--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libervia/backend/plugins/plugin_xep_0115.py	Fri Jun 02 11:49:51 2023 +0200
@@ -0,0 +1,212 @@
+#!/usr/bin/env python3
+
+
+# SAT plugin for managing xep-0115
+# Copyright (C) 2009-2021 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 libervia.backend.core.i18n import _
+from libervia.backend.core.constants import Const as C
+from libervia.backend.core.log import getLogger
+
+log = getLogger(__name__)
+from twisted.words.xish import domish
+from twisted.words.protocols.jabber import jid
+from twisted.internet import defer, error
+from zope.interface import implementer
+from wokkel import disco, iwokkel
+
+try:
+    from twisted.words.protocols.xmlstream import XMPPHandler
+except ImportError:
+    from wokkel.subprotocols import XMPPHandler
+
+PRESENCE = "/presence"
+NS_ENTITY_CAPABILITY = "http://jabber.org/protocol/caps"
+NS_CAPS_OPTIMIZE = "http://jabber.org/protocol/caps#optimize"
+CAPABILITY_UPDATE = PRESENCE + '/c[@xmlns="' + NS_ENTITY_CAPABILITY + '"]'
+
+PLUGIN_INFO = {
+    C.PI_NAME: "XEP 0115 Plugin",
+    C.PI_IMPORT_NAME: "XEP-0115",
+    C.PI_TYPE: "XEP",
+    C.PI_MODES: C.PLUG_MODE_BOTH,
+    C.PI_PROTOCOLS: ["XEP-0115"],
+    C.PI_DEPENDENCIES: [],
+    C.PI_MAIN: "XEP_0115",
+    C.PI_HANDLER: "yes",
+    C.PI_DESCRIPTION: _("""Implementation of entity capabilities"""),
+}
+
+
+class XEP_0115(object):
+    cap_hash = None  # capabilities hash is class variable as it is common to all profiles
+
+    def __init__(self, host):
+        log.info(_("Plugin XEP_0115 initialization"))
+        self.host = host
+        host.trigger.add("Presence send", self._presence_trigger)
+
+    def get_handler(self, client):
+        return XEP_0115_handler(self)
+
+    @defer.inlineCallbacks
+    def _prepare_caps(self, client):
+        # we have to calculate hash for client
+        # because disco infos/identities may change between clients
+
+        # optimize check
+        client._caps_optimize = yield self.host.hasFeature(client, NS_CAPS_OPTIMIZE)
+        if client._caps_optimize:
+            log.info(_("Caps optimisation enabled"))
+            client._caps_sent = False
+        else:
+            log.warning(_("Caps optimisation not available"))
+
+        # hash generation
+        _infos = yield client.discoHandler.info(client.jid, client.jid, "")
+        disco_infos = disco.DiscoInfo()
+        for item in _infos:
+            disco_infos.append(item)
+        cap_hash = client._caps_hash = self.host.memory.disco.generate_hash(disco_infos)
+        log.info(
+            "Our capability hash has been generated: [{cap_hash}]".format(
+                cap_hash=cap_hash
+            )
+        )
+        log.debug("Generating capability domish.Element")
+        c_elt = domish.Element((NS_ENTITY_CAPABILITY, "c"))
+        c_elt["hash"] = "sha-1"
+        c_elt["node"] = C.APP_URL
+        c_elt["ver"] = cap_hash
+        client._caps_elt = c_elt
+        if client._caps_optimize:
+            client._caps_sent = False
+        if cap_hash not in self.host.memory.disco.hashes:
+            self.host.memory.disco.hashes[cap_hash] = disco_infos
+            self.host.memory.update_entity_data(
+                client, client.jid, C.ENTITY_CAP_HASH, cap_hash
+            )
+
+    def _presence_add_elt(self, client, obj):
+        if client._caps_optimize:
+            if client._caps_sent:
+                return
+            client.caps_sent = True
+        obj.addChild(client._caps_elt)
+
+    def _presence_trigger(self, client, obj, presence_d):
+        if not hasattr(client, "_caps_optimize"):
+            presence_d.addCallback(lambda __: self._prepare_caps(client))
+
+        presence_d.addCallback(lambda __: self._presence_add_elt(client, obj))
+        return True
+
+
+@implementer(iwokkel.IDisco)
+class XEP_0115_handler(XMPPHandler):
+
+    def __init__(self, plugin_parent):
+        self.plugin_parent = plugin_parent
+        self.host = plugin_parent.host
+
+    @property
+    def client(self):
+        return self.parent
+
+    def connectionInitialized(self):
+        self.xmlstream.addObserver(CAPABILITY_UPDATE, self.update)
+
+    def getDiscoInfo(self, requestor, target, nodeIdentifier=""):
+        return [
+            disco.DiscoFeature(NS_ENTITY_CAPABILITY),
+            disco.DiscoFeature(NS_CAPS_OPTIMIZE),
+        ]
+
+    def getDiscoItems(self, requestor, target, nodeIdentifier=""):
+        return []
+
+    def update(self, presence):
+        """
+        Manage the capabilities of the entity
+
+        Check if we know the version of this capabilities and get the capabilities if necessary
+        """
+        from_jid = jid.JID(presence["from"])
+        c_elem = next(presence.elements(NS_ENTITY_CAPABILITY, "c"))
+        try:
+            c_ver = c_elem["ver"]
+            c_hash = c_elem["hash"]
+            c_node = c_elem["node"]
+        except KeyError:
+            log.warning(_("Received invalid capabilities tag: %s") % c_elem.toXml())
+            return
+
+        if c_ver in self.host.memory.disco.hashes:
+            # we already know the hash, we update the jid entity
+            log.debug(
+                "hash [%(hash)s] already in cache, updating entity [%(jid)s]"
+                % {"hash": c_ver, "jid": from_jid.full()}
+            )
+            self.host.memory.update_entity_data(
+                self.client, from_jid, C.ENTITY_CAP_HASH, c_ver
+            )
+            return
+
+        if c_hash != "sha-1":  # unknown hash method
+            log.warning(
+                _(
+                    "Unknown hash method for entity capabilities: [{hash_method}] "
+                    "(entity: {entity_jid}, node: {node})"
+                )
+                .format(hash_method = c_hash, entity_jid = from_jid, node = c_node)
+            )
+
+        def cb(__):
+            computed_hash = self.host.memory.get_entity_datum(
+                self.client, from_jid, C.ENTITY_CAP_HASH
+            )
+            if computed_hash != c_ver:
+                log.warning(
+                    _(
+                        "Computed hash differ from given hash:\n"
+                        "given: [{given}]\n"
+                        "computed: [{computed}]\n"
+                        "(entity: {entity_jid}, node: {node})"
+                    ).format(
+                        given = c_ver,
+                        computed = computed_hash,
+                        entity_jid = from_jid,
+                        node = c_node,
+                    )
+                )
+
+        def eb(failure):
+            if isinstance(failure.value, error.ConnectionDone):
+                return
+            msg = (
+                failure.value.condition
+                if hasattr(failure.value, "condition")
+                else failure.getErrorMessage()
+            )
+            log.error(
+                _("Couldn't retrieve disco info for {jid}: {error}").format(
+                    jid=from_jid.full(), error=msg
+                )
+            )
+
+        d = self.host.get_disco_infos(self.parent, from_jid)
+        d.addCallbacks(cb, eb)
+        # TODO: me must manage the full algorithm described at XEP-0115 #5.4 part 3