class ChannelRequests(BitRequests):
"""BitRequests for making channel payments."""
HTTP_BITCOIN_PRICE = 'price'
HTTP_BITCOIN_MICROPAYMENT_SERVER = 'bitcoin-micropayment-server'
HTTP_BITCOIN_MICROPAYMENT_TOKEN = 'bitcoin-micropayment-token'
DEFAULT_DEPOSIT_AMOUNT = 100000
DEFAULT_DURATION = 86400
DEFAULT_CLOSE_AMOUNT = 1000
def __init__(self, wallet, deposit_amount=DEFAULT_DEPOSIT_AMOUNT, duration=DEFAULT_DURATION, close_amount=DEFAULT_CLOSE_AMOUNT):
"""Initialize the channel requests with a payment channel client."""
super().__init__()
from two1.lib.channels import PaymentChannelClient
self._channelclient = PaymentChannelClient(wallet)
self._deposit_amount = deposit_amount
self._duration = duration
self._close_amount = close_amount
def make_402_payment(self, response, max_price):
"""Make a channel payment."""
# Retrieve payment headers
price = response.headers.get(ChannelRequests.HTTP_BITCOIN_PRICE)
server_url = response.headers.get(ChannelRequests.HTTP_BITCOIN_MICROPAYMENT_SERVER)
# Verify that the payment method is supported
if price is None or server_url is None:
raise UnsupportedPaymentMethodError(
'Resource does not support channels payment method.')
# Convert string headers into correct data types
price = int(price)
# Verify resource cost against our budget
if max_price and price > max_price:
max_price_err = 'Resource price ({}) exceeds max price ({}).'
raise ValueError(max_price_err.format(price, max_price))
# Look up channel
channel_urls = self._channelclient.list(server_url)
channel_url = channel_urls[0] if channel_urls else None
if channel_url:
# Get channel status
status = self._channelclient.status(channel_url)
# Check if channel has expired
if status.ready and status.expired:
logger.debug("[ChannelRequests] Channel expired. Refreshing channel.")
self._channelclient.sync(channel_url)
channel_url = None
# Check if the channel balance is sufficient
elif status.ready and (status.balance - price) < self._close_amount:
logger.debug("[ChannelRequests] Channel balance low. Refreshing channel.")
self._channelclient.close(channel_url)
status = self._channelclient.status(channel_url)
logger.debug("[ChannelRequests] Channel spend txid is {}".format(status.spend_txid))
channel_url = None
# Open a new channel if we don't have a usable one
if not channel_url or not status.ready:
logger.debug("[ChannelRequests] Opening channel at {} with deposit {}.".format(channel_url, self._deposit_amount))
channel_url = self._channelclient.open(server_url, self._deposit_amount, self._duration, zeroconf=True, use_unconfirmed=True)
status = self._channelclient.status(channel_url)
logger.debug("[ChannelRequests] Channel deposit txid is {}".format(status.deposit_txid))
# Pay through the channel
logger.debug("[ChannelRequests] Paying channel {} with amount {}.".format(channel_url, price))
token = self._channelclient.pay(channel_url, price)
return {ChannelRequests.HTTP_BITCOIN_MICROPAYMENT_TOKEN: token}
def get_402_info(self, url):
"""Get channel payment information about the resource."""
response = requests.get(url)
price = response.headers.get(ChannelRequests.HTTP_BITCOIN_PRICE)
channel_url = response.headers.get(ChannelRequests.HTTP_BITCOIN_MICROPAYMENT_SERVER)
return {ChannelRequests.HTTP_BITCOIN_PRICE: price,
ChannelRequests.HTTP_BITCOIN_MICROPAYMENT_SERVER: channel_url}
