text: // Copyright (c) 2014-2017 The Dash Core developers
  // Copyright (c) 2018 The Encocoin Core developers
  // Distributed under the MIT/X11 software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  #include "activemasternode.h"
  #include "consensus/validation.h"
  #include "governance-classes.h"
  #include "masternode-payments.h"
  #include "masternode-sync.h"
  #include "masternodeman.h"
  #include "messagesigner.h"
  #include "netfulfilledman.h"
  #include "netmessagemaker.h"
  #include "spork.h"
  #include "util.h"
  
  #include <boost/lexical_cast.hpp>
  
  /** Object for who's going to get paid on which blocks */
  CMasternodePayments mnpayments;
  
  CCriticalSection cs_vecPayees;
  CCriticalSection cs_mapMasternodeBlocks;
  CCriticalSection cs_mapMasternodePaymentVotes;
  
  /**
  * IsBlockValueValid
  *
  *   Determine if coinbase outgoing created money is the correct value
  *
  *   Why is this needed?
  *   - In Encocoin some blocks are superblocks, which output much higher amounts of coins
  *   - Otherblocks are 10% lower in outgoing value, so in total, no extra coins are created
  *   - When non-superblocks are detected, the normal schedule should be maintained
  */
  
  bool IsBlockValueValid(const CBlock& block, int nBlockHeight, CAmount blockReward, std::string& strErrorRet)
  {
      strErrorRet = "";
  
      bool isBlockRewardValueMet = (block.vtx[0]->GetValueOut() <= blockReward);
      if(fDebug) LogPrintf("block.vtx[0]->GetValueOut() %lld <= blockReward %lld\n", block.vtx[0]->GetValueOut(), blockReward);
  
      // we are still using budgets, but we have no data about them anymore,
      // all we know is predefined budget cycle and window
  
      const Consensus::Params& consensusParams = Params().GetConsensus();
  
      if(nBlockHeight < consensusParams.nSuperblockStartBlock) {
          int nOffset = nBlockHeight % consensusParams.nBudgetPaymentsCycleBlocks;
          if(nBlockHeight >= consensusParams.nBudgetPaymentsStartBlock &&
              nOffset < consensusParams.nBudgetPaymentsWindowBlocks) {
              // NOTE: old budget system is disabled since 12.1
              if(masternodeSync.IsSynced()) {
                  // no old budget blocks should be accepted here on mainnet,
                  // testnet/devnet/regtest should produce regular blocks only
                  LogPrint("gobject", "IsBlockValueValid -- WARNING: Client synced but old budget system is disabled, checking block value against block reward\n");
                  if(!isBlockRewardValueMet) {
                      strErrorRet = strprintf("coinbase pays too much at height %d (actual=%d vs limit=%d), exceeded block reward, old budgets are disabled",
                                              nBlockHeight, block.vtx[0]->GetValueOut(), blockReward);
                  }
                  return isBlockRewardValueMet;
              }
              // when not synced, rely on online nodes (all networks)
              LogPrint("gobject", "IsBlockValueValid -- WARNING: Skipping old budget block value checks, accepting block\n");
              return true;
          }
          // LogPrint("gobject", "IsBlockValueValid -- Block is not in budget cycle window, checking block value against block reward\n");
          if(!isBlockRewardValueMet) {
              strErrorRet = strprintf("coinbase pays too much at height %d (actual=%d vs limit=%d), exceeded block reward, block is not in old budget cycle window",
                                      nBlockHeight, block.vtx[0]->GetValueOut(), blockReward);
          }
          return isBlockRewardValueMet;
      }
  
      // superblocks started
  
      CAmount nSuperblockMaxValue =  blockReward + CSuperblock::GetPaymentsLimit(nBlockHeight);
      bool isSuperblockMaxValueMet = (block.vtx[0]->GetValueOut() <= nSuperblockMaxValue);
  
      LogPrint("gobject", "block.vtx[0]->GetValueOut() %lld <= nSuperblockMaxValue %lld\n", block.vtx[0]->GetValueOut(), nSuperblockMaxValue);
  
      if(!masternodeSync.IsSynced() || fLiteMode) {
          // not enough data but at least it must NOT exceed superblock max value
          if(CSuperblock::IsValidBlockHeight(nBlockHeight)) {
              if(fDebug) LogPrintf("IsBlockPayeeValid -- WARNING: Not enough data, checking superblock max bounds only\n");
              if(!isSuperblockMaxValueMet) {
                  strErrorRet = strprintf("coinbase pays too much at height %d (actual=%d vs limit=%d), exceeded superblock max value",
                                          nBlockHeight, block.vtx[0]->GetValueOut(), nSuperblockMaxValue);
              }
              return isSuperblockMaxValueMet;
          }
          if(!isBlockRewardValueMet) {
              strErrorRet = strprintf("coinbase pays too much at height %d (actual=%d vs limit=%d), exceeded block reward, only regular blocks are allowed at this height",
                                      nBlockHeight, block.vtx[0]->GetValueOut(), blockReward);
          }
          // it MUST be a regular block otherwise
          return isBlockRewardValueMet;
      }
  
      // we are synced, let's try to check as much data as we can
  
      if(sporkManager.IsSporkActive(SPORK_9_SUPERBLOCKS_ENABLED)) {
          if(CSuperblockManager::IsSuperblockTriggered(nBlockHeight)) {
              if(CSuperblockManager::IsValid(*block.vtx[0], nBlockHeight, blockReward)) {
                  LogPrint("gobject", "IsBlockValueValid -- Valid superblock at height %d: %s", nBlockHeight, block.vtx[0]->ToString());
                  // all checks are done in CSuperblock::IsValid, nothing to do here
                  return true;
              }
  
              // triggered but invalid? that's weird
              LogPrintf("IsBlockValueValid -- ERROR: Invalid superblock detected at height %d: %s", nBlockHeight, block.vtx[0]->ToString());
              // should NOT allow invalid superblocks, when superblocks are enabled
              strErrorRet = strprintf("invalid superblock detected at height %d", nBlockHeight);
              return false;
          }
          LogPrint("gobject", "IsBlockValueValid -- No triggered superblock detected at height %d\n", nBlockHeight);
          if(!isBlockRewardValueMet) {
              strErrorRet = strprintf("coinbase pays too much at height %d (actual=%d vs limit=%d), exceeded block reward, no triggered superblock detected",
                                      nBlockHeight, block.vtx[0]->GetValueOut(), blockReward);
          }
      } else {
          // should NOT allow superblocks at all, when superblocks are disabled
          LogPrint("gobject", "IsBlockValueValid -- Superblocks are disabled, no superblocks allowed\n");
          if(!isBlockRewardValueMet) {
              strErrorRet = strprintf("coinbase pays too much at height %d (actual=%d vs limit=%d), exceeded block reward, superblocks are disabled",
                                      nBlockHeight, block.vtx[0]->GetValueOut(), blockReward);
          }
      }
  
      // it MUST be a regular block
      return isBlockRewardValueMet;
  }
  
  bool IsBlockPayeeValid(const CTransaction& txNew, int nBlockHeight, CAmount blockReward)
  {
      if(!masternodeSync.IsSynced() || fLiteMode) {
          //there is no budget data to use to check anything, let's just accept the longest chain
          if(fDebug) LogPrintf("IsBlockPayeeValid -- WARNING: Not enough data, skipping block payee checks\n");
          return true;
      }
  
      // we are still using budgets, but we have no data about them anymore,
      // we can only check masternode payments
  
      const Consensus::Params& consensusParams = Params().GetConsensus();
  
      if(nBlockHeight < consensusParams.nSuperblockStartBlock) {
          // NOTE: old budget system is disabled since 12.1 and we should never enter this branch
          // anymore when sync is finished (on mainnet). We have no old budget data but these blocks
          // have tons of confirmations and can be safely accepted without payee verification
          LogPrint("gobject", "IsBlockPayeeValid -- WARNING: Client synced but old budget system is disabled, accepting any payee\n");
          return true;
      }
  
      // superblocks started
      // SEE IF THIS IS A VALID SUPERBLOCK
  
      if(sporkManager.IsSporkActive(SPORK_9_SUPERBLOCKS_ENABLED)) {
          if(CSuperblockManager::IsSuperblockTriggered(nBlockHeight)) {
              if(CSuperblockManager::IsValid(txNew, nBlockHeight, blockReward)) {
                  LogPrint("gobject", "IsBlockPayeeValid -- Valid superblock at height %d: %s", nBlockHeight, txNew.ToString());
                  return true;
              }
  
              LogPrintf("IsBlockPayeeValid -- ERROR: Invalid superblock detected at height %d: %s", nBlockHeight, txNew.ToString());
              // should NOT allow such superblocks, when superblocks are enabled
              return false;
          }
          // continue validation, should pay MN
          LogPrint("gobject", "IsBlockPayeeValid -- No triggered superblock detected at height %d\n", nBlockHeight);
      } else {
          // should NOT allow superblocks at all, when superblocks are disabled
          LogPrint("gobject", "IsBlockPayeeValid -- Superblocks are disabled, no superblocks allowed\n");
      }
  
      // IF THIS ISN'T A SUPERBLOCK OR SUPERBLOCK IS INVALID, IT SHOULD PAY A MASTERNODE DIRECTLY
      if(mnpayments.IsTransactionValid(txNew, nBlockHeight)) {
          LogPrint("mnpayments", "IsBlockPayeeValid -- Valid masternode payment at height %d: %s", nBlockHeight, txNew.ToString());
          return true;
      }
  
      if(sporkManager.IsSporkActive(SPORK_8_MASTERNODE_PAYMENT_ENFORCEMENT)) {
          LogPrintf("IsBlockPayeeValid -- ERROR: Invalid masternode payment detected at height %d: %s", nBlockHeight, txNew.ToString());
          return false;
      }
  
      LogPrintf("IsBlockPayeeValid -- WARNING: Masternode payment enforcement is disabled, accepting any payee\n");
      return true;
  }
  
  void FillBlockPayments(CMutableTransaction& txNew, int nBlockHeight, CAmount blockReward, CTxOut& txoutMasternodeRet, std::vector<CTxOut>& voutSuperblockRet)
  {
      // only create superblocks if spork is enabled AND if superblock is actually triggered
      // (height should be validated inside)
      if(sporkManager.IsSporkActive(SPORK_9_SUPERBLOCKS_ENABLED) &&
          CSuperblockManager::IsSuperblockTriggered(nBlockHeight)) {
              LogPrint("gobject", "FillBlockPayments -- triggered superblock creation at height %d\n", nBlockHeight);
              CSuperblockManager::CreateSuperblock(txNew, nBlockHeight, voutSuperblockRet);
              return;
      }
  
      // FILL BLOCK PAYEE WITH MASTERNODE PAYMENT OTHERWISE
      mnpayments.FillBlockPayee(txNew, nBlockHeight, blockReward, txoutMasternodeRet);
      LogPrint("mnpayments", "FillBlockPayments -- nBlockHeight %d blockReward %lld txoutMasternodeRet %s txNew %s",
                              nBlockHeight, blockReward, txoutMasternodeRet.ToString(), txNew.ToString());
  }
  
  std::string GetRequiredPaymentsString(int nBlockHeight)
  {
      // IF WE HAVE A ACTIVATED TRIGGER FOR THIS HEIGHT - IT IS A SUPERBLOCK, GET THE REQUIRED PAYEES
      if(CSuperblockManager::IsSuperblockTriggered(nBlockHeight)) {
          return CSuperblockManager::GetRequiredPaymentsString(nBlockHeight);
      }
  
      // OTHERWISE, PAY MASTERNODE
      return mnpayments.GetRequiredPaymentsString(nBlockHeight);
  }
  
  void CMasternodePayments::Clear()
  {
      LOCK2(cs_mapMasternodeBlocks, cs_mapMasternodePaymentVotes);
      mapMasternodeBlocks.clear();
      mapMasternodePaymentVotes.clear();
  }
  
  bool CMasternodePayments::UpdateLastVote(const CMasternodePaymentVote& vote)
  {
      LOCK(cs_mapMasternodePaymentVotes);
  
      const auto it = mapMasternodesLastVote.find(vote.masternodeOutpoint);
      if (it != mapMasternodesLastVote.end()) {
          if (it->second == vote.nBlockHeight)
              return false;
          it->second = vote.nBlockHeight;
          return true;
      }
  
      //record this masternode voted
      mapMasternodesLastVote.emplace(vote.masternodeOutpoint, vote.nBlockHeight);
      return true;
  }
  
  /**
  *   FillBlockPayee
  *
  *   Fill Masternode ONLY payment block
  */
  
  void CMasternodePayments::FillBlockPayee(CMutableTransaction& txNew, int nBlockHeight, CAmount blockReward, CTxOut& txoutMasternodeRet) const
  {
      // make sure it's not filled yet
      txoutMasternodeRet = CTxOut();
  
      CScript payee;
  
      if(!GetBlockPayee(nBlockHeight, payee)) {
          // no masternode detected...
          int nCount = 0;
          masternode_info_t mnInfo;
          if(!mnodeman.GetNextMasternodeInQueueForPayment(nBlockHeight, true, nCount, mnInfo)) {
              // ...and we can't calculate it on our own
              LogPrintf("CMasternodePayments::FillBlockPayee -- Failed to detect masternode to pay\n");
              return;
          }
          // fill payee with locally calculated winner and hope for the best
          payee = GetScriptForDestination(mnInfo.pubKeyCollateralAddress.GetID());
      }
  
      // GET MASTERNODE PAYMENT VARIABLES SETUP
      CAmount masternodePayment = GetMasternodePayment(nBlockHeight, blockReward);
  
      // split reward between miner ...
      txNew.vout[0].nValue -= masternodePayment;
      // ... and masternode
      txoutMasternodeRet = CTxOut(masternodePayment, payee);
      txNew.vout.push_back(txoutMasternodeRet);
  
      CTxDestination address1;
      ExtractDestination(payee, address1);
      CBitcoinAddress address2(address1);
  
      LogPrintf("CMasternodePayments::FillBlockPayee -- Masternode payment %lld to %s\n", masternodePayment, address2.ToString());
  }
  
  int CMasternodePayments::GetMinMasternodePaymentsProto() const {
      return sporkManager.IsSporkActive(SPORK_10_MASTERNODE_PAY_UPDATED_NODES)
              ? MIN_MASTERNODE_PAYMENT_PROTO_VERSION_2
              : MIN_MASTERNODE_PAYMENT_PROTO_VERSION_1;
  }
  
  void CMasternodePayments::ProcessMessage(CNode* pfrom, const std::string& strCommand, CDataStream& vRecv, CConnman& connman)
  {
      if(fLiteMode) return; // disable all Encocoin specific functionality
  
      if (strCommand == NetMsgType::MASTERNODEPAYMENTSYNC) { //Masternode Payments Request Sync
  
          if(pfrom->nVersion < GetMinMasternodePaymentsProto()) {
              LogPrint("mnpayments", "MASTERNODEPAYMENTSYNC -- peer=%d using obsolete version %i\n", pfrom->id, pfrom->nVersion);
              connman.PushMessage(pfrom, CNetMsgMaker(pfrom->GetSendVersion()).Make(NetMsgType::REJECT, strCommand, REJECT_OBSOLETE,
                                 strprintf("Version must be %d or greater", GetMinMasternodePaymentsProto())));
              return;
          }
  
          // Ignore such requests until we are fully synced.
          // We could start processing this after masternode list is synced
          // but this is a heavy one so it's better to finish sync first.
          if (!masternodeSync.IsSynced()) return;
  
          // DEPRECATED, should be removed on next protocol bump
          if(pfrom->nVersion == 70208) {
              int nCountNeeded;
              vRecv >> nCountNeeded;
          }
  
          if(netfulfilledman.HasFulfilledRequest(pfrom->addr, NetMsgType::MASTERNODEPAYMENTSYNC)) {
              LOCK(cs_main);
              // Asking for the payments list multiple times in a short period of time is no good
              LogPrintf("MASTERNODEPAYMENTSYNC -- peer already asked me for the list, peer=%d\n", pfrom->id);
              Misbehaving(pfrom->GetId(), 20);
              return;
          }
          netfulfilledman.AddFulfilledRequest(pfrom->addr, NetMsgType::MASTERNODEPAYMENTSYNC);
  
          Sync(pfrom, connman);
          LogPrintf("MASTERNODEPAYMENTSYNC -- Sent Masternode payment votes to peer=%d\n", pfrom->id);
  
      } else if (strCommand == NetMsgType::MASTERNODEPAYMENTVOTE) { // Masternode Payments Vote for the Winner
  
          CMasternodePaymentVote vote;
          vRecv >> vote;
  
          if(pfrom->nVersion < GetMinMasternodePaymentsProto()) {
              LogPrint("mnpayments", "MASTERNODEPAYMENTVOTE -- peer=%d using obsolete version %i\n", pfrom->id, pfrom->nVersion);
              connman.PushMessage(pfrom, CNetMsgMaker(pfrom->GetSendVersion()).Make(NetMsgType::REJECT, strCommand, REJECT_OBSOLETE,
                                 strprintf("Version must be %d or greater", GetMinMasternodePaymentsProto())));
              return;
          }
  
          uint256 nHash = vote.GetHash();
  
          pfrom->setAskFor.erase(nHash);
  
          // TODO: clear setAskFor for MSG_MASTERNODE_PAYMENT_BLOCK too
  
          // Ignore any payments messages until masternode list is synced
          if(!masternodeSync.IsMasternodeListSynced()) return;
  
          {
              LOCK(cs_mapMasternodePaymentVotes);
  
              auto res = mapMasternodePaymentVotes.emplace(nHash, vote);
  
              // Avoid processing same vote multiple times if it was already verified earlier
              if(!res.second && res.first->second.IsVerified()) {
                  LogPrint("mnpayments", "MASTERNODEPAYMENTVOTE -- hash=%s, nBlockHeight=%d/%d seen\n",
                              nHash.ToString(), vote.nBlockHeight, nCachedBlockHeight);
                  return;
              }
  
              // Mark vote as non-verified when it's seen for the first time,
              // AddOrUpdatePaymentVote() below should take care of it if vote is actually ok
              res.first->second.MarkAsNotVerified();
          }
  
          int nFirstBlock = nCachedBlockHeight - GetStorageLimit();
          if(vote.nBlockHeight < nFirstBlock || vote.nBlockHeight > nCachedBlockHeight+20) {
              LogPrint("mnpayments", "MASTERNODEPAYMENTVOTE -- vote out of range: nFirstBlock=%d, nBlockHeight=%d, nHeight=%d\n", nFirstBlock, vote.nBlockHeight, nCachedBlockHeight);
              return;
          }
  
          std::string strError = "";
          if(!vote.IsValid(pfrom, nCachedBlockHeight, strError, connman)) {
              LogPrint("mnpayments", "MASTERNODEPAYMENTVOTE -- invalid message, error: %s\n", strError);
              return;
          }
  
          masternode_info_t mnInfo;
          if(!mnodeman.GetMasternodeInfo(vote.masternodeOutpoint, mnInfo)) {
              // mn was not found, so we can't check vote, some info is probably missing
              LogPrintf("MASTERNODEPAYMENTVOTE -- masternode is missing %s\n", vote.masternodeOutpoint.ToStringShort());
              mnodeman.AskForMN(pfrom, vote.masternodeOutpoint, connman);
              return;
          }
  
          int nDos = 0;
          if(!vote.CheckSignature(mnInfo.pubKeyMasternode, nCachedBlockHeight, nDos)) {
              if(nDos) {
                  LOCK(cs_main);
                  LogPrintf("MASTERNODEPAYMENTVOTE -- ERROR: invalid signature\n");
                  Misbehaving(pfrom->GetId(), nDos);
              } else {
                  // only warn about anything non-critical (i.e. nDos == 0) in debug mode
                  LogPrint("mnpayments", "MASTERNODEPAYMENTVOTE -- WARNING: invalid signature\n");
              }
              // Either our info or vote info could be outdated.
              // In case our info is outdated, ask for an update,
              mnodeman.AskForMN(pfrom, vote.masternodeOutpoint, connman);
              // but there is nothing we can do if vote info itself is outdated
              // (i.e. it was signed by a mn which changed its key),
              // so just quit here.
              return;
          }
  
          if(!UpdateLastVote(vote)) {
              LogPrintf("MASTERNODEPAYMENTVOTE -- masternode already voted, masternode=%s\n", vote.masternodeOutpoint.ToStringShort());
              return;
          }
  
          CTxDestination address1;
          ExtractDestination(vote.payee, address1);
          CBitcoinAddress address2(address1);
  
          LogPrint("mnpayments", "MASTERNODEPAYMENTVOTE -- vote: address=%s, nBlockHeight=%d, nHeight=%d, prevout=%s, hash=%s new\n",
                      address2.ToString(), vote.nBlockHeight, nCachedBlockHeight, vote.masternodeOutpoint.ToStringShort(), nHash.ToString());
  
          if(AddOrUpdatePaymentVote(vote)){
              vote.Relay(connman);
              masternodeSync.BumpAssetLastTime("MASTERNODEPAYMENTVOTE");
          }
      }
  }
  
  uint256 CMasternodePaymentVote::GetHash() const
  {
      // Note: doesn't match serialization
  
      CHashWriter ss(SER_GETHASH, PROTOCOL_VERSION);
      ss << *(CScriptBase*)(&payee);
      ss << nBlockHeight;
      ss << masternodeOutpoint;
      return ss.GetHash();
  }
  
  uint256 CMasternodePaymentVote::GetSignatureHash() const
  {
      return SerializeHash(*this);
  }
  
  bool CMasternodePaymentVote::Sign()
  {
      std::string strError;
  
      if (sporkManager.IsSporkActive(SPORK_6_NEW_SIGS)) {
          uint256 hash = GetSignatureHash();
  
          if(!CHashSigner::SignHash(hash, activeMasternode.keyMasternode, vchSig)) {
              LogPrintf("CMasternodePaymentVote::Sign -- SignHash() failed\n");
              return false;
          }
  
          if (!CHashSigner::VerifyHash(hash, activeMasternode.pubKeyMasternode, vchSig, strError)) {
              LogPrintf("CMasternodePaymentVote::Sign -- VerifyHash() failed, error: %s\n", strError);
              return false;
          }
      } else {
          std::string strMessage = masternodeOutpoint.ToStringShort() +
                      boost::lexical_cast<std::string>(nBlockHeight) +
                      ScriptToAsmStr(payee);
  
          if(!CMessageSigner::SignMessage(strMessage, vchSig, activeMasternode.keyMasternode)) {
              LogPrintf("CMasternodePaymentVote::Sign -- SignMessage() failed\n");
              return false;
          }
  
          if(!CMessageSigner::VerifyMessage(activeMasternode.pubKeyMasternode, vchSig, strMessage, strError)) {
              LogPrintf("CMasternodePaymentVote::Sign -- VerifyMessage() failed, error: %s\n", strError);
              return false;
          }
      }
  
      return true;
  }
  
  bool CMasternodePayments::GetBlockPayee(int nBlockHeight, CScript& payeeRet) const
  {
      LOCK(cs_mapMasternodeBlocks);
  
      auto it = mapMasternodeBlocks.find(nBlockHeight);
      return it != mapMasternodeBlocks.end() && it->second.GetBestPayee(payeeRet);
  }
  
  // Is this masternode scheduled to get paid soon?
  // -- Only look ahead up to 8 blocks to allow for propagation of the latest 2 blocks of votes
  bool CMasternodePayments::IsScheduled(const masternode_info_t& mnInfo, int nNotBlockHeight) const
  {
      LOCK(cs_mapMasternodeBlocks);
  
      if(!masternodeSync.IsMasternodeListSynced()) return false;
  
      CScript mnpayee;
      mnpayee = GetScriptForDestination(mnInfo.pubKeyCollateralAddress.GetID());
  
      CScript payee;
      for(int64_t h = nCachedBlockHeight; h <= nCachedBlockHeight + 8; h++){
          if(h == nNotBlockHeight) continue;
          if(GetBlockPayee(h, payee) && mnpayee == payee) {
              return true;
          }
      }
  
      return false;
  }
  
  bool CMasternodePayments::AddOrUpdatePaymentVote(const CMasternodePaymentVote& vote)
  {
      uint256 blockHash = uint256();
      if(!GetBlockHash(blockHash, vote.nBlockHeight - 101)) return false;
  
      uint256 nVoteHash = vote.GetHash();
  
      if(HasVerifiedPaymentVote(nVoteHash)) return false;
  
      LOCK2(cs_mapMasternodeBlocks, cs_mapMasternodePaymentVotes);
  
      mapMasternodePaymentVotes[nVoteHash] = vote;
  
      auto it = mapMasternodeBlocks.emplace(vote.nBlockHeight, CMasternodeBlockPayees(vote.nBlockHeight)).first;
      it->second.AddPayee(vote);
  
      LogPrint("mnpayments", "CMasternodePayments::AddOrUpdatePaymentVote -- added, hash=%s\n", nVoteHash.ToString());
  
      return true;
  }
  
  bool CMasternodePayments::HasVerifiedPaymentVote(const uint256& hashIn) const
  {
      LOCK(cs_mapMasternodePaymentVotes);
      const auto it = mapMasternodePaymentVotes.find(hashIn);
      return it != mapMasternodePaymentVotes.end() && it->second.IsVerified();
  }
  
  void CMasternodeBlockPayees::AddPayee(const CMasternodePaymentVote& vote)
  {
      LOCK(cs_vecPayees);
  
      uint256 nVoteHash = vote.GetHash();
  
      for (auto& payee : vecPayees) {
          if (payee.GetPayee() == vote.payee) {
              payee.AddVoteHash(nVoteHash);
              return;
          }
      }
      CMasternodePayee payeeNew(vote.payee, nVoteHash);
      vecPayees.push_back(payeeNew);
  }
  
  bool CMasternodeBlockPayees::GetBestPayee(CScript& payeeRet) const
  {
      LOCK(cs_vecPayees);
  
      if(vecPayees.empty()) {
          LogPrint("mnpayments", "CMasternodeBlockPayees::GetBestPayee -- ERROR: couldn't find any payee\n");
          return false;
      }
  
      int nVotes = -1;
      for (const auto& payee : vecPayees) {
          if (payee.GetVoteCount() > nVotes) {
              payeeRet = payee.GetPayee();
              nVotes = payee.GetVoteCount();
          }
      }
  
      return (nVotes > -1);
  }
  
  bool CMasternodeBlockPayees::HasPayeeWithVotes(const CScript& payeeIn, int nVotesReq) const
  {
      LOCK(cs_vecPayees);
  
      for (const auto& payee : vecPayees) {
          if (payee.GetVoteCount() >= nVotesReq && payee.GetPayee() == payeeIn) {
              return true;
          }
      }
  
      LogPrint("mnpayments", "CMasternodeBlockPayees::HasPayeeWithVotes -- ERROR: couldn't find any payee with %d+ votes\n", nVotesReq);
      return false;
  }
  
  bool CMasternodeBlockPayees::IsTransactionValid(const CTransaction& txNew) const
  {
      LOCK(cs_vecPayees);
  
      int nMaxSignatures = 0;
      std::string strPayeesPossible = "";
  
      CAmount nMasternodePayment = GetMasternodePayment(nBlockHeight, txNew.GetValueOut());
  
      //require at least MNPAYMENTS_SIGNATURES_REQUIRED signatures
  
      for (const auto& payee : vecPayees) {
          if (payee.GetVoteCount() >= nMaxSignatures) {
              nMaxSignatures = payee.GetVoteCount();
          }
      }
  
      // if we don't have at least MNPAYMENTS_SIGNATURES_REQUIRED signatures on a payee, approve whichever is the longest chain
      if(nMaxSignatures < MNPAYMENTS_SIGNATURES_REQUIRED) return true;
  
      for (const auto& payee : vecPayees) {
          if (payee.GetVoteCount() >= MNPAYMENTS_SIGNATURES_REQUIRED) {
              for (const auto& txout : txNew.vout) {
                  if (payee.GetPayee() == txout.scriptPubKey && nMasternodePayment == txout.nValue) {
                      LogPrint("mnpayments", "CMasternodeBlockPayees::IsTransactionValid -- Found required payment\n");
                      return true;
                  }
              }
  
              CTxDestination address1;
              ExtractDestination(payee.GetPayee(), address1);
              CBitcoinAddress address2(address1);
  
              if(strPayeesPossible == "") {
                  strPayeesPossible = address2.ToString();
              } else {
                  strPayeesPossible += "," + address2.ToString();
              }
          }
      }
  
      LogPrintf("CMasternodeBlockPayees::IsTransactionValid -- ERROR: Missing required payment, possible payees: '%s', amount: %f XNK\n", strPayeesPossible, (float)nMasternodePayment/COIN);
      return false;
  }
  
  std::string CMasternodeBlockPayees::GetRequiredPaymentsString() const
  {
      LOCK(cs_vecPayees);
  
      std::string strRequiredPayments = "";
  
      for (const auto& payee : vecPayees)
      {
          CTxDestination address1;
          ExtractDestination(payee.GetPayee(), address1);
          CBitcoinAddress address2(address1);
  
          if (!strRequiredPayments.empty())
              strRequiredPayments += ", ";
  
          strRequiredPayments += strprintf("%s:%d", address2.ToString(), payee.GetVoteCount());
      }
  
      if (strRequiredPayments.empty())
          return "Unknown";
  
      return strRequiredPayments;
  }
  
  std::string CMasternodePayments::GetRequiredPaymentsString(int nBlockHeight) const
  {
      LOCK(cs_mapMasternodeBlocks);
  
      const auto it = mapMasternodeBlocks.find(nBlockHeight);
      return it == mapMasternodeBlocks.end() ? "Unknown" : it->second.GetRequiredPaymentsString();
  }
  
  bool CMasternodePayments::IsTransactionValid(const CTransaction& txNew, int nBlockHeight) const
  {
      LOCK(cs_mapMasternodeBlocks);
  
      const auto it = mapMasternodeBlocks.find(nBlockHeight);
      return it == mapMasternodeBlocks.end() ? true : it->second.IsTransactionValid(txNew);
  }
  
  void CMasternodePayments::CheckAndRemove()
  {
      if(!masternodeSync.IsBlockchainSynced()) return;
  
      LOCK2(cs_mapMasternodeBlocks, cs_mapMasternodePaymentVotes);
  
      int nLimit = GetStorageLimit();
  
      std::map<uint256, CMasternodePaymentVote>::iterator it = mapMasternodePaymentVotes.begin();
      while(it != mapMasternodePaymentVotes.end()) {
          CMasternodePaymentVote vote = (*it).second;
  
          if(nCachedBlockHeight - vote.nBlockHeight > nLimit) {
              LogPrint("mnpayments", "CMasternodePayments::CheckAndRemove -- Removing old Masternode payment: nBlockHeight=%d\n", vote.nBlockHeight);
              mapMasternodePaymentVotes.erase(it++);
              mapMasternodeBlocks.erase(vote.nBlockHeight);
          } else {
              ++it;
          }
      }
      LogPrintf("CMasternodePayments::CheckAndRemove -- %s\n", ToString());
  }
  
  bool CMasternodePaymentVote::IsValid(CNode* pnode, int nValidationHeight, std::string& strError, CConnman& connman) const
  {
      masternode_info_t mnInfo;
  
      if(!mnodeman.GetMasternodeInfo(masternodeOutpoint, mnInfo)) {
          strError = strprintf("Unknown masternode=%s", masternodeOutpoint.ToStringShort());
          // Only ask if we are already synced and still have no idea about that Masternode
          if(masternodeSync.IsMasternodeListSynced()) {
              mnodeman.AskForMN(pnode, masternodeOutpoint, connman);
          }
  
          return false;
      }
  
      int nMinRequiredProtocol;
      if(nBlockHeight >= nValidationHeight) {
          // new votes must comply SPORK_10_MASTERNODE_PAY_UPDATED_NODES rules
          nMinRequiredProtocol = mnpayments.GetMinMasternodePaymentsProto();
      } else {
          // allow non-updated masternodes for old blocks
          nMinRequiredProtocol = MIN_MASTERNODE_PAYMENT_PROTO_VERSION_1;
      }
  
      if(mnInfo.nProtocolVersion < nMinRequiredProtocol) {
          strError = strprintf("Masternode protocol is too old: nProtocolVersion=%d, nMinRequiredProtocol=%d", mnInfo.nProtocolVersion, nMinRequiredProtocol);
          return false;
      }
  
      // Only masternodes should try to check masternode rank for old votes - they need to pick the right winner for future blocks.
      // Regular clients (miners included) need to verify masternode rank for future block votes only.
      if(!fMasternodeMode && nBlockHeight < nValidationHeight) return true;
  
      int nRank;
  
      if(!mnodeman.GetMasternodeRank(masternodeOutpoint, nRank, nBlockHeight - 101, nMinRequiredProtocol)) {
          LogPrint("mnpayments", "CMasternodePaymentVote::IsValid -- Can't calculate rank for masternode %s\n",
                      masternodeOutpoint.ToStringShort());
          return false;
      }
  
      if(nRank > MNPAYMENTS_SIGNATURES_TOTAL) {
          // It's common to have masternodes mistakenly think they are in the top 10
          // We don't want to print all of these messages in normal mode, debug mode should print though
          strError = strprintf("Masternode %s is not in the top %d (%d)", masternodeOutpoint.ToStringShort(), MNPAYMENTS_SIGNATURES_TOTAL, nRank);
          // Only ban for new mnw which is out of bounds, for old mnw MN list itself might be way too much off
          if(nRank > MNPAYMENTS_SIGNATURES_TOTAL*2 && nBlockHeight > nValidationHeight) {
              LOCK(cs_main);
              strError = strprintf("Masternode %s is not in the top %d (%d)", masternodeOutpoint.ToStringShort(), MNPAYMENTS_SIGNATURES_TOTAL*2, nRank);
              LogPrintf("CMasternodePaymentVote::IsValid -- Error: %s\n", strError);
              Misbehaving(pnode->GetId(), 20);
          }
          // Still invalid however
          return false;
      }
  
      return true;
  }
  
  bool CMasternodePayments::ProcessBlock(int nBlockHeight, CConnman& connman)
  {
      // DETERMINE IF WE SHOULD BE VOTING FOR THE NEXT PAYEE
  
      if(fLiteMode || !fMasternodeMode) return false;
  
      // We have little chances to pick the right winner if winners list is out of sync
      // but we have no choice, so we'll try. However it doesn't make sense to even try to do so
      // if we have not enough data about masternodes.
      if(!masternodeSync.IsMasternodeListSynced()) return false;
  
      int nRank;
  
      if (!mnodeman.GetMasternodeRank(activeMasternode.outpoint, nRank, nBlockHeight - 101, GetMinMasternodePaymentsProto())) {
          LogPrint("mnpayments", "CMasternodePayments::ProcessBlock -- Unknown Masternode\n");
          return false;
      }
  
      if (nRank > MNPAYMENTS_SIGNATURES_TOTAL) {
          LogPrint("mnpayments", "CMasternodePayments::ProcessBlock -- Masternode not in the top %d (%d)\n", MNPAYMENTS_SIGNATURES_TOTAL, nRank);
          return false;
      }
  
  
      // LOCATE THE NEXT MASTERNODE WHICH SHOULD BE PAID
  
      LogPrintf("CMasternodePayments::ProcessBlock -- Start: nBlockHeight=%d, masternode=%s\n", nBlockHeight, activeMasternode.outpoint.ToStringShort());
  
      // pay to the oldest MN that still had no payment but its input is old enough and it was active long enough
      int nCount = 0;
      masternode_info_t mnInfo;
  
      if (!mnodeman.GetNextMasternodeInQueueForPayment(nBlockHeight, true, nCount, mnInfo)) {
          LogPrintf("CMasternodePayments::ProcessBlock -- ERROR: Failed to find masternode to pay\n");
          return false;
      }
  
      LogPrintf("CMasternodePayments::ProcessBlock -- Masternode found by GetNextMasternodeInQueueForPayment(): %s\n", mnInfo.outpoint.ToStringShort());
  
  
      CScript payee = GetScriptForDestination(mnInfo.pubKeyCollateralAddress.GetID());
  
      CMasternodePaymentVote voteNew(activeMasternode.outpoint, nBlockHeight, payee);
  
      CTxDestination address1;
      ExtractDestination(payee, address1);
      CBitcoinAddress address2(address1);
  
      LogPrintf("CMasternodePayments::ProcessBlock -- vote: payee=%s, nBlockHeight=%d\n", address2.ToString(), nBlockHeight);
  
      // SIGN MESSAGE TO NETWORK WITH OUR MASTERNODE KEYS
  
      LogPrintf("CMasternodePayments::ProcessBlock -- Signing vote\n");
      if (voteNew.Sign()) {
          LogPrintf("CMasternodePayments::ProcessBlock -- AddOrUpdatePaymentVote()\n");
  
          if (AddOrUpdatePaymentVote(voteNew)) {
              voteNew.Relay(connman);
              return true;
          }
      }
  
      return false;
  }
  
  void CMasternodePayments::CheckBlockVotes(int nBlockHeight)
  {
      if (!masternodeSync.IsWinnersListSynced()) return;
  
      CMasternodeMan::rank_pair_vec_t mns;
      if (!mnodeman.GetMasternodeRanks(mns, nBlockHeight - 101, GetMinMasternodePaymentsProto())) {
          LogPrintf("CMasternodePayments::CheckBlockVotes -- nBlockHeight=%d, GetMasternodeRanks failed\n", nBlockHeight);
          return;
      }
  
      std::string debugStr;
  
      debugStr += strprintf("CMasternodePayments::CheckBlockVotes -- nBlockHeight=%d,\n  Expected voting MNs:\n", nBlockHeight);
  
      LOCK2(cs_mapMasternodeBlocks, cs_mapMasternodePaymentVotes);
  
      int i{0};
      for (const auto& mn : mns) {
          CScript payee;
          bool found = false;
  
          const auto it = mapMasternodeBlocks.find(nBlockHeight);
          if (it != mapMasternodeBlocks.end()) {
              for (const auto& p : it->second.vecPayees) {
                  for (const auto& voteHash : p.GetVoteHashes()) {
                      const auto itVote = mapMasternodePaymentVotes.find(voteHash);
                      if (itVote == mapMasternodePaymentVotes.end()) {
                          debugStr += strprintf("    - could not find vote %s\n",
                                                voteHash.ToString());
                          continue;
                      }
                      if (itVote->second.masternodeOutpoint == mn.second.outpoint) {
                          payee = itVote->second.payee;
                          found = true;
                          break;
                      }
                  }
              }
          }
  
          if (found) {
              CTxDestination address1;
              ExtractDestination(payee, address1);
              CBitcoinAddress address2(address1);
  
              debugStr += strprintf("    - %s - voted for %s\n",
                                    mn.second.outpoint.ToStringShort(), address2.ToString());
          } else {
              mapMasternodesDidNotVote.emplace(mn.second.outpoint, 0).first->second++;
  
              debugStr += strprintf("    - %s - no vote received\n",
                                    mn.second.outpoint.ToStringShort());
          }
  
          if (++i >= MNPAYMENTS_SIGNATURES_TOTAL) break;
      }
  
      if (mapMasternodesDidNotVote.empty()) {
          LogPrint("mnpayments", "%s", debugStr);
          return;
      }
  
      debugStr += "  Masternodes which missed a vote in the past:\n";
      for (const auto& item : mapMasternodesDidNotVote) {
          debugStr += strprintf("    - %s: %d\n", item.first.ToStringShort(), item.second);
      }
  
      LogPrint("mnpayments", "%s", debugStr);
  }
  
  void CMasternodePaymentVote::Relay(CConnman& connman) const
  {
      // Do not relay until fully synced
      if(!masternodeSync.IsSynced()) {
          LogPrint("mnpayments", "CMasternodePayments::Relay -- won't relay until fully synced\n");
          return;
      }
  
      CInv inv(MSG_MASTERNODE_PAYMENT_VOTE, GetHash());
      connman.RelayInv(inv);
  }
  
  bool CMasternodePaymentVote::CheckSignature(const CPubKey& pubKeyMasternode, int nValidationHeight, int &nDos) const
  {
      // do not ban by default
      nDos = 0;
      std::string strError = "";
  
      if (sporkManager.IsSporkActive(SPORK_6_NEW_SIGS)) {
          uint256 hash = GetSignatureHash();
  
          if (!CHashSigner::VerifyHash(hash, pubKeyMasternode, vchSig, strError)) {
              // could be a signature in old format
              std::string strMessage = masternodeOutpoint.ToStringShort() +
                          boost::lexical_cast<std::string>(nBlockHeight) +
                          ScriptToAsmStr(payee);
              if(!CMessageSigner::VerifyMessage(pubKeyMasternode, vchSig, strMessage, strError)) {
                  // nope, not in old format either
                  // Only ban for future block vote when we are already synced.
                  // Otherwise it could be the case when MN which signed this vote is using another key now
                  // and we have no idea about the old one.
                  if(masternodeSync.IsMasternodeListSynced() && nBlockHeight > nValidationHeight) {
                      nDos = 20;
                  }
                  return error("CMasternodePaymentVote::CheckSignature -- Got bad Masternode payment signature, masternode=%s, error: %s",
                              masternodeOutpoint.ToStringShort(), strError);
              }
          }
      } else {
          std::string strMessage = masternodeOutpoint.ToStringShort() +
                      boost::lexical_cast<std::string>(nBlockHeight) +
                      ScriptToAsmStr(payee);
  
          if (!CMessageSigner::VerifyMessage(pubKeyMasternode, vchSig, strMessage, strError)) {
              // Only ban for future block vote when we are already synced.
              // Otherwise it could be the case when MN which signed this vote is using another key now
              // and we have no idea about the old one.
              if(masternodeSync.IsMasternodeListSynced() && nBlockHeight > nValidationHeight) {
                  nDos = 20;
              }
              return error("CMasternodePaymentVote::CheckSignature -- Got bad Masternode payment signature, masternode=%s, error: %s",
                          masternodeOutpoint.ToStringShort(), strError);
          }
      }
  
      return true;
  }
  
  std::string CMasternodePaymentVote::ToString() const
  {
      std::ostringstream info;
  
      info << masternodeOutpoint.ToStringShort() <<
              ", " << nBlockHeight <<
              ", " << ScriptToAsmStr(payee) <<
              ", " << (int)vchSig.size();
  
      return info.str();
  }
  
  // Send only votes for future blocks, node should request every other missing payment block individually
  void CMasternodePayments::Sync(CNode* pnode, CConnman& connman) const
  {
      LOCK(cs_mapMasternodeBlocks);
  
      if(!masternodeSync.IsWinnersListSynced()) return;
  
      int nInvCount = 0;
  
      for(int h = nCachedBlockHeight; h < nCachedBlockHeight + 20; h++) {
          const auto it = mapMasternodeBlocks.find(h);
          if(it != mapMasternodeBlocks.end()) {
              for (const auto& payee : it->second.vecPayees) {
                  std::vector<uint256> vecVoteHashes = payee.GetVoteHashes();
                  for (const auto& hash : vecVoteHashes) {
                      if(!HasVerifiedPaymentVote(hash)) continue;
                      pnode->PushInventory(CInv(MSG_MASTERNODE_PAYMENT_VOTE, hash));
                      nInvCount++;
                  }
              }
          }
      }
  
      LogPrintf("CMasternodePayments::Sync -- Sent %d votes to peer=%d\n", nInvCount, pnode->id);
      CNetMsgMaker msgMaker(pnode->GetSendVersion());
      connman.PushMessage(pnode, msgMaker.Make(NetMsgType::SYNCSTATUSCOUNT, MASTERNODE_SYNC_MNW, nInvCount));
  }
  
  // Request low data/unknown payment blocks in batches directly from some node instead of/after preliminary Sync.
  void CMasternodePayments::RequestLowDataPaymentBlocks(CNode* pnode, CConnman& connman) const
  {
      if(!masternodeSync.IsMasternodeListSynced()) return;
  
      CNetMsgMaker msgMaker(pnode->GetSendVersion());
      LOCK2(cs_main, cs_mapMasternodeBlocks);
  
      std::vector<CInv> vToFetch;
      int nLimit = GetStorageLimit();
  
      const CBlockIndex *pindex = chainActive.Tip();
  
      while(nCachedBlockHeight - pindex->nHeight < nLimit) {
          const auto it = mapMasternodeBlocks.find(pindex->nHeight);
          if(it == mapMasternodeBlocks.end()) {
              // We have no idea about this block height, let's ask
              vToFetch.push_back(CInv(MSG_MASTERNODE_PAYMENT_BLOCK, pindex->GetBlockHash()));
              // We should not violate GETDATA rules
              if(vToFetch.size() == MAX_INV_SZ) {
                  LogPrintf("CMasternodePayments::RequestLowDataPaymentBlocks -- asking peer=%d for %d blocks\n", pnode->id, MAX_INV_SZ);
                  connman.PushMessage(pnode, msgMaker.Make(NetMsgType::GETDATA, vToFetch));
                  // Start filling new batch
                  vToFetch.clear();
              }
          }
          if(!pindex->pprev) break;
          pindex = pindex->pprev;
      }
  
      auto it = mapMasternodeBlocks.begin();
  
      while(it != mapMasternodeBlocks.end()) {
          int nTotalVotes = 0;
          bool fFound = false;
          for (const auto& payee : it->second.vecPayees) {
              if(payee.GetVoteCount() >= MNPAYMENTS_SIGNATURES_REQUIRED) {
                  fFound = true;
                  break;
              }
              nTotalVotes += payee.GetVoteCount();
          }
          // A clear winner (MNPAYMENTS_SIGNATURES_REQUIRED+ votes) was found
          // or no clear winner was found but there are at least avg number of votes
          if(fFound || nTotalVotes >= (MNPAYMENTS_SIGNATURES_TOTAL + MNPAYMENTS_SIGNATURES_REQUIRED)/2) {
              // so just move to the next block
              ++it;
              continue;
          }
          // DEBUG
          DBG (
              // Let's see why this failed
              for (const auto& payee : it->second.vecPayees) {
                  CTxDestination address1;
                  ExtractDestination(payee.GetPayee(), address1);
                  CBitcoinAddress address2(address1);
                  printf("payee %s votes %d\n", address2.ToString().c_str(), payee.GetVoteCount());
              }
              printf("block %d votes total %d\n", it->first, nTotalVotes);
          )
          // END DEBUG
          // Low data block found, let's try to sync it
          uint256 hash;
          if(GetBlockHash(hash, it->first)) {
              vToFetch.push_back(CInv(MSG_MASTERNODE_PAYMENT_BLOCK, hash));
          }
          // We should not violate GETDATA rules
          if(vToFetch.size() == MAX_INV_SZ) {
              LogPrintf("CMasternodePayments::RequestLowDataPaymentBlocks -- asking peer=%d for %d payment blocks\n", pnode->id, MAX_INV_SZ);
              connman.PushMessage(pnode, msgMaker.Make(NetMsgType::GETDATA, vToFetch));
              // Start filling new batch
              vToFetch.clear();
          }
          ++it;
      }
      // Ask for the rest of it
      if(!vToFetch.empty()) {
          LogPrintf("CMasternodePayments::RequestLowDataPaymentBlocks -- asking peer=%d for %d payment blocks\n", pnode->id, vToFetch.size());
          connman.PushMessage(pnode, msgMaker.Make(NetMsgType::GETDATA, vToFetch));
      }
  }
  
  std::string CMasternodePayments::ToString() const
  {
      std::ostringstream info;
  
      info << "Votes: " << (int)mapMasternodePaymentVotes.size() <<
              ", Blocks: " << (int)mapMasternodeBlocks.size();
  
      return info.str();
  }
  
  bool CMasternodePayments::IsEnoughData() const
  {
      float nAverageVotes = (MNPAYMENTS_SIGNATURES_TOTAL + MNPAYMENTS_SIGNATURES_REQUIRED) / 2;
      int nStorageLimit = GetStorageLimit();
      return GetBlockCount() > nStorageLimit && GetVoteCount() > nStorageLimit * nAverageVotes;
  }
  
  int CMasternodePayments::GetStorageLimit() const
  {
      return std::max(int(mnodeman.size() * nStorageCoeff), nMinBlocksToStore);
  }
  
  void CMasternodePayments::UpdatedBlockTip(const CBlockIndex *pindex, CConnman& connman)
  {
      if(!pindex) return;
  
      nCachedBlockHeight = pindex->nHeight;
      LogPrint("mnpayments", "CMasternodePayments::UpdatedBlockTip -- nCachedBlockHeight=%d\n", nCachedBlockHeight);
  
      int nFutureBlock = nCachedBlockHeight + 10;
  
      CheckBlockVotes(nFutureBlock - 1);
      ProcessBlock(nFutureBlock, connman);
  }
  