plugin XEP-0066: "Out of Band Data" implementation

libervia/backend/plugins/plugin_xep_0066.py

@@ -0,0 +1,175 @@
+#!/usr/bin/env python3
+
+# Copyright (C) 2009-2026 Jérôme Poisson (goffi@goffi.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 collections.abc import Iterator
+from typing import Any, Final, Self
+
+from pydantic import BaseModel, Field, RootModel
+from twisted.internet import defer
+from twisted.words.protocols.jabber import xmlstream
+from twisted.words.xish import domish
+from tx_xmpp import disco, itx_xmpp
+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
+
+log = getLogger(__name__)
+
+EXTRA_KEY: Final = "oob"
+
+
+PLUGIN_INFO = {
+    C.PI_NAME: "Out of Band Data",
+    C.PI_IMPORT_NAME: "XEP-0066",
+    C.PI_TYPE: "XEP",
+    C.PI_MODES: C.PLUG_MODE_BOTH,
+    C.PI_PROTOCOLS: ["XEP-0066"],
+    C.PI_MAIN: "XEP_0066",
+    C.PI_HANDLER: "yes",
+    C.PI_DESCRIPTION: _("""Implementation of XEP-0066 (Out of Band Data)"""),
+}
+
+NS_OOB = "jabber:x:oob"
+
+
+class OOB(BaseModel):
+    """OOB data"""
+
+    url: str = Field(description="URI of the resource.")
+    desc: str | None = Field(
+        default=None,
+        description="Description of the resource.",
+    )
+
+    def to_element(self) -> domish.Element:
+        """Build the ``<x>`` element from this instance's data.
+
+        @return: <x> OOB element.
+        """
+        x_elt = domish.Element((NS_OOB, "x"))
+        url_elt = x_elt.addElement("url")
+        url_elt.addContent(self.url)
+        if self.desc is not None:
+            desc_elt = x_elt.addElement("desc")
+            desc_elt.addContent(self.desc)
+        return x_elt
+
+    @classmethod
+    def from_element(cls, element: domish.Element) -> Self:
+        """Create an OOB instance from an <x> element.
+
+        @param element: <x> OOB element.
+        @return: OOB instance.
+        @raise exceptions.DataError: The <url> element is missing.
+        """
+        url_elt = next(element.elements(NS_OOB, "url"), None)
+        if url_elt is None:
+            raise exceptions.DataError("<url> element is missing")
+
+        desc_elt = next(element.elements(NS_OOB, "desc"), None)
+        return cls(url=str(url_elt), desc=str(desc_elt) if desc_elt is not None else None)
+
+
+class OOBList(RootModel):
+    """List of OOB data."""
+
+    root: list[OOB]
+
+    def __iter__(self) -> Iterator[OOB]:  # type: ignore[override]
+        return iter(self.root)
+
+    def __getitem__(self, item: int) -> OOB:
+        return self.root[item]
+
+    def __len__(self) -> int:
+        return len(self.root)
+
+    def append(self, item: OOB) -> None:
+        self.root.append(item)
+
+    @classmethod
+    def from_element(cls, parent_elt: domish.Element) -> Self:
+        """Create an OOBList instance from a parent element.
+
+        @param parent_elt: Parent element containing <x> OOB children.
+        @return: OOBList instance.
+        """
+        return cls([OOB.from_element(elt) for elt in parent_elt.elements(NS_OOB, "x")])
+
+
+class XEP_0066:
+
+    def __init__(self, host):
+        log.info(f"Plugin {PLUGIN_INFO[C.PI_NAME]!r} initialization.")
+        host.register_namespace("oob", NS_OOB)
+        host.trigger.add("message_received", self._message_received_trigger)
+
+    def generate_oob(self, url: str, desc: str | None = None) -> domish.Element:
+        """Generate an OOB element.
+
+        @param url: URI of the resource.
+        @param desc: Optional description of the resource.
+        @return: ``<x xmlns='jabber:x:oob'>`` element.
+        """
+        return OOB(url=url, desc=desc).to_element()
+
+    def _message_received_trigger(
+        self,
+        client: SatXMPPEntity,
+        message_elt: domish.Element,
+        post_treat: defer.Deferred,
+    ) -> bool:
+        """Check presence of OOB in message.
+
+        @param client: client instance.
+        @param message_elt: the <message/> element.
+        @param post_treat: deferred to add post-treatments to.
+        @return: True to continue message processing.
+        """
+        oob_list = OOBList.from_element(message_elt)
+        if oob_list:
+            post_treat.addCallback(self._add_oob, oob_list)
+        return True
+
+    def _add_oob(self, data: dict[str, Any], oob_list: OOBList) -> dict[str, Any]:
+        """Add OOB data to message extra.
+
+        @param data: message data dict.
+        @param oob_list: parsed OOB list.
+        @return: updated message data dict.
+        """
+        data["extra"][EXTRA_KEY] = oob_list.model_dump()
+        return data
+
+    def get_handler(self, client: SatXMPPEntity) -> "XEP_0066Handler":
+        return XEP_0066Handler()
+
+
+@implementer(itx_xmpp.IDisco)
+class XEP_0066Handler(xmlstream.XMPPHandler):
+
+    def getDiscoInfo(self, requestor: str, target: str, nodeIdentifier: str = "") -> list:
+        return [disco.DiscoFeature(NS_OOB)]
+
+    def getDiscoItems(
+        self, requestor: str, target: str, nodeIdentifier: str = ""
+    ) -> list:
+        return []