class Nerd_Plugin_Virtual(EventEmitter):
'''
### LedgerPlugin API ###
Create a Nerd plugin
'''
def __init__(self, opts):
super().__init__()
# DEBUGGING
self.DEBUG = None
self._handle = lambda err: self.emit('exception', err)
on_exception = lambda err: self._log('Exception {}'.format(err))
self.on('exception', on_exception)
# self.id = opts['id'] # compatibility with five-bells-connector?
self.auth = opts['auth']
self.store = opts['store']
self.timers = dict()
self.transfer_log = Transfer_Log(opts['store'])
self.connected = False
self.connection_config = opts['auth']
self.connection = Connection(self.connection_config)
on_receive = lambda obj: self._receive(obj).catch(self._handle)
self.connection.on('receive', on_receive)
self.balance = Balance({
'store': opts['store'],
'limit': opts['auth']['limit'],
'balance': opts['auth']['balance']
})
self.balance.on('_balanceChanged', self.on_balance_change)
self.balance.on('_settlement', self.on_settlement)
self._log("Initialized Nerd Plugin Virtual: {}".format(self.auth))
def on_balance_change(self, balance):
self._log('balance changed to ' + balance)
self.emit('_balanceChanged')
self._send_balance()
def on_settlement(self, balance):
self._log('you should settle your balance of ' + balance)
self.emit('settlement', balance)
self._send_settle()
def get_account(self):
return self.auth['account']
def connect(self):
self.connection.connect()
def fulfill_connect(resolve, reject):
def noob_connect():
self.connected = True
self.emit('connect')
resolve(None)
self.connection.on('connect', noob_connect())
return Promise(fulfill_connect)
def disconnect(self):
def fulfill_disconnect():
self.connected = False
self.emit('disconnect')
return Promise.resolve(None)
return self.connection.disconnect().then(success=fulfill_disconnect)
def is_connected(self):
return self.connected
def get_connectors(self):
# Currently, only connections between two plugins are supported
# Thus, the list is empty
return Promise.resolve([])
def send(self, outgoing_transfer):
self._log("sending out a Transfer with tid: {}"
.format(outgoing_transfer['id']))
def send_then():
self.connection.send({
'type': 'transfer',
'transfer': outgoing_transfer
})
return self.transfer_log.store_outgoing(outgoing_transfer) \
.then(send_then()) \
.catch(self._handle)
def get_info(self):
# Using placeholder values in promise resolution
# TO-DO: What should these values be
return Promise.resolve({
'precision': '15',
'scale': '15',
'currencyCode': 'GBP',
'currencySymbol': '$'
})
def fulfill_condition(self, transfer_id, fulfillment_buffer):
fulfillment = str(fulfillment_buffer)
transfer = None
self._log('fulfilling: ' + fulfillment)
def fulfill_condition_then(stored_transfer):
transfer = stored_transfer
return self._fulfill_condition_local(transfer, fulfillment)
return self.transfer_log.get_id(transfer_id) \
.then(fulfill_condition_then) \
.catch(self._handle)
def _validate(self, fulfillment, condition):
try:
parsed_fulfillment = cc.Fulfillment.from_uri(fulfillment)
is_valid = condition == parsed_fulfillment.condition_uri
return is_valid
except Exception:
return False
def _fulfill_condition_local(self, transfer, fulfillment):
if not transfer:
raise Exception('got transfer ID for nonexistent transfer')
elif not transfer['executionCondition']:
raise Exception('got transfer ID for OTP transfer')
def _fulfill_condition_local_then(fulfilled):
if fulfilled:
raise Exception('this transfer has already been fulfilled')
else:
return Promise.resolve(None)
def _fulfill_transfer_then():
execute = transfer['executionCondition']
cancel = transfer['cancellationCondition']
# FIX DATETIME ISSUES HERE
time = str(datetime.isoformat(datetime.now()))
expires_at = str(datetime(transfer['expiresAt']))
timed_out = time > expires_at
if self._validate(fulfillment, execute) and not timed_out:
return self._execute_transfer(transfer, fulfillment)
elif cancel and self._validate(fulfillment, cancel):
return self._cancel_transfer(transfer, fulfillment)
elif timed_out:
return self._timeout_transfer(transfer)
else:
raise Exception('Invalid fulfillment')
return self.transfer_log.is_fulfilled(transfer) \
.then(_fulfill_condition_local_then) \
.then(_fulfill_transfer_then) \
.catch(self._handle)
def _execute_transfer(self, transfer, fulfillment):
fulfillment_buffer = fulfillment.encode('utf-8')
self.emit('fulfill_execution_condition', transfer, fulfillment_buffer)
# Because there is only one balance kept,
# money is not actually kept in escrow
# although it behaves as though it were
# So there is nothing to do for the execution condition
def _execute_transfer_then(type):
if type == self.transfer_log.outgoing:
return self.balance.add(transfer['amount'])
elif type == self.transfer_log.incoming:
return self.balance.sub(transfer['amount'])
else:
raise Exception("nonexistent transfer type")
return self.transfer_log.get_type(transfer) \
.then(_execute_transfer_then) \
.then(lambda _: self.transfer_log.fulfill(transfer)) \
.then(lambda _: self.connection.send({
'type': 'fulfill_execution_condition',
'transfer': transfer,
'fulfillment': fulfillment
})) \
.catch(self._handle)
def _cancel_transfer(self, transfer, fulfillment):
fulfillment_buffer = fulfillment.encode('utf-8')
self.emit('fulfill_cancellation_condition', transfer, fulfillment_buffer)
# A cancellation on an outgoing transfer means nothing
# because balances aren't affected until it executes
def _cancel_transfer_then(type):
if type == self.transfer_log.incoming:
return self.balance.add(transfer['amount'])
return self.transfer_log.get_type(transfer) \
.then(_cancel_transfer_then) \
.then(lambda _: self.transfer_log.fulfill(transfer)) \
.then(lambda _: self.connection.send({
'type': 'fulfill_cancellation_condition',
'transfer': transfer,
'fulfillment': fulfillment
}))
def _timeout_transfer(self, transfer):
self.emit('reject', transfer, 'timed out')
transaction_type = None
def _timeout_transfer_then(type):
transaction_type = type
if type == self.transfer_log.incoming:
return self.balance.add(transfer['amount'])
def _fulfill_transfer_then():
# potential problem here: figure out how to get transaction_type
# into the scope of this callback
if transaction_type == self.transfer_log.incoming:
return self.connection.send({
'type': 'reject',
'transfer': transfer,
'message': 'timed out'
})
else:
return Promise.resolve(None)
return self.transfer_log.get_type(transfer) \
.then(_timeout_transfer_then) \
.then(lambda: self.transfer_log.fulfill(transfer)) \
.then(_fulfill_transfer_then)
def get_balance(self):
return self.balance.get()
def reply_to_transfer(self, transfer_id, reply_message):
return self.transfer_log.get_id(transfer_id) \
.then(lambda stored_transfer: self.connection.send({
'type': 'reply',
'transfer': stored_transfer,
'message': reply_message
}))
def _receive(self, obj):
'''
Cases:
* obj.type == transfer
* obj.type == acknowledge
* obj.type == reject
* obj.type == reply
* obj.type == fulfillment
* obj.type == balance
* obj.type == info
'''
if obj['type'] == 'transfer':
self._log('received a Transfer with tid: ' + obj['transfer']['id'])
self.emit('receive', obj['transfer'])
return self._handle_transfer(obj['transfer'])
elif obj['type'] == 'acknowledge':
self._log('received an ACK on tid: ' + obj['transfer']['id'])
self.emit('accept', obj['transfer'], obj['message'].encode('utf-8'))
return self._handle_acknowledge(obj['transfer'])
elif obj['type'] == 'reject':
self._log('received a reject on tid: ' + obj['transfer']['id'])
self.emit('reject', obj['transfer'], obj['message'].encode('utf-8'))
return self._handle_reject(obj['transfer'])
elif obj['type'] == 'reply':
self._log('received a reply on tid: ' + obj['transfer']['id'])
def _receive_reply_then(transfer):
self.emit('reply', transfer, obj['message'].encode('utf-8'))
return Promise.resolve(None)
return self.transfer_log.get_id(obj['transfer']['id']) \
.then(_receive_reply_then)
elif obj['type'] == 'fulfillment':
self._log('received a fulfillment for tid: ' + obj['transfer']['id'])
def _receive_fulfillment_then(transfer):
self.emit('fulfillment', transfer, obj['fulfillment'].encode('utf-8'))
return self._fulfill_condition_local(transfer, obj['fulfillment'])
return self.transfer_log.get_id(obj['transfer']['id']) \
.then(_receive_fulfillment_then)
elif obj['type'] == 'balance':
self._log('received a query for the balance...')
return self._send_balance()
elif obj['type'] == 'info':
return self._send_info()
else:
self._handle(Exception('Invalid message received'))
def _handle_reject(self, transfer):
def _handle_reject_then(exists):
if exists:
print("_handle_reject_then exists")
self._complete_transfer(transfer)
else:
self.emit('_falseReject', transfer)
# used for debugging purposes
return self.transfer_log.exists(transfer) \
.then(_handle_reject_then)
def _send_balance(self):
def _send_balance_then(balance):
self._log('sending balance: ' + balance)
return self.connection.send({
'type': 'balance',
'balance': balance
})
return self.balance.get() \
.then(_send_balance_then)
def _send_settle(self):
def _send_settle_then(balance):
self._log('sending settlement notification: ' + balance)
return self.connection.send({
'type': 'settlement',
'balance': balance
})
return self.balance.get() \
.then(_send_settle_then)
def _send_info(self):
return self.get_info() \
.then(lambda info: self.connection.send({
'type': 'info',
'info': info
}))
def _handle_transfer(self, transfer):
def _handle_transfer_then(stored_transfer):
def _repeat_transfer():
raise Exception('repeat transfer id')
if stored_transfer:
self.emit('_repeateTransfer', transfer)
return self._reject_transfer(transfer, 'repeat transfer id') \
.then(_repeat_transfer)
else:
return Promise.resolve(None)
def is_valid_incoming_then(valid):
def is_valid_then(_):
self._handle_timer(transfer)
self._accept_transfer(transfer)
if valid:
return self.balance.sub(transfer['amount']) \
.then(is_valid_then)
else:
return self._reject_transfer(transfer, 'invalid transfer amount')
return self.transfer_log.get(transfer) \
.then(_handle_transfer_then) \
.then(lambda _: self.transfer_log.store_incoming(transfer)) \
.then(lambda _: self.balance.is_valid_incoming(transfer['amount'])) \
.then(is_valid_incoming_then) \
.catch(self._handle)
def _handle_acknowledge(self, transfer):
def _handle_acknowledge_then(stored_transfer):
if equals(stored_transfer, transfer):
return self.transfer_log.is_complete(transfer)
else:
self._false_acknowledge(transfer)
def is_complete_transfer_then(is_complete):
self.DEBUG = transfer
if is_complete:
self._false_acknowledge(transfer)
# don't add to balance yet if it's UTP/ATP transfer
elif not transfer['executionCondition']:
self.balance.add(transfer['amount'])
def acknowledge_transfer_then(_):
self._handle_timer(transfer)
self._complete_transfer(transfer)
return self.transfer_log.get(transfer) \
.then(_handle_acknowledge_then) \
.then(is_complete_transfer_then) \
.then(acknowledge_transfer_then)
def _false_acknowledge(self, transfer):
self.emit('_falseAcknowledge', transfer)
raise Exception("Received false acknowledge for tid: " + transfer['id'])
def _handle_timer(self, transfer):
if transfer['expiresAt']:
now = datetime.now(pytz.utc)
expiry = dateutil.parser.parse(transfer['expiresAt'])
def timer():
def timer_then(is_fulfilled):
if not is_fulfilled:
self._timeout_transfer(transfer)
self._log('automatic timeout on tid: ' + transfer['id'])
self.transfer_log.is_fulfilled(transfer) \
.then(timer_then) \
.catch(self._handle)
self.timers[transfer['id']] = Timer(5, timer)
self.timers[transfer['id']].start()
# for debugging purposes
self.emit('_timing', transfer['id'])
def _accept_transfer(self, transfer):
self._log('sending out an ACK for tid: ' + transfer['id'])
return self.connection.send({
'type': 'acknowledge',
'transfer': transfer,
'message': 'transfer accepted'
})
def _reject_transfer(self, transfer, reason):
self._log('sending out a reject for tid: ' + transfer['id'])
self._complete_transfer(transfer)
return self.connection.send({
'type': 'reject',
'transfer': transfer,
'message': reason
})
def _complete_transfer(self, transfer):
promises = list(self.transfer_log.complete(transfer))
if not transfer['executionCondition']:
promises.append(self.transfer_log.fulfill(transfer))
return Promise.all(promises)
def _log(self, msg):
log.log("{}: {}".format(self.auth['account'], msg))
class Noob_Plugin_Virtual(EventEmitter):
'''
Create a Noob plugin
@param opts
@param opts.store
@param opts.auth
@param opts.auth.account
@param opts.auth.token
@param opts.auth.host
'''
def __init__(self, opts):
self.DEBUG = None # for debugging
super().__init__()
# self.id = opts.id
# Compatibility with five bells connector; is this necessary?
self.auth = opts['auth']
self.connected = False
self.connection_config = opts['auth']
self.connection = Connection(self.connection_config)
on_receive = lambda obj: self._receive(obj).catch(self._handle)
self.connection.on('receive', on_receive)
self.connection.on('disconnect', self.disconnect)
self._expects = dict()
self._seen = dict()
self._fulfilled = dict()
self._log("Initialized Noob Plugin Virtual: {}".format(self.auth))
def _handle(self, err):
self.emit('exception', err)
raise err
def can_connect_to_ledger(self, auth):
implement()
def _log(self, msg):
log.log(self.auth['account'] + ': ' + msg)
def _expect_response(self, tid):
self._expects[tid] = True
def _expected_response(self, tid):
if tid not in self._expects:
self._expect_response(tid)
return self._expects[tid]
def _receive_response(self, tid):
self._expects[tid] = False
def _see_transfer(self, tid):
self._seen[tid] = True
def _seen_transfer(self, tid):
return tid in self._seen
def _fulfill_transfer(self, tid):
self._fulfilled[tid] = True
def _fulfilled_transfer(self, tid):
if tid not in self._fulfilled:
self._fulfilled[tid] = False
return self._fulfilled[tid]
def _receive(self, obj):
'''
Cases:
* obj.type == transfer && not seen_transfer(obj.transfer.id)
* obj.type == acknowledge && expected_response(obj.transfer.id)
* obj.type == fulfill_execution_condition &&
not fulfilled_transfer(obj.transfer.id)
* obj.type == fulfill_cancellation_condition &&
not fulfilled_trasnfer(obj.transfer.id)
* obj.type == reject && not fulfilled_transfer(obj.transfer.id)
* obj.type == reply
* obj.type == balance
* obj.type == info
* obj.type == settlement
'''
print('_receive called with obj: {}, type: {}'.format(obj, type(obj))) # debugging
if type(obj) is not dict:
self._log("unexpected non-JSON message: '{}'".format(obj))
return Promise.resolve(None)
self.DEBUG = obj # debugging
if obj['type'] == 'transfer' \
and not self._seen_transfer(obj['transfer']['id']):
self._see_transfer(obj['transfer']['id'])
self._log('received a Transfer with tid {}'
.format(obj['transfer']['id']))
self.emit("receive", obj['transfer'])
return self.connection.send({
"type": "acknowledge",
"transfer": obj['transfer'],
"message": "transfer accepted"
})
elif obj['type'] == 'acknowledge' \
and self._expected_response(obj['transfer']['id']):
self._receive_response(obj['transfer']['id'])
self._log('received an ACK on tid: {}'
.format(obj['transfer']['id']))
# TO-DO: Should accept be fulfill execution condition in OTP
self.emit("accept",
obj['transfer'],
obj['message'].encode('utf-8'))
return Promise.resolve(None)
elif obj['type'] == 'fulfill_execution_condition' \
and not self._fulfilled_transfer(obj['transfer']['id']):
self.emit("fulfill_execution_condition",
obj['transfer'],
obj['fulfillment'].encode('utf-8'))
self._fulfill_transfer(obj['transfer']['id'])
return Promise.resolve(None)
elif obj['type'] == 'fulfill_cancellation_condtion' \
and not self._fulfilled_transfer(obj['transfer']['id']):
self.emit('fullfill_cancellation_condition',
obj['transfer'],
obj['fulfillment'].encode('utf-8'))
self._fulfill_transfer(obj['transfer']['id'])
return Promise.resolve(None)
elif obj['type'] == 'reject' \
and not self._fulfilled_transfer(obj['transfer']['id']):
self._log('received a reject on tid: {}'
.format(obj['transfer']['id']))
self.emit('reject',
obj['transfer'],
obj['message'].encode('utf-8'))
return Promise.resolve(None)
elif obj['type'] == 'reply':
self._log('received a reply on tid: {}'
.format(obj['transfer']['id']))
self.emit('reply',
obj['transfer'],
obj['message'].encode('utf-8'))
return Promise.resolve(None)
elif obj['type'] == 'balance':
self._log('received balance: {}'.format(obj['balance']))
self.emit('balance', obj['balance'])
return Promise.resolve(None)
elif obj['type'] == 'info':
self.log('received info.')
self.emit('_info', obj['info'])
return Promise.resolve(None)
elif obj['type'] == 'settlement':
self._log('received settlement notification.')
self.emit('settlement', obj['balance'])
return Promise.resolve(None)
else:
raise Exception("Invalid message received")
return Promise.resolve(None)
def connect(self):
self.connection.connect()
def fulfill_connect(resolve, reject):
def noob_connect():
self.connected = True
self.emit('connect')
resolve(None)
self.connection.on('connect', noob_connect())
return Promise(fulfill_connect)
def disconnect(self):
def fulfill_disconnect():
self.connected = False
self.emit('disconnect')
return Promise.resolve(None)
return self.connection.disconnect().then(success=fulfill_disconnect)
def is_connected(self):
return self.connected
def get_connectors(self):
# Currently, only connections between two plugins are supported
# Thus, the list is empty
return Promise.resolve([])
def send(self, outgoing_transfer):
self._log("Sending out a Transfer with tid: {}"
.format(outgoing_transfer['id']))
self._expect_response(outgoing_transfer['id'])
return self.connection.send({
"type": "transfer",
"transfer": outgoing_transfer
}).catch(self._handle)
def get_balance(self):
self._log("sending balance query...")
self.connection.send({
"type": "balance"
})
def fulfill_get_balance(resolve, reject):
self.once("balance", lambda balance: resolve(balance))
return Promise(fulfill_get_balance)
def get_info(self):
self._log("sending getInfo query...")
self.connection.send({
"type": "info"
})
def fulfill_get_info(resolve, reject):
self.once("_info", lambda info: resolve(info))
return Promise(fulfill_get_info)
def get_account(self):
return self.auth['account']
def fulfill_condition(self, transfer_id, fulfillment):
return self.connection.send({
"type": "fulfillment",
"transferId": transfer_id,
"fulfillment": fulfillment
})
def reply_to_transfer(self, transfer_id, reply_message):
return self.connection.send({
"type": "reply",
"transferId": transfer_id,
"message": reply_message
})