB walletdb(*dbw);
  
          for (int64_t nIndex : setInternalKeyPool) {
              walletdb.ErasePool(nIndex);
          }
          setInternalKeyPool.clear();
  
          for (int64_t nIndex : setExternalKeyPool) {
              walletdb.ErasePool(nIndex);
          }
          setExternalKeyPool.clear();
  
          m_pool_key_to_index.clear();
  
          if (!TopUpKeyPool()) {
              return false;
          }
          LogPrintf("CWallet::NewKeyPool rewrote keypool\n");
      }
      return true;
  }
  
  size_t CWallet::KeypoolCountExternalKeys()
  {
      AssertLockHeld(cs_wallet); // setExternalKeyPool
      return setExternalKeyPool.size();
  }
  
  void CWallet::LoadKeyPool(int64_t nIndex, const CKeyPool &keypool)
  {
      AssertLockHeld(cs_wallet);
      if (keypool.fInternal) {
          setInternalKeyPool.insert(nIndex);
      } else {
          setExternalKeyPool.insert(nIndex);
      }
      m_max_keypool_index = std::max(m_max_keypool_index, nIndex);
      m_pool_key_to_index[keypool.vchPubKey.GetID()] = nIndex;
  
      // If no metadata exists yet, create a default with the pool key's
      // creation time. Note that this may be overwritten by actually
      // stored metadata for that key later, which is fine.
      CKeyID keyid = keypool.vchPubKey.GetID();
      if (mapKeyMetadata.count(keyid) == 0)
          mapKeyMetadata[keyid] = CKeyMetadata(keypool.nTime);
  }
  
  bool CWallet::TopUpKeyPool(unsigned int kpSize)
  {
      {
          LOCK(cs_wallet);
  
          if (IsLocked())
              return false;
  
          // Top up key pool
          unsigned int nTargetSize;
          if (kpSize > 0)
              nTargetSize = kpSize;
          else
              nTargetSize = std::max(gArgs.GetArg("-keypool", DEFAULT_KEYPOOL_SIZE), (int64_t) 0);
  
          // count amount of available keys (internal, external)
          // make sure the keypool of external and internal keys fits the user selected target (-keypool)
          int64_t missingExternal = std::max(std::max((int64_t) nTargetSize, (int64_t) 1) - (int64_t)setExternalKeyPool.size(), (int64_t) 0);
          int64_t missingInternal = std::max(std::max((int64_t) nTargetSize, (int64_t) 1) - (int64_t)setInternalKeyPool.size(), (int64_t) 0);
  
          if (!IsHDEnabled() || !CanSupportFeature(FEATURE_HD_SPLIT))
          {
              // don't create extra internal keys
              missingInternal = 0;
          }
          bool internal = false;
          CWalletDB walletdb(*dbw);
          for (int64_t i = missingInternal + missingExternal; i--;)
          {
              if (i < missingInternal) {
                  internal = true;
              }
  
              assert(m_max_keypool_index < std::numeric_limits<int64_t>::max()); // How in the hell did you use so many keys?
              int64_t index = ++m_max_keypool_index;
  
              CPubKey pubkey(GenerateNewKey(walletdb, internal));
              if (!walletdb.WritePool(index, CKeyPool(pubkey, internal))) {
                  throw std::runtime_error(std::string(__func__) + ": writing generated key failed");
              }
  
              if (internal) {
                  setInternalKeyPool.insert(index);
              } else {
                  setExternalKeyPool.insert(index);
              }
              m_pool_key_to_index[pubkey.GetID()] = index;
          }
          if (missingInternal + missingExternal > 0) {
              LogPrintf("keypool added %d keys (%d internal), size=%u (%u internal)\n", missingInternal + missingExternal, missingInternal, setInternalKeyPool.size() + setExternalKeyPool.size(), setInternalKeyPool.size());
          }
      }
      return true;
  }
  
  void CWallet::ReserveKeyFromKeyPool(int64_t& nIndex, CKeyPool& keypool, bool fRequestedInternal)
  {
      nIndex = -1;
      keypool.vchPubKey = CPubKey();
      {
          LOCK(cs_wallet);
  
          if (!IsLocked())
              TopUpKeyPool();
  
          bool fReturningInternal = IsHDEnabled() && CanSupportFeature(FEATURE_HD_SPLIT) && fRequestedInternal;
          std::set<int64_t>& setKeyPool = fReturningInternal ? setInternalKeyPool : setExternalKeyPool;
  
          // Get the oldest key
          if(setKeyPool.empty())
              return;
  
          CWalletDB walletdb(*dbw);
  
          auto it = setKeyPool.begin();
          nIndex = *it;
          setKeyPool.erase(it);
          if (!walletdb.ReadPool(nIndex, keypool)) {
              throw std::runtime_error(std::string(__func__) + ": read failed");
          }
          if (!HaveKey(keypool.vchPubKey.GetID())) {
              throw std::runtime_error(std::string(__func__) + ": unknown key in key pool");
          }
          if (keypool.fInternal != fReturningInternal) {
              throw std::runtime_error(std::string(__func__) + ": keypool entry misclassified");
          }
  
          assert(keypool.vchPubKey.IsValid());
          m_pool_key_to_index.erase(keypool.vchPubKey.GetID());
          LogPrintf("keypool reserve %d\n", nIndex);
      }
  }
  
  void CWallet::KeepKey(int64_t nIndex)
  {
      // Remove from key pool
      CWalletDB walletdb(*dbw);
      walletdb.ErasePool(nIndex);
      LogPrintf("keypool keep %d\n", nIndex);
  }
  
  void CWallet::ReturnKey(int64_t nIndex, bool fInternal, const CPubKey& pubkey)
  {
      // Return to key pool
      {
          LOCK(cs_wallet);
          if (fInternal) {
              setInternalKeyPool.insert(nIndex);
          } else {
              setExternalKeyPool.insert(nIndex);
          }
          m_pool_key_to_index[pubkey.GetID()] = nIndex;
      }
      LogPrintf("keypool return %d\n", nIndex);
  }
  
  bool CWallet::GetKeyFromPool(CPubKey& result, bool internal)
  {
      CKeyPool keypool;
      {
          LOCK(cs_wallet);
          int64_t nIndex = 0;
          ReserveKeyFromKeyPool(nIndex, keypool, internal);
          if (nIndex == -1)
          {
              if (IsLocked()) return false;
              CWalletDB walletdb(*dbw);
              result = GenerateNewKey(walletdb, internal);
              return true;
          }
          KeepKey(nIndex);
          result = keypool.vchPubKey;
      }
      return true;
  }
  
  static int64_t GetOldestKeyTimeInPool(const std::set<int64_t>& setKeyPool, CWalletDB& walletdb) {
      if (setKeyPool.empty()) {
          return GetTime();
      }
  
      CKeyPool keypool;
      int64_t nIndex = *(setKeyPool.begin());
      if (!walletdb.ReadPool(nIndex, keypool)) {
          throw std::runtime_error(std::string(__func__) + ": read oldest key in keypool failed");
      }
      assert(keypool.vchPubKey.IsValid());
      return keypool.nTime;
  }
  
  int64_t CWallet::GetOldestKeyPoolTime()
  {
      LOCK(cs_wallet);
  
      CWalletDB walletdb(*dbw);
  
      // load oldest key from keypool, get time and return
      int64_t oldestKey = GetOldestKeyTimeInPool(setExternalKeyPool, walletdb);
      if (IsHDEnabled() && CanSupportFeature(FEATURE_HD_SPLIT)) {
          oldestKey = std::max(GetOldestKeyTimeInPool(setInternalKeyPool, walletdb), oldestKey);
      }
  
      return oldestKey;
  }
  
  std::map<CTxDestination, CAmount> CWallet::GetAddressBalances()
  {
      std::map<CTxDestination, CAmount> balances;
  
      {
          LOCK(cs_wallet);
          for (const auto& walletEntry : mapWallet)
          {
              const CWalletTx *pcoin = &walletEntry.second;
  
              if (!pcoin->IsTrusted())
                  continue;
  
              if (pcoin->IsCoinBase() && pcoin->GetBlocksToMaturity() > 0)
                  continue;
  
              int nDepth = pcoin->GetDepthInMainChain();
              if (nDepth < (pcoin->IsFromMe(ISMINE_ALL) ? 0 : 1))
                  continue;
  
              for (unsigned int i = 0; i < pcoin->tx->vout.size(); i++)
              {
                  CTxDestination addr;
                  if (!IsMine(pcoin->tx->vout[i]))
                      continue;
                  if(!ExtractDestination(pcoin->tx->vout[i].scriptPubKey, addr))
                      continue;
  
                  CAmount n = IsSpent(walletEntry.first, i) ? 0 : pcoin->tx->vout[i].nValue;
  
                  if (!balances.count(addr))
                      balances[addr] = 0;
                  balances[addr] += n;
              }
          }
      }
  
      return balances;
  }
  
  std::set< std::set<CTxDestination> > CWallet::GetAddressGroupings()
  {
      AssertLockHeld(cs_wallet); // mapWallet
      std::set< std::set<CTxDestination> > groupings;
      std::set<CTxDestination> grouping;
  
      for (const auto& walletEntry : mapWallet)
      {
          const CWalletTx *pcoin = &walletEntry.second;
  
          if (pcoin->tx->vin.size() > 0)
          {
              bool any_mine = false;
              // group all input addresses with each other
              for (CTxIn txin : pcoin->tx->vin)
              {
                  CTxDestination address;
                  if(!IsMine(txin)) /* If this input isn't mine, ignore it */
                      continue;
                  if(!ExtractDestination(mapWallet[txin.prevout.hash].tx->vout[txin.prevout.n].scriptPubKey, address))
                      continue;
                  grouping.insert(address);
                  any_mine = true;
              }
  
              // group change with input addresses
              if (any_mine)
              {
                 for (CTxOut txout : pcoin->tx->vout)
                     if (IsChange(txout))
                     {
                         CTxDestination txoutAddr;
                         if(!ExtractDestination(txout.scriptPubKey, txoutAddr))
                             continue;
                         grouping.insert(txoutAddr);
                     }
              }
              if (grouping.size() > 0)
              {
                  groupings.insert(grouping);
                  grouping.clear();
              }
          }
  
          // group lone addrs by themselves
          for (const auto& txout : pcoin->tx->vout)
              if (IsMine(txout))
              {
                  CTxDestination address;
                  if(!ExtractDestination(txout.scriptPubKey, address))
                      continue;
                  grouping.insert(address);
                  groupings.insert(grouping);
                  grouping.clear();
              }
      }
  
      std::set< std::set<CTxDestination>* > uniqueGroupings; // a set of pointers to groups of addresses
      std::map< CTxDestination, std::set<CTxDestination>* > setmap;  // map addresses to the unique group containing it
      for (std::set<CTxDestination> _grouping : groupings)
      {
          // make a set of all the groups hit by this new group
          std::set< std::set<CTxDestination>* > hits;
          std::map< CTxDestination, std::set<CTxDestination>* >::iterator it;
          for (CTxDestination address : _grouping)
              if ((it = setmap.find(address)) != setmap.end())
                  hits.insert((*it).second);
  
          // merge all hit groups into a new single group and delete old groups
          std::set<CTxDestination>* merged = new std::set<CTxDestination>(_grouping);
          for (std::set<CTxDestination>* hit : hits)
          {
              merged->insert(hit->begin(), hit->end());
              uniqueGroupings.erase(hit);
              delete hit;
          }
          uniqueGroupings.insert(merged);
  
          // update setmap
          for (CTxDestination element : *merged)
              setmap[element] = merged;
      }
  
      std::set< std::set<CTxDestination> > ret;
      for (std::set<CTxDestination>* uniqueGrouping : uniqueGroupings)
      {
          ret.insert(*uniqueGrouping);
          delete uniqueGrouping;
      }
  
      return ret;
  }
  
  std::set<CTxDestination> CWallet::GetAccountAddresses(const std::string& strAccount) const
  {
      LOCK(cs_wallet);
      std::set<CTxDestination> result;
      for (const std::pair<CTxDestination, CAddressBookData>& item : mapAddressBook)
      {
          const CTxDestination& address = item.first;
          const std::string& strName = item.second.name;
          if (strName == strAccount)
              result.insert(address);
      }
      return result;
  }
  
  bool CReserveKey::GetReservedKey(CPubKey& pubkey, bool internal)
  {
      if (nIndex == -1)
      {
          CKeyPool keypool;
          pwallet->ReserveKeyFromKeyPool(nIndex, keypool, internal);
          if (nIndex != -1)
              vchPubKey = keypool.vchPubKey;
          else {
              return false;
          }
          fInternal = keypool.fInternal;
      }
      assert(vchPubKey.IsValid());
      pubkey = vchPubKey;
      return true;
  }
  
  void CReserveKey::KeepKey()
  {
      if (nIndex != -1)
          pwallet->KeepKey(nIndex);
      nIndex = -1;
      vchPubKey = CPubKey();
  }
  
  void CReserveKey::ReturnKey()
  {
      if (nIndex != -1) {
          pwallet->ReturnKey(nIndex, fInternal, vchPubKey);
      }
      nIndex = -1;
      vchPubKey = CPubKey();
  }
  
  void CWallet::MarkReserveKeysAsUsed(int64_t keypool_id)
  {
      AssertLockHeld(cs_wallet);
      bool internal = setInternalKeyPool.count(keypool_id);
      if (!internal) assert(setExternalKeyPool.count(keypool_id));
      std::set<int64_t> *setKeyPool = internal ? &setInternalKeyPool : &setExternalKeyPool;
      auto it = setKeyPool->begin();
  
      CWalletDB walletdb(*dbw);
      while (it != std::end(*setKeyPool)) {
          const int64_t& index = *(it);
          if (index > keypool_id) break; // set*KeyPool is ordered
  
          CKeyPool keypool;
          if (walletdb.ReadPool(index, keypool)) { //TODO: This should be unnecessary
              m_pool_key_to_index.erase(keypool.vchPubKey.GetID());
          }
          walletdb.ErasePool(index);
          LogPrintf("keypool index %d removed\n", index);
          it = setKeyPool->erase(it);
      }
  }
  
  void CWallet::GetScriptForMining(std::shared_ptr<CReserveScript> &script)
  {
      std::shared_ptr<CReserveKey> rKey = std::make_shared<CReserveKey>(this);
      CPubKey pubkey;
      if (!rKey->GetReservedKey(pubkey))
          return;
  
      script = rKey;
      script->reserveScript = CScript() << ToByteVector(pubkey) << OP_CHECKSIG;
  }
  
  void CWallet::LockCoin(const COutPoint& output)
  {
      AssertLockHeld(cs_wallet); // setLockedCoins
      setLockedCoins.insert(output);
  }
  
  void CWallet::UnlockCoin(const COutPoint& output)
  {
      AssertLockHeld(cs_wallet); // setLockedCoins
      setLockedCoins.erase(output);
  }
  
  void CWallet::UnlockAllCoins()
  {
      AssertLockHeld(cs_wallet); // setLockedCoins
      setLockedCoins.clear();
  }
  
  bool CWallet::IsLockedCoin(uint256 hash, unsigned int n) const
  {
      AssertLockHeld(cs_wallet); // setLockedCoins
      COutPoint outpt(hash, n);
  
      return (setLockedCoins.count(outpt) > 0);
  }
  
  void CWallet::ListLockedCoins(std::vector<COutPoint>& vOutpts) const
  {
      AssertLockHeld(cs_wallet); // setLockedCoins
      for (std::set<COutPoint>::iterator it = setLockedCoins.begin();
           it != setLockedCoins.end(); it++) {
          COutPoint outpt = (*it);
          vOutpts.push_back(outpt);
      }
  }
  
  /** @} */ // end of Actions
  
  void CWallet::GetKeyBirthTimes(std::map<CTxDestination, int64_t> &mapKeyBirth) const {
      AssertLockHeld(cs_wallet); // mapKeyMetadata
      mapKeyBirth.clear();
  
      // get birth times for keys with metadata
      for (const auto& entry : mapKeyMetadata) {
          if (entry.second.nCreateTime) {
              mapKeyBirth[entry.first] = entry.second.nCreateTime;
          }
      }
  
      // map in which we'll infer heights of other keys
      CBlockIndex *pindexMax = chainActive[std::max(0, chainActive.Height() - 144)]; // the tip can be reorganized; use a 144-block safety margin
      std::map<CKeyID, CBlockIndex*> mapKeyFirstBlock;
      std::set<CKeyID> setKeys;
      GetKeys(setKeys);
      for (const CKeyID &keyid : setKeys) {
          if (mapKeyBirth.count(keyid) == 0)
              mapKeyFirstBlock[keyid] = pindexMax;
      }
      setKeys.clear();
  
      // if there are no such keys, we're done
      if (mapKeyFirstBlock.empty())
          return;
  
      // find first block that affects those keys, if there are any left
      std::vector<CKeyID> vAffected;
      for (std::map<uint256, CWalletTx>::const_iterator it = mapWallet.begin(); it != mapWallet.end(); it++) {
          // iterate over all wallet transactions...
          const CWalletTx &wtx = (*it).second;
          BlockMap::const_iterator blit = mapBlockIndex.find(wtx.hashBlock);
          if (blit != mapBlockIndex.end() && chainActive.Contains(blit->second)) {
              // ... which are already in a block
              int nHeight = blit->second->nHeight;
              for (const CTxOut &txout : wtx.tx->vout) {
                  // iterate over all their outputs
                  CAffectedKeysVisitor(*this, vAffected).Process(txout.scriptPubKey);
                  for (const CKeyID &keyid : vAffected) {
                      // ... and all their affected keys
                      std::map<CKeyID, CBlockIndex*>::iterator rit = mapKeyFirstBlock.find(keyid);
                      if (rit != mapKeyFirstBlock.end() && nHeight < rit->second->nHeight)
                          rit->second = blit->second;
                  }
                  vAffected.clear();
              }
          }
      }
  
      // Extract block timestamps for those keys
      for (std::map<CKeyID, CBlockIndex*>::const_iterator it = mapKeyFirstBlock.begin(); it != mapKeyFirstBlock.end(); it++)
          mapKeyBirth[it->first] = it->second->GetBlockTime() - TIMESTAMP_WINDOW; // block times can be 2h off
  }
  
  /**
   * Compute smart timestamp for a transaction being added to the wallet.
   *
   * Logic:
   * - If sending a transaction, assign its timestamp to the current time.
   * - If receiving a transaction outside a block, assign its timestamp to the
   *   current time.
   * - If receiving a block with a future timestamp, assign all its (not already
   *   known) transactions' timestamps to the current time.
   * - If receiving a block with a past timestamp, before the most recent known
   *   transaction (that we care about), assign all its (not already known)
   *   transactions' timestamps to the same timestamp as that most-recent-known
   *   transaction.
   * - If receiving a block with a past timestamp, but after the most recent known
   *   transaction, assign all its (not already known) transactions' timestamps to
   *   the block time.
   *
   * For more information see CWalletTx::nTimeSmart,
   * https://fabcointalk.org/?topic=54527, or
   * https://github.com/blockchaingate/fabcoin/pull/1393.
   */
  unsigned int CWallet::ComputeTimeSmart(const CWalletTx& wtx) const
  {
      unsigned int nTimeSmart = wtx.nTimeReceived;
      if (!wtx.hashUnset()) {
          if (mapBlockIndex.count(wtx.hashBlock)) {
              int64_t latestNow = wtx.nTimeReceived;
              int64_t latestEntry = 0;
  
              // Tolerate times up to the last timestamp in the wallet not more than 5 minutes into the future
              int64_t latestTolerated = latestNow + 300;
              const TxItems& txOrdered = wtxOrdered;
              for (auto it = txOrdered.rbegin(); it != txOrdered.rend(); ++it) {
                  CWalletTx* const pwtx = it->second.first;
                  if (pwtx == &wtx) {
                      continue;
                  }
                  CAccountingEntry* const pacentry = it->second.second;
                  int64_t nSmartTime;
                  if (pwtx) {
                      nSmartTime = pwtx->nTimeSmart;
                      if (!nSmartTime) {
                          nSmartTime = pwtx->nTimeReceived;
                      }
                  } else {
                      nSmartTime = pacentry->nTime;
                  }
                  if (nSmartTime <= latestTolerated) {
                      latestEntry = nSmartTime;
                      if (nSmartTime > latestNow) {
                          latestNow = nSmartTime;
                      }
                      break;
                  }
              }
  
              int64_t blocktime = mapBlockIndex[wtx.hashBlock]->GetBlockTime();
              nTimeSmart = std::max(latestEntry, std::min(blocktime, latestNow));
          } else {
              LogPrintf("%s: found %s in block %s not in index\n", __func__, wtx.GetHash().ToString(), wtx.hashBlock.ToString());
          }
      }
      return nTimeSmart;
  }
  
  bool CWallet::AddDestData(const CTxDestination &dest, const std::string &key, const std::string &value)
  {
      if (boost::get<CNoDestination>(&dest))
          return false;
  
      mapAddressBook[dest].destdata.insert(std::make_pair(key, value));
      return CWalletDB(*dbw).WriteDestData(CFabcoinAddress(dest).ToString(), key, value);
  }
  
  bool CWallet::EraseDestData(const CTxDestination &dest, const std::string &key)
  {
      if (!mapAddressBook[dest].destdata.erase(key))
          return false;
      return CWalletDB(*dbw).EraseDestData(CFabcoinAddress(dest).ToString(), key);
  }
  
  bool CWallet::LoadDestData(const CTxDestination &dest, const std::string &key, const std::string &value)
  {
      mapAddressBook[dest].destdata.insert(std::make_pair(key, value));
      return true;
  }
  
  bool CWallet::GetDestData(const CTxDestination &dest, const std::string &key, std::string *value) const
  {
      std::map<CTxDestination, CAddressBookData>::const_iterator i = mapAddressBook.find(dest);
      if(i != mapAddressBook.end())
      {
          CAddressBookData::StringMap::const_iterator j = i->second.destdata.find(key);
          if(j != i->second.destdata.end())
          {
              if(value)
                  *value = j->second;
              return true;
          }
      }
      return false;
  }
  
  std::vector<std::string> CWallet::GetDestValues(const std::string& prefix) const
  {
      LOCK(cs_wallet);
      std::vector<std::string> values;
      for (const auto& address : mapAddressBook) {
          for (const auto& data : address.second.destdata) {
              if (!data.first.compare(0, prefix.size(), prefix)) {
                  values.emplace_back(data.second);
              }
          }
      }
      return values;
  }
  
  std::string CWallet::GetWalletHelpString(bool showDebug)
  {
      std::string strUsage = HelpMessageGroup(_("Wallet options:"));
      strUsage += HelpMessageOpt("-disablewallet", _("Do not load the wallet and disable wallet RPC calls"));
      strUsage += HelpMessageOpt("-keypool=<n>", strprintf(_("Set key pool size to <n> (default: %u)"), DEFAULT_KEYPOOL_SIZE));
      strUsage += HelpMessageOpt("-fallbackfee=<amt>", strprintf(_("A fee rate (in %s/kB) that will be used when fee estimation has insufficient data (default: %s)"),
                                                                 CURRENCY_UNIT, FormatMoney(DEFAULT_FALLBACK_FEE)));
      strUsage += HelpMessageOpt("-discardfee=<amt>", strprintf(_("The fee rate (in %s/kB) that indicates your tolerance for discarding change by adding it to the fee (default: %s). "
                                                                  "Note: An output is discarded if it is dust at this rate, but we will always discard up to the dust relay fee and a discard fee above that is limited by the fee estimate for the longest target"),
                                                                CURRENCY_UNIT, FormatMoney(DEFAULT_DISCARD_FEE)));
      strUsage += HelpMessageOpt("-mintxfee=<amt>", strprintf(_("Fees (in %s/kB) smaller than this are considered zero fee for transaction creation (default: %s)"),
                                                              CURRENCY_UNIT, FormatMoney(DEFAULT_TRANSACTION_MINFEE)));
      strUsage += HelpMessageOpt("-paytxfee=<amt>", strprintf(_("Fee (in %s/kB) to add to transactions you send (default: %s)"),
                                                              CURRENCY_UNIT, FormatMoney(payTxFee.GetFeePerK())));
      strUsage += HelpMessageOpt("-rescan", _("Rescan the block chain for missing wallet transactions on startup"));
      strUsage += HelpMessageOpt("-salvagewallet", _("Attempt to recover private keys from a corrupt wallet on startup"));
      strUsage += HelpMessageOpt("-spendzeroconfchange", strprintf(_("Spend unconfirmed change when sending transactions (default: %u)"), DEFAULT_SPEND_ZEROCONF_CHANGE));
      strUsage += HelpMessageOpt("-txconfirmtarget=<n>", strprintf(_("If paytxfee is not set, include enough fee so transactions begin confirmation on average within n blocks (default: %u)"), DEFAULT_TX_CONFIRM_TARGET));
      strUsage += HelpMessageOpt("-usehd", _("Use hierarchical deterministic key generation (HD) after BIP32. Only has effect during wallet creation/first start") + " " + strprintf(_("(default: %u)"), DEFAULT_USE_HD_WALLET));
      strUsage += HelpMessageOpt("-walletrbf", strprintf(_("Send transactions with full-RBF opt-in enabled (default: %u)"), DEFAULT_WALLET_RBF));
      strUsage += HelpMessageOpt("-upgradewallet", _("Upgrade wallet to latest format on startup"));
      strUsage += HelpMessageOpt("-wallet=<file>", _("Specify wallet file (within data directory)") + " " + strprintf(_("(default: %s)"), DEFAULT_WALLET_DAT));
      strUsage += HelpMessageOpt("-walletbroadcast", _("Make the wallet broadcast transactions") + " " + strprintf(_("(default: %u)"), DEFAULT_WALLETBROADCAST));
      strUsage += HelpMessageOpt("-walletnotify=<cmd>", _("Execute command when a wallet transaction changes (%s in cmd is replaced by TxID)"));
      strUsage += HelpMessageOpt("-zapwallettxes=<mode>", _("Delete all wallet transactions and only recover those parts of the blockchain through -rescan on startup") +
                                 " " + _("(1 = keep tx meta data e.g. account owner and payment request information, 2 = drop tx meta data)"));
  
      if (showDebug)
      {
          strUsage += HelpMessageGroup(_("Wallet debugging/testing options:"));
  
          strUsage += HelpMessageOpt("-dblogsize=<n>", strprintf("Flush wallet database activity from memory to disk log every <n> megabytes (default: %u)", DEFAULT_WALLET_DBLOGSIZE));
          strUsage += HelpMessageOpt("-flushwallet", strprintf("Run a thread to flush wallet periodically (default: %u)", DEFAULT_FLUSHWALLET));
          strUsage += HelpMessageOpt("-privdb", strprintf("Sets the DB_PRIVATE flag in the wallet db environment (default: %u)", DEFAULT_WALLET_PRIVDB));
          strUsage += HelpMessageOpt("-walletrejectlongchains", strprintf(_("Wallet will not create transactions that violate mempool chain limits (default: %u)"), DEFAULT_WALLET_REJECT_LONG_CHAINS));
      }
  
      return strUsage;
  }
  
  CWallet* CWallet::CreateWalletFromFile(const std::string walletFile)
  {
      // needed to restore wallet transaction meta data after -zapwallettxes
      std::vector<CWalletTx> vWtx;
  
      if (gArgs.GetBoolArg("-zapwallettxes", false)) {
          uiInterface.InitMessage(_("Zapping all transactions from wallet..."));
  
          std::unique_ptr<CWalletDBWrapper> dbw(new CWalletDBWrapper(&bitdb, walletFile));
          CWallet *tempWallet = new CWallet(std::move(dbw));
          DBErrors nZapWalletRet = tempWallet->ZapWalletTx(vWtx);
          if (nZapWalletRet != DB_LOAD_OK) {
              InitError(strprintf(_("Error loading %s: Wallet corrupted"), walletFile));
              return nullptr;
          }
  
          delete tempWallet;
          tempWallet = nullptr;
      }
  
      uiInterface.InitMessage(_("Loading wallet..."));
  
      int64_t nStart = GetTimeMillis();
      bool fFirstRun = true;
      std::unique_ptr<CWalletDBWrapper> dbw(new CWalletDBWrapper(&bitdb, walletFile));
      CWallet *walletInstance = new CWallet(std::move(dbw));
      DBErrors nLoadWalletRet = walletInstance->LoadWallet(fFirstRun);
      if (nLoadWalletRet != DB_LOAD_OK)
      {
          if (nLoadWalletRet == DB_CORRUPT) {
              InitError(strprintf(_("Error loading %s: Wallet corrupted"), walletFile));
              return nullptr;
          }
          else if (nLoadWalletRet == DB_NONCRITICAL_ERROR)
          {
              InitWarning(strprintf(_("Error reading %s! All keys read correctly, but transaction data"
                                           " or address book entries might be missing or incorrect."),
                  walletFile));
          }
          else if (nLoadWalletRet == DB_TOO_NEW) {
              InitError(strprintf(_("Error loading %s: Wallet requires newer version of %s"), walletFile, _(PACKAGE_NAME)));
              return nullptr;
          }
          else if (nLoadWalletRet == DB_NEED_REWRITE)
          {
              InitError(strprintf(_("Wallet needed to be rewritten: restart %s to complete"), _(PACKAGE_NAME)));
              return nullptr;
          }
          else {
              InitError(strprintf(_("Error loading %s"), walletFile));
              return nullptr;
          }
      }
  
      if (gArgs.GetBoolArg("-upgradewallet", fFirstRun))
      {
          int nMaxVersion = gArgs.GetArg("-upgradewallet", 0);
          if (nMaxVersion == 0) // the -upgradewallet without argument case
          {
              LogPrintf("Performing wallet upgrade to %i\n", FEATURE_LATEST);
              nMaxVersion = CLIENT_VERSION;
              walletInstance->SetMinVersion(FEATURE_LATEST); // permanently upgrade the wallet immediately
          }
          else
              LogPrintf("Allowing wallet upgrade up to %i\n", nMaxVersion);
          if (nMaxVersion < walletInstance->GetVersion())
          {
              InitError(_("Cannot downgrade wallet"));
              return nullptr;
          }
          walletInstance->SetMaxVersion(nMaxVersion);
      }
  
      if (fFirstRun)
      {
          // Create new keyUser and set as default key
          if (gArgs.GetBoolArg("-usehd", DEFAULT_USE_HD_WALLET) && !walletInstance->IsHDEnabled()) {
  
              // ensure this wallet.dat can only be opened by clients supporting HD with chain split
              walletInstance->SetMinVersion(FEATURE_HD_SPLIT);
  
              // generate a new master key
              CPubKey masterPubKey = walletInstance->GenerateNewHDMasterKey();
              if (!walletInstance->SetHDMasterKey(masterPubKey))
                  throw std::runtime_error(std::string(__func__) + ": Storing master key failed");
          }
          CPubKey newDefaultKey;
          if (walletInstance->GetKeyFromPool(newDefaultKey, false)) {
              walletInstance->SetDefaultKey(newDefaultKey);
              if (!walletInstance->SetAddressBook(walletInstance->vchDefaultKey.GetID(), "", "receive")) {
                  InitError(_("Cannot write default address") += "\n");
                  return nullptr;
              }
          }
  
          walletInstance->SetBestChain(chainActive.GetLocator());
      }
      else if (gArgs.IsArgSet("-usehd")) {
          bool useHD = gArgs.GetBoolArg("-usehd", DEFAULT_USE_HD_WALLET);
          if (walletInstance->IsHDEnabled() && !useHD) {
              InitError(strprintf(_("Error loading %s: You can't disable HD on an already existing HD wallet"), walletFile));
              return nullptr;
          }
          if (!walletInstance->IsHDEnabled() && useHD) {
              InitError(strprintf(_("Error loading %s: You can't enable HD on an already existing non-HD wallet"), walletFile));
              return nullptr;
          }
      }
  
      LogPrintf(" wallet      %15dms\n", GetTimeMillis() - nStart);
  
      RegisterValidationInterface(walletInstance);
  
      // Try to top up keypool. No-op if the wallet is locked.
      walletInstance->TopUpKeyPool();
  
      CBlockIndex *pindexRescan = chainActive.Genesis();
      if (!gArgs.GetBoolArg("-rescan", false))
      {
          CWalletDB walletdb(*walletInstance->dbw);
          CBlockLocator locator;
          if (walletdb.ReadBestBlock(locator))
              pindexRescan = FindForkInGlobalIndex(chainActive, locator);
      }
      if (chainActive.Tip() && chainActive.Tip() != pindexRescan)
      {
          //We can't rescan beyond non-pruned blocks, stop and throw an error
          //this might happen if a user uses an old wallet within a pruned node
          // or if he ran -disablewallet for a longer time, then decided to re-enable
          if (fPruneMode)
          {
              CBlockIndex *block = chainActive.Tip();
              while (block && block->pprev && (block->pprev->nStatus & BLOCK_HAVE_DATA) && block->pprev->nTx > 0 && pindexRescan != block)
                  block = block->pprev;
  
              if (pindexRescan != block) {
                  InitError(_("Prune: last wallet synchronisation goes beyond pruned data. You need to -reindex (download the whole blockchain again in case of pruned node)"));
                  return nullptr;
              }
          }
  
          uiInterface.InitMessage(_("Rescanning..."));
          LogPrintf("Rescanning last %i blocks (from block %i)...\n", chainActive.Height() - pindexRescan->nHeight, pindexRescan->nHeight);
  
          // No need to read and scan block if block was created before
          // our wallet birthday (as adjusted for block time variability)
          while (pindexRescan && walletInstance->nTimeFirstKey && (pindexRescan->GetBlockTime() < (walletInstance->nTimeFirstKey - TIMESTAMP_WINDOW))) {
              pindexRescan = chainActive.Next(pindexRescan);
          }
  
          nStart = GetTimeMillis();
          walletInstance->ScanForWalletTransactions(pindexRescan, true);
          LogPrintf(" rescan      %15dms\n", GetTimeMillis() - nStart);
          walletInstance->SetBestChain(chainActive.GetLocator());
          walletInstance->dbw->IncrementUpdateCounter();
  
          // Restore wallet transaction metadata after -zapwallettxes=1
          if (gArgs.GetBoolArg("-zapwallettxes", false) && gArgs.GetArg("-zapwallettxes", "1") != "2")
          {
              CWalletDB walletdb(*walletInstance->dbw);
  
              for (const CWalletTx& wtxOld : vWtx)
              {
                  uint256 hash = wtxOld.GetHash();
                  std::map<uint256, CWalletTx>::iterator mi = walletInstance->mapWallet.find(hash);
                  if (mi != walletInstance->mapWallet.end())
                  {
                      const CWalletTx* copyFrom = &wtxOld;
                      CWalletTx* copyTo = &mi->second;
                      copyTo->mapValue = copyFrom->mapValue;
                      copyTo->vOrderForm = copyFrom->vOrderForm;
                      copyTo->nTimeReceived = copyFrom->nTimeReceived;
                      copyTo->nTimeSmart = copyFrom->nTimeSmart;
                      copyTo->fFromMe = copyFrom->fFromMe;
                      copyTo->strFromAccount = copyFrom->strFromAccount;
                      copyTo->nOrderPos = copyFrom->nOrderPos;
                      walletdb.WriteTx(*copyTo);
                  }
              }
          }
      }
      walletInstance->SetBroadcastTransactions(gArgs.GetBoolArg("-walletbroadcast", DEFAULT_WALLETBROADCAST));
  
      {
          LOCK(walletInstance->cs_wallet);
          LogPrintf("setKeyPool.size() = %u\n",      walletInstance->GetKeyPoolSize());
          LogPrintf("mapWallet.size() = %u\n",       walletInstance->mapWallet.size());
          LogPrintf("mapAddressBook.size() = %u\n",  walletInstance->mapAddressBook.size());
      }
  
      return walletInstance;
  }
  
  bool CWallet::InitLoadWallet()
  {
      if (gArgs.GetBoolArg("-disablewallet", DEFAULT_DISABLE_WALLET)) {
          LogPrintf("Wallet disabled!\n");
          return true;
      }
  
      for (const std::string& walletFile : gArgs.GetArgs("-wallet")) {
          CWallet * const pwallet = CreateWalletFromFile(walletFile);
          if (!pwallet) {
              return false;
          }
          vpwallets.push_back(pwallet);
      }
  
      return true;
  }
  
  std::atomic<bool> CWallet::fFlushScheduled(false);
  
  void CWallet::postInitProcess(CScheduler& scheduler)
  {
      // Add wallet transactions that aren't already in a block to mempool
      // Do this here as mempool requires genesis block to be loaded
      ReacceptWalletTransactions();
  
      // Run a thread to flush wallet periodically
      if (!CWallet::fFlushScheduled.exchange(true)) {
          scheduler.scheduleEvery(MaybeCompactWalletDB, 500);
      }
  }
  
  bool CWallet::ParameterInteraction()
  {
      gArgs.SoftSetArg("-wallet", DEFAULT_WALLET_DAT);
      const bool is_multiwallet = gArgs.GetArgs("-wallet").size() > 1;
  
      if (gArgs.GetBoolArg("-disablewallet", DEFAULT_DISABLE_WALLET))
          return true;
  
      if (gArgs.GetBoolArg("-blocksonly", DEFAULT_BLOCKSONLY) && gArgs.SoftSetBoolArg("-walletbroadcast", false)) {
          LogPrintf("%s: parameter interaction: -blocksonly=1 -> setting -walletbroadcast=0\n", __func__);
      }
  
      if (gArgs.GetBoolArg("-salvagewallet", false)) {
          if (is_multiwallet) {
              return InitError(strprintf("%s is only allowed with a single wallet file", "-salvagewallet"));
          }
          // Rewrite just private keys: rescan to find transactions
          if (gArgs.SoftSetBoolArg("-rescan", true)) {
              LogPrintf("%s: parameter interaction: -salvagewallet=1 -> setting -rescan=1\n", __func__);
          }
      }
  
      int zapwallettxes = gArgs.GetArg("-zapwallettxes", 0);
      // -zapwallettxes implies dropping the mempool on startup
      if (zapwallettxes != 0 && gArgs.SoftSetBoolArg("-persistmempool", false)) {
          LogPrintf("%s: parameter interaction: -zapwallettxes=%s -> setting -persistmempool=0\n", __func__, zapwallettxes);
      }
  
      // -zapwallettxes implies a rescan
      if (zapwallettxes != 0) {
          if (is_multiwallet) {
              return InitError(strprintf("%s is only allowed with a single wallet file", "-zapwallettxes"));
          }
          if (gArgs.SoftSetBoolArg("-rescan", true)) {
              LogPrintf("%s: parameter interaction: -zapwallettxes=%s -> setting -rescan=1\n", __func__, zapwallettxes);
          }
      }
  
      if (is_multiwallet) {
          if (gArgs.GetBoolArg("-upgradewallet", false)) {
              return InitError(strprintf("%s is only allowed with a single wallet file", "-upgradewallet"));
          }
      }
  
      if (gArgs.GetBoolArg("-sysperms", false))
          return InitError("-sysperms is not allowed in combination with enabled wallet functionality");
      if (gArgs.GetArg("-prune", 0) && gArgs.GetBoolArg("-rescan", false))
          return InitError(_("Rescans are not possible in pruned mode. You will need to use -reindex which will download the whole blockchain again."));
  
      if (::minRelayTxFee.GetFeePerK() > HIGH_TX_FEE_PER_KB)
          InitWarning(AmountHighWarn("-minrelaytxfee") + " " +
                      _("The wallet will avoid paying less than the minimum relay fee."));
  
      if (gArgs.IsArgSet("-mintxfee"))
      {
          CAmount n = 0;
          if (!ParseMoney(gArgs.GetArg("-mintxfee", ""), n) || 0 == n)
              return InitError(AmountErrMsg("mintxfee", gArgs.GetArg("-mintxfee", "")));
          if (n > HIGH_TX_FEE_PER_KB)
              InitWarning(AmountHighWarn("-mintxfee") + " " +
                          _("This is the minimum transaction fee you pay on every transaction."));
          CWallet::minTxFee = CFeeRate(n);
      }
      if (gArgs.IsArgSet("-fallbackfee"))
      {
          CAmount nFeePerK = 0;
          if (!ParseMoney(gArgs.GetArg("-fallbackfee", ""), nFeePerK))
              return InitError(strprintf(_("Invalid amount for -fallbackfee=<amount>: '%s'"), gArgs.GetArg("-fallbackfee", "")));
          if (nFeePerK > HIGH_TX_FEE_PER_KB)
              InitWarning(AmountHighWarn("-fallbackfee") + " " +
                          _("This is the transaction fee you may pay when fee estimates are not available."));
          CWallet::fallbackFee = CFeeRate(nFeePerK);
      }
      if (gArgs.IsArgSet("-discardfee"))
      {
          CAmount nFeePerK = 0;
          if (!ParseMoney(gArgs.GetArg("-discardfee", ""), nFeePerK))
              return InitError(strprintf(_("Invalid amount for -discardfee=<amount>: '%s'"), gArgs.GetArg("-discardfee", "")));
          if (nFeePerK > HIGH_TX_FEE_PER_KB)
              InitWarning(AmountHighWarn("-discardfee") + " " +
                          _("This is the transaction fee you may discard if change is smaller than dust at this level"));
          CWallet::m_discard_rate = CFeeRate(nFeePerK);
      }
      if (gArgs.IsArgSet("-paytxfee"))
      {
          CAmount nFeePerK = 0;
          if (!ParseMoney(gArgs.GetArg("-paytxfee", ""), nFeePerK))
              return InitError(AmountErrMsg("paytxfee", gArgs.GetArg("-paytxfee", "")));
          if (nFeePerK > HIGH_TX_FEE_PER_KB)
              InitWarning(AmountHighWarn("-paytxfee") + " " +
                          _("This is the transaction fee you will pay if you send a transaction."));
  
          payTxFee = CFeeRate(nFeePerK, 1000);
          if (payTxFee < ::minRelayTxFee)
          {
              return InitError(strprintf(_("Invalid amount for -paytxfee=<amount>: '%s' (must be at least %s)"),
                                         gArgs.GetArg("-paytxfee", ""), ::minRelayTxFee.ToString()));
          }
      }
      if (gArgs.IsArgSet("-maxtxfee"))
      {
          CAmount nMaxFee = 0;
          if (!ParseMoney(gArgs.GetArg("-maxtxfee", ""), nMaxFee))
              return InitError(AmountErrMsg("maxtxfee", gArgs.GetArg("-maxtxfee", "")));
          if (nMaxFee > HIGH_MAX_TX_FEE)
              InitWarning(_("-maxtxfee is set very high! Fees this large could be paid on a single transaction."));
          maxTxFee = nMaxFee;
          if (CFeeRate(maxTxFee, 1000) < ::minRelayTxFee)
          {
              return InitError(strprintf(_("Invalid amount for -maxtxfee=<amount>: '%s' (must be at least the minrelay fee of %s to prevent stuck transactions)"),
                                         gArgs.GetArg("-maxtxfee", ""), ::minRelayTxFee.ToString()));
          }
      }
      nTxConfirmTarget = gArgs.GetArg("-txconfirmtarget", DEFAULT_TX_CONFIRM_TARGET);
      bSpendZeroConfChange = gArgs.GetBoolArg("-spendzeroconfchange", DEFAULT_SPEND_ZEROCONF_CHANGE);
      fWalletRbf = gArgs.GetBoolArg("-walletrbf", DEFAULT_WALLET_RBF);
  
      return true;
  }
  
  bool CWallet::BackupWallet(const std::string& strDest)
  {
      return dbw->Backup(strDest);
  }
  
  CKeyPool::CKeyPool()
  {
      nTime = GetTime();
      fInternal = false;
  }
  
  CKeyPool::CKeyPool(const CPubKey& vchPubKeyIn, bool internalIn)
  {
      nTime = GetTime();
      vchPubKey = vchPubKeyIn;
      fInternal = internalIn;
  }
  
  CWalletKey::CWalletKey(int64_t nExpires)
  {
      nTimeCreated = (nExpires ? GetTime() : 0);
      nTimeExpires = nExpires;
  }
  
  void CMerkleTx::SetMerkleBranch(const CBlockIndex* pindex, int posInBlock)
  {
      // Update the tx's hashBlock
      hashBlock = pindex->GetBlockHash();
  
      // set the position of the transaction in the block
      nIndex = posInBlock;
  }
  
  int CMerkleTx::GetHeight() const
  {
      if (hashUnset())
          return 0;
  
      AssertLockHeld(cs_main);
  
      // Find the block it claims to be in
      BlockMap::iterator mi = mapBlockIndex.find(hashBlock);
      if (mi == mapBlockIndex.end())
          return 0;
      CBlockIndex* pindex = (*mi).second;
      if (!pindex || !chainActive.Contains(pindex))
          return 0;
  
      return pindex->nHeight;
  }
  
  int CMerkleTx::GetDepthInMainChain(const CBlockIndex* &pindexRet) const
  {
      if (hashUnset())
          return 0;
  
      AssertLockHeld(cs_main);
  
      // Find the block it claims to be in
      BlockMap::iterator mi = mapBlockIndex.find(hashBlock);
      if (mi == mapBlockIndex.end())
          return 0;
      CBlockIndex* pindex = (*mi).second;
      if (!pindex || !chainActive.Contains(pindex))
          return 0;
  
      pindexRet = pindex;
      return ((nIndex == -1) ? (-1) : 1) * (chainActive.Height() - pindex->nHeight + 1);
  }
  
  int CMerkleTx::GetBlocksToMaturity() const
  {
      if (!IsCoinBase())
          return 0;
  
      const Consensus::Params& consensus = Params().GetConsensus();
      if( this->GetHeight() < consensus.CoinbaseLock  && this->GetHeight() != 2 )
          return std::max(0, (consensus.CoinbaseLock+1) - GetDepthInMainChain());
      else
          return std::max(0, (COINBASE_MATURITY+1) - GetDepthInMainChain());
  }
  
  
  bool CMerkleTx::AcceptToMemoryPool(const CAmount& nAbsurdFee, CValidationState& state)
  {
      return ::AcceptToMemoryPool(mempool, state, tx, true, nullptr, nullptr, false, nAbsurdFee);
  }
  