libervia-backend/libervia/backend/plugins/plugin_xep_0359.py

#!/usr/bin/env python3

# Libervia plugin for Message Archive Management (XEP-0359)
# Copyright (C) 2009-2023 Jérôme Poisson (goffi@goffi.org)
# Copyright (C) 2013-2016 Adrien Cossa (souliane@mailoo.org)

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.

# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

from typing import Optional
import uuid

from twisted.words.protocols.jabber import xmlstream
from twisted.words.xish import domish
from wokkel import disco
from zope.interface import implementer

from libervia.backend.core import exceptions
from libervia.backend.core.constants import Const as C
from libervia.backend.core.core_types import SatXMPPEntity
from libervia.backend.core.i18n import _
from libervia.backend.core.log import getLogger
from libervia.backend.models.core import MessageData

log = getLogger(__name__)


PLUGIN_INFO = {
    C.PI_NAME: "Unique and Stable Stanza IDs",
    C.PI_IMPORT_NAME: "XEP-0359",
    C.PI_TYPE: "XEP",
    C.PI_MODES: C.PLUG_MODE_BOTH,
    C.PI_PROTOCOLS: ["XEP-0359"],
    C.PI_MAIN: "XEP_0359",
    C.PI_HANDLER: "yes",
    C.PI_DESCRIPTION: _("""Implementation of Unique and Stable Stanza IDs"""),
}

NS_SID = "urn:xmpp:sid:0"


class XEP_0359(object):

    def __init__(self, host):
        log.info(_("Unique and Stable Stanza IDs plugin initialization"))
        self.host = host
        host.register_namespace("stanza_id", NS_SID)
        host.trigger.add("message_parse", self._message_parse_trigger)
        host.trigger.add("send_message_data", self._send_message_data_trigger)

    def _message_parse_trigger(
        self,
        client: SatXMPPEntity,
        message_elt: domish.Element,
        mess_data: MessageData
    ) -> bool:
        """Check if message has a stanza-id"""
        stanza_id = self.get_stanza_id(message_elt, client.jid.userhostJID())
        if stanza_id is not None:
            mess_data['extra']['stanza_id'] = stanza_id
        try:
            origin_id = self.get_origin_id(message_elt) or message_elt["id"]
        except KeyError:
            pass
        else:
            mess_data['extra']['origin_id'] = origin_id
        return True

    def _send_message_data_trigger(self, client, mess_data):
        origin_id = mess_data["extra"].setdefault("origin_id", mess_data.get("uid"))
        if not origin_id:
            origin_id = str(uuid.uuid4())
            mess_data["extra"]["origin_id"] = origin_id
        message_elt = mess_data["xml"]
        self.add_origin_id(message_elt, origin_id)

    def get_stanza_id(self, element, by):
        """Return stanza-id if found in element

        @param element(domish.Element): element to parse
        @param by(jid.JID): entity which should have set a stanza-id
        @return (unicode, None): stanza-id if found
        """
        stanza_id = None
        for stanza_elt in element.elements(NS_SID, "stanza-id"):
            if stanza_elt.getAttribute("by") == by.full():
                if stanza_id is not None:
                    # we must not have more than one element (§3 #4)
                    raise exceptions.DataError(
                        "More than one corresponding stanza-id found!")
                stanza_id = stanza_elt.getAttribute("id")
                # we don't break to be sure that there is no more than one element
                # with this "by" attribute

        return stanza_id

    def add_stanza_id(self, client, element, stanza_id, by=None):
        """Add a <stanza-id/> to a stanza

        @param element(domish.Element): stanza where the <stanza-id/> must be added
        @param stanza_id(unicode): id to use
        @param by(jid.JID, None): jid to use or None to use client.jid
        """
        sid_elt = element.addElement((NS_SID, "stanza-id"))
        sid_elt["by"] = client.jid.userhost() if by is None else by.userhost()
        sid_elt["id"] = stanza_id

    def get_origin_id(self, element: domish.Element) -> Optional[str]:
        """Return origin-id if found in element

        @param element: element to parse
        @return: origin-id if found
        """
        try:
            origin_elt = next(element.elements(NS_SID, "origin-id"))
        except StopIteration:
            return None
        else:
            return origin_elt.getAttribute("id")

    def add_origin_id(self, element: domish.Element, origin_id: str) -> None:
        """Add a <origin-id/> to a stanza

        @param element(domish.Element): stanza where the <origin-id/> must be added
        @param origin_id(str): id to use, None to automatically generate
        @return (str): origin_id
        """
        sid_elt = element.addElement((NS_SID, "origin-id"))
        sid_elt["id"] = origin_id

    def get_handler(self, client):
        return XEP_0359_handler()


@implementer(disco.IDisco)
class XEP_0359_handler(xmlstream.XMPPHandler):

    def getDiscoInfo(self, requestor, target, nodeIdentifier=""):
        return [disco.DiscoFeature(NS_SID)]

    def getDiscoItems(self, requestor, target, nodeIdentifier=""):
        return []