text: # Copyright (c) 2014 The Bitcoin Core developers
  # Copyright (c) 2014-2015 The Dash developers
  # Copyright (c) 2015-2018 The PIVX developers
  # Copyright (c) 2019 The BDRcoin developers
  # Distributed under the MIT/X11 software license, see the accompanying
  # file COPYING or http://www.opensource.org/licenses/mit-license.php.
  #
  # Helpful routines for regression testing
  #
  
  # Add python-bitcoinrpc to module search path:
  import os
  import sys
  sys.path.append(os.path.join(os.path.dirname(os.path.abspath(__file__)), "python-bitcoinrpc"))
  
  from decimal import Decimal, ROUND_DOWN
  import json
  import random
  import shutil
  import subprocess
  import time
  import re
  
  from bitcoinrpc.authproxy import AuthServiceProxy, JSONRPCException
  from util import *
  
  def p2p_port(n):
      return 11000 + n + os.getpid()%999
  def rpc_port(n):
      return 12000 + n + os.getpid()%999
  
  def check_json_precision():
      """Make sure json library being used does not lose precision converting BTC values"""
      n = Decimal("20000000.00000003")
      satoshis = int(json.loads(json.dumps(float(n)))*1.0e8)
      if satoshis != 2000000000000003:
          raise RuntimeError("JSON encode/decode loses precision")
  
  def sync_blocks(rpc_connections):
      """
      Wait until everybody has the same block count
      """
      while True:
          counts = [ x.getblockcount() for x in rpc_connections ]
          if counts == [ counts[0] ]*len(counts):
              break
          time.sleep(1)
  
  def sync_mempools(rpc_connections):
      """
      Wait until everybody has the same transactions in their memory
      pools
      """
      while True:
          pool = set(rpc_connections[0].getrawmempool())
          num_match = 1
          for i in range(1, len(rpc_connections)):
              if set(rpc_connections[i].getrawmempool()) == pool:
                  num_match = num_match+1
          if num_match == len(rpc_connections):
              break
          time.sleep(1)
  
  bitcoind_processes = {}
  
  def initialize_datadir(dirname, n):
      datadir = os.path.join(dirname, "node"+str(n))
      if not os.path.isdir(datadir):
          os.makedirs(datadir)
      with open(os.path.join(datadir, "bdrcoin.conf"), 'w') as f:
          f.write("regtest=1\n");
          f.write("rpcuser=rt\n");
          f.write("rpcpassword=rt\n");
          f.write("port="+str(p2p_port(n))+"\n");
          f.write("rpcport="+str(rpc_port(n))+"\n");
      return datadir
  
  def initialize_chain(test_dir):
      """
      Create (or copy from cache) a 200-block-long chain and
      4 wallets.
      bdrcoind and bdrcoin-cli must be in search path.
      """
  
      if not os.path.isdir(os.path.join("cache", "node0")):
          devnull = open("/dev/null", "w+")
          # Create cache directories, run bdrcoind:
          for i in range(4):
              datadir=initialize_datadir("cache", i)
              args = [ os.getenv("BITCOIND", "bdrcoind"), "-keypool=1", "-datadir="+datadir, "-discover=0" ]
              if i > 0:
                  args.append("-connect=127.0.0.1:"+str(p2p_port(0)))
              bitcoind_processes[i] = subprocess.Popen(args)
              subprocess.check_call([ os.getenv("BITCOINCLI", "bdrcoin-cli"), "-datadir="+datadir,
                                      "-rpcwait", "getblockcount"], stdout=devnull)
          devnull.close()
          rpcs = []
          for i in range(4):
              try:
                  url = "http://rt:rt@127.0.0.1:%d"%(rpc_port(i),)
                  rpcs.append(AuthServiceProxy(url))
              except:
                  sys.stderr.write("Error connecting to "+url+"\n")
                  sys.exit(1)
  
          # Create a 200-block-long chain; each of the 4 nodes
          # gets 25 mature blocks and 25 immature.
          # blocks are created with timestamps 10 minutes apart, starting
          # at 1 Jan 2014
          block_time = 1388534400
          for i in range(2):
              for peer in range(4):
                  for j in range(25):
                      set_node_times(rpcs, block_time)
                      rpcs[peer].setgenerate(True, 1)
                      block_time += 10*60
                  # Must sync before next peer starts generating blocks
                  sync_blocks(rpcs)
  
          # Shut them down, and clean up cache directories:
          stop_nodes(rpcs)
          wait_bitcoinds()
          for i in range(4):
              os.remove(log_filename("cache", i, "debug.log"))
              os.remove(log_filename("cache", i, "db.log"))
              os.remove(log_filename("cache", i, "peers.dat"))
              os.remove(log_filename("cache", i, "fee_estimates.dat"))
  
      for i in range(4):
          from_dir = os.path.join("cache", "node"+str(i))
          to_dir = os.path.join(test_dir,  "node"+str(i))
          shutil.copytree(from_dir, to_dir)
          initialize_datadir(test_dir, i) # Overwrite port/rpcport in bdrcoin.conf
  
  def initialize_chain_clean(test_dir, num_nodes):
      """
      Create an empty blockchain and num_nodes wallets.
      Useful if a test case wants complete control over initialization.
      """
      for i in range(num_nodes):
          datadir=initialize_datadir(test_dir, i)
  
  
  def _rpchost_to_args(rpchost):
      '''Convert optional IP:port spec to rpcconnect/rpcport args'''
      if rpchost is None:
          return []
  
      match = re.match('(\[[0-9a-fA-f:]+\]|[^:]+)(?::([0-9]+))?$', rpchost)
      if not match:
          raise ValueError('Invalid RPC host spec ' + rpchost)
  
      rpcconnect = match.group(1)
      rpcport = match.group(2)
  
      if rpcconnect.startswith('['): # remove IPv6 [...] wrapping
          rpcconnect = rpcconnect[1:-1]
  
      rv = ['-rpcconnect=' + rpcconnect]
      if rpcport:
          rv += ['-rpcport=' + rpcport]
      return rv
  
  def start_node(i, dirname, extra_args=None, rpchost=None):
      """
      Start a bdrcoind and return RPC connection to it
      """
      datadir = os.path.join(dirname, "node"+str(i))
      args = [ os.getenv("BITCOIND", "bdrcoind"), "-datadir="+datadir, "-keypool=1", "-discover=0", "-rest" ]
      if extra_args is not None: args.extend(extra_args)
      bitcoind_processes[i] = subprocess.Popen(args)
      devnull = open("/dev/null", "w+")
      subprocess.check_call([ os.getenv("BITCOINCLI", "bdrcoin-cli"), "-datadir="+datadir] +
                            _rpchost_to_args(rpchost)  +
                            ["-rpcwait", "getblockcount"], stdout=devnull)
      devnull.close()
      url = "http://rt:rt@%s:%d" % (rpchost or '127.0.0.1', rpc_port(i))
      proxy = AuthServiceProxy(url)
      proxy.url = url # store URL on proxy for info
      return proxy
  
  def start_nodes(num_nodes, dirname, extra_args=None, rpchost=None):
      """
      Start multiple bdrcoinds, return RPC connections to them
      """
      if extra_args is None: extra_args = [ None for i in range(num_nodes) ]
      return [ start_node(i, dirname, extra_args[i], rpchost) for i in range(num_nodes) ]
  
  def log_filename(dirname, n_node, logname):
      return os.path.join(dirname, "node"+str(n_node), "regtest", logname)
  
  def stop_node(node, i):
      node.stop()
      bitcoind_processes[i].wait()
      del bitcoind_processes[i]
  
  def stop_nodes(nodes):
      for node in nodes:
          node.stop()
      del nodes[:] # Emptying array closes connections as a side effect
  
  def set_node_times(nodes, t):
      for node in nodes:
          node.setmocktime(t)
  
  def wait_bitcoinds():
      # Wait for all bitcoinds to cleanly exit
      for bitcoind in bitcoind_processes.values():
          bitcoind.wait()
      bitcoind_processes.clear()
  
  def connect_nodes(from_connection, node_num):
      ip_port = "127.0.0.1:"+str(p2p_port(node_num))
      from_connection.addnode(ip_port, "onetry")
      # poll until version handshake complete to avoid race conditions
      # with transaction relaying
      while any(peer['version'] == 0 for peer in from_connection.getpeerinfo()):
          time.sleep(0.1)
  
  def connect_nodes_bi(nodes, a, b):
      connect_nodes(nodes[a], b)
      connect_nodes(nodes[b], a)
  
  def find_output(node, txid, amount):
      """
      Return index to output of txid with value amount
      Raises exception if there is none.
      """
      txdata = node.getrawtransaction(txid, 1)
      for i in range(len(txdata["vout"])):
          if txdata["vout"][i]["value"] == amount:
              return i
      raise RuntimeError("find_output txid %s : %s not found"%(txid,str(amount)))
  
  
  def gather_inputs(from_node, amount_needed, confirmations_required=1):
      """
      Return a random set of unspent txouts that are enough to pay amount_needed
      """
      assert(confirmations_required >=0)
      utxo = from_node.listunspent(confirmations_required)
      random.shuffle(utxo)
      inputs = []
      total_in = Decimal("0.00000000")
      while total_in < amount_needed and len(utxo) > 0:
          t = utxo.pop()
          total_in += t["amount"]
          inputs.append({ "txid" : t["txid"], "vout" : t["vout"], "address" : t["address"] } )
      if total_in < amount_needed:
          raise RuntimeError("Insufficient funds: need %d, have %d"%(amount_needed, total_in))
      return (total_in, inputs)
  
  def make_change(from_node, amount_in, amount_out, fee):
      """
      Create change output(s), return them
      """
      outputs = {}
      amount = amount_out+fee
      change = amount_in - amount
      if change > amount*2:
          # Create an extra change output to break up big inputs
          change_address = from_node.getnewaddress()
          # Split change in two, being careful of rounding:
          outputs[change_address] = Decimal(change/2).quantize(Decimal('0.00000001'), rounding=ROUND_DOWN)
          change = amount_in - amount - outputs[change_address]
      if change > 0:
          outputs[from_node.getnewaddress()] = change
      return outputs
  
  def send_zeropri_transaction(from_node, to_node, amount, fee):
      """
      Create&broadcast a zero-priority transaction.
      Returns (txid, hex-encoded-txdata)
      Ensures transaction is zero-priority by first creating a send-to-self,
      then using it's output
      """
  
      # Create a send-to-self with confirmed inputs:
      self_address = from_node.getnewaddress()
      (total_in, inputs) = gather_inputs(from_node, amount+fee*2)
      outputs = make_change(from_node, total_in, amount+fee, fee)
      outputs[self_address] = float(amount+fee)
  
      self_rawtx = from_node.createrawtransaction(inputs, outputs)
      self_signresult = from_node.signrawtransaction(self_rawtx)
      self_txid = from_node.sendrawtransaction(self_signresult["hex"], True)
  
      vout = find_output(from_node, self_txid, amount+fee)
      # Now immediately spend the output to create a 1-input, 1-output
      # zero-priority transaction:
      inputs = [ { "txid" : self_txid, "vout" : vout } ]
      outputs = { to_node.getnewaddress() : float(amount) }
  
      rawtx = from_node.createrawtransaction(inputs, outputs)
      signresult = from_node.signrawtransaction(rawtx)
      txid = from_node.sendrawtransaction(signresult["hex"], True)
  
      return (txid, signresult["hex"])
  
  def random_zeropri_transaction(nodes, amount, min_fee, fee_increment, fee_variants):
      """
      Create a random zero-priority transaction.
      Returns (txid, hex-encoded-transaction-data, fee)
      """
      from_node = random.choice(nodes)
      to_node = random.choice(nodes)
      fee = min_fee + fee_increment*random.randint(0,fee_variants)
      (txid, txhex) = send_zeropri_transaction(from_node, to_node, amount, fee)
      return (txid, txhex, fee)
  
  def random_transaction(nodes, amount, min_fee, fee_increment, fee_variants):
      """
      Create a random transaction.
      Returns (txid, hex-encoded-transaction-data, fee)
      """
      from_node = random.choice(nodes)
      to_node = random.choice(nodes)
      fee = min_fee + fee_increment*random.randint(0,fee_variants)
  
      (total_in, inputs) = gather_inputs(from_node, amount+fee)
      outputs = make_change(from_node, total_in, amount, fee)
      outputs[to_node.getnewaddress()] = float(amount)
  
      rawtx = from_node.createrawtransaction(inputs, outputs)
      signresult = from_node.signrawtransaction(rawtx)
      txid = from_node.sendrawtransaction(signresult["hex"], True)
  
      return (txid, signresult["hex"], fee)
  
  def assert_equal(thing1, thing2):
      if thing1 != thing2:
          raise AssertionError("%s != %s"%(str(thing1),str(thing2)))
  
  def assert_greater_than(thing1, thing2):
      if thing1 <= thing2:
          raise AssertionError("%s <= %s"%(str(thing1),str(thing2)))
  
  def assert_raises(exc, fun, *args, **kwds):
      try:
          fun(*args, **kwds)
      except exc:
          pass
      except Exception as e:
          raise AssertionError("Unexpected exception raised: "+type(e).__name__)
      else:
          raise AssertionError("No exception raised")
  