from __future__ import annotations
import asyncio
import functools
import inspect
import json
import logging
import re
import time
from collections.abc import Coroutine
from typing import Any, Callable, Dict, Type, List, Optional, TYPE_CHECKING, Tuple
import slixmpp
import slixmpp.exceptions
from slixmpp import ElementBase
from slixmpp.xmlstream import ET
import xml.sax.saxutils
from pyobs.comm import Comm
from pyobs.events import Event, LogEvent, ModuleOpenedEvent, ModuleClosedEvent
from pyobs.events.event import EventFactory
from pyobs.interfaces import Interface
from pyobs.utils import exceptions as exc
from .rpc import RPC
from .xmppclient import XmppClient
if TYPE_CHECKING:
from pyobs.modules import Module
log = logging.getLogger(__name__)
class EventStanza(ElementBase): # type: ignore
name = "event"
namespace = "pyobs:event"
class XmppComm(Comm):
"""A Comm class using XMPP.
This Comm class uses an XMPP server (e.g. `ejabberd <https://www.ejabberd.im>`_) for communication between modules.
Essentially required for a connection to the server is a JID, a JabberID. It can be specified in the configuration
like this::
comm:
class: pyobs.comm.xmpp.XmppComm
jid: someuser@example.com/pyobs
Using this, *pyobs* tries to connect to example.com as user ``someuser`` with resource ``pyobs``. Since ``pyobs``
is the default resource, it can be omitted::
jid: someuser@example.com
Alternatively, one can split the user, domain, and resource (if required) into three different parameters::
user: someuser
domain: example.com
This comes in handy, if one wants to put the basic Comm configuration into a separate file. Imagine a ``_comm.yaml``
in the same directory as the module config::
comm_cfg: &comm
class: pyobs.comm.sleekxmpp.XmppComm
domain: example.com
Now in the module configuration, one can simply do this::
{include _comm.yaml}
comm:
<<: *comm
user: someuser
password: supersecret
This allows for a super easy change of the domain for all configurations, which especially makes developing on
different machines a lot easier.
The ``server`` parameter can be used, when the server's hostname is different from the XMPP domain. This might,
e.g., be the case, when connecting to a server via SSH port forwarding::
jid: someuser@example.com/pyobs
server: localhost:52222
Finally, always make sure that ``use_tls`` is set according to the server's settings, i.e. if it uses TLS, this
parameter must be True, and False otherwise. Cryptic error messages will follow, if one does not set this properly.
"""
__module__ = "pyobs.comm.xmpp"
def __init__(
self,
jid: Optional[str] = None,
user: Optional[str] = None,
domain: Optional[str] = None,
resource: str = "pyobs",
password: str = "",
server: Optional[str] = None,
use_tls: bool = False,
*args: Any,
**kwargs: Any,
):
"""Create a new XMPP Comm module.
Either a fill JID needs to be provided, or a set of user/domian/resource, from which a JID is built.
Args:
jid: JID to connect as.
user: Username part of the JID.
domain: Domain part of the JID.
resource: Resource part of the JID.
password: Password for given JID.
server: Server to connect to. If not given, domain from JID is used.
use_tls: Whether or not to use TLS.
"""
Comm.__init__(self, *args, **kwargs)
# variables
self._connected = False
self._online_clients: List[str] = []
self._interface_cache: Dict[str, asyncio.Future[List[Type[Interface]]]] = {}
self._user = user
self._password = password
self._domain = domain
self._resource = resource
self._server = server
self._use_tls = use_tls
self._loop = asyncio.get_event_loop()
self._safe_send_attempts = 5
self._safe_send_wait = 1
self._module: Optional[Module] = None
# build jid
if jid:
# resource given in jid?
if "/" not in jid:
jid += "/" + resource
# get user/domain/resource and write it back to config
m = re.match(r"([\w_\-\.]+)@([\w_\-\.]+)\/([\w_\-\.]+)", jid)
if not m:
log.error("Invalid JID format.")
raise ValueError()
self._user = m.group(1)
self._domain = m.group(2)
self._resource = m.group(3)
# set jid itself
self._jid = jid
else:
self._jid = "%s@%s/%s" % (self._user, self._domain, self._resource)
# client and RPC handler
self._xmpp: Optional[XmppClient] = None
self._rpc: Optional[RPC] = None
def _set_module(self, module: Module) -> None:
"""Called, when the module connected to this Comm changes.
Args:
module: The module.
"""
self._module = module
[docs] async def open(self) -> None:
"""Open the connection to the XMPP server.
Returns:
Whether opening was successful.
"""
# create client
self._xmpp = XmppClient(self._jid, self._password)
# self._xmpp = slixmpp.ClientXMPP(self._jid, password)
self._xmpp.add_event_handler("pubsub_publish", self._handle_event)
self._xmpp.add_event_handler("got_online", self._got_online)
self._xmpp.add_event_handler("got_offline", self._got_offline)
# server given?
server = () if self._server is None else tuple(self._server.split(":"))
# add features
if self._module is not None:
for i in self._module.interfaces:
self._xmpp["xep_0030"].add_feature("pyobs:interface:%s" % i.__name__)
# RPC
self._rpc = RPC(self, self._xmpp, None)
self._rpc.set_handler(self._module)
# connect
self._xmpp.connect(address=server, force_starttls=self._use_tls, disable_starttls=not self._use_tls)
self._xmpp.init_plugins()
# wait for connected
if not await self._xmpp.wait_connect():
if self.module is not None:
self.module.quit()
return
# subscribe to events
await self.register_event(LogEvent)
# open Comm
await Comm.open(self)
# wait a little and finished
await asyncio.sleep(1)
self._connected = True
[docs] async def close(self) -> None:
"""Close connection."""
# close parent class
await Comm.close(self)
# disconnect from sleekxmpp server
await self._xmpp.disconnect()
@property
def name(self) -> Optional[str]:
"""Name of this client."""
return self._user
def _failed_auth(self, event: Any) -> None:
"""Authentication failed.
Args:
event: XMPP event.
"""
print("Authorization at server failed.")
def _get_full_client_name(self, name: str) -> str:
"""Builds full JID from a given username.
Args:
name: Username to build JID for.
Returns:
Full JID for given user.
"""
return name if "@" in name else "%s@%s/%s" % (name, self._domain, self._resource)
[docs] async def get_interfaces(self, client: str) -> List[Type[Interface]]:
"""Returns list of interfaces for given client.
Args:
client: Name of client.
Returns:
List of supported interfaces.
Raises:
IndexError: If client cannot be found.
"""
# full JID given?
if "@" not in client:
client = "%s@%s/%s" % (client, self._domain, self._resource)
# return them from cache
return await self._interface_cache[client]
async def _get_interfaces(self, jid: str, attempts: int = 3) -> List[str]:
"""Return list of interfaces for the given JID.
Args:
jid: JID to get interfaces for.
Returns:
List of interface names or empty list, if an error occurred.
"""
# request features
try:
info = await self._safe_send(self._xmpp["xep_0030"].get_info, jid=jid, cached=False)
except (slixmpp.exceptions.IqError, slixmpp.exceptions.IqTimeout):
return []
# extract pyobs interface names
if info is None:
return []
try:
if isinstance(info, slixmpp.stanza.iq.Iq):
info = info["disco_info"]
prefix = "pyobs:interface:"
interface_names = [i[len(prefix) :] for i in info["features"] if i.startswith(prefix)]
except TypeError:
raise IndexError()
# IModule not in list?
if "IModule" not in interface_names:
# try again or quit?
if attempts == 0:
return []
else:
await asyncio.sleep(5)
interface_names = await self._get_interfaces(jid, attempts - 1)
# finished
return interface_names
async def _supports_interface(self, client: str, interface: Type[Interface]) -> bool:
"""Checks, whether the given client supports the given interface.
Args:
client: Client to check.
interface: Interface to check.
Returns:
Whether or not interface is supported.
"""
# full JID given?
if "@" not in client:
client = "%s@%s/%s" % (client, self._domain, self._resource)
# update interface cache and get interface names
interfaces = await self.get_interfaces(client)
# supported?
return interface in interfaces
[docs] async def execute(self, client: str, method: str, annotation: Dict[str, Any], *args: Any) -> Any:
"""Execute a given method on a remote client.
Args:
client (str): ID of client.
method (str): Method to call.
annotation: Method annotation.
*args: List of parameters for given method.
Returns:
Passes through return from method call.
"""
# prepare
if self._rpc is None:
raise ValueError("No RPC.")
jid = self._get_full_client_name(client)
# call
try:
return await self._rpc.call(jid, method, annotation, *args)
except slixmpp.exceptions.IqError:
raise exc.RemoteError(client, f"Could not call {method} on {client}.")
except slixmpp.exceptions.IqTimeout:
raise exc.RemoteTimeoutError(client, f"Call to {method} on {client} timed out.")
async def _got_online(self, msg: Any) -> None:
"""If a new client connects, add it to list.
Args:
msg: XMPP message.
"""
# get jid, ignore event if it's myself
jid = msg["from"].full
if jid == self._jid:
return
# clear interface cache, just in case there is something there
if jid in self._interface_cache:
del self._interface_cache[jid]
# create future for interfaces
self._interface_cache[jid] = asyncio.get_running_loop().create_future()
# request interfaces
interface_names = await self._get_interfaces(jid)
# if no interfaces are implemented (not even IModule), quit here
if len(interface_names) == 0:
module = jid[: jid.index["@"]]
log.error(f"Module {module} does not seem to implement IModule, ignoring.")
return
# store interfaces
self._interface_cache[jid].set_result(self._interface_names_to_classes(interface_names))
# append to list
if jid not in self._online_clients:
self._online_clients.append(jid)
# send event
self._send_event_to_module(ModuleOpenedEvent(), msg["from"].username)
def _got_offline(self, msg: Any) -> None:
"""If a new client disconnects, remove it from list.
Args:
msg: XMPP message.
"""
# remove from list
jid = msg["from"].full
self._online_clients.remove(jid)
# clear interface cache
if jid in self._interface_cache:
del self._interface_cache[jid]
# send event
self._send_event_to_module(ModuleClosedEvent(), msg["from"].username)
@property
def clients(self) -> List[str]:
"""Returns list of currently connected clients.
Returns:
(list) List of currently connected clients.
"""
return [c[: c.find("@")] for c in self._online_clients]
@property
def client(self) -> XmppClient:
"""Returns the XMPP client.
Returns:
The XMPP client.
"""
return self._xmpp
[docs] async def send_event(self, event: Event) -> None:
"""Send an event to other clients.
Args:
event (Event): Event to send
"""
# create stanza
stanza = EventStanza()
# dump event to JSON and escape it
body = xml.sax.saxutils.escape(json.dumps(event.to_json()))
# set xml and send event
stanza.xml = ET.fromstring('<event xmlns="pyobs:event">%s</event>' % body)
# send it
await self._safe_send(
self._xmpp["xep_0163"].publish,
stanza,
node="pyobs:event:%s" % event.__class__.__name__,
callback=functools.partial(self._send_event_callback, event=event),
)
@staticmethod
def _send_event_callback(iq: Any, event: Optional[Event] = None) -> None:
"""Called when an event has been successfully sent.
Args:
iq: Response package.
event: Sent event.
"""
log.debug("%s successfully sent.", event.__class__.__name__)
async def _register_events(
self, events: List[Type[Event]], handler: Optional[Callable[[Event, str], Coroutine[Any, Any, bool]]] = None
) -> None:
# loop events
for ev in events:
# register event at XMPP
self._xmpp["xep_0030"].add_feature("pyobs:event:%s" % ev.__name__)
# if we have a handler, we're also interested in receiving such events
if handler:
# add interest
self._xmpp["xep_0163"].add_interest("pyobs:event:%s" % ev.__name__)
# update caps and send presence
await self._safe_send(self._xmpp["xep_0115"].update_caps)
self._xmpp.send_presence()
async def _handle_event(self, msg: Any) -> None:
"""Handles an event.
Args:
msg: Received XMPP message.
"""
# get body, unescape it, parse it
# node = msg['pubsub_event'][items']['node']
body = json.loads(xml.sax.saxutils.unescape(msg["pubsub_event"]["items"]["item"]["payload"].text))
# do we have a <delay> element?
delay = msg.xml.findall("{urn:sleekxmpp:delay}delay")
if len(delay) > 0:
# ignore this message
return
# did we send this?
if msg["from"] == self._xmpp.boundjid.bare:
return
# create event and check timestamp
event = EventFactory.from_dict(body)
if event is None:
return
if time.time() - event.timestamp > 30:
# event is more than 30 seconds old, ignore it
# we do this do avoid resent events after a reconnect
return
# send it to module
self._send_event_to_module(event, msg["from"].username)
async def _safe_send(self, method: Callable[[Any], Coroutine[Any, Any, None]], *args: Any, **kwargs: Any) -> Any:
"""Safely send an XMPP message.
Args:
method: Method to call.
*args: Parameters for method.
**kwargs: Parameters for method. except slixmpp.exceptions.IqError:
raise RemoteException("Could not send command.")
except slixmpp.exceptions.IqTimeout:
raise exc()
Returns:
Return value from method.
"""
# try multiple times
for i in range(self._safe_send_attempts):
try:
# execute method and return result
return await method(*args, **kwargs)
except slixmpp.exceptions.IqTimeout:
# timeout occurred, try again after some wait
await asyncio.sleep(self._safe_send_wait)
# never should reach this
raise slixmpp.exceptions.IqTimeout
[docs] def cast_to_simple_pre(self, value: Any, annotation: Optional[Any] = None) -> Tuple[bool, Any]:
"""Special treatment of single parameters when converting them to be sent via Comm.
Args:
value: Value to be treated.
annotation: Annotation for value.
Returns:
A tuple containing a tuple that indicates whether this value should be further processed and a new value.
"""
if type(value) == str:
return True, xml.sax.saxutils.escape(value)
else:
return False, value
[docs] def cast_to_real_post(self, value: Any, annotation: Optional[Any] = None) -> Tuple[bool, Any]:
"""Special treatment of single parameters when converting them after being sent via Comm.
Args:
value: Value to be treated.
annotation: Annotation for value.
Returns:
A tuple containing a tuple that indicates whether this value should be further processed and a new value.
"""
if type(value) == str:
return True, xml.sax.saxutils.unescape(value)
else:
return False, value
__all__ = ["XmppComm"]