--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sat/plugins/plugin_xep_0191.py	Fri May 27 12:12:16 2022 +0200
@@ -0,0 +1,210 @@
+#!/usr/bin/env python3
+
+# Libervia plugin for XEP-0191
+# Copyright (C) 2009-2022 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 typing import List, Set
+
+from twisted.words.protocols.jabber import xmlstream, jid
+from twisted.words.xish import domish
+from twisted.internet import defer
+from zope.interface import implementer
+from wokkel import disco, iwokkel
+
+from sat.core.constants import Const as C
+from sat.core.i18n import _
+from sat.core.log import getLogger
+from sat.core.core_types import SatXMPPEntity
+from sat.tools.utils import ensure_deferred
+
+log = getLogger(__name__)
+
+PLUGIN_INFO = {
+    C.PI_NAME: "Pubsub Public Subscriptions",
+    C.PI_IMPORT_NAME: "XEP-0191",
+    C.PI_TYPE: C.PLUG_TYPE_XEP,
+    C.PI_MODES: C.PLUG_MODE_BOTH,
+    C.PI_PROTOCOLS: ["XEP-0191"],
+    C.PI_DEPENDENCIES: ["XEP-0060", "XEP-0376"],
+    C.PI_MAIN: "XEP_0191",
+    C.PI_HANDLER: "yes",
+    C.PI_DESCRIPTION: _("""Pubsub Public Subscriptions implementation"""),
+}
+
+NS_BLOCKING = "urn:xmpp:blocking"
+IQ_BLOCK_PUSH = f'{C.IQ_SET}/block[@xmlns="{NS_BLOCKING}"]'
+IQ_UNBLOCK_PUSH = f'{C.IQ_SET}/unblock[@xmlns="{NS_BLOCKING}"]'
+
+
+class XEP_0191:
+
+    def __init__(self, host):
+        log.info(_("Blocking Command initialization"))
+        host.registerNamespace("blocking", NS_BLOCKING)
+        self.host = host
+        host.bridge.addMethod(
+            "blockingList",
+            ".plugin",
+            in_sign="s",
+            out_sign="as",
+            method=self._blockList,
+            async_=True,
+        )
+        host.bridge.addMethod(
+            "blockingBlock",
+            ".plugin",
+            in_sign="ass",
+            out_sign="",
+            method=self._block,
+            async_=True,
+        )
+        host.bridge.addMethod(
+            "blockingUnblock",
+            ".plugin",
+            in_sign="ass",
+            out_sign="",
+            method=self._unblock,
+            async_=True,
+        )
+
+    def getHandler(self, client):
+        return XEP_0191_Handler(self)
+
+    @ensure_deferred
+    async def _blockList(
+        self,
+        profile_key=C.PROF_KEY_NONE
+    ) -> List[str]:
+        client = self.host.getClient(profile_key)
+        blocked_jids = await self.blockList(client)
+        return [j.full() for j in blocked_jids]
+
+    async def blockList(self, client: SatXMPPEntity) -> Set[jid.JID]:
+        await self.host.checkFeature(client, NS_BLOCKING)
+        iq_elt = client.IQ("get")
+        iq_elt.addElement((NS_BLOCKING, "blocklist"))
+        iq_result_elt = await iq_elt.send()
+        try:
+            blocklist_elt = next(iq_result_elt.elements(NS_BLOCKING, "blocklist"))
+        except StopIteration:
+            log.warning(f"missing <blocklist> element: {iq_result_elt.toXml()}")
+            return []
+        blocked_jids = set()
+        for item_elt in blocklist_elt.elements(NS_BLOCKING, "item"):
+            try:
+                blocked_jid = jid.JID(item_elt["jid"])
+            except (RuntimeError, AttributeError):
+                log.warning(f"Invalid <item> element in block list: {item_elt.toXml()}")
+            else:
+                blocked_jids.add(blocked_jid)
+
+        return blocked_jids
+
+    def _block(
+        self,
+        entities: List[str],
+        profile_key: str = C.PROF_KEY_NONE
+    ) -> str:
+        client = self.host.getClient(profile_key)
+        return defer.ensureDeferred(
+            self.block(client, [jid.JID(entity) for entity in entities])
+        )
+
+    async def block(self, client: SatXMPPEntity, entities: List[jid.JID]) -> None:
+        await self.host.checkFeature(client, NS_BLOCKING)
+        iq_elt = client.IQ("set")
+        block_elt = iq_elt.addElement((NS_BLOCKING, "block"))
+        for entity in entities:
+            item_elt = block_elt.addElement("item")
+            item_elt["jid"] = entity.full()
+        await iq_elt.send()
+
+    def _unblock(
+        self,
+        entities: List[str],
+        profile_key: str = C.PROF_KEY_NONE
+    ) -> None:
+        client = self.host.getClient(profile_key)
+        return defer.ensureDeferred(
+            self.unblock(client, [jid.JID(e) for e in entities])
+        )
+
+    async def unblock(self, client: SatXMPPEntity, entities: List[jid.JID]) -> None:
+        await self.host.checkFeature(client, NS_BLOCKING)
+        iq_elt = client.IQ("set")
+        unblock_elt = iq_elt.addElement((NS_BLOCKING, "unblock"))
+        for entity in entities:
+            item_elt = unblock_elt.addElement("item")
+            item_elt["jid"] = entity.full()
+        await iq_elt.send()
+
+    def onBlockPush(self, iq_elt: domish.Element, client: SatXMPPEntity) -> None:
+        # TODO: send notification to user
+        iq_elt.handled = True
+        for item_elt in iq_elt.block.elements(NS_BLOCKING, "item"):
+            try:
+                entity = jid.JID(item_elt["jid"])
+            except (KeyError, RuntimeError):
+                log.warning(f"invalid item received in block push: {item_elt.toXml()}")
+            else:
+                log.info(f"{entity.full()} has been blocked for {client.profile}")
+        iq_result_elt = xmlstream.toResponse(iq_elt, "result")
+        client.send(iq_result_elt)
+
+    def onUnblockPush(self, iq_elt: domish.Element, client: SatXMPPEntity) -> None:
+        # TODO: send notification to user
+        iq_elt.handled = True
+        items = list(iq_elt.unblock.elements(NS_BLOCKING, "item"))
+        if not items:
+            log.info(f"All entities have been unblocked for {client.profile}")
+        else:
+            for item_elt in items:
+                try:
+                    entity = jid.JID(item_elt["jid"])
+                except (KeyError, RuntimeError):
+                    log.warning(
+                        f"invalid item received in unblock push: {item_elt.toXml()}"
+                    )
+                else:
+                    log.info(f"{entity.full()} has been unblocked for {client.profile}")
+        iq_result_elt = xmlstream.toResponse(iq_elt, "result")
+        client.send(iq_result_elt)
+
+
+@implementer(iwokkel.IDisco)
+class XEP_0191_Handler(xmlstream.XMPPHandler):
+
+    def __init__(self, plugin_parent: XEP_0191):
+        self.plugin_parent = plugin_parent
+
+    def connectionInitialized(self):
+        self.xmlstream.addObserver(
+            IQ_BLOCK_PUSH,
+            self.plugin_parent.onBlockPush,
+            client=self.parent
+
+        )
+        self.xmlstream.addObserver(
+            IQ_UNBLOCK_PUSH,
+            self.plugin_parent.onUnblockPush,
+            client=self.parent
+        )
+
+    def getDiscoInfo(self, requestor, service, nodeIdentifier=""):
+        return [disco.DiscoFeature(NS_BLOCKING)]
+
+    def getDiscoItems(self, requestor, service, nodeIdentifier=""):
+        return []