import attr
import random
import paho.mqtt.client
import requests
from ._common import log, kw_only
from . import _util, _exception, _session, _graphql, _events
from typing import Iterable, Optional, Mapping, List
HOST = "edge-chat.messenger.com"
TOPICS = [
# Things that happen in chats (e.g. messages)
"/t_ms",
# Group typing notifications
"/thread_typing",
# Private chat typing notifications
"/orca_typing_notifications",
# Active notifications
"/orca_presence",
# Other notifications not related to chats (e.g. friend requests)
"/legacy_web",
# Facebook's continuous error reporting/logging?
"/br_sr",
# Response to /br_sr
"/sr_res",
# Data about user-to-user calls
# TODO: Investigate the response from this! (A bunch of binary data)
# "/t_rtc",
# TODO: Find out what this does!
# TODO: Investigate the response from this! (A bunch of binary data)
# "/t_p",
# TODO: Find out what this does!
"/webrtc",
# TODO: Find out what this does!
"/onevc",
# TODO: Find out what this does!
"/notify_disconnect",
# Old, no longer active topics
# These are here just in case something interesting pops up
"/inbox",
"/mercury",
"/messaging_events",
"/orca_message_notifications",
"/pp",
"/webrtc_response",
]
def get_cookie_header(session: requests.Session, url: str) -> str:
"""Extract a cookie header from a requests session."""
# The cookies are extracted this way to make sure they're escaped correctly
return requests.cookies.get_cookie_header(
session.cookies, requests.Request("GET", url),
)
def generate_session_id() -> int:
"""Generate a random session ID between 1 and 9007199254740991."""
return random.randint(1, 2 ** 53)
def mqtt_factory() -> paho.mqtt.client.Client:
# Configure internal MQTT handler
mqtt = paho.mqtt.client.Client(
client_id="mqttwsclient",
clean_session=True,
protocol=paho.mqtt.client.MQTTv31,
transport="websockets",
)
mqtt.enable_logger()
# mqtt.max_inflight_messages_set(20) # The rest will get queued
# mqtt.max_queued_messages_set(0) # Unlimited messages can be queued
# mqtt.message_retry_set(20) # Retry sending for at least 20 seconds
# mqtt.reconnect_delay_set(min_delay=1, max_delay=120)
mqtt.tls_set()
mqtt.connect_async(HOST, 443, keepalive=10)
return mqtt
def fetch_sequence_id(session: _session.Session) -> int:
"""Fetch sequence ID."""
params = {
"limit": 0,
"tags": ["INBOX"],
"before": None,
"includeDeliveryReceipts": False,
"includeSeqID": True,
}
log.debug("Fetching MQTT sequence ID")
# Same doc id as in `Client.fetch_threads`
(j,) = session._graphql_requests(_graphql.from_doc_id("1349387578499440", params))
sequence_id = j["viewer"]["message_threads"]["sync_sequence_id"]
if not sequence_id:
raise _exception.NotLoggedIn("Failed fetching sequence id")
return int(sequence_id)
[docs]@attr.s(slots=True, kw_only=kw_only, eq=False)
class Listener:
"""Listen to incoming Facebook events.
Initialize a connection to the Facebook MQTT service.
Args:
session: The session to use when making requests.
chat_on: Whether ...
foreground: Whether ...
Example:
>>> listener = fbchat.Listener(session, chat_on=True, foreground=True)
"""
session = attr.ib(type=_session.Session)
_chat_on = attr.ib(type=bool)
_foreground = attr.ib(type=bool)
_mqtt = attr.ib(factory=mqtt_factory, type=paho.mqtt.client.Client)
_sync_token = attr.ib(None, type=Optional[str])
_sequence_id = attr.ib(None, type=Optional[int])
_tmp_events = attr.ib(factory=list, type=List[_events.Event])
def __attrs_post_init__(self):
# Configure callbacks
self._mqtt.on_message = self._on_message_handler
self._mqtt.on_connect = self._on_connect_handler
def _handle_ms(self, j):
"""Handle /t_ms special logic.
Returns whether to continue parsing the message.
"""
# TODO: Merge this with the parsing in _events
# Update sync_token when received
# This is received in the first message after we've created a messenger
# sync queue.
if "syncToken" in j and "firstDeltaSeqId" in j:
self._sync_token = j["syncToken"]
self._sequence_id = j["firstDeltaSeqId"]
return False
if "errorCode" in j:
error = j["errorCode"]
# TODO: 'F\xfa\x84\x8c\x85\xf8\xbc-\x88 FB_PAGES_INSUFFICIENT_PERMISSION\x00'
if error in ("ERROR_QUEUE_NOT_FOUND", "ERROR_QUEUE_OVERFLOW"):
# ERROR_QUEUE_NOT_FOUND means that the queue was deleted, since too
# much time passed, or that it was simply missing
# ERROR_QUEUE_OVERFLOW means that the sequence id was too small, so
# the desired events could not be retrieved
log.error(
"The MQTT listener was disconnected for too long,"
" events may have been lost"
)
# TODO: Find a way to tell the user that they may now be missing events
self._sync_token = None
self._sequence_id = None
return False
log.error("MQTT error code %s received", error)
return False
# Update last sequence id
# Except for the two cases above, this is always received
self._sequence_id = j["lastIssuedSeqId"]
return True
def _on_message_handler(self, client, userdata, message):
# Parse payload JSON
try:
j = _util.parse_json(message.payload.decode("utf-8"))
except (_exception.FacebookError, UnicodeDecodeError):
log.debug(message.payload)
log.exception("Failed parsing MQTT data on %s as JSON", message.topic)
return
log.debug("MQTT payload: %s, %s", message.topic, j)
if message.topic == "/t_ms":
if not self._handle_ms(j):
return
try:
# TODO: Don't handle this in a callback
self._tmp_events = list(
_events.parse_events(self.session, message.topic, j)
)
except _exception.ParseError:
log.exception("Failed parsing MQTT data")
def _on_connect_handler(self, client, userdata, flags, rc):
if rc == 21:
raise _exception.FacebookError(
"Failed connecting. Maybe your cookies are wrong?"
)
if rc != 0:
err = paho.mqtt.client.connack_string(rc)
log.error("MQTT Connection Error: %s", err)
return # Don't try to send publish if the connection failed
self._messenger_queue_publish()
def _messenger_queue_publish(self):
# configure receiving messages.
payload = {
"sync_api_version": 10,
"max_deltas_able_to_process": 1000,
"delta_batch_size": 500,
"encoding": "JSON",
"entity_fbid": self.session.user.id,
}
# If we don't have a sync_token, create a new messenger queue
# This is done so that across reconnects, if we've received a sync token, we
# SHOULD receive a piece of data in /t_ms exactly once!
if self._sync_token is None:
topic = "/messenger_sync_create_queue"
payload["initial_titan_sequence_id"] = str(self._sequence_id)
payload["device_params"] = None
else:
topic = "/messenger_sync_get_diffs"
payload["last_seq_id"] = str(self._sequence_id)
payload["sync_token"] = self._sync_token
self._mqtt.publish(topic, _util.json_minimal(payload), qos=1)
def _configure_connect_options(self):
# Generate a new session ID on each reconnect
session_id = generate_session_id()
username = {
# The user ID
"u": self.session.user.id,
# Session ID
"s": session_id,
# Active status setting
"chat_on": self._chat_on,
# foreground_state - Whether the window is focused
"fg": self._foreground,
# Can be any random ID
"d": self.session._client_id,
# Application ID, taken from facebook.com
"aid": 219994525426954,
# MQTT extension by FB, allows making a SUBSCRIBE while CONNECTing
"st": TOPICS,
# MQTT extension by FB, allows making a PUBLISH while CONNECTing
# Using this is more efficient, but the same can be acheived with:
# def on_connect(*args):
# mqtt.publish(topic, payload, qos=1)
# mqtt.on_connect = on_connect
# TODO: For some reason this doesn't work!
"pm": [
# {
# "topic": topic,
# "payload": payload,
# "qos": 1,
# "messageId": 65536,
# }
],
# Unknown parameters
"cp": 3,
"ecp": 10,
"ct": "websocket",
"mqtt_sid": "",
"dc": "",
"no_auto_fg": True,
"gas": None,
"pack": [],
}
self._mqtt.username_pw_set(_util.json_minimal(username))
headers = {
"Cookie": get_cookie_header(
self.session._session, "https://edge-chat.messenger.com/chat"
),
"User-Agent": self.session._session.headers["User-Agent"],
"Origin": "https://www.messenger.com",
"Host": HOST,
}
# TODO: Is region (lla | atn | odn | others?) important?
self._mqtt.ws_set_options(
path="/chat?sid={}".format(session_id), headers=headers
)
def _reconnect(self) -> bool:
# Try reconnecting
self._configure_connect_options()
try:
self._mqtt.reconnect()
return True
except (
# Taken from .loop_forever
paho.mqtt.client.socket.error,
OSError,
paho.mqtt.client.WebsocketConnectionError,
) as e:
log.debug("MQTT reconnection failed: %s", e)
# Wait before reconnecting
self._mqtt._reconnect_wait()
return False
[docs] def listen(self) -> Iterable[_events.Event]:
"""Run the listening loop continually.
This is a blocking call, that will yield events as they arrive.
This will automatically reconnect on errors, except if the errors are one of
`PleaseRefresh` or `NotLoggedIn`.
Example:
Print events continually.
>>> for event in listener.listen():
... print(event)
"""
if self._sequence_id is None:
self._sequence_id = fetch_sequence_id(self.session)
# Make sure we're connected
while not self._reconnect():
pass
yield _events.Connect()
while True:
rc = self._mqtt.loop(timeout=1.0)
# The sequence ID was reset in _handle_ms
# TODO: Signal to the user that they should reload their data!
if self._sequence_id is None:
self._sequence_id = fetch_sequence_id(self.session)
self._messenger_queue_publish()
# If disconnect() has been called
# Beware, internal API, may have to change this to something more stable!
if self._mqtt._state == paho.mqtt.client.mqtt_cs_disconnecting:
break # Stop listening
if rc != paho.mqtt.client.MQTT_ERR_SUCCESS:
# If known/expected error
if rc == paho.mqtt.client.MQTT_ERR_CONN_LOST:
yield _events.Disconnect(reason="Connection lost, retrying")
elif rc == paho.mqtt.client.MQTT_ERR_NOMEM:
# This error is wrongly classified
# See https://github.com/eclipse/paho.mqtt.python/issues/340
yield _events.Disconnect(reason="Connection error, retrying")
elif rc == paho.mqtt.client.MQTT_ERR_CONN_REFUSED:
raise _exception.NotLoggedIn("MQTT connection refused")
else:
err = paho.mqtt.client.error_string(rc)
log.error("MQTT Error: %s", err)
reason = "MQTT Error: {}, retrying".format(err)
yield _events.Disconnect(reason=reason)
while not self._reconnect():
pass
yield _events.Connect()
if self._tmp_events:
yield from self._tmp_events
self._tmp_events = []
[docs] def disconnect(self) -> None:
"""Disconnect the MQTT listener.
Can be called while listening, which will stop the listening loop.
The `Listener` object should not be used after this is called!
Example:
Stop the listener when receiving a message with the text "/stop"
>>> for event in listener.listen():
... if isinstance(event, fbchat.MessageEvent):
... if event.message.text == "/stop":
... listener.disconnect() # Almost the same "break"
"""
self._mqtt.disconnect()
[docs] def set_foreground(self, value: bool) -> None:
"""Set the ``foreground`` value while listening."""
# TODO: Document what this actually does!
payload = _util.json_minimal({"foreground": value})
info = self._mqtt.publish("/foreground_state", payload=payload, qos=1)
self._foreground = value
# TODO: We can't wait for this, since the loop is running within the same thread
# info.wait_for_publish()
[docs] def set_chat_on(self, value: bool) -> None:
"""Set the ``chat_on`` value while listening."""
# TODO: Document what this actually does!
# TODO: Is this the right request to make?
data = {"make_user_available_when_in_foreground": value}
payload = _util.json_minimal(data)
info = self._mqtt.publish("/set_client_settings", payload=payload, qos=1)
self._chat_on = value
# TODO: We can't wait for this, since the loop is running within the same thread
# info.wait_for_publish()
# def send_additional_contacts(self, additional_contacts):
# payload = _util.json_minimal({"additional_contacts": additional_contacts})
# info = self._mqtt.publish("/send_additional_contacts", payload=payload, qos=1)
#
# def browser_close(self):
# info = self._mqtt.publish("/browser_close", payload=b"{}", qos=1)
