text: #!/usr/bin/env python
  #
  # Electrum - lightweight Bitcoin client
  # Copyright (C) 2014 Thomas Voegtlin
  #
  # Permission is hereby granted, free of charge, to any person
  # obtaining a copy of this software and associated documentation files
  # (the "Software"), to deal in the Software without restriction,
  # including without limitation the rights to use, copy, modify, merge,
  # publish, distribute, sublicense, and/or sell copies of the Software,
  # and to permit persons to whom the Software is furnished to do so,
  # subject to the following conditions:
  #
  # The above copyright notice and this permission notice shall be
  # included in all copies or substantial portions of the Software.
  #
  # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  # EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  # MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  # BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  # ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  # CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  # SOFTWARE.
  import asyncio
  import hashlib
  from typing import Dict, List, TYPE_CHECKING, Tuple
  from collections import defaultdict
  import logging
  import json
  
  from aiorpcx import TaskGroup, run_in_thread, RPCError
  
  from .transaction import Transaction
  from .util import bh2u, make_aiohttp_session, NetworkJobOnDefaultServer
  from .bitcoin import address_to_scripthash, is_address
  from .network import UntrustedServerReturnedError
  from .logging import Logger
  from .interface import GracefulDisconnect
  
  if TYPE_CHECKING:
      from .network import Network
      from .address_synchronizer import AddressSynchronizer
  
  OUTCOME = {
      1 : "Money Line Home",
      2 : "Money Line Away",
      3 : "Money Line Draw",
      4 : "Home to Cover Spread",
      5 : "Away to Cover Spread",
      6 : "Total Over",
      7 : "Total Under"
  }
  
  class SynchronizerFailure(Exception): pass
  
  
  def history_status(h):
      if not h:
          return None
      status = ''
      for tx_hash, height in h:
          status += tx_hash + ':%d:' % height
      return bh2u(hashlib.sha256(status.encode('ascii')).digest())
  
  
  class SynchronizerBase(NetworkJobOnDefaultServer):
      """Subscribe over the network to a set of addresses, and monitor their statuses.
      Every time a status changes, run a coroutine provided by the subclass.
      """
      def __init__(self, network: 'Network'):
          self.asyncio_loop = network.asyncio_loop
          NetworkJobOnDefaultServer.__init__(self, network)
          self._reset_request_counters()
  
      def _reset(self):
          super()._reset()
          self.requested_addrs = set()
          self.scripthash_to_address = {}
          self._processed_some_notifications = False  # so that we don't miss them
          self._reset_request_counters()
          # Queues
          self.add_queue = asyncio.Queue()
          self.status_queue = asyncio.Queue()
  
      async def _start_tasks(self):
          try:
              async with self.group as group:
                  await group.spawn(self.send_subscriptions())
                  await group.spawn(self.handle_status())
                  await group.spawn(self.main())
          finally:
              # we are being cancelled now
              self.session.unsubscribe(self.status_queue)
  
      def _reset_request_counters(self):
          self._requests_sent = 0
          self._requests_answered = 0
  
      def add(self, addr):
          asyncio.run_coroutine_threadsafe(self._add_address(addr), self.asyncio_loop)
  
      async def _add_address(self, addr: str):
          if not is_address(addr): raise ValueError(f"invalid Wagerr address {addr}")
          if addr in self.requested_addrs: return
          self.requested_addrs.add(addr)
          await self.add_queue.put(addr)
  
      async def _on_address_status(self, addr, status):
          """Handle the change of the status of an address."""
          raise NotImplementedError()  # implemented by subclasses
  
      async def send_subscriptions(self):
          async def subscribe_to_address(addr):
              h = address_to_scripthash(addr)
              self.scripthash_to_address[h] = addr
              self._requests_sent += 1
              try:
                  await self.session.subscribe('blockchain.scripthash.subscribe', [h], self.status_queue)
              except RPCError as e:
                  if e.message == 'history too large':  # no unique error code
                      raise GracefulDisconnect(e, log_level=logging.ERROR) from e
                  raise
              self._requests_answered += 1
              self.requested_addrs.remove(addr)
  
          while True:
              addr = await self.add_queue.get()
              await self.group.spawn(subscribe_to_address, addr)
  
      async def handle_status(self):
          while True:
              h, status = await self.status_queue.get()
              addr = self.scripthash_to_address[h]
              await self.group.spawn(self._on_address_status, addr, status)
              self._processed_some_notifications = True
  
      def num_requests_sent_and_answered(self) -> Tuple[int, int]:
          return self._requests_sent, self._requests_answered
  
      async def main(self):
          raise NotImplementedError()  # implemented by subclasses
  
  
  class Synchronizer(SynchronizerBase):
      '''The synchronizer keeps the wallet up-to-date with its set of
      addresses and their transactions.  It subscribes over the network
      to wallet addresses, gets the wallet to generate new addresses
      when necessary, requests the transaction history of any addresses
      we don't have the full history of, and requests binary transaction
      data of any transactions the wallet doesn't have.
      '''
      def __init__(self, wallet: 'AddressSynchronizer'):
          self.wallet = wallet
          SynchronizerBase.__init__(self, wallet.network)
  
      def _reset(self):
          super()._reset()
          self.requested_tx = {}
          self.requested_histories = set()
  
      def diagnostic_name(self):
          return self.wallet.diagnostic_name()
  
      def is_up_to_date(self):
          return (not self.requested_addrs
                  and not self.requested_histories
                  and not self.requested_tx)
  
      async def _on_address_status(self, addr, status):
          history = self.wallet.db.get_addr_history(addr)
          if history_status(history) == status:
              return
          if (addr, status) in self.requested_histories:
              return
          # request address history
          self.requested_histories.add((addr, status))
          h = address_to_scripthash(addr)
          self._requests_sent += 1
          result = await self.network.get_history_for_scripthash(h)
          self._requests_answered += 1
          self.logger.info(f"receiving history {addr} {len(result)}")
          hashes = set(map(lambda item: item['tx_hash'], result))
          hist = list(map(lambda item: (item['tx_hash'], item['height']), result))
          # tx_fees
          tx_fees = [(item['tx_hash'], item.get('fee')) for item in result]
          tx_fees = dict(filter(lambda x:x[1] is not None, tx_fees))
          # Check that txids are unique
          if len(hashes) != len(result):
              self.logger.info(f"error: server history has non-unique txids: {addr}")
          # Check that the status corresponds to what was announced
          elif history_status(hist) != status:
              self.logger.info(f"error: status mismatch: {addr}")
          else:
              # Store received history
              self.wallet.receive_history_callback(addr, hist, tx_fees)
              # Request transactions we don't have
              await self._request_missing_txs(hist)
  
          # Remove request; this allows up_to_date to be True
          self.requested_histories.discard((addr, status))
  
      async def _request_missing_txs(self, hist, *, allow_server_not_finding_tx=False):
          # "hist" is a list of [tx_hash, tx_height] lists
          transaction_hashes = []
          for tx_hash, tx_height in hist:
              if tx_hash in self.requested_tx:
                  continue
              if self.wallet.db.get_transaction(tx_hash):
                  continue
              transaction_hashes.append(tx_hash)
              self.requested_tx[tx_hash] = tx_height
  
          if not transaction_hashes: return
          async with TaskGroup() as group:
              for tx_hash in transaction_hashes:
                  await group.spawn(self._get_transaction(tx_hash, allow_server_not_finding_tx=allow_server_not_finding_tx))
  
      async def _get_transaction(self, tx_hash, *, allow_server_not_finding_tx=False):
          self._requests_sent += 1
          
          try:
              result = await self.network.get_transaction(tx_hash)
          except UntrustedServerReturnedError as e:
              # most likely, "No such mempool or blockchain transaction"
              if allow_server_not_finding_tx:
                  self.requested_tx.pop(tx_hash)
                  return
              else:
                  raise
          finally:
              self._requests_answered += 1
          tx = Transaction(result)
          print("tx_hash",tx_hash)
          print("tx.txid",tx.txid())
          try:
              tx.deserialize()  # see if raises
          except Exception as e:
              # possible scenarios:
              # 1: server is sending garbage
              # 2: there is a bug in the deserialization code
              # 3: there was a segwit-like upgrade that changed the tx structure
              #    that we don't know about
              raise SynchronizerFailure(f"cannot deserialize transaction {tx_hash}") from e
  
          # if tx_hash != tx.txid():
          #     raise SynchronizerFailure(f"received tx does not match expected txid ({tx_hash} != {tx.txid()})")
          tx_height = self.requested_tx.pop(tx_hash)
          self.wallet.receive_tx_callback(tx_hash, tx, tx_height)
          
          self.logger.info(f"received tx {tx_hash} height: {tx_height} bytes: {len(tx.raw)}")
          # callbacks
          self.wallet.network.trigger_callback('new_transaction', self.wallet, tx)
  
      async def main(self):
          self.wallet.set_up_to_date(False)
          # request missing txns, if any
          for addr in self.wallet.db.get_history():
              history = self.wallet.db.get_addr_history(addr)
              # Old electrum servers returned ['*'] when all history for the address
              # was pruned. This no longer happens but may remain in old wallets.
              if history == ['*']: continue
              await self._request_missing_txs(history, allow_server_not_finding_tx=True)
          # add addresses to bootstrap
          for addr in self.wallet.get_addresses():
              await self._add_address(addr)
          # main loop
          while True:
              await asyncio.sleep(0.1)
              await run_in_thread(self.wallet.synchronize)
              up_to_date = self.is_up_to_date()
              if (up_to_date != self.wallet.is_up_to_date()
                      or up_to_date and self._processed_some_notifications):
                  self._processed_some_notifications = False
                  if up_to_date:
                      self._reset_request_counters()
                  self.wallet.set_up_to_date(up_to_date)
                  self.wallet.network.trigger_callback('wallet_updated', self.wallet)
  
  
  class Notifier(SynchronizerBase):
      """Watch addresses. Every time the status of an address changes,
      an HTTP POST is sent to the corresponding URL.
      """
      def __init__(self, network):
          SynchronizerBase.__init__(self, network)
          self.watched_addresses = defaultdict(list)  # type: Dict[str, List[str]]
          self.start_watching_queue = asyncio.Queue()
  
      async def main(self):
          # resend existing subscriptions if we were restarted
          for addr in self.watched_addresses:
              await self._add_address(addr)
          # main loop
          while True:
              addr, url = await self.start_watching_queue.get()
              self.watched_addresses[addr].append(url)
              await self._add_address(addr)
  
      async def _on_address_status(self, addr, status):
          self.logger.info(f'new status for addr {addr}')
          headers = {'content-type': 'application/json'}
          data = {'address': addr, 'status': status}
          for url in self.watched_addresses[addr]:
              try:
                  async with make_aiohttp_session(proxy=self.network.proxy, headers=headers) as session:
                      async with session.post(url, json=data, headers=headers) as resp:
                          await resp.text()
              except Exception as e:
                  self.logger.info(str(e))
              else:
                  self.logger.info(f'Got Response for {addr}')
  