text: // Copyright (c) 2012-2019 The Peercoin developers
  // Copyright (c) 2017-2019 The BitGreen Core developers
  // Distributed under the MIT/X11 software license, see the accompanying
  // file COPYING or http://www.opensource.org/licenses/mit-license.php.
  #ifndef BITGREEN_POS_POS_H
  #define BITGREEN_POS_POS_H
  
  #include <uint256.h>
  #include <primitives/transaction.h> // CTransaction(Ref)
  
  class CBlock;
  class CBlockHeader;
  class COutPoint;
  class CBlockIndex;
  class CValidationState;
  
  void RetrieveStakeAgeHeights(int nHeight, int& nStakeMinAge, int& nStakeMaxAge);
  
  // MODIFIER_INTERVAL_RATIO:
  // ratio of group interval length between the last group and the first group
  static const int MODIFIER_INTERVAL_RATIO = 3;
  
  // Compute the hash modifier for proof-of-stake
  bool ComputeNextStakeModifier(const CBlockIndex* pindexCurrent, uint64_t& nStakeModifier, bool& fGeneratedStakeModifier);
  
  // Check whether stake kernel meets hash target
  // Sets hashProofOfStake on success return
  bool CheckStakeKernelHash(unsigned int nBits, CBlockIndex* pindexPrev, const CBlockHeader blockFrom, const CTransactionRef& txPrev, const COutPoint& prevout, unsigned int nTimeTx, uint256& hashProofOfStake, bool fPrintProofOfStake=false);
  
  // Check kernel hash target and coinstake signature
  // Sets hashProofOfStake on success return
  bool CheckProofOfStake(const CBlock &block, CBlockIndex* pindexPrev, uint256& hashProofOfStake);
  
  // Get stake modifier checksum
  unsigned int GetStakeModifierChecksum(const CBlockIndex* pindex);
  
  // Check stake modifier hard checkpoints
  bool CheckStakeModifierCheckpoints(int nHeight, unsigned int nStakeModifierChecksum);
  
  // Entropy bit for stake modifier if chosen by modifier
  unsigned int GetStakeEntropyBit(const CBlock& block);
  
  #endif // BITGREEN_POS_POS_H
  