websockets.py

#!/usr/bin/env python
#
# Electrum - lightweight Bitcoin client
# Copyright (C) 2015 Thomas Voegtlin
#
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation files
# (the "Software"), to deal in the Software without restriction,
# including without limitation the rights to use, copy, modify, merge,
# publish, distribute, sublicense, and/or sell copies of the Software,
# and to permit persons to whom the Software is furnished to do so,
# subject to the following conditions:
#
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.
import threading
import os
import json
from collections import defaultdict
import asyncio
from typing import Dict, List, Tuple, TYPE_CHECKING
import traceback
import sys

try:
    from SimpleWebSocketServer import WebSocket, SimpleSSLWebSocketServer
except ImportError:
    sys.exit("install SimpleWebSocketServer")

from . import bitcoin
from .synchronizer import SynchronizerBase
from .logging import Logger

if TYPE_CHECKING:
    from .network import Network
    from .simple_config import SimpleConfig


request_queue = asyncio.Queue()


class ElectrumWebSocket(WebSocket, Logger):

    def __init__(self):
        WebSocket.__init__(self)
        Logger.__init__(self)

    def handleMessage(self):
        assert self.data[0:3] == 'id:'
        self.logger.info(f"message received {self.data}")
        request_id = self.data[3:]
        asyncio.run_coroutine_threadsafe(
            request_queue.put((self, request_id)), asyncio.get_event_loop())

    def handleConnected(self):
        self.logger.info(f"connected {self.address}")

    def handleClose(self):
        self.logger.info(f"closed {self.address}")


class BalanceMonitor(SynchronizerBase):

    def __init__(self, config: 'SimpleConfig', network: 'Network'):
        SynchronizerBase.__init__(self, network)
        self.config = config
        self.expected_payments = defaultdict(list)  # type: Dict[str, List[Tuple[WebSocket, int]]]

    def make_request(self, request_id):
        # read json file
        rdir = self.config.get('requests_dir')
        n = os.path.join(rdir, 'req', request_id[0], request_id[1], request_id, request_id + '.json')
        with open(n, encoding='utf-8') as f:
            s = f.read()
        d = json.loads(s)
        addr = d.get('address')
        amount = d.get('amount')
        return addr, amount

    async def main(self):
        # resend existing subscriptions if we were restarted
        for addr in self.expected_payments:
            await self._add_address(addr)
        # main loop
        while True:
            ws, request_id = await request_queue.get()
            try:
                addr, amount = self.make_request(request_id)
            except Exception:
                self.logger.exception('')
                continue
            self.expected_payments[addr].append((ws, amount))
            await self._add_address(addr)

    async def _on_address_status(self, addr, status):
        self.logger.info(f'new status for addr {addr}')
        sh = bitcoin.address_to_scripthash(addr)
        balance = await self.network.get_balance_for_scripthash(sh)
        for ws, amount in self.expected_payments[addr]:
            if not ws.closed:
                if sum(balance.values()) >= amount:
                    ws.sendMessage('paid')


class WebSocketServer(threading.Thread):

    def __init__(self, config: 'SimpleConfig', network: 'Network'):
        threading.Thread.__init__(self)
        self.config = config
        self.network = network
        asyncio.set_event_loop(network.asyncio_loop)
        self.daemon = True
        self.balance_monitor = BalanceMonitor(self.config, self.network)
        self.start()

    def run(self):
        asyncio.set_event_loop(self.network.asyncio_loop)
        host = self.config.get('websocket_server')
        port = self.config.get('websocket_port', 9999)
        certfile = self.config.get('ssl_chain')
        keyfile = self.config.get('ssl_privkey')
        self.server = SimpleSSLWebSocketServer(host, port, ElectrumWebSocket, certfile, keyfile)
        self.server.serveforever()