text: #!/usr/bin/env python3
  # Copyright (c) 2019 The WORX developers
  # Distributed under the MIT software license, see the accompanying
  # file COPYING or http://www.opensource.org/licenses/mit-license.php.
  
  '''
  Covers the scenario of a zPoS block where the coinstake input is a zerocoin spend
  of an already spent coin.
  '''
  
  from time import sleep
  
  from test_framework.authproxy import JSONRPCException
  
  from fake_stake.base_test import WORX_FakeStakeTest
  
  class zPoSFakeStake(WORX_FakeStakeTest):
  
      def run_test(self):
          self.description = "Covers the scenario of a zPoS block where the coinstake input is a zerocoin spend of an already spent coin."
          self.init_test()
  
          DENOM_TO_USE = 5000         # zc denomination
          INITAL_MINED_BLOCKS = 321   # First mined blocks (rewards collected to mint)
          MORE_MINED_BLOCKS = 301     # More blocks mined before spending zerocoins
          self.NUM_BLOCKS = 2         # Number of spammed blocks
  
          # 1) Starting mining blocks
          self.log.info("Mining %d blocks to get to zPOS activation...." % INITAL_MINED_BLOCKS)
          self.node.generate(INITAL_MINED_BLOCKS)
          sleep(2)
  
          # 2) Collect the possible prevouts and mint zerocoins with those
          self.log.info("Collecting all unspent coins which we generated from mining...")
          balance = self.node.getbalance("*", 100)
          self.log.info("Minting zerocoins...")
          initial_mints = 0
          while balance > DENOM_TO_USE:
              try:
                  self.node.mintzerocoin(DENOM_TO_USE)
              except JSONRPCException:
                  break
              sleep(1)
              initial_mints += 1
              self.node.generate(1)
              sleep(1)
  
              if initial_mints % 5 == 0:
                  self.log.info("Minted %d coins" % initial_mints)
              if initial_mints >= 70:
                  break
              balance = self.node.getbalance("*", 100)
          self.log.info("Minted %d coins in the %d-denom, remaining balance %d", initial_mints, DENOM_TO_USE, balance)
          sleep(2)
  
          # 3) mine more blocks
          self.log.info("Mining %d more blocks ... and getting spendable zerocoins" % MORE_MINED_BLOCKS)
          self.node.generate(MORE_MINED_BLOCKS)
          sleep(2)
          mints = self.node.listmintedzerocoins(True, True)
          mints_hashes = [x["serial hash"] for x in mints]
  
          # This mints are not ready spendable, only few of them.
          self.log.info("Got %d confirmed mints" % len(mints_hashes))
  
          # 4) spend mints
          self.log.info("Spending mints in block %d..." % self.node.getblockcount())
          spends = 0
          spent_mints = []
          for mint in mints_hashes:
              # create a single element list to pass to RPC spendzerocoinmints
              mint_arg = []
              mint_arg.append(mint)
              try:
                  self.node.spendzerocoinmints(mint_arg)
                  sleep(1)
                  spends += 1
                  spent_mints.append(mint)
              except JSONRPCException as e:
                  self.log.warning(str(e))
                  continue
          sleep(1)
          self.log.info("Successfully spent %d mints" % spends)
  
          # 5) Start mining again so that spends get confirmed in a block.
          self.log.info("Mining 5 more blocks...")
          self.node.generate(5)
          sleep(2)
  
          # 6) Collect some prevouts for random txes
          self.log.info("Collecting inputs for txes...")
          spending_utxo_list = self.node.listunspent()
          sleep(1)
  
          # 7) Create "Fake Stake" blocks and send them
          self.log.info("Creating Fake stake zPoS blocks...")
          err_msgs = self.test_spam("Main", mints, spending_utxo_list=spending_utxo_list, fZPoS=True)
  
          if not len(err_msgs) == 0:
              self.log.error("result: " + " | ".join(err_msgs))
              raise AssertionError("TEST FAILED")
  
          self.log.info("%s PASSED" % self.__class__.__name__)
  
  if __name__ == '__main__':
      zPoSFakeStake().main()
  