basicswap_miserver/basicswap/basicswap.py

# -*- coding: utf-8 -*-

# Copyright (c) 2019 tecnovert
# Distributed under the MIT software license, see the accompanying
# file LICENSE.txt or http://www.opensource.org/licenses/mit-license.php.

import os
import re
import time
import datetime as dt
import zmq
import threading
import traceback
import hashlib
import subprocess
import logging
import sqlalchemy as sa
import shutil
import json
import random
import secrets
from sqlalchemy.orm import sessionmaker, scoped_session
from enum import IntEnum, auto

from . import __version__
from .util import (
    COIN,
    callrpc,
    pubkeyToAddress,
    format8,
    encodeAddress,
    decodeAddress,
    SerialiseNum,
    DeserialiseNum,
    decodeWif,
    toWIF,
    getKeyID,
    makeInt,
)
from .chainparams import (
    chainparams,
    Coins,
)
from .messages_pb2 import (
    OfferMessage,
    BidMessage,
    BidAcceptMessage,
)
from .db import (
    CURRENT_DB_VERSION,
    Base,
    DBKVInt,
    DBKVString,
    Offer,
    Bid,
    SwapTx,
    PooledAddress,
    SentOffer,
    SmsgAddress,
    EventQueue,
)

from .explorers import ExplorerInsight, ExplorerBitAps, ExplorerChainz
import basicswap.config as cfg
import basicswap.segwit_addr as segwit_addr


DEBUG = True


MIN_OFFER_VALID_TIME = 60 * 10
MAX_OFFER_VALID_TIME = 60 * 60 * 48
MIN_BID_VALID_TIME = 60 * 10
MAX_BID_VALID_TIME = 60 * 60 * 48


class MessageTypes(IntEnum):
    OFFER = auto()
    BID = auto()
    BID_ACCEPT = auto()


class SwapTypes(IntEnum):
    SELLER_FIRST = auto()
    BUYER_FIRST = auto()
    SELLER_FIRST_2MSG = auto()
    BUYER_FIRST_2MSG = auto()


class OfferStates(IntEnum):
    OFFER_SENT = auto()
    OFFER_RECEIVED = auto()
    OFFER_ABANDONED = auto()


class BidStates(IntEnum):
    BID_SENT = auto()
    BID_RECEIVED = auto()
    BID_ACCEPTED = auto()           # BidAcceptMessage received/sent
    SWAP_INITIATED = auto()         # Initiate txn validated
    SWAP_PARTICIPATING = auto()     # Participate txn validated
    SWAP_COMPLETED = auto()         # All swap txns spent
    SWAP_TIMEDOUT = auto()
    BID_ABANDONED = auto()          # Bid will no longer be processed
    BID_ERROR = auto()              # An error occurred


class TxStates(IntEnum):
    TX_NONE = auto()
    TX_SENT = auto()
    TX_CONFIRMED = auto()
    TX_REDEEMED = auto()
    TX_REFUNDED = auto()


class OpCodes(IntEnum):
    OP_0 = 0x00,
    OP_PUSHDATA1 = 0x4c,
    OP_1 = 0x51,
    OP_IF = 0x63,
    OP_ELSE = 0x67,
    OP_ENDIF = 0x68,
    OP_DROP = 0x75,
    OP_DUP = 0x76,
    OP_SIZE = 0x82,
    OP_EQUAL = 0x87,
    OP_EQUALVERIFY = 0x88,
    OP_SHA256 = 0xa8,
    OP_HASH160 = 0xa9,
    OP_CHECKSIG = 0xac,
    OP_CHECKLOCKTIMEVERIFY = 0xb1,
    OP_CHECKSEQUENCEVERIFY = 0xb2,


class TxTypes(IntEnum):
    ITX = auto()
    PTX = auto()
    ITX_REDEEM = auto()
    ITX_REFUND = auto()
    PTX_REDEEM = auto()
    PTX_REFUND = auto()


class EventTypes(IntEnum):
    ACCEPT_BID = auto()


SEQUENCE_LOCK_BLOCKS = 1
SEQUENCE_LOCK_TIME = 2
ABS_LOCK_BLOCKS = 3
ABS_LOCK_TIME = 4

SEQUENCE_LOCKTIME_GRANULARITY = 9  # 512 seconds
SEQUENCE_LOCKTIME_TYPE_FLAG = (1 << 22)
SEQUENCE_LOCKTIME_MASK = 0x0000ffff
INITIATE_TX_TIMEOUT = 40 * 60  # TODO: make variable per coin


def strOfferState(state):
    if state == OfferStates.OFFER_SENT:
        return 'Sent'
    if state == OfferStates.OFFER_RECEIVED:
        return 'Received'
    if state == OfferStates.OFFER_ABANDONED:
        return 'Abandoned'
    return 'Unknown'


def strBidState(state):
    if state == BidStates.BID_SENT:
        return 'Sent'
    if state == BidStates.BID_RECEIVED:
        return 'Received'
    if state == BidStates.BID_ACCEPTED:
        return 'Accepted'
    if state == BidStates.SWAP_INITIATED:
        return 'Initiated'
    if state == BidStates.SWAP_PARTICIPATING:
        return 'Participating'
    if state == BidStates.SWAP_COMPLETED:
        return 'Completed'
    if state == BidStates.SWAP_TIMEDOUT:
        return 'Timed-out'
    if state == BidStates.BID_ABANDONED:
        return 'Abandoned'
    if state == BidStates.BID_ERROR:
        return 'Error'
    return 'Unknown'


def strTxState(state):
    if state == TxStates.TX_NONE:
        return 'None'
    if state == TxStates.TX_SENT:
        return 'Sent'
    if state == TxStates.TX_CONFIRMED:
        return 'Confirmed'
    if state == TxStates.TX_REDEEMED:
        return 'Redeemed'
    if state == TxStates.TX_REFUNDED:
        return 'Refunded'
    return 'Unknown'


def getLockName(lock_type):
    if lock_type == SEQUENCE_LOCK_BLOCKS:
        return 'Sequence lock, blocks'
    if lock_type == SEQUENCE_LOCK_TIME:
        return 'Sequence lock, time'
    if lock_type == ABS_LOCK_BLOCKS:
        return 'blocks'
    if lock_type == ABS_LOCK_TIME:
        return 'time'


def getExpectedSequence(lockType, lockVal, coin_type):
    assert(lockVal >= 1), 'Bad lockVal'
    if lockType == SEQUENCE_LOCK_BLOCKS:
        return lockVal
    if lockType == SEQUENCE_LOCK_TIME:
        secondsLocked = lockVal
        # Ensure the locked time is never less than lockVal
        if secondsLocked % (1 << SEQUENCE_LOCKTIME_GRANULARITY) != 0:
            secondsLocked += (1 << SEQUENCE_LOCKTIME_GRANULARITY)
        secondsLocked >>= SEQUENCE_LOCKTIME_GRANULARITY
        return secondsLocked | SEQUENCE_LOCKTIME_TYPE_FLAG
    raise ValueError('Unknown lock type')


def decodeSequence(lock_value):
    # Return the raw value
    if lock_value & SEQUENCE_LOCKTIME_TYPE_FLAG:
        return (lock_value & SEQUENCE_LOCKTIME_MASK) << SEQUENCE_LOCKTIME_GRANULARITY
    return lock_value & SEQUENCE_LOCKTIME_MASK


def buildContractScript(lock_val, secret_hash, pkh_redeem, pkh_refund, op_lock=OpCodes.OP_CHECKSEQUENCEVERIFY):
    script = bytearray([
        OpCodes.OP_IF,
        OpCodes.OP_SIZE,
        0x01, 0x20,  # 32
        OpCodes.OP_EQUALVERIFY,
        OpCodes.OP_SHA256,
        0x20]) \
        + secret_hash \
        + bytearray([
            OpCodes.OP_EQUALVERIFY,
            OpCodes.OP_DUP,
            OpCodes.OP_HASH160,
            0x14]) \
        + pkh_redeem \
        + bytearray([OpCodes.OP_ELSE, ]) \
        + SerialiseNum(lock_val) \
        + bytearray([
            op_lock,
            OpCodes.OP_DROP,
            OpCodes.OP_DUP,
            OpCodes.OP_HASH160,
            0x14]) \
        + pkh_refund \
        + bytearray([
            OpCodes.OP_ENDIF,
            OpCodes.OP_EQUALVERIFY,
            OpCodes.OP_CHECKSIG])
    return script


def extractScriptSecretHash(script):
    return script[7:39]


def getVoutByAddress(txjs, p2sh):
    for o in txjs['vout']:
        try:
            if p2sh in o['scriptPubKey']['addresses']:
                return o['n']
        except Exception:
            pass
    raise ValueError('Address output not found in txn')


def getVoutByP2WSH(txjs, p2wsh_hex):
    for o in txjs['vout']:
        try:
            if p2wsh_hex == o['scriptPubKey']['hex']:
                return o['n']
        except Exception:
            pass
    raise ValueError('P2WSH output not found in txn')


def getP2SHScriptForHash(p2sh):
    return bytearray([OpCodes.OP_HASH160, 0x14]) \
        + p2sh \
        + bytearray([OpCodes.OP_EQUAL])


def getP2WSH(script):
    return bytearray([OpCodes.OP_0, 0x20]) + hashlib.sha256(script).digest()


def replaceAddrPrefix(addr, coin_type, chain_name, addr_type='pubkey_address'):
    return encodeAddress(bytes((chainparams[coin_type][chain_name][addr_type],)) + decodeAddress(addr)[1:])


class BasicSwap():
    def __init__(self, fp, data_dir, settings, chain, log_name='BasicSwap'):
        self.log_name = log_name
        self.fp = fp
        self.is_running = True
        self.fail_code = 0

        self.data_dir = data_dir
        self.chain = chain
        self.settings = settings
        self.coin_clients = {}
        self.mxDB = threading.RLock()
        self.debug = self.settings.get('debug', DEBUG)

        self.check_progress_seconds = self.settings.get('check_progress_seconds', 60)
        self.check_watched_seconds = self.settings.get('check_watched_seconds', 60)
        self.check_expired_seconds = self.settings.get('check_expired_seconds', 60 * 5)
        self.check_events_seconds = self.settings.get('check_events_seconds', 10)
        self.last_checked_progress = 0
        self.last_checked_watched = 0
        self.last_checked_expired = 0
        self.last_checked_events = 0

        # TODO: Adjust ranges
        self.min_delay_auto_accept = self.settings.get('min_delay_auto_accept', 10)
        self.max_delay_auto_accept = self.settings.get('max_delay_auto_accept', 60)

        self.swaps_in_progress = dict()

        if self.chain == 'regtest':
            self.SMSG_SECONDS_IN_DAY = 600
            self.SMSG_SECONDS_IN_HOUR = 60 * 2
        else:
            self.SMSG_SECONDS_IN_DAY = 86400
            self.SMSG_SECONDS_IN_HOUR = 60 * 60

        self.prepareLogging()
        self.log.info('Network: {}'.format(self.chain))

        # Encode key to match network
        wif_prefix = chainparams[Coins.PART][self.chain]['key_prefix']
        self.network_key = toWIF(wif_prefix, decodeWif(self.settings['network_key']))

        self.network_pubkey = self.settings['network_pubkey']
        self.network_addr = pubkeyToAddress(chainparams[Coins.PART][self.chain]['pubkey_address'], bytearray.fromhex(self.network_pubkey))
        self.wallet = self.settings.get('wallet', None)  # TODO: Move to coin_clients

        self.sqlite_file = os.path.join(self.data_dir, 'db{}.sqlite'.format('' if self.chain == 'mainnet' else ('_' + self.chain)))
        db_exists = os.path.exists(self.sqlite_file)
        self.engine = sa.create_engine('sqlite:///' + self.sqlite_file)
        if not db_exists:
            Base.metadata.create_all(self.engine)
        self.session_factory = sessionmaker(bind=self.engine, expire_on_commit=False)

        session = scoped_session(self.session_factory)
        try:
            self.db_version = session.query(DBKVInt).filter_by(key='db_version').first().value
        except Exception:
            self.log.info('First run')
            self.db_version = CURRENT_DB_VERSION
            session.add(DBKVInt(
                key='db_version',
                value=self.db_version
            ))
            session.commit()
        try:
            self._contract_count = session.query(DBKVInt).filter_by(key='contract_count').first().value
        except Exception:
            self._contract_count = 0
        session.close()
        session.remove()

        self.zmqContext = zmq.Context()
        self.zmqSubscriber = self.zmqContext.socket(zmq.SUB)

        self.zmqSubscriber.connect(self.settings['zmqhost'] + ':' + str(self.settings['zmqport']))
        self.zmqSubscriber.setsockopt_string(zmq.SUBSCRIBE, 'smsg')

        for c in Coins:
            self.setCoinConnectParams(c)

        if self.chain == 'mainnet':
            self.coin_clients[Coins.PART]['explorers'].append(ExplorerInsight(
                self, Coins.PART,
                'https://explorer.particl.io/particl-insight-api'))
            self.coin_clients[Coins.LTC]['explorers'].append(ExplorerBitAps(
                self, Coins.LTC,
                'https://api.bitaps.com/ltc/v1/blockchain'))
            self.coin_clients[Coins.LTC]['explorers'].append(ExplorerChainz(
                self, Coins.LTC,
                'http://chainz.cryptoid.info/ltc/api.dws'))
        elif self.chain == 'testnet':
            self.coin_clients[Coins.PART]['explorers'].append(ExplorerInsight(
                self, Coins.PART,
                'https://explorer-testnet.particl.io/particl-insight-api'))
            self.coin_clients[Coins.LTC]['explorers'].append(ExplorerBitAps(
                self, Coins.LTC,
                'https://api.bitaps.com/ltc/testnet/v1/blockchain'))

            # non-segwit
            # https://testnet.litecore.io/insight-api

        random.seed(secrets.randbits(128))

    def prepareLogging(self):
        self.log = logging.getLogger(self.log_name)
        self.log.propagate = False

        formatter = logging.Formatter('%(asctime)s %(levelname)s : %(message)s')
        stream_stdout = logging.StreamHandler()
        if self.log_name != 'BasicSwap':
            stream_stdout.setFormatter(logging.Formatter('%(asctime)s %(name)s %(levelname)s : %(message)s'))
        else:
            stream_stdout.setFormatter(formatter)
        stream_fp = logging.StreamHandler(self.fp)
        stream_fp.setFormatter(formatter)

        self.log.setLevel(logging.DEBUG if self.debug else logging.INFO)
        self.log.addHandler(stream_fp)
        self.log.addHandler(stream_stdout)

    def getChainClientSettings(self, coin):
        try:
            return self.settings['chainclients'][chainparams[coin]['name']]
        except Exception:
            return {}

    def setCoinConnectParams(self, coin):
        # Set anything that does not require the daemon to be running
        chain_client_settings = self.getChainClientSettings(coin)

        bindir = os.path.expanduser(chain_client_settings.get('bindir', ''))
        datadir = os.path.expanduser(chain_client_settings.get('datadir', os.path.join(cfg.DATADIRS, chainparams[coin]['name'])))

        connection_type = chain_client_settings.get('connection_type', 'none')
        rpcauth = None
        if connection_type == 'rpc':
            if 'rpcauth' in chain_client_settings:
                rpcauth = chain_client_settings['rpcauth']
                self.log.debug('Read %s rpc credentials from json settings', coin)
            elif 'rpcpassword' in chain_client_settings:
                rpcauth = chain_client_settings['rpcuser'] + ':' + chain_client_settings['rpcpassword']
                self.log.debug('Read %s rpc credentials from json settings', coin)

        session = scoped_session(self.session_factory)
        try:
            last_height_checked = session.query(DBKVInt).filter_by(key='last_height_checked_' + chainparams[coin]['name']).first().value
        except Exception:
            last_height_checked = 0
        session.close()
        session.remove()

        self.coin_clients[coin] = {
            'coin': coin,
            'name': chainparams[coin]['name'],
            'connection_type': connection_type,
            'bindir': bindir,
            'datadir': datadir,
            'rpcport': chain_client_settings.get('rpcport', chainparams[coin][self.chain]['rpcport']),
            'rpcauth': rpcauth,
            'blocks_confirmed': chain_client_settings.get('blocks_confirmed', 6),
            'conf_target': chain_client_settings.get('conf_target', 2),
            'watched_outputs': [],
            'last_height_checked': last_height_checked,
            'use_segwit': chain_client_settings.get('use_segwit', False),
            'use_csv': chain_client_settings.get('use_csv', True),
            'core_version_group': chain_client_settings.get('core_version_group', 0),
            'pid': None,
            'core_version': None,
            'explorers': [],
            'chain_lookups': chain_client_settings.get('chain_lookups', 'local'),
        }

    def setDaemonPID(self, name, pid):
        if isinstance(name, Coins):
            self.coin_clients[name]['pid'] = pid
            return
        for c, v in self.coin_clients.items():
            if v['name'] == name:
                v['pid'] = pid

    def getChainDatadirPath(self, coin):
        datadir = self.coin_clients[coin]['datadir']
        testnet_name = '' if self.chain == 'mainnet' else chainparams[coin][self.chain].get('name', self.chain)
        return os.path.join(datadir, testnet_name)

    def setCoinRunParams(self, coin):
        cc = self.coin_clients[coin]
        if cc['connection_type'] == 'rpc' and cc['rpcauth'] is None:
            chain_client_settings = self.getChainClientSettings(coin)
            authcookiepath = os.path.join(self.getChainDatadirPath(coin), '.cookie')

            pidfilename = cc['name']
            if cc['name'] == 'bitcoin' or cc['name'] == 'namecoin':
                pidfilename += 'd'
            pidfilepath = os.path.join(self.getChainDatadirPath(coin), pidfilename + '.pid')
            self.log.debug('Reading %s rpc credentials from auth cookie %s', coin, authcookiepath)
            # Wait for daemon to start
            # Test pids to ensure authcookie is read for the correct process
            datadir_pid = -1
            for i in range(20):
                try:
                    with open(pidfilepath, 'rb') as fp:
                        datadir_pid = int(fp.read().decode('utf-8'))
                    assert(datadir_pid == cc['pid'])
                    assert(os.path.exists(authcookiepath))
                except Exception:
                    time.sleep(0.5)
            try:
                if os.name != 'nt' or cc['core_version_group'] > 17:  # litecoin on windows doesn't write a pid file
                    assert(datadir_pid == cc['pid'])
                with open(authcookiepath, 'rb') as fp:
                    cc['rpcauth'] = fp.read().decode('utf-8')
            except Exception:
                self.log.error('Unable to read authcookie for %s, %s, datadir pid %d, daemon pid %s', str(coin), authcookiepath, datadir_pid, cc['pid'])
                raise ValueError('Error, terminating')

    def start(self):
        self.log.info('Starting BasicSwap %s\n\n', __version__)
        self.log.info('sqlalchemy version %s', sa.__version__)

        self.upgradeDatabase(self.db_version)

        for c in Coins:
            self.setCoinRunParams(c)
            if self.coin_clients[c]['connection_type'] == 'rpc':
                self.waitForDaemonRPC(c)
                core_version = self.callcoinrpc(c, 'getnetworkinfo')['version']
                self.log.info('%s Core version %d', chainparams[c]['name'].capitalize(), core_version)
                self.coin_clients[c]['core_version'] = core_version

                # Sanity checks
                if c == Coins.PART:
                    if self.callcoinrpc(c, 'getstakinginfo')['enabled'] is not False:
                        self.log.warning('%s staking is not disabled.', chainparams[c]['name'].capitalize())

        self.initialise()

    def stopDaemon(self, coin):
        num_tries = 10
        authcookiepath = os.path.join(self.getChainDatadirPath(coin), '.cookie')
        stopping = False
        try:
            for i in range(num_tries):
                rv = self.callcoincli(coin, 'stop', timeout=10)
                self.log.debug('Trying to stop %s', str(coin))
                stopping = True
                time.sleep(i + 1)
        except Exception as ex:
            if 'Could not connect' in str(ex):
                if stopping:
                    for i in range(30):
                        # The lock file doesn't get deleted
                        # Using .cookie is a temporary workaround, will only work if rpc password is unset.
                        # TODO: Query lock on .lock properly
                        if os.path.exists(authcookiepath):
                            self.log.debug('Waiting on .cookie file %s', str(coin))
                            time.sleep(i + 1)
                    time.sleep(4)  # Extra time to settle
                return
            self.log.error('stopDaemon %s', str(ex))
            traceback.print_exc()
        raise ValueError('Could not stop {}'.format(str(coin)))

    def stopDaemons(self):
        for c in Coins:
            chain_client_settings = self.getChainClientSettings(c)
            if self.coin_clients[c]['connection_type'] == 'rpc' and chain_client_settings['manage_daemon'] is True:
                self.stopDaemon(c)

    def stopRunning(self, with_code=0):
        self.fail_code = with_code
        self.is_running = False

    def upgradeDatabase(self, db_version):
        if db_version >= CURRENT_DB_VERSION:
            return

        self.log.info('Upgrading Database from version %d to %d.', db_version, CURRENT_DB_VERSION)

        raise ValueError('Scripted database upgrade not found.')

    def waitForDaemonRPC(self, coin_type):
        for i in range(21):
            if not self.is_running:
                return
            try:
                self.callcoinrpc(coin_type, 'getwalletinfo', [], self.wallet)
                return
            except Exception as ex:
                self.log.warning('Can\'t connect to %s RPC: %s.  Trying again in %d second/s.', coin_type, str(ex), (1 + i))
                time.sleep(1 + i)
        self.log.error('Can\'t connect to %s RPC, exiting.', coin_type)
        self.stopRunning(1)  # systemd will try restart if fail_code != 0

    def checkSynced(self, coin_from, coin_to):
        check_coins = [coin_from, coin_to]
        for c in check_coins:
            if self.coin_clients[c]['connection_type'] != 'rpc':
                continue
                synced = round(self.callcoinrpc(c, 'getblockchaininfo')['verificationprogress'], 3)
                if synced < 1.0:
                    raise ValueError('{} chain is still syncing, currently at {}.'.format(synced))

    def setIntKV(self, str_key, int_val):
        session = scoped_session(self.session_factory)
        kv = session.query(DBKVInt).filter_by(key=str_key).first()
        if not kv:
            kv = DBKVInt(key=str_key, value=int_val)
        session.add(kv)
        session.commit()
        session.close()
        session.remove()

    def activateBid(self, session, bid):
        if bid.bid_id in self.swaps_in_progress:
            self.log.debug('Bid %s is already in progress', bid.bid_id.hex())

        self.log.debug('Loading active bid %s', bid.bid_id.hex())

        offer = session.query(Offer).filter_by(offer_id=bid.offer_id).first()
        assert(offer), 'Offer not found'

        bid.initiate_tx = session.query(SwapTx).filter(sa.and_(SwapTx.bid_id == bid.bid_id, SwapTx.tx_type == TxTypes.ITX)).first()
        bid.participate_tx = session.query(SwapTx).filter(sa.and_(SwapTx.bid_id == bid.bid_id, SwapTx.tx_type == TxTypes.PTX)).first()

        self.swaps_in_progress[bid.bid_id] = (bid, offer)

        coin_from = Coins(offer.coin_from)
        coin_to = Coins(offer.coin_to)
        if bid.initiate_tx and bid.initiate_tx.txid:
            self.addWatchedOutput(coin_from, bid.bid_id, bid.initiate_tx.txid.hex(), bid.initiate_tx.vout, BidStates.SWAP_INITIATED)
        if bid.participate_tx and bid.participate_tx.txid:
            self.addWatchedOutput(coin_to, bid.bid_id, bid.participate_tx.txid.hex(), bid.participate_tx.vout, BidStates.SWAP_PARTICIPATING)

        if self.coin_clients[coin_from]['last_height_checked'] < 1:
            if bid.initiate_tx and bid.initiate_tx.chain_height:
                self.coin_clients[coin_from]['last_height_checked'] = bid.initiate_tx.chain_height
        if self.coin_clients[coin_to]['last_height_checked'] < 1:
            if bid.participate_tx and bid.participate_tx.chain_height:
                self.coin_clients[coin_to]['last_height_checked'] = bid.participate_tx.chain_height

        # TODO process addresspool if bid has previously been abandoned

    def deactivateBid(self, offer, bid):
        # Remove from in progress
        self.swaps_in_progress.pop(bid.bid_id, None)

        # Remove any watched outputs
        self.removeWatchedOutput(Coins(offer.coin_from), bid.bid_id, None)
        self.removeWatchedOutput(Coins(offer.coin_to), bid.bid_id, None)

        if bid.state == BidStates.BID_ABANDONED or bid.state == BidStates.SWAP_COMPLETED:
            # Return unused addrs to pool
            if bid.getITxState() != TxStates.TX_REDEEMED:
                self.returnAddressToPool(bid.bid_id, TxTypes.ITX_REDEEM)
            if bid.getITxState() != TxStates.TX_REFUNDED:
                self.returnAddressToPool(bid.bid_id, TxTypes.ITX_REFUND)
            if bid.getPTxState() != TxStates.TX_REDEEMED:
                self.returnAddressToPool(bid.bid_id, TxTypes.PTX_REDEEM)
            if bid.getPTxState() != TxStates.TX_REFUNDED:
                self.returnAddressToPool(bid.bid_id, TxTypes.PTX_REFUND)

    def loadFromDB(self):
        self.log.info('Loading data from db')
        self.mxDB.acquire()
        try:
            session = scoped_session(self.session_factory)
            for bid in session.query(Bid):
                if bid.state and bid.state > BidStates.BID_RECEIVED and bid.state < BidStates.SWAP_COMPLETED:
                    self.activateBid(session, bid)

        finally:
            session.close()
            session.remove()
            self.mxDB.release()

    def initialise(self):
        self.log.debug('network_key %s\nnetwork_pubkey %s\nnetwork_addr %s',
                       self.network_key, self.network_pubkey, self.network_addr)

        ro = self.callrpc('smsglocalkeys')
        found = False
        for k in ro['smsg_keys']:
            if k['address'] == self.network_addr:
                found = True
                break
        if not found:
            self.log.info('Importing network key to SMSG')
            self.callrpc('smsgimportprivkey', [self.network_key, 'basicswap offers'])
            ro = self.callrpc('smsglocalkeys', ['anon', '-', self.network_addr])
            assert(ro['result'] == 'Success.'), 'smsglocalkeys failed'

        # TODO: Ensure smsg is enabled for the active wallet.

        self.loadFromDB()

        # Scan inbox
        options = {'encoding': 'hex'}
        ro = self.callrpc('smsginbox', ['unread', '', options])
        nm = 0
        for msg in ro['messages']:
            msg['hex'] += '00'  # Add nullbtye to match output from 'smsg' cmd - TODO: make consistent
            self.processMsg(msg)
            nm += 1
        self.log.info('Scanned %d unread messages.', nm)

    def validateOfferAmounts(self, coin_from, coin_to, amount, rate, min_bid_amount):
        assert(amount >= min_bid_amount), 'amount < min_bid_amount'
        assert(amount > chainparams[coin_from][self.chain]['min_amount']), 'From amount below min value for chain'
        assert(amount < chainparams[coin_from][self.chain]['max_amount']), 'From amount above max value for chain'

        amount_to = (amount * rate) // COIN
        assert(amount_to > chainparams[coin_to][self.chain]['min_amount']), 'To amount below min value for chain'
        assert(amount_to < chainparams[coin_to][self.chain]['max_amount']), 'To amount above max value for chain'

    def validateOfferLockValue(self, coin_from, coin_to, lock_type, lock_value):
        if lock_type == OfferMessage.SEQUENCE_LOCK_TIME:
            assert(lock_value >= 2 * 60 * 60 and lock_value <= 96 * 60 * 60), 'Invalid lock_value time'
            assert(self.coin_clients[coin_from]['use_csv'] and self.coin_clients[coin_to]['use_csv']), 'Both coins need CSV activated.'
        elif lock_type == OfferMessage.SEQUENCE_LOCK_BLOCKS:
            assert(lock_value >= 5 and lock_value <= 1000), 'Invalid lock_value blocks'
            assert(self.coin_clients[coin_from]['use_csv'] and self.coin_clients[coin_to]['use_csv']), 'Both coins need CSV activated.'
        elif lock_type == ABS_LOCK_TIME:
            # TODO: range?
            assert(not self.coin_clients[coin_from]['use_csv'] or not self.coin_clients[coin_to]['use_csv']), 'Should use CSV.'
            assert(lock_value >= 4 * 60 * 60 and lock_value <= 96 * 60 * 60), 'Invalid lock_value time'
        elif lock_type == ABS_LOCK_BLOCKS:
            # TODO: range?
            assert(not self.coin_clients[coin_from]['use_csv'] or not self.coin_clients[coin_to]['use_csv']), 'Should use CSV.'
            assert(lock_value >= 10 and lock_value <= 1000), 'Invalid lock_value blocks'
        else:
            raise ValueError('Unknown locktype')

    def postOffer(self, coin_from, coin_to, amount, rate, min_bid_amount, swap_type,
                  lock_type=SEQUENCE_LOCK_TIME, lock_value=48 * 60 * 60, auto_accept_bids=False, addr_send_from=None):
        # Offer to send offer.amount_from of coin_from in exchange for offer.amount_from * offer.rate of coin_to

        assert(coin_from != coin_to), 'coin_from == coin_to'
        try:
            coin_from_t = Coins(coin_from)
        except Exception:
            raise ValueError('Unknown coin from type')
        try:
            coin_to_t = Coins(coin_to)
        except Exception:
            raise ValueError('Unknown coin to type')

        self.validateOfferAmounts(coin_from_t, coin_to_t, amount, rate, min_bid_amount)
        self.validateOfferLockValue(coin_from_t, coin_to_t, lock_type, lock_value)

        self.mxDB.acquire()
        try:
            self.checkSynced(coin_from_t, coin_to_t)
            proof_addr, proof_sig = self.getProofOfFunds(coin_from_t, amount)
            # TODO: require prrof of funds on offers?

            msg_buf = OfferMessage()
            msg_buf.coin_from = int(coin_from)
            msg_buf.coin_to = int(coin_to)
            msg_buf.amount_from = int(amount)
            msg_buf.rate = int(rate)
            msg_buf.min_bid_amount = int(min_bid_amount)

            msg_buf.time_valid = 60 * 60
            msg_buf.lock_type = lock_type
            msg_buf.lock_value = lock_value
            msg_buf.swap_type = swap_type

            offer_bytes = msg_buf.SerializeToString()
            payload_hex = str.format('{:02x}', MessageTypes.OFFER) + offer_bytes.hex()

            if addr_send_from is None:
                offer_addr = self.callrpc('getnewaddress')
            else:
                offer_addr = addr_send_from
            self.callrpc('smsgaddlocaladdress', [offer_addr])  # Enable receiving smsg
            options = {'decodehex': True, 'ttl_is_seconds': True}
            msg_valid = self.SMSG_SECONDS_IN_HOUR * 1
            ro = self.callrpc('smsgsend', [offer_addr, self.network_addr, payload_hex, False, msg_valid, False, options])
            msg_id = ro['msgid']

            offer_id = bytes.fromhex(msg_id)

            session = scoped_session(self.session_factory)
            offer = Offer(
                offer_id=offer_id,

                coin_from=msg_buf.coin_from,
                coin_to=msg_buf.coin_to,
                amount_from=msg_buf.amount_from,
                rate=msg_buf.rate,
                min_bid_amount=msg_buf.min_bid_amount,
                time_valid=msg_buf.time_valid,
                lock_type=int(msg_buf.lock_type),
                lock_value=msg_buf.lock_value,
                swap_type=msg_buf.swap_type,

                addr_from=offer_addr,
                created_at=int(time.time()),
                expire_at=int(time.time()) + msg_buf.time_valid,
                was_sent=True,
                auto_accept_bids=auto_accept_bids,)
            offer.setState(OfferStates.OFFER_SENT)

            session.add(offer)
            session.add(SentOffer(offer_id=offer_id))
            if addr_send_from is None:
                session.add(SmsgAddress(addr=offer_addr, use_type=MessageTypes.OFFER))
            session.commit()
            session.close()
            session.remove()
        finally:
            self.mxDB.release()
        self.log.info('Sent OFFER %s', offer_id.hex())
        return offer_id

    def getContractPubkey(self, date, contract_count):
        account = self.callcoinrpc(Coins.PART, 'extkey', ['account'])

        # Derive an address to use for a contract
        evkey = self.callcoinrpc(Coins.PART, 'extkey', ['account', 'default', 'true'])['evkey']

        # Should the coin path be included?
        path = '44445555h'
        path += '/' + str(date.year) + '/' + str(date.month) + '/' + str(date.day)
        path += '/' + str(contract_count)

        extkey = self.callcoinrpc(Coins.PART, 'extkey', ['info', evkey, path])['key_info']['result']
        pubkey = self.callcoinrpc(Coins.PART, 'extkey', ['info', extkey])['key_info']['pubkey']
        return bytes.fromhex(pubkey)

    def getContractPrivkey(self, date, contract_count):
        # Derive an address to use for a contract
        evkey = self.callcoinrpc(Coins.PART, 'extkey', ['account', 'default', 'true'])['evkey']

        path = '44445555h'
        path += '/' + str(date.year) + '/' + str(date.month) + '/' + str(date.day)
        path += '/' + str(contract_count)

        extkey = self.callcoinrpc(Coins.PART, 'extkey', ['info', evkey, path])['key_info']['result']
        privkey = self.callcoinrpc(Coins.PART, 'extkey', ['info', extkey])['key_info']['privkey']
        raw = decodeAddress(privkey)[1:]
        if len(raw) > 32:
            raw = raw[:32]
        return raw

    def getContractSecret(self, date, contract_count):
        # Derive a key to use for a contract secret
        evkey = self.callcoinrpc(Coins.PART, 'extkey', ['account', 'default', 'true'])['evkey']

        path = '44445555h/99999'
        path += '/' + str(date.year) + '/' + str(date.month) + '/' + str(date.day)
        path += '/' + str(contract_count)

        return hashlib.sha256(bytes(self.callcoinrpc(Coins.PART, 'extkey', ['info', evkey, path])['key_info']['result'], 'utf-8')).digest()

    def getReceiveAddressFromPool(self, coin_type, bid_id, tx_type):
        self.log.debug('Get address from pool bid_id {}, type {}, coin {}'.format(bid_id.hex(), tx_type, coin_type))
        self.mxDB.acquire()
        try:
            session = scoped_session(self.session_factory)
            record = session.query(PooledAddress).filter(sa.and_(PooledAddress.coin_type == int(coin_type), PooledAddress.bid_id == None)).first()  # noqa E712
            if not record:
                address = self.getReceiveAddressForCoin(coin_type)
                record = PooledAddress(
                    addr=address,
                    coin_type=int(coin_type))
            record.bid_id = bid_id
            record.tx_type = tx_type
            addr = record.addr
            session.add(record)
            session.commit()
            session.close()
            session.remove()
        finally:
            self.mxDB.release()
        return addr

    def returnAddressToPool(self, bid_id, tx_type):
        self.log.debug('Return address to pool bid_id {}, type {}'.format(bid_id.hex(), tx_type))
        self.mxDB.acquire()
        try:
            session = scoped_session(self.session_factory)
            try:
                record = session.query(PooledAddress).filter(sa.and_(PooledAddress.bid_id == bid_id, PooledAddress.tx_type == tx_type)).one()
                self.log.debug('Returning address to pool addr {}'.format(record.addr))
                record.bid_id = None
                session.commit()
            except Exception as ex:
                pass
            session.close()
            session.remove()
        finally:
            self.mxDB.release()

    def getReceiveAddressForCoin(self, coin_type):
        if coin_type == Coins.PART:
            new_addr = self.callcoinrpc(Coins.PART, 'getnewaddress')
        elif coin_type == Coins.LTC or coin_type == Coins.BTC or coin_type == Coins.NMC:
            args = []
            if self.coin_clients[coin_type]['use_segwit']:
                args = ['swap_receive', 'bech32']
            new_addr = self.callcoinrpc(coin_type, 'getnewaddress', args)
        else:
            raise ValueError('Unknown coin type.')
        self.log.debug('Generated new receive address %s for %s', new_addr, str(coin_type))
        return new_addr

    def getRelayFeeRateForCoin(self, coin_type):
        return self.callcoinrpc(coin_type, 'getnetworkinfo')['relayfee']

    def getFeeRateForCoin(self, coin_type):
        # TODO: Per coin settings to override feerate
        override_feerate = self.coin_clients[coin_type].get('override_feerate', None)
        if override_feerate:
            return override_feerate
        try:
            return self.callcoinrpc(coin_type, 'estimatesmartfee', [2])['feerate']
        except Exception:
            try:
                fee_rate = self.callcoinrpc(coin_type, 'getwalletinfo')['paytxfee']
                assert(fee_rate > 0.0), '0 feerate'
                return fee_rate
            except Exception:
                return self.callcoinrpc(coin_type, 'getnetworkinfo')['relayfee']

    def getTicker(self, coin_type):
        ticker = chainparams[coin_type]['ticker']
        if self.chain == 'testnet':
            ticker = 't' + ticker
        if self.chain == 'regtest':
            ticker = 'rt' + ticker
        return ticker

    def withdrawCoin(self, coin_type, value, addr_to, subfee):
        self.log.info('withdrawCoin %s %s to %s %s', value, self.getTicker(coin_type), addr_to, ' subfee' if subfee else '')
        params = [addr_to, value, '', '', subfee, True, self.coin_clients[coin_type]['conf_target']]
        if coin_type == Coins.PART:
            params.insert(5, '')  # narration
        return self.callcoinrpc(coin_type, 'sendtoaddress', params)

    def cacheNewAddressForCoin(self, coin_type):
        self.log.debug('cacheNewAddressForCoin %s', coin_type)
        key_str = 'receive_addr_' + chainparams[coin_type]['name']
        session = scoped_session(self.session_factory)
        addr = self.getReceiveAddressForCoin(coin_type)
        self.mxDB.acquire()
        try:
            session = scoped_session(self.session_factory)
            try:
                kv = session.query(DBKVString).filter_by(key=key_str).first()
                kv.value = addr
            except Exception:
                kv = DBKVString(
                    key=key_str,
                    value=addr
                )
            session.add(kv)
            session.commit()
            session.close()
            session.remove()
        finally:
            self.mxDB.release()
        return addr

    def getCachedAddressForCoin(self, coin_type):
        self.log.debug('getCachedAddressForCoin %s', coin_type)
        # TODO: auto refresh after used

        key_str = 'receive_addr_' + chainparams[coin_type]['name']
        self.mxDB.acquire()
        try:
            session = scoped_session(self.session_factory)
            try:
                addr = session.query(DBKVString).filter_by(key=key_str).first().value
            except Exception:
                addr = self.getReceiveAddressForCoin(coin_type)
                session.add(DBKVString(
                    key=key_str,
                    value=addr
                ))
                session.commit()
            session.close()
            session.remove()
        finally:
            self.mxDB.release()
        return addr

    def getNewContractId(self):
        self.mxDB.acquire()
        try:
            self._contract_count += 1
            session = scoped_session(self.session_factory)
            self.engine.execute('UPDATE kv_int SET value = {} WHERE KEY="contract_count"'.format(self._contract_count))
            session.commit()
            session.close()
            session.remove()
        finally:
            self.mxDB.release()

        return self._contract_count

    def getProofOfFunds(self, coin_type, amount_for):
        self.log.debug('getProofOfFunds %s %s', str(coin_type), format8(amount_for))

        if self.coin_clients[coin_type]['connection_type'] != 'rpc':
            return (None, None)

        # TODO: Lock unspent and use same output/s to fund bid
        unspent_addr = dict()
        unspent = self.callcoinrpc(coin_type, 'listunspent')
        for u in unspent:
            unspent_addr[u['address']] = unspent_addr.get(u['address'], 0.0) * COIN + u['amount'] * COIN

        sign_for_addr = None
        for addr, value in unspent_addr.items():
            if value >= amount_for:
                sign_for_addr = addr
                break

        assert(sign_for_addr is not None), 'Could not find address with enough funds for proof'

        self.log.debug('sign_for_addr %s', sign_for_addr)
        if self.coin_clients[coin_type]['use_segwit']:
            # 'Address does not refer to key' for non p2pkh
            addrinfo = self.callcoinrpc(coin_type, 'getaddressinfo', [sign_for_addr])
            pkh = addrinfo['scriptPubKey'][4:]
            sign_for_addr = encodeAddress(bytes((chainparams[coin_type][self.chain]['pubkey_address'],)) + bytes.fromhex(pkh))
            self.log.debug('sign_for_addr converted %s', sign_for_addr)
        signature = self.callcoinrpc(coin_type, 'signmessage', [sign_for_addr, sign_for_addr + '_swap_proof'])

        return (sign_for_addr, signature)

    def saveBidInSession(self, bid_id, bid, session):
        session.add(bid)
        if bid.initiate_tx:
            session.add(bid.initiate_tx)
        if bid.participate_tx:
            session.add(bid.participate_tx)

    def saveBid(self, bid_id, bid):
        self.mxDB.acquire()
        try:
            session = scoped_session(self.session_factory)
            self.saveBidInSession(bid_id, bid, session)
            session.commit()
            session.close()
            session.remove()
        finally:
            self.mxDB.release()

    def createEvent(self, delay, event_type, linked_id):
        self.log.debug('createEvent %d %s', event_type, linked_id.hex())
        self.mxDB.acquire()
        try:
            session = scoped_session(self.session_factory)
            event = EventQueue()
            event.active_ind = 1
            event.created_at = int(time.time())
            event.trigger_at = event.created_at + delay
            event.event_type = event_type
            event.linked_id = linked_id
            session.add(event)
            session.commit()
            session.close()
            session.remove()
        finally:
            self.mxDB.release()

    def postBid(self, offer_id, amount, addr_send_from=None):
        # Bid to send bid.amount * offer.rate of coin_to in exchange for bid.amount of coin_from
        self.log.debug('postBid %s %s', offer_id.hex(), format8(amount))

        self.mxDB.acquire()
        try:
            offer = self.getOffer(offer_id)
            assert(offer), 'Offer not found: {}.'.format(offer_id.hex())
            assert(offer.expire_at > int(time.time())), 'Offer has expired'

            msg_buf = BidMessage()
            msg_buf.offer_msg_id = offer_id
            msg_buf.time_valid = 60 * 10
            msg_buf.amount = int(amount)  # amount of coin_from

            coin_from = Coins(offer.coin_from)
            coin_to = Coins(offer.coin_to)

            self.checkSynced(coin_from, coin_to)

            contract_count = self.getNewContractId()

            now = int(time.time())
            if offer.swap_type == SwapTypes.SELLER_FIRST:
                msg_buf.pkhash_buyer = getKeyID(self.getContractPubkey(dt.datetime.fromtimestamp(now).date(), contract_count))

                proof_addr, proof_sig = self.getProofOfFunds(coin_to, msg_buf.amount)
                msg_buf.proof_address = proof_addr
                msg_buf.proof_signature = proof_sig

            bid_bytes = msg_buf.SerializeToString()
            payload_hex = str.format('{:02x}', MessageTypes.BID) + bid_bytes.hex()

            if addr_send_from is None:
                bid_addr = self.callrpc('getnewaddress')
            else:
                bid_addr = addr_send_from
            self.callrpc('smsgaddlocaladdress', [bid_addr])  # Enable receiving smsg
            options = {'decodehex': True, 'ttl_is_seconds': True}
            msg_valid = self.SMSG_SECONDS_IN_HOUR * 1
            ro = self.callrpc('smsgsend', [bid_addr, offer.addr_from, payload_hex, False, msg_valid, False, options])
            msg_id = ro['msgid']

            bid_id = bytes.fromhex(msg_id)
            bid = Bid(
                bid_id=bid_id,
                offer_id=offer_id,
                amount=msg_buf.amount,
                pkhash_buyer=msg_buf.pkhash_buyer,
                proof_address=msg_buf.proof_address,

                created_at=now,
                contract_count=contract_count,
                amount_to=(msg_buf.amount * offer.rate) // COIN,
                expire_at=now + msg_buf.time_valid,
                bid_addr=bid_addr,
                was_sent=True,
            )
            bid.setState(BidStates.BID_SENT)

            session = scoped_session(self.session_factory)
            self.saveBidInSession(bid_id, bid, session)
            if addr_send_from is None:
                session.add(SmsgAddress(addr=bid_addr, use_type=MessageTypes.BID))
            session.commit()
            session.close()
            session.remove()

            self.log.info('Sent BID %s', bid_id.hex())
            return bid_id
        finally:
            self.mxDB.release()

    def getOffer(self, offer_id, sent=False):
        self.mxDB.acquire()
        try:
            session = scoped_session(self.session_factory)
            return session.query(Offer).filter_by(offer_id=offer_id).first()
        finally:
            session.close()
            session.remove()
            self.mxDB.release()

    def getBid(self, bid_id):
        self.mxDB.acquire()
        try:
            session = scoped_session(self.session_factory)
            bid = session.query(Bid).filter_by(bid_id=bid_id).first()
            if bid:
                bid.initiate_tx = session.query(SwapTx).filter(sa.and_(SwapTx.bid_id == bid_id, SwapTx.tx_type == TxTypes.ITX)).first()
                bid.participate_tx = session.query(SwapTx).filter(sa.and_(SwapTx.bid_id == bid_id, SwapTx.tx_type == TxTypes.PTX)).first()
            return bid
        finally:
            session.close()
            session.remove()
            self.mxDB.release()

    def getBidAndOffer(self, bid_id):
        self.mxDB.acquire()
        try:
            session = scoped_session(self.session_factory)
            bid = session.query(Bid).filter_by(bid_id=bid_id).first()
            if bid:
                bid.initiate_tx = session.query(SwapTx).filter(sa.and_(SwapTx.bid_id == bid_id, SwapTx.tx_type == TxTypes.ITX)).first()
                bid.participate_tx = session.query(SwapTx).filter(sa.and_(SwapTx.bid_id == bid_id, SwapTx.tx_type == TxTypes.PTX)).first()
            return bid, session.query(Offer).filter_by(offer_id=bid.offer_id).first() if bid is not None else None
        finally:
            session.close()
            session.remove()
            self.mxDB.release()

    def acceptBid(self, bid_id):
        self.log.info('Accepting bid %s', bid_id.hex())

        bid, offer = self.getBidAndOffer(bid_id)
        assert(bid), 'Bid not found'
        assert(offer), 'Offer not found'

        # Ensure bid is still valid
        now = int(time.time())
        assert(bid.expire_at > now), 'Bid expired'
        assert(bid.state == BidStates.BID_RECEIVED), 'Wrong bid state: {}'.format(BidStates(bid.state))

        if bid.contract_count is None:
            bid.contract_count = self.getNewContractId()

        coin_from = Coins(offer.coin_from)
        bid_date = dt.datetime.fromtimestamp(bid.created_at).date()

        secret = self.getContractSecret(bid_date, bid.contract_count)
        secret_hash = hashlib.sha256(secret).digest()

        pubkey_refund = self.getContractPubkey(bid_date, bid.contract_count)
        pkhash_refund = getKeyID(pubkey_refund)

        if bid.initiate_tx is not None:
            self.log.warning('Initiate txn %s already exists for bid %s', bid.initiate_tx.txid, bid_id.hex())
            txid = bid.initiate_tx.txid
            script = bid.initiate_tx.script
        else:
            if offer.lock_type < ABS_LOCK_BLOCKS:
                sequence = getExpectedSequence(offer.lock_type, offer.lock_value, coin_from)
                script = buildContractScript(sequence, secret_hash, bid.pkhash_buyer, pkhash_refund)
            else:
                if offer.lock_type == ABS_LOCK_BLOCKS:
                    lock_value = self.callcoinrpc(coin_from, 'getblockchaininfo')['blocks'] + offer.lock_value
                else:
                    lock_value = int(time.time()) + offer.lock_value
                self.log.debug('Initiate %s lock_value %d %d', coin_from, offer.lock_value, lock_value)
                script = buildContractScript(lock_value, secret_hash, bid.pkhash_buyer, pkhash_refund, OpCodes.OP_CHECKLOCKTIMEVERIFY)

            p2sh = self.callcoinrpc(Coins.PART, 'decodescript', [script.hex()])['p2sh']

            bid.pkhash_seller = pkhash_refund

            txn = self.createInitiateTxn(coin_from, bid_id, bid, script)

            # Store the signed refund txn in case wallet is locked when refund is possible
            refund_txn = self.createRefundTxn(coin_from, txn, offer, bid, script)
            bid.initiate_txn_refund = bytes.fromhex(refund_txn)

            txid = self.submitTxn(coin_from, txn)
            self.log.debug('Submitted initiate txn %s to %s chain for bid %s', txid, chainparams[coin_from]['name'], bid_id.hex())
            bid.initiate_tx = SwapTx(
                bid_id=bid_id,
                tx_type=TxTypes.ITX,
                txid=bytes.fromhex(txid),
                script=script,
            )
            bid.setITxState(TxStates.TX_SENT)

            # Check non-bip68 final
            try:
                txid = self.submitTxn(coin_from, bid.initiate_txn_refund.hex())
                self.log.error('Submit refund_txn unexpectedly worked: ' + txid)
            except Exception as ex:
                if 'non-BIP68-final' not in str(ex) and 'non-final' not in str(ex):
                    self.log.error('Submit refund_txn unexpected error' + str(ex))

        if txid is not None:
            msg_buf = BidAcceptMessage()
            msg_buf.bid_msg_id = bid_id
            msg_buf.initiate_txid = bytes.fromhex(txid)
            msg_buf.contract_script = bytes(script)

            bid_bytes = msg_buf.SerializeToString()
            payload_hex = str.format('{:02x}', MessageTypes.BID_ACCEPT) + bid_bytes.hex()
            options = {'decodehex': True, 'ttl_is_seconds': True}
            # TODO: set msg_valid based on bid / offer parameters
            msg_valid = self.SMSG_SECONDS_IN_HOUR * 48
            ro = self.callrpc('smsgsend', [offer.addr_from, bid.bid_addr, payload_hex, False, msg_valid, False, options])
            msg_id = ro['msgid']

            accept_msg_id = bytes.fromhex(msg_id)

            bid.accept_msg_id = accept_msg_id
            bid.setState(BidStates.BID_ACCEPTED)

            self.log.info('Sent BID_ACCEPT %s', accept_msg_id.hex())

            self.saveBid(bid_id, bid)
            self.swaps_in_progress[bid_id] = (bid, offer)

    def abandonOffer(self, offer_id):
        self.log.info('Abandoning Offer %s', offer_id.hex())
        self.mxDB.acquire()
        try:
            session = scoped_session(self.session_factory)
            offer = session.query(Offer).filter_by(offer_id=offer_id).first()
            assert(offer), 'Offer not found'

            # TODO: abandon linked bids?

            # Mark bid as abandoned, no further processing will be done
            offer.setState(OfferStates.OFFER_ABANDONED)
            session.commit()
        finally:
            session.close()
            session.remove()
            self.mxDB.release()

    def abandonBid(self, bid_id):
        self.log.info('Abandoning Bid %s', bid_id.hex())
        self.mxDB.acquire()
        try:
            session = scoped_session(self.session_factory)
            bid = session.query(Bid).filter_by(bid_id=bid_id).first()
            assert(bid), 'Bid not found'
            offer = session.query(Offer).filter_by(offer_id=bid.offer_id).first()
            assert(offer), 'Offer not found'

            # Mark bid as abandoned, no further processing will be done
            bid.setState(BidStates.BID_ABANDONED)
            session.commit()

            self.deactivateBid(offer, bid)
        finally:
            session.close()
            session.remove()
            self.mxDB.release()

    def encodeSegwitP2WSH(self, coin_type, p2wsh):
        return segwit_addr.encode(chainparams[coin_type][self.chain]['hrp'], 0, p2wsh[2:])

    def encodeSegwit(self, coin_type, raw):
        return segwit_addr.encode(chainparams[coin_type][self.chain]['hrp'], 0, raw)

    def decodeSegwit(self, coin_type, addr):
        return bytes(segwit_addr.decode(chainparams[coin_type][self.chain]['hrp'], addr)[1])

    def getScriptAddress(self, coin_type, script):
        return pubkeyToAddress(chainparams[coin_type][self.chain]['script_address'], script)

    def setBidError(self, bif_id, bid, error_str):
        bid.setState(BidStates.BID_ERROR)
        bid.state_note = 'error msg: ' + error_str
        self.saveBid(bif_id, bid)

    def createInitiateTxn(self, coin_type, bid_id, bid, initiate_script):
        if self.coin_clients[coin_type]['connection_type'] != 'rpc':
            return None

        if self.coin_clients[coin_type]['use_segwit']:
            addr_to = self.encodeSegwitP2WSH(coin_type, getP2WSH(initiate_script))
        else:
            addr_to = self.getScriptAddress(coin_type, initiate_script)
        self.log.debug('Create initiate txn for coin %s to %s for bid %s', str(coin_type), addr_to, bid_id.hex())
        txn = self.callcoinrpc(coin_type, 'createrawtransaction', [[], {addr_to: format8(bid.amount)}])

        options = {
            'lockUnspents': True,
            'conf_target': self.coin_clients[coin_type]['conf_target'],
        }
        txn_funded = self.callcoinrpc(coin_type, 'fundrawtransaction', [txn, options])['hex']
        txn_signed = self.callcoinrpc(coin_type, 'signrawtransactionwithwallet', [txn_funded])['hex']
        return txn_signed

    def deriveParticipateScript(self, bid_id, bid, offer):
        self.log.debug('deriveParticipateScript for bid %s', bid_id.hex())

        coin_to = Coins(offer.coin_to)

        bid_date = dt.datetime.fromtimestamp(bid.created_at).date()

        secret_hash = extractScriptSecretHash(bid.initiate_tx.script)
        pkhash_seller = bid.pkhash_seller
        pkhash_buyer_refund = bid.pkhash_buyer

        # Participate txn is locked for half the time of the initiate txn
        lock_value = offer.lock_value // 2
        if offer.lock_type < ABS_LOCK_BLOCKS:
            sequence = getExpectedSequence(offer.lock_type, lock_value, coin_to)
            participate_script = buildContractScript(sequence, secret_hash, pkhash_seller, pkhash_buyer_refund)
        else:
            # Lock from the height or time of the block containing the initiate txn
            coin_from = Coins(offer.coin_from)
            initiate_tx_block_hash = self.callcoinrpc(coin_from, 'getblockhash', [bid.initiate_tx.chain_height, ])
            initiate_tx_block_time = int(self.callcoinrpc(coin_from, 'getblock', [initiate_tx_block_hash, ])['time'])
            if offer.lock_type == ABS_LOCK_BLOCKS:
                # Walk the coin_to chain back until block time matches
                blockchaininfo = self.callcoinrpc(coin_to, 'getblockchaininfo')
                cblock_hash = blockchaininfo['bestblockhash']
                cblock_height = blockchaininfo['blocks']
                max_tries = 1000
                for i in range(max_tries):
                    self.log.debug('wtf %d', i)
                    prev_block = self.callcoinrpc(coin_to, 'getblock', [cblock_hash, ])
                    self.log.debug('prev_block %s', str(prev_block))

                    if prev_block['time'] <= initiate_tx_block_time:
                        break
                    # cblock_hash and height are out of step unless loop breaks
                    cblock_hash = prev_block['previousblockhash']
                    cblock_height = prev_block['height']

                assert(prev_block['time'] <= initiate_tx_block_time), 'Block not found for lock height'

                self.log.debug('Setting lock value from height of block %s %s', coin_to, cblock_hash)
                contract_lock_value = cblock_height + lock_value
            else:
                self.log.debug('Setting lock value from time of block %s %s', coin_from, initiate_tx_block_hash)
                contract_lock_value = initiate_tx_block_time + lock_value
            self.log.debug('participate %s lock_value %d %d', coin_to, lock_value, contract_lock_value)
            participate_script = buildContractScript(contract_lock_value, secret_hash, pkhash_seller, pkhash_buyer_refund, OpCodes.OP_CHECKLOCKTIMEVERIFY)
        return participate_script

    def createParticipateTxn(self, bid_id, bid, offer, participate_script):
        self.log.debug('createParticipateTxn')

        offer_id = bid.offer_id
        coin_to = Coins(offer.coin_to)

        if self.coin_clients[coin_to]['connection_type'] != 'rpc':
            return None

        amount_to = bid.amount_to
        # Check required?
        assert(amount_to == (bid.amount * offer.rate) // COIN)

        if self.coin_clients[coin_to]['use_segwit']:
            p2wsh = getP2WSH(participate_script)
            addr_to = self.encodeSegwitP2WSH(coin_to, p2wsh)
        else:
            addr_to = self.getScriptAddress(coin_to, participate_script)

        txn = self.callcoinrpc(coin_to, 'createrawtransaction', [[], {addr_to: format8(amount_to)}])
        options = {
            'lockUnspents': True,
            'conf_target': self.coin_clients[coin_to]['conf_target'],
        }
        txn_funded = self.callcoinrpc(coin_to, 'fundrawtransaction', [txn, options])['hex']
        txn_signed = self.callcoinrpc(coin_to, 'signrawtransactionwithwallet', [txn_funded])['hex']

        refund_txn = self.createRefundTxn(coin_to, txn_signed, offer, bid, participate_script, tx_type=TxTypes.PTX_REFUND)
        bid.participate_txn_refund = bytes.fromhex(refund_txn)

        chain_height = self.callcoinrpc(coin_to, 'getblockchaininfo')['blocks']
        txjs = self.callcoinrpc(coin_to, 'decoderawtransaction', [txn_signed])
        txid = txjs['txid']

        if self.coin_clients[coin_to]['use_segwit']:
            vout = getVoutByP2WSH(txjs, p2wsh.hex())
        else:
            vout = getVoutByAddress(txjs, addr_to)
        self.addParticipateTxn(bid_id, bid, coin_to, txid, vout, chain_height)
        bid.participate_tx.script = participate_script

        return txn_signed

    def getContractSpendTxVSize(self, coin_type, redeem=True):
        tx_vsize = 5  # Add a few bytes, sequence in script takes variable amount of bytes
        if coin_type == Coins.PART:
            tx_vsize += 204 if redeem else 187
        if self.coin_clients[coin_type]['use_segwit']:
            tx_vsize += 143 if redeem else 134
        else:
            tx_vsize += 323 if redeem else 287
        return tx_vsize

    def createRedeemTxn(self, coin_type, bid, for_txn_type='participate', addr_redeem_out=None, fee_rate=None):
        self.log.debug('createRedeemTxn for coin %s', str(coin_type))

        if for_txn_type == 'participate':
            prev_txnid = bid.participate_tx.txid.hex()
            prev_n = bid.participate_tx.vout
            txn_script = bid.participate_tx.script
            prev_amount = bid.amount_to
        else:
            prev_txnid = bid.initiate_tx.txid.hex()
            prev_n = bid.initiate_tx.vout
            txn_script = bid.initiate_tx.script
            prev_amount = bid.amount

        if self.coin_clients[coin_type]['use_segwit']:
            prev_p2wsh = getP2WSH(txn_script)
            script_pub_key = prev_p2wsh.hex()
        else:
            script_pub_key = getP2SHScriptForHash(getKeyID(txn_script)).hex()

        prevout = {
            'txid': prev_txnid,
            'vout': prev_n,
            'scriptPubKey': script_pub_key,
            'redeemScript': txn_script.hex(),
            'amount': format8(prev_amount)}

        bid_date = dt.datetime.fromtimestamp(bid.created_at).date()
        wif_prefix = chainparams[Coins.PART][self.chain]['key_prefix']
        pubkey = self.getContractPubkey(bid_date, bid.contract_count)
        privkey = toWIF(wif_prefix, self.getContractPrivkey(bid_date, bid.contract_count))

        secret = bid.recovered_secret
        if secret is None:
            secret = self.getContractSecret(bid_date, bid.contract_count)
        assert(len(secret) == 32), 'Bad secret length'

        if self.coin_clients[coin_type]['connection_type'] != 'rpc':
            return None

        prevout_s = ' in={}:{}'.format(prev_txnid, prev_n)

        if fee_rate is None:
            fee_rate = self.getFeeRateForCoin(coin_type)

        tx_vsize = self.getContractSpendTxVSize(coin_type)
        tx_fee = (fee_rate * tx_vsize) / 1000

        self.log.debug('Redeem tx fee %s, rate %s', format8(tx_fee * COIN), str(fee_rate))

        amount_out = prev_amount - tx_fee * COIN
        assert(amount_out > 0), 'Amount out <= 0'

        if addr_redeem_out is None:
            addr_redeem_out = self.getReceiveAddressFromPool(coin_type, bid.bid_id, TxTypes.PTX_REDEEM if for_txn_type == 'participate' else TxTypes.ITX_REDEEM)
        assert(addr_redeem_out is not None)

        if self.coin_clients[coin_type]['use_segwit']:
            # Change to btc hrp
            addr_redeem_out = self.encodeSegwit(Coins.PART, self.decodeSegwit(coin_type, addr_redeem_out))
        else:
            addr_redeem_out = replaceAddrPrefix(addr_redeem_out, Coins.PART, self.chain)
        self.log.debug('addr_redeem_out %s', addr_redeem_out)
        output_to = ' outaddr={}:{}'.format(format8(amount_out), addr_redeem_out)
        if coin_type == Coins.PART:
            redeem_txn = self.calltx('-create' + prevout_s + output_to)
        else:
            redeem_txn = self.calltx('-btcmode -create nversion=2' + prevout_s + output_to)

        options = {}
        if self.coin_clients[coin_type]['use_segwit']:
            options['force_segwit'] = True
        redeem_sig = self.callcoinrpc(Coins.PART, 'createsignaturewithkey', [redeem_txn, prevout, privkey, 'ALL', options])
        if coin_type == Coins.PART or self.coin_clients[coin_type]['use_segwit']:
            witness_stack = [
                redeem_sig,
                pubkey.hex(),
                secret.hex(),
                '01',
                txn_script.hex()]
            redeem_txn = self.calltx(redeem_txn + ' witness=0:' + ':'.join(witness_stack))
        else:
            script = format(len(redeem_sig) // 2, '02x') + redeem_sig
            script += format(33, '02x') + pubkey.hex()
            script += format(32, '02x') + secret.hex()
            script += format(OpCodes.OP_1, '02x')
            script += format(OpCodes.OP_PUSHDATA1, '02x') + format(len(txn_script), '02x') + txn_script.hex()
            redeem_txn = self.calltx(redeem_txn + ' scriptsig=0:' + script)

        ro = self.callcoinrpc(Coins.PART, 'verifyrawtransaction', [redeem_txn, [prevout]])
        assert(ro['inputs_valid'] is True), 'inputs_valid is false'
        assert(ro['complete'] is True), 'complete is false'
        assert(ro['validscripts'] == 1), 'validscripts != 1'

        if self.debug:
            # Check fee
            if self.coin_clients[coin_type]['connection_type'] == 'rpc':
                redeem_txjs = self.callcoinrpc(coin_type, 'decoderawtransaction', [redeem_txn])
                self.log.debug('vsize paid, actual vsize %d %d', tx_vsize, redeem_txjs['vsize'])
                assert(tx_vsize >= redeem_txjs['vsize']), 'Underpaid fee'

            redeem_txjs = self.callcoinrpc(Coins.PART, 'decoderawtransaction', [redeem_txn])
            self.log.debug('Have valid redeem txn %s for contract %s tx %s', redeem_txjs['txid'], for_txn_type, prev_txnid)

        return redeem_txn

    def createRefundTxn(self, coin_type, txn, offer, bid, txn_script, addr_refund_out=None, tx_type=TxTypes.ITX_REFUND):
        self.log.debug('createRefundTxn')
        if self.coin_clients[coin_type]['connection_type'] != 'rpc':
            return None

        txjs = self.callcoinrpc(Coins.PART, 'decoderawtransaction', [txn])
        if self.coin_clients[coin_type]['use_segwit']:
            p2wsh = getP2WSH(txn_script)
            vout = getVoutByP2WSH(txjs, p2wsh.hex())
        else:
            addr_to = self.getScriptAddress(Coins.PART, txn_script)
            vout = getVoutByAddress(txjs, addr_to)

        bid_date = dt.datetime.fromtimestamp(bid.created_at).date()
        wif_prefix = chainparams[Coins.PART][self.chain]['key_prefix']
        pubkey = self.getContractPubkey(bid_date, bid.contract_count)
        privkey = toWIF(wif_prefix, self.getContractPrivkey(bid_date, bid.contract_count))

        prev_amount = txjs['vout'][vout]['value']
        prevout = {
            'txid': txjs['txid'],
            'vout': vout,
            'scriptPubKey': txjs['vout'][vout]['scriptPubKey']['hex'],
            'redeemScript': txn_script.hex(),
            'amount': prev_amount}

        lock_value = DeserialiseNum(txn_script, 64)
        if offer.lock_type < ABS_LOCK_BLOCKS:
            sequence = lock_value
        else:
            sequence = 1
        prevout_s = ' in={}:{}:{}'.format(txjs['txid'], vout, sequence)

        fee_rate = self.getFeeRateForCoin(coin_type)

        tx_vsize = self.getContractSpendTxVSize(coin_type, False)
        tx_fee = (fee_rate * tx_vsize) / 1000

        self.log.debug('Refund tx fee %s, rate %s', format8(tx_fee * COIN), str(fee_rate))

        amount_out = prev_amount * COIN - tx_fee * COIN
        if amount_out <= 0:
            raise ValueError('Refund amount out <= 0')

        if addr_refund_out is None:
            addr_refund_out = self.getReceiveAddressFromPool(coin_type, bid.bid_id, tx_type)
        assert(addr_refund_out is not None), 'addr_refund_out is null'
        if self.coin_clients[coin_type]['use_segwit']:
            # Change to btc hrp
            addr_refund_out = self.encodeSegwit(Coins.PART, self.decodeSegwit(coin_type, addr_refund_out))
        else:
            addr_refund_out = replaceAddrPrefix(addr_refund_out, Coins.PART, self.chain)
        self.log.debug('addr_refund_out %s', addr_refund_out)

        output_to = ' outaddr={}:{}'.format(format8(amount_out), addr_refund_out)
        if coin_type == Coins.PART:
            refund_txn = self.calltx('-create' + prevout_s + output_to)
        else:
            refund_txn = self.calltx('-btcmode -create nversion=2' + prevout_s + output_to)

        if offer.lock_type == ABS_LOCK_BLOCKS or offer.lock_type == ABS_LOCK_TIME:
            refund_txn = self.calltx('{} locktime={}'.format(refund_txn, lock_value))

        options = {}
        if self.coin_clients[coin_type]['use_segwit']:
            options['force_segwit'] = True
        refund_sig = self.callcoinrpc(Coins.PART, 'createsignaturewithkey', [refund_txn, prevout, privkey, 'ALL', options])
        if coin_type == Coins.PART or self.coin_clients[coin_type]['use_segwit']:
            witness_stack = [
                refund_sig,
                pubkey.hex(),
                '',  # SCRIPT_VERIFY_MINIMALIF
                txn_script.hex()]
            refund_txn = self.calltx(refund_txn + ' witness=0:' + ':'.join(witness_stack))
        else:
            script = format(len(refund_sig) // 2, '02x') + refund_sig
            script += format(33, '02x') + pubkey.hex()
            script += format(OpCodes.OP_0, '02x')
            script += format(OpCodes.OP_PUSHDATA1, '02x') + format(len(txn_script), '02x') + txn_script.hex()
            refund_txn = self.calltx(refund_txn + ' scriptsig=0:' + script)

        ro = self.callcoinrpc(Coins.PART, 'verifyrawtransaction', [refund_txn, [prevout]])
        assert(ro['inputs_valid'] is True), 'inputs_valid is false'
        assert(ro['complete'] is True), 'complete is false'
        assert(ro['validscripts'] == 1), 'validscripts != 1'

        if self.debug:
            # Check fee
            if self.coin_clients[coin_type]['connection_type'] == 'rpc':
                refund_txjs = self.callcoinrpc(coin_type, 'decoderawtransaction', [refund_txn])
                self.log.debug('vsize paid, actual vsize %d %d', tx_vsize, refund_txjs['vsize'])
                assert(tx_vsize >= refund_txjs['vsize']), 'underpaid fee'

            refund_txjs = self.callcoinrpc(Coins.PART, 'decoderawtransaction', [refund_txn])
            self.log.debug('Have valid refund txn %s for contract tx %s', refund_txjs['txid'], txjs['txid'])

        return refund_txn

    def submitTxn(self, coin_type, txn):
        # self.log.debug('submitTxn %s', str(coin_type))
        if txn is None:
            return None
        if self.coin_clients[coin_type]['connection_type'] != 'rpc':
            return None
        return self.callcoinrpc(coin_type, 'sendrawtransaction', [txn])

    def initiateTxnConfirmed(self, bid_id, bid, offer):
        self.log.debug('initiateTxnConfirmed for bid %s', bid_id.hex())
        bid.setState(BidStates.SWAP_INITIATED)
        bid.setITxState(TxStates.TX_CONFIRMED)

        # Seller first mode, buyer participates
        participate_script = self.deriveParticipateScript(bid_id, bid, offer)
        if bid.was_sent:
            if bid.participate_tx is not None:
                self.log.warning('Participate txn %s already exists for bid %s', bid.participate_tx.txid, bid_id.hex())
            else:
                self.log.debug('Preparing participate txn for bid %s', bid_id.hex())

                coin_to = Coins(offer.coin_to)
                txn = self.createParticipateTxn(bid_id, bid, offer, participate_script)
                txid = self.submitTxn(coin_to, txn)
                self.log.debug('Submitted participate txn %s to %s chain for bid %s', txid, chainparams[coin_to]['name'], bid_id.hex())
                bid.setPTxState(TxStates.TX_SENT)
        else:
            bid.participate_tx = SwapTx(
                bid_id=bid_id,
                tx_type=TxTypes.PTX,
                script=participate_script,
            )

        # bid saved in checkBidState

    def setLastHeightChecked(self, coin_type, tx_height):
        chain_name = chainparams[coin_type]['name']
        if tx_height < 1:
            tx_height = self.lookupChainHeight(coin_type)

        if len(self.coin_clients[coin_type]['watched_outputs']) == 0:
            self.coin_clients[coin_type]['last_height_checked'] = tx_height
            self.log.debug('Start checking %s chain at height %d', chain_name, tx_height)

        if self.coin_clients[coin_type]['last_height_checked'] > tx_height:
            self.coin_clients[coin_type]['last_height_checked'] = tx_height
            self.log.debug('Rewind checking of %s chain to height %d', chain_name, tx_height)

        return tx_height

    def addParticipateTxn(self, bid_id, bid, coin_type, txid_hex, vout, tx_height):

        # TODO: Check connection type
        participate_txn_height = self.setLastHeightChecked(coin_type, tx_height)

        if bid.participate_tx is None:
            bid.participate_tx = SwapTx(
                bid_id=bid_id,
                tx_type=TxTypes.PTX,
            )
        bid.participate_tx.txid = bytes.fromhex(txid_hex)
        bid.participate_tx.vout = vout
        bid.participate_tx.chain_height = participate_txn_height

        # Start checking for spends of participate_txn before fully confirmed
        self.log.debug('Watching %s chain for spend of output %s %d', chainparams[coin_type]['name'], txid_hex, vout)
        self.addWatchedOutput(coin_type, bid_id, txid_hex, vout, BidStates.SWAP_PARTICIPATING)

    def participateTxnConfirmed(self, bid_id, bid, offer):
        self.log.debug('participateTxnConfirmed for bid %s', bid_id.hex())
        bid.setState(BidStates.SWAP_PARTICIPATING)
        bid.setPTxState(TxStates.TX_CONFIRMED)

        # Seller redeems from participate txn
        if bid.was_received:
            coin_to = Coins(offer.coin_to)
            txn = self.createRedeemTxn(coin_to, bid)
            txid = self.submitTxn(coin_to, txn)
            self.log.debug('Submitted participate redeem txn %s to %s chain for bid %s', txid, chainparams[coin_to]['name'], bid_id.hex())
            # TX_REDEEMED will be set when spend is detected
            # TODO: Wait for depth?

        # bid saved in checkBidState

    def getAddressBalance(self, coin_type, address):
        if self.coin_clients[coin_type]['chain_lookups'] == 'explorer':
            explorers = self.coin_clients[coin_type]['explorers']

            # TODO: random offset into explorers, try blocks
            for exp in explorers:
                return exp.getBalance(address)
        return self.lookupUnspentByAddress(coin_type, address, sum_output=True)

    def lookupChainHeight(self, coin_type):
        return self.callcoinrpc(coin_type, 'getblockchaininfo')['blocks']

    def lookupUnspentByAddress(self, coin_type, address, sum_output=False, assert_amount=None, assert_txid=None):

        if self.coin_clients[coin_type]['chain_lookups'] == 'explorer':
            explorers = self.coin_clients[coin_type]['explorers']

            # TODO: random offset into explorers, try blocks
            for exp in explorers:

                # TODO: ExplorerBitAps use only gettransaction if assert_txid is set
                rv = exp.lookupUnspentByAddress(address)

                if assert_amount is not None:
                    assert(rv['value'] == int(assert_amount)), 'Incorrect output amount in txn {}: {} != {}.'.format(assert_txid, rv['value'], int(assert_amount))
                if assert_txid is not None:
                    assert(rv['txid)'] == assert_txid), 'Incorrect txid'

                return rv

            raise ValueError('No explorer for lookupUnspentByAddress {}'.format(str(coin_type)))

        if self.coin_clients[coin_type]['connection_type'] != 'rpc':
            raise ValueError('No RPC connection for lookupUnspentByAddress {}'.format(str(coin_type)))

        if assert_txid is not None:
            try:
                ro = self.callcoinrpc(coin_type, 'getmempoolentry', [assert_txid])
                self.log.debug('Tx %s found in mempool, fee %s', assert_txid, ro['fee'])
                # TODO: Save info
                return None
            except Exception:
                pass

        num_blocks = self.callcoinrpc(coin_type, 'getblockchaininfo')['blocks']

        sum_unspent = 0
        self.log.debug('[rm] scantxoutset start')  # scantxoutset is slow
        ro = self.callcoinrpc(coin_type, 'scantxoutset', ['start', ['addr({})'.format(address)]])
        self.log.debug('[rm] scantxoutset end')
        for o in ro['unspents']:
            if assert_txid and o['txid'] != assert_txid:
                continue
            # Verify amount
            if assert_amount:
                assert(makeInt(o['amount']) == int(assert_amount)), 'Incorrect output amount in txn {}: {} != {}.'.format(assert_txid, makeInt(o['amount']), int(assert_amount))

            if not sum_output:
                if o['height'] > 0:
                    n_conf = num_blocks - o['height']
                else:
                    n_conf = -1
                return {
                    'txid': o['txid'],
                    'index': o['vout'],
                    'height': o['height'],
                    'n_conf': n_conf,
                    'value': makeInt(o['amount']),
                }
            else:
                sum_unspent += o['amount'] * COIN
        if sum_output:
            return sum_unspent
        return None

    def checkBidState(self, bid_id, bid, offer):
        # assert(self.mxDB.locked())
        # Return True to remove bid from in-progress list

        state = BidStates(bid.state)
        self.log.debug('checkBidState %s %s', bid_id.hex(), str(state))

        save_bid = False
        coin_from = Coins(offer.coin_from)
        coin_to = Coins(offer.coin_to)
        # TODO: Batch calls to scantxoutset
        # TODO: timeouts
        if state == BidStates.BID_ACCEPTED:
            # Waiting for initiate txn to be confirmed in 'from' chain
            initiate_txnid_hex = bid.initiate_tx.txid.hex()
            p2sh = self.getScriptAddress(coin_from, bid.initiate_tx.script)
            index = None
            tx_height = None
            last_initiate_txn_conf = bid.initiate_tx.conf
            if coin_from == Coins.PART:  # Has txindex
                try:
                    initiate_txn = self.callcoinrpc(coin_from, 'getrawtransaction', [initiate_txnid_hex, True])
                    # Verify amount
                    vout = getVoutByAddress(initiate_txn, p2sh)

                    out_value = makeInt(initiate_txn['vout'][vout]['value'])
                    assert(out_value == int(bid.amount)), 'Incorrect output amount in initiate txn {}: {} != {}.'.format(initiate_txnid_hex, out_value, int(bid.amount))

                    bid.initiate_tx.conf = initiate_txn['confirmations']
                    try:
                        tx_height = initiate_txn['height']
                    except Exception:
                        tx_height = -1
                    index = vout
                except Exception:
                    pass
            else:
                if self.coin_clients[coin_from]['use_segwit']:
                    addr = self.encodeSegwitP2WSH(coin_from, getP2WSH(bid.initiate_tx.script))
                else:
                    addr = p2sh
                found = self.lookupUnspentByAddress(coin_from, addr, assert_amount=bid.amount, assert_txid=initiate_txnid_hex)
                if found:
                    bid.initiate_tx.conf = found['n_conf']
                    index = found['index']
                    tx_height = found['height']

            if bid.initiate_tx.conf != last_initiate_txn_conf:
                save_bid = True

            if bid.initiate_tx.conf is not None:
                self.log.debug('initiate_txnid %s confirms %d', initiate_txnid_hex, bid.initiate_tx.conf)

                if bid.initiate_tx.vout is None:
                    bid.initiate_tx.vout = index
                    # Start checking for spends of initiate_txn before fully confirmed
                    bid.initiate_tx.chain_height = self.setLastHeightChecked(coin_from, tx_height)
                    self.addWatchedOutput(coin_from, bid_id, initiate_txnid_hex, bid.initiate_tx.vout, BidStates.SWAP_INITIATED)
                    if bid.getITxState() is None or bid.getITxState() < TxStates.TX_SENT:
                        bid.setITxState(TxStates.TX_SENT)
                    save_bid = True

                if bid.initiate_tx.conf >= self.coin_clients[coin_from]['blocks_confirmed']:
                    self.initiateTxnConfirmed(bid_id, bid, offer)
                    save_bid = True

            # Bid times out if buyer doesn't see tx in chain within INITIATE_TX_TIMEOUT seconds
            if bid.initiate_tx is None and \
               bid.state_time + INITIATE_TX_TIMEOUT < int(time.time()):
                self.log.info('Swap timed out waiting for initiate tx for bid %s', bid_id.hex())
                bid.setState(BidStates.SWAP_TIMEDOUT)
                self.saveBid(bid_id, bid)
                return True  # Mark bid for archiving
        elif state == BidStates.SWAP_INITIATED:
            # Waiting for participate txn to be confirmed in 'to' chain
            if self.coin_clients[coin_to]['use_segwit']:
                addr = self.encodeSegwitP2WSH(coin_to, getP2WSH(bid.participate_tx.script))
            else:
                addr = self.getScriptAddress(coin_to, bid.participate_tx.script)

            found = self.lookupUnspentByAddress(coin_to, addr, assert_amount=bid.amount_to)
            if found:
                if bid.participate_tx.conf != found['n_conf']:
                    save_bid = True
                bid.participate_tx.conf = found['n_conf']
                index = found['index']
                if bid.participate_tx is None or bid.participate_tx.txid is None:
                    self.log.debug('Found bid %s participate txn %s in chain %s', bid_id.hex(), found['txid'], coin_to)
                    self.addParticipateTxn(bid_id, bid, coin_to, found['txid'], found['index'], found['height'])
                    bid.setPTxState(TxStates.TX_SENT)
                    save_bid = True

            if bid.participate_tx.conf is not None:
                self.log.debug('participate txid %s confirms %d', bid.participate_tx.txid.hex(), bid.participate_tx.conf)
                if bid.participate_tx.conf >= self.coin_clients[coin_to]['blocks_confirmed']:
                    self.participateTxnConfirmed(bid_id, bid, offer)
                    save_bid = True
        elif state == BidStates.SWAP_PARTICIPATING:
            # Waiting for initiate txn spend
            pass
        else:
            self.log.warning('checkBidState unknown state %s', state)

        if state > BidStates.BID_ACCEPTED:
            # Wait for spend of all known swap txns
            if (bid.getITxState() is None or bid.getITxState() >= TxStates.TX_REDEEMED) \
               and (bid.getPTxState() is None or bid.getPTxState() >= TxStates.TX_REDEEMED):
                self.log.info('Swap completed for bid %s', bid_id.hex())

                if bid.getITxState() == TxStates.TX_REDEEMED:
                    self.returnAddressToPool(bid_id, TxTypes.ITX_REFUND)
                else:
                    self.returnAddressToPool(bid_id, TxTypes.ITX_REDEEM)
                if bid.getPTxState() == TxStates.TX_REDEEMED:
                    self.returnAddressToPool(bid_id, TxTypes.PTX_REFUND)
                else:
                    self.returnAddressToPool(bid_id, TxTypes.PTX_REDEEM)

                bid.setState(BidStates.SWAP_COMPLETED)
                self.saveBid(bid_id, bid)
                return True  # Mark bid for archiving

        if save_bid:
            self.saveBid(bid_id, bid)

        # Try refund, keep trying until sent tx is spent
        if (bid.getITxState() == TxStates.TX_SENT or bid.getITxState() == TxStates.TX_CONFIRMED) \
           and bid.initiate_txn_refund is not None:
            try:
                txid = self.submitTxn(coin_from, bid.initiate_txn_refund.hex())
                self.log.debug('Submitted initiate refund txn %s to %s chain for bid %s', txid, chainparams[coin_from]['name'], bid_id.hex())
                # State will update when spend is detected
            except Exception as ex:
                if 'non-BIP68-final (code 64)' not in str(ex) and 'non-final' not in str(ex):
                    self.log.warning('Error trying to submit initiate refund txn: %s', str(ex))
        if (bid.getPTxState() == TxStates.TX_SENT or bid.getPTxState() == TxStates.TX_CONFIRMED) \
           and bid.participate_txn_refund is not None:
            try:
                txid = self.submitTxn(coin_to, bid.participate_txn_refund.hex())
                self.log.debug('Submitted participate refund txn %s to %s chain for bid %s', txid, chainparams[coin_to]['name'], bid_id.hex())
                # State will update when spend is detected
            except Exception as ex:
                if 'non-BIP68-final (code 64)' not in str(ex) and 'non-final' not in str(ex):
                    self.log.warning('Error trying to submit participate refund txn: %s', str(ex))
        return False  # Bid is still active

    def extractSecret(self, coin_type, bid, spend_in):
        try:
            if coin_type == Coins.PART or self.coin_clients[coin_type]['use_segwit']:
                assert(len(spend_in['txinwitness']) == 5), 'Bad witness size'
                return bytes.fromhex(spend_in['txinwitness'][2])
            else:
                script_sig = spend_in['scriptSig']['asm'].split(' ')
                assert(len(script_sig) == 5), 'Bad witness size'
                return bytes.fromhex(script_sig[2])
        except Exception:
            return None

    def addWatchedOutput(self, coin_type, bid_id, txid_hex, vout, tx_type):
        self.log.debug('Adding watched output %s bid %s tx %s type %s', coin_type, bid_id.hex(), txid_hex, tx_type)
        self.coin_clients[coin_type]['watched_outputs'].append((bid_id, txid_hex, vout, tx_type))

    def removeWatchedOutput(self, coin_type, bid_id, txid_hex):
        # Remove all for bid if txid is None
        self.log.debug('removeWatchedOutput %s %s %s', str(coin_type), bid_id.hex(), txid_hex)
        old_len = len(self.coin_clients[coin_type]['watched_outputs'])
        for i in range(old_len - 1, -1, -1):
            wo = self.coin_clients[coin_type]['watched_outputs'][i]
            if wo[0] == bid_id and (txid_hex is None or wo[1] == txid_hex):
                del self.coin_clients[coin_type]['watched_outputs'][i]
                self.log.debug('Removed watched output %s %s %s', str(coin_type), bid_id.hex(), wo[1])

    def initiateTxnSpent(self, bid_id, spend_txid, spend_n, spend_txn):
        self.log.debug('Bid %s initiate txn spent by %s %d', bid_id.hex(), spend_txid, spend_n)

        if bid_id in self.swaps_in_progress:
            bid = self.swaps_in_progress[bid_id][0]
            offer = self.swaps_in_progress[bid_id][1]

            bid.initiate_tx.spend_txid = bytes.fromhex(spend_txid)
            bid.initiate_tx.spend_n = spend_n
            spend_in = spend_txn['vin'][spend_n]

            coin_from = Coins(offer.coin_from)
            coin_to = Coins(offer.coin_to)

            secret = self.extractSecret(coin_from, bid, spend_in)
            if secret is None:
                self.log.info('Bid %s initiate txn refunded by %s %d', bid_id.hex(), spend_txid, spend_n)
                # TODO: Wait for depth?
                bid.setITxState(TxStates.TX_REFUNDED)
            else:
                self.log.info('Bid %s initiate txn redeemed by %s %d', bid_id.hex(), spend_txid, spend_n)
                # TODO: Wait for depth?
                bid.setITxState(TxStates.TX_REDEEMED)

            self.removeWatchedOutput(coin_from, bid_id, bid.initiate_tx.txid.hex())
            self.saveBid(bid_id, bid)

    def participateTxnSpent(self, bid_id, spend_txid, spend_n, spend_txn):
        self.log.debug('Bid %s participate txn spent by %s %d', bid_id.hex(), spend_txid, spend_n)

        # TODO: More SwapTypes
        if bid_id in self.swaps_in_progress:
            bid = self.swaps_in_progress[bid_id][0]
            offer = self.swaps_in_progress[bid_id][1]

            bid.participate_tx.spend_txid = bytes.fromhex(spend_txid)
            bid.participate_tx.spend_n = spend_n
            spend_in = spend_txn['vin'][spend_n]

            coin_from = Coins(offer.coin_from)
            coin_to = Coins(offer.coin_to)

            secret = self.extractSecret(coin_to, bid, spend_in)
            if secret is None:
                self.log.info('Bid %s participate txn refunded by %s %d', bid_id.hex(), spend_txid, spend_n)
                # TODO: Wait for depth?
                bid.setPTxState(TxStates.TX_REFUNDED)
            else:
                self.log.debug('Secret %s extracted from participate spend %s %d', secret.hex(), spend_txid, spend_n)
                bid.recovered_secret = secret
                # TODO: Wait for depth?
                bid.setPTxState(TxStates.TX_REDEEMED)

            if bid.was_sent:
                txn = self.createRedeemTxn(coin_from, bid, for_txn_type='initiate')
                txid = self.submitTxn(coin_from, txn)

                bid.initiate_tx.spend_txid = bytes.fromhex(txid)
                # bid.initiate_txn_redeem = bytes.fromhex(txn)  # Worth keeping?
                self.log.debug('Submitted initiate redeem txn %s to %s chain for bid %s', txid, chainparams[coin_from]['name'], bid_id.hex())

                # TODO: Wait for depth? new state SWAP_TXI_REDEEM_SENT?

            self.removeWatchedOutput(coin_to, bid_id, bid.participate_tx.txid.hex())
            self.saveBid(bid_id, bid)

    def checkForSpends(self, coin_type, c):
        # assert(self.mxDB.locked()) self.log.debug('checkForSpends %s', coin_type)

        if coin_type == Coins.PART:
            # TODO: batch getspentinfo
            for o in c['watched_outputs']:
                found_spend = None
                try:
                    found_spend = self.callcoinrpc(Coins.PART, 'getspentinfo', [{'txid': o[1], 'index': o[2]}])
                except Exception as ex:
                    if 'Unable to get spent info' not in str(ex):
                        self.log.warning('getspentinfo %s', str(ex))
                if found_spend is not None:
                    self.log.debug('Found spend in spentindex %s %d in %s %d', o[1], o[2], found_spend['txid'], found_spend['index'])
                    bid_id = o[0]
                    spend_txid = found_spend['txid']
                    spend_n = found_spend['index']
                    spend_txn = self.callcoinrpc(Coins.PART, 'getrawtransaction', [spend_txid, True])
                    if o[3] == BidStates.SWAP_PARTICIPATING:
                        self.participateTxnSpent(bid_id, spend_txid, spend_n, spend_txn)
                    else:
                        self.initiateTxnSpent(bid_id, spend_txid, spend_n, spend_txn)
        else:
            chain_blocks = self.callcoinrpc(coin_type, 'getblockchaininfo')['blocks']
            last_height_checked = c['last_height_checked']
            self.log.debug('chain_blocks, last_height_checked %s %s', chain_blocks, last_height_checked)
            while last_height_checked < chain_blocks:
                block_hash = self.callcoinrpc(coin_type, 'getblockhash', [last_height_checked + 1])
                block = self.callcoinrpc(coin_type, 'getblock', [block_hash, 2])

                for tx in block['tx']:
                    for i, inp in enumerate(tx['vin']):
                        for o in c['watched_outputs']:
                            inp_txid = inp.get('txid', None)
                            if inp_txid is None:  # Coinbase
                                continue
                            if inp_txid == o[1] and inp['vout'] == o[2]:
                                self.log.debug('Found spend from search %s %d in %s %d', o[1], o[2], tx['txid'], i)
                                bid_id = o[0]
                                if o[3] == BidStates.SWAP_PARTICIPATING:
                                    self.participateTxnSpent(bid_id, tx['txid'], i, tx)
                                else:
                                    self.initiateTxnSpent(bid_id, tx['txid'], i, tx)
                last_height_checked += 1
            if c['last_height_checked'] != last_height_checked:
                c['last_height_checked'] = last_height_checked
                self.setIntKV('last_height_checked_' + chainparams[coin_type]['name'], last_height_checked)

    def expireMessages(self):
        self.mxDB.acquire()
        try:
            now = int(time.time())
            options = {'encoding': 'none'}
            ro = self.callrpc('smsginbox', ['all', '', options])
            for msg in ro['messages']:
                expire_at = msg['sent'] + msg['daysretention'] * self.SMSG_SECONDS_IN_DAY
                if expire_at < now:
                    options = {'encoding': 'none', 'delete': True}
                    del_msg = self.callrpc('smsg', [msg['msgid'], options])

            # TODO: remove offers from db

        finally:
            self.mxDB.release()

    def checkEvents(self):
        self.mxDB.acquire()
        try:
            now = int(time.time())

            session = scoped_session(self.session_factory)

            q = session.query(EventQueue).filter(EventQueue.trigger_at >= now)
            for row in q:

                if row.event_type == EventTypes.ACCEPT_BID:
                    self.acceptBid(row.linked_id)
                else:
                    self.log.warning('Unknown event type: %d', row.event_type)

                session.query.filter(EventQueue.event_id == row.event_id).delete()

            session.commit()
            session.close()
            session.remove()
        finally:
            self.mxDB.release()

    def processOffer(self, msg):
        assert(msg['to'] == self.network_addr), 'Offer received on wrong address'

        offer_bytes = bytes.fromhex(msg['hex'][2:-2])
        offer_data = OfferMessage()
        offer_data.ParseFromString(offer_bytes)

        # Validate data
        now = int(time.time())
        coin_from = Coins(offer_data.coin_from)
        coin_to = Coins(offer_data.coin_to)
        chain_from = chainparams[coin_from][self.chain]
        assert(offer_data.coin_from != offer_data.coin_to), 'coin_from == coin_to'

        self.validateOfferAmounts(coin_from, coin_to, offer_data.amount_from, offer_data.rate, offer_data.min_bid_amount)
        self.validateOfferLockValue(coin_from, coin_to, offer_data.lock_type, offer_data.lock_value)

        assert(offer_data.time_valid >= MIN_OFFER_VALID_TIME and offer_data.time_valid <= MAX_OFFER_VALID_TIME), 'Invalid time_valid'
        assert(msg['sent'] + offer_data.time_valid >= now), 'Offer expired'

        if offer_data.swap_type == SwapTypes.SELLER_FIRST:
            assert(len(offer_data.proof_address) == 0), 'Unexpected data'
            assert(len(offer_data.proof_signature) == 0), 'Unexpected data'
            assert(len(offer_data.pkhash_seller) == 0), 'Unexpected data'
            assert(len(offer_data.secret_hash) == 0), 'Unexpected data'
        elif offer_data.swap_type == SwapTypes.BUYER_FIRST:
            raise ValueError('TODO')
        else:
            raise ValueError('Unknown swap type {}.'.format(offer_data.swap_type))

        offer_id = bytes.fromhex(msg['msgid'])

        session = scoped_session(self.session_factory)
        # Check for sent
        existing_offer = self.getOffer(offer_id)
        if existing_offer is None:
            offer = Offer(
                offer_id=offer_id,

                coin_from=offer_data.coin_from,
                coin_to=offer_data.coin_to,
                amount_from=offer_data.amount_from,
                rate=offer_data.rate,
                min_bid_amount=offer_data.min_bid_amount,
                time_valid=offer_data.time_valid,
                lock_type=int(offer_data.lock_type),
                lock_value=offer_data.lock_value,
                swap_type=offer_data.swap_type,

                addr_from=msg['from'],
                created_at=msg['sent'],
                expire_at=msg['sent'] + offer_data.time_valid,
                was_sent=False)
            offer.setState(OfferStates.OFFER_RECEIVED)
            session.add(offer)
            self.log.debug('Received new offer %s', offer_id.hex())
        else:
            existing_offer.setState(OfferStates.OFFER_RECEIVED)
            session.add(existing_offer)
        session.commit()
        session.close()
        session.remove()

    def processBid(self, msg):
        self.log.debug('Processing bid msg %s', msg['msgid'])
        now = int(time.time())
        bid_bytes = bytes.fromhex(msg['hex'][2:-2])
        bid_data = BidMessage()
        bid_data.ParseFromString(bid_bytes)

        # Validate data
        assert(len(bid_data.offer_msg_id) == 28), 'Bad offer_id length'
        assert(bid_data.time_valid >= MIN_BID_VALID_TIME and bid_data.time_valid <= MAX_BID_VALID_TIME), 'Invalid time_valid'

        offer_id = bid_data.offer_msg_id
        offer = self.getOffer(offer_id, sent=True)
        assert(offer and offer.was_sent), 'Unknown offerid'

        assert(offer.state == OfferStates.OFFER_RECEIVED), 'Bad offer state'
        assert(msg['to'] == offer.addr_from), 'Received on incorrect address'
        assert(now <= offer.expire_at), 'Offer expired'
        assert(bid_data.amount >= offer.min_bid_amount), 'Bid amount below minimum'
        assert(now <= msg['sent'] + bid_data.time_valid), 'Bid expired'

        # TODO: allow higher bids
        # assert(bid_data.rate != offer['data'].rate), 'Bid rate mismatch'

        coin_to = Coins(offer.coin_to)
        swap_type = offer.swap_type
        if swap_type == SwapTypes.SELLER_FIRST:
            assert(len(bid_data.pkhash_buyer) == 20), 'Bad pkhash_buyer length'

            # Verify proof of funds
            bid_proof_address = replaceAddrPrefix(bid_data.proof_address, Coins.PART, self.chain)
            mm = chainparams[coin_to]['message_magic']
            passed = self.callcoinrpc(Coins.PART, 'verifymessage', [bid_proof_address, bid_data.proof_signature, bid_data.proof_address + '_swap_proof', mm])
            assert(passed is True), 'Proof of funds signature invalid'

            if self.coin_clients[coin_to]['use_segwit']:
                addr_search = self.encodeSegwit(coin_to, decodeAddress(bid_data.proof_address)[1:])
            else:
                addr_search = bid_data.proof_address

            sum_unspent = self.getAddressBalance(coin_to, addr_search)
            self.log.debug('Proof of funds %s %s', bid_data.proof_address, format8(sum_unspent))
            assert(sum_unspent >= bid_data.amount), 'Proof of funds failed'

        elif swap_type == SwapTypes.BUYER_FIRST:
            raise ValueError('TODO')
        else:
            raise ValueError('Unknown swap type {}.'.format(swap_type))

        bid_id = bytes.fromhex(msg['msgid'])

        bid = self.getBid(bid_id)
        if bid is None:
            bid = Bid(
                bid_id=bid_id,
                offer_id=offer_id,
                amount=bid_data.amount,
                pkhash_buyer=bid_data.pkhash_buyer,

                created_at=msg['sent'],
                amount_to=(bid_data.amount * offer.rate) // COIN,
                expire_at=msg['sent'] + bid_data.time_valid,
                bid_addr=msg['from'],
                was_received=True,
            )
        else:
            bid.created_at = msg['sent']
            bid.expire_at = msg['sent'] + bid_data.time_valid
            bid.was_received = True
        if len(bid_data.proof_address) > 0:
            bid.proof_address = bid_data.proof_address

        bid.setState(BidStates.BID_RECEIVED)

        self.log.info('Received valid bid %s for offer %s', bid_id.hex(), bid_data.offer_msg_id.hex())
        self.saveBid(bid_id, bid)

        # Auto accept bid if set and no other non-abandoned bid for this order exists
        if offer.auto_accept_bids:
            if self.countAcceptedBids(offer_id) > 0:
                self.log.info('Not auto accepting bid %s, already have', bid_id.hex())
            else:
                delay = random.randrange(self.min_delay_auto_accept, self.max_delay_auto_accept)
                self.log.info('Auto accepting bid %s in %d seconds', bid_id.hex(), delay)

                self.createEvent(delay, EventTypes.ACCEPT_BID, bid_id)

    def processBidAccept(self, msg):
        self.log.debug('Processing bid accepted msg %s', msg['msgid'])
        now = int(time.time())
        bid_accept_bytes = bytes.fromhex(msg['hex'][2:-2])
        bid_accept_data = BidAcceptMessage()
        bid_accept_data.ParseFromString(bid_accept_bytes)

        assert(len(bid_accept_data.bid_msg_id) == 28), 'Bad bid_msg_id length'
        assert(len(bid_accept_data.initiate_txid) == 32), 'Bad initiate_txid length'
        assert(len(bid_accept_data.contract_script) < 100), 'Bad contract_script length'

        self.log.debug('for bid %s', bid_accept_data.bid_msg_id.hex())

        bid_id = bid_accept_data.bid_msg_id
        bid, offer = self.getBidAndOffer(bid_id)
        assert(bid is not None and bid.was_sent is True), 'Unknown bidid'
        assert(offer), 'Offer not found ' + bid.offer_id.hex()
        coin_from = Coins(offer.coin_from)

        # assert(bid.expire_at > now), 'Bid expired'  # How much time over to accept

        if bid.state >= BidStates.BID_ACCEPTED:
            if bid.was_received:  # Sent to self
                self.log.info('Received valid bid accept %s for bid %s sent to self', bid.accept_msg_id.hex(), bid_id.hex())
                return
            raise ValueError('Wrong bid state: {}'.format(str(BidStates(bid.state))))

        use_csv = True if offer.lock_type < ABS_LOCK_BLOCKS else False

        # TODO: Verify script without decoding?
        decoded_script = self.callcoinrpc(Coins.PART, 'decodescript', [bid_accept_data.contract_script.hex()])
        lock_check_op = 'OP_CHECKSEQUENCEVERIFY' if use_csv else 'OP_CHECKLOCKTIMEVERIFY'
        prog = re.compile(r'OP_IF OP_SIZE 32 OP_EQUALVERIFY OP_SHA256 (\w+) OP_EQUALVERIFY OP_DUP OP_HASH160 (\w+) OP_ELSE (\d+) {} OP_DROP OP_DUP OP_HASH160 (\w+) OP_ENDIF OP_EQUALVERIFY OP_CHECKSIG'.format(lock_check_op))
        rr = prog.match(decoded_script['asm'])
        if not rr:
            raise ValueError('Bad script')
        scriptvalues = rr.groups()

        assert(len(scriptvalues[0]) == 64), 'Bad secret_hash length'
        assert(bytes.fromhex(scriptvalues[1]) == bid.pkhash_buyer), 'pkhash_buyer mismatch'

        script_lock_value = int(scriptvalues[2])
        if use_csv:
            expect_sequence = getExpectedSequence(offer.lock_type, offer.lock_value, coin_from)
            assert(script_lock_value == expect_sequence), 'sequence mismatch'
        else:
            if offer.lock_type == ABS_LOCK_BLOCKS:
                self.log.warning('TODO: validate absolute lock values')
            else:
                assert(script_lock_value <= bid.created_at + offer.lock_value + INITIATE_TX_TIMEOUT), 'script lock time too high'
                assert(script_lock_value >= bid.created_at + offer.lock_value), 'script lock time too low'

        assert(len(scriptvalues[3]) == 40), 'pkhash_refund bad length'

        assert(bid.accept_msg_id is None), 'Bid already accepted'

        bid.accept_msg_id = bytes.fromhex(msg['msgid'])
        bid.initiate_tx = SwapTx(
            bid_id=bid_id,
            tx_type=TxTypes.ITX,
            txid=bid_accept_data.initiate_txid,
            script=bid_accept_data.contract_script,
        )
        bid.pkhash_seller = bytes.fromhex(scriptvalues[3])
        bid.setState(BidStates.BID_ACCEPTED)
        bid.setITxState(TxStates.TX_NONE)

        self.log.info('Received valid bid accept %s for bid %s', bid.accept_msg_id.hex(), bid_id.hex())

        self.saveBid(bid_id, bid)
        self.swaps_in_progress[bid_id] = (bid, offer)

    def processMsg(self, msg):
        self.mxDB.acquire()
        try:
            msg_type = int(msg['hex'][:2], 16)

            rv = None
            if msg_type == MessageTypes.OFFER:
                self.processOffer(msg)
            elif msg_type == MessageTypes.BID:
                self.processBid(msg)
            elif msg_type == MessageTypes.BID_ACCEPT:
                self.processBidAccept(msg)

        except Exception as ex:
            self.log.error('processMsg %s', str(ex))
            traceback.print_exc()
        finally:
            self.mxDB.release()

    def processZmqSmsg(self):
        message = self.zmqSubscriber.recv()
        clear = self.zmqSubscriber.recv()

        if message[0] == 3:  # Paid smsg
            return  # TODO: Switch to paid?

        msg_id = message[2:]
        options = {'encoding': 'hex', 'setread': True}
        msg = self.callrpc('smsg', [msg_id.hex(), options])
        self.processMsg(msg)

    def update(self):
        try:
            # while True:
            message = self.zmqSubscriber.recv(flags=zmq.NOBLOCK)
            if message == b'smsg':
                self.processZmqSmsg()
        except zmq.Again as ex:
            pass
        except Exception as ex:
            self.log.error('smsg zmq %s', str(ex))
            traceback.print_exc()

        self.mxDB.acquire()
        try:
            # TODO: Wait for blocks / txns, would need to check multiple coins
            now = int(time.time())
            if now - self.last_checked_progress >= self.check_progress_seconds:
                to_remove = []
                for bid_id, v in self.swaps_in_progress.items():
                    try:
                        if self.checkBidState(bid_id, v[0], v[1]) is True:
                            to_remove.append(bid_id)
                    except Exception as ex:
                        self.log.error('checkBidState %s %s', bid_id.hex(), str(ex))
                        traceback.print_exc()
                        self.setBidError(bid_id, v[0], str(ex))

                for bid_id in to_remove:
                    self.log.debug('Removing bid from in-progress: %s', bid_id.hex())
                    del self.swaps_in_progress[bid_id]
                self.last_checked_progress = now

            if now - self.last_checked_watched >= self.check_watched_seconds:
                for k, c in self.coin_clients.items():
                    if len(c['watched_outputs']) > 0:
                        self.checkForSpends(k, c)
                self.last_checked_watched = now

            if now - self.last_checked_expired >= self.check_expired_seconds:
                self.expireMessages()
                self.last_checked_expired = now

            if now - self.last_checked_events >= self.check_events_seconds:
                self.checkEvents()
                self.last_checked_events = now

        except Exception as ex:
            self.log.error('update %s', str(ex))
            traceback.print_exc()
        finally:
            self.mxDB.release()

    def manualBidUpdate(self, bid_id, data):
        self.log.info('Manually updating bid %s', bid_id.hex())
        self.mxDB.acquire()
        try:
            bid, offer = self.getBidAndOffer(bid_id)
            assert(bid), 'Bid not found {}'.format(bid_id.hex())
            assert(offer), 'Offer not found {}'.format(bid.offer_id.hex())

            has_changed = False
            if bid.state != data['bid_state']:
                bid.setState(data['bid_state'])
                self.log.debug('Set state to %s', strBidState(bid.state))
                has_changed = True

            if has_changed:
                session = scoped_session(self.session_factory)
                try:
                    self.saveBidInSession(bid_id, bid, session)
                    session.commit()
                    if bid.state and bid.state > BidStates.BID_RECEIVED and bid.state < BidStates.SWAP_COMPLETED:
                        self.activateBid(session, bid)
                    else:
                        self.deactivateBid(offer, bid)
                finally:
                    session.close()
                    session.remove()
            else:
                raise ValueError('No changes')
        finally:
            self.mxDB.release()

    def editSettings(self, coin_name, data):
        self.log.info('Updating settings %s', coin_name)
        self.mxDB.acquire()
        try:
            if 'lookups' in data:
                self.settings['chainclients'][coin_name]['chain_lookups'] = data['lookups']
                settings_path = os.path.join(self.data_dir, 'basicswap.json')
                shutil.copyfile(settings_path, settings_path + '.last')
                with open(settings_path, 'w') as fp:
                    json.dump(self.settings, fp, indent=4)

                for c in self.coin_clients:
                    if c['name'] == coin_name:
                        c['chain_lookups'] = data['lookups']
        finally:
            self.mxDB.release()

    def getSummary(self, opts=None):
        num_watched_outputs = 0
        for c, v in self.coin_clients.items():
            num_watched_outputs += len(v['watched_outputs'])

        bids_sent = 0
        bids_received = 0
        q = self.engine.execute('SELECT was_sent, was_received, COUNT(*) FROM bids GROUP BY was_sent, was_received ')
        for r in q:
            if r[0]:
                bids_sent += r[2]
            if r[1]:
                bids_received += r[2]

        now = int(time.time())
        q = self.engine.execute('SELECT COUNT(*) FROM offers WHERE expire_at > {}'.format(now)).first()
        num_offers = q[0]

        q = self.engine.execute('SELECT COUNT(*) FROM offers WHERE was_sent = 1'.format(now)).first()
        num_sent_offers = q[0]

        rv = {
            'network': self.chain,
            'num_swapping': len(self.swaps_in_progress),
            'num_network_offers': num_offers,
            'num_sent_offers': num_sent_offers,
            'num_recv_bids': bids_received,
            'num_sent_bids': bids_sent,
            'num_watched_outputs': num_watched_outputs,
        }
        return rv

    def getWalletInfo(self, coin):

        blockchaininfo = self.callcoinrpc(coin, 'getblockchaininfo')
        walletinfo = self.callcoinrpc(coin, 'getwalletinfo')
        rv = {
            'version': self.coin_clients[coin]['core_version'],
            'deposit_address': self.getCachedAddressForCoin(coin),
            'name': chainparams[coin]['name'].capitalize(),
            'blocks': blockchaininfo['blocks'],
            'balance': format8(makeInt(walletinfo['balance'])),
            'unconfirmed': format8(makeInt(walletinfo.get('unconfirmed_balance'))),
            'synced': '{0:.2f}'.format(round(blockchaininfo['verificationprogress'], 2)),
        }
        return rv

    def getWalletsInfo(self, opts=None):
        rv = {}
        for c in Coins:
            if self.coin_clients[c]['connection_type'] == 'rpc':
                try:
                    rv[c] = self.getWalletInfo(c)
                except Exception as ex:
                    rv[c] = {'name': chainparams[c]['name'].capitalize(), 'error': str(ex)}
        return rv

    def countAcceptedBids(self, offer_id=None):
        self.mxDB.acquire()
        try:
            session = scoped_session(self.session_factory)
            if offer_id:
                q = self.engine.execute('SELECT COUNT(*) FROM bids WHERE state >= {} AND offer_id = x\'{}\''.format(BidStates.BID_ACCEPTED, offer_id.hex())).first()
            else:
                q = self.engine.execute('SELECT COUNT(*) FROM bids WHERE state >= {}'.format(BidStates.BID_ACCEPTED)).first()
            return q[0]
        finally:
            session.close()
            session.remove()
            self.mxDB.release()

    def listOffers(self, sent=False, filters={}):
        self.mxDB.acquire()
        try:
            rv = []
            now = int(time.time())
            session = scoped_session(self.session_factory)

            if sent:
                q = session.query(Offer).filter(Offer.was_sent == True)  # noqa E712
            else:
                q = session.query(Offer).filter(Offer.expire_at > now)

            filter_coin_from = filters.get('coin_from', None)
            if filter_coin_from and filter_coin_from > -1:
                q = q.filter(Offer.coin_from == int(filter_coin_from))
            filter_coin_to = filters.get('coin_to', None)
            if filter_coin_to and filter_coin_to > -1:
                q = q.filter(Offer.coin_to == int(filter_coin_to))

            order_dir = filters.get('sort_dir', 'desc')
            order_by = filters.get('order_by', 'created_at')
            if order_by == 'created_at':
                q = q.order_by(Offer.created_at.desc() if order_dir == 'desc' else Offer.created_at.asc())
            elif order_by == 'rate':
                q = q.order_by(Offer.rate.desc() if order_dir == 'desc' else Offer.rate.asc())

            limit = filters.get('limit', None)
            if limit is not None:
                q = q.limit(limit)
            offset = filters.get('offset', None)
            if offset is not None:
                q = q.offset(offset)
            for row in q:
                rv.append(row)
            return rv
        finally:
            session.close()
            session.remove()
            self.mxDB.release()

    def listBids(self, sent=False, offer_id=None, for_html=False):
        self.mxDB.acquire()
        try:
            rv = []
            now = int(time.time())
            session = scoped_session(self.session_factory)

            query_str = 'SELECT bids.created_at, bids.bid_id, bids.offer_id, bids.amount, bids.state, bids.was_received, tx1.state, tx2.state FROM bids ' + \
                        'LEFT JOIN transactions AS tx1 ON tx1.bid_id = bids.bid_id AND tx1.tx_type = {} '.format(TxTypes.ITX) + \
                        'LEFT JOIN transactions AS tx2 ON tx2.bid_id = bids.bid_id AND tx2.tx_type = {} '.format(TxTypes.PTX)

            if offer_id is not None:
                query_str += 'WHERE bids.offer_id = x\'{}\' '.format(offer_id.hex())
            elif sent:
                query_str += 'WHERE bids.was_sent = 1 '
            else:
                query_str += 'WHERE bids.was_received = 1 '
            query_str += 'ORDER BY bids.created_at DESC'
            q = self.engine.execute(query_str)
            for row in q:
                rv.append(row)
            return rv
        finally:
            session.close()
            session.remove()
            self.mxDB.release()

    def listSwapsInProgress(self, for_html=False):
        self.mxDB.acquire()
        try:
            rv = []
            for k, v in self.swaps_in_progress.items():
                rv.append((k, v[0].offer_id.hex(), v[0].state, v[0].getITxState(), v[0].getPTxState()))
            return rv
        finally:
            self.mxDB.release()

    def listWatchedOutputs(self):
        self.mxDB.acquire()
        try:
            rv = []
            rv_heights = []
            for c, v in self.coin_clients.items():
                if self.coin_clients[c]['connection_type'] == 'rpc':
                    rv_heights.append((c, v['last_height_checked']))
                for o in v['watched_outputs']:
                    rv.append((c, o[0], o[1], o[2], o[3]))
            return (rv, rv_heights)
        finally:
            self.mxDB.release()

    def listSmsgAddresses(self, use_type_str):
        use_type = MessageTypes.OFFER if use_type_str == 'offer' else MessageTypes.BID
        self.mxDB.acquire()
        try:
            session = scoped_session(self.session_factory)
            rv = []
            q = self.engine.execute('SELECT addr FROM smsgaddresses WHERE use_type = {} ORDER BY addr_id DESC'.format(use_type))
            for row in q:
                rv.append(row[0])
            return rv
        finally:
            session.close()
            session.remove()
            self.mxDB.release()

    def callrpc(self, method, params=[], wallet=None):
        return callrpc(self.coin_clients[Coins.PART]['rpcport'], self.coin_clients[Coins.PART]['rpcauth'], method, params, wallet)

    def callcoinrpc(self, coin, method, params=[], wallet=None):
        return callrpc(self.coin_clients[coin]['rpcport'], self.coin_clients[coin]['rpcauth'], method, params, wallet)

    def calltx(self, cmd):
        bindir = self.coin_clients[Coins.PART]['bindir']
        command_tx = os.path.join(bindir, cfg.PARTICL_TX)
        chainname = '' if self.chain == 'mainnet' else (' -' + self.chain)
        args = command_tx + chainname + ' ' + cmd
        p = subprocess.Popen(args, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
        out = p.communicate()
        if len(out[1]) > 0:
            raise ValueError('TX error ' + str(out[1]))
        return out[0].decode('utf-8').strip()

    def callcoincli(self, coin_type, params, wallet=None, timeout=None):
        bindir = self.coin_clients[coin_type]['bindir']
        datadir = self.coin_clients[coin_type]['datadir']
        command_cli = os.path.join(bindir, chainparams[coin_type]['name'] + '-cli' + ('.exe' if os.name == 'nt' else ''))
        chainname = '' if self.chain == 'mainnet' else (' -' + self.chain)
        args = command_cli + chainname + ' ' + '-datadir=' + datadir + ' ' + params
        p = subprocess.Popen(args, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE, shell=True)
        out = p.communicate(timeout=timeout)
        if len(out[1]) > 0:
            raise ValueError('CLI error ' + str(out[1]))
        return out[0].decode('utf-8').strip()