--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/sat/plugins/plugin_xep_0334.py	Mon Apr 02 19:44:50 2018 +0200
@@ -0,0 +1,117 @@
+#!/usr/bin/env python2
+# -*- coding: utf-8 -*-
+
+# SAT plugin for Delayed Delivery (XEP-0334)
+# Copyright (C) 2009-2018 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 sat.core.i18n import _, D_
+from sat.core.log import getLogger
+log = getLogger(__name__)
+from sat.core.constants import Const as C
+
+from sat.tools.common import data_format
+
+from wokkel import disco, iwokkel
+try:
+    from twisted.words.protocols.xmlstream import XMPPHandler
+except ImportError:
+    from wokkel.subprotocols import XMPPHandler
+from zope.interface import implements
+from textwrap import dedent
+
+
+PLUGIN_INFO = {
+    C.PI_NAME: u"Message Processing Hints",
+    C.PI_IMPORT_NAME: u"XEP-0334",
+    C.PI_TYPE: u"XEP",
+    C.PI_PROTOCOLS: [u"XEP-0334"],
+    C.PI_MAIN: "XEP_0334",
+    C.PI_HANDLER: u"yes",
+    C.PI_DESCRIPTION: D_(u"""Implementation of Message Processing Hints"""),
+    C.PI_USAGE: dedent(D_(u"""\
+             Frontends can use HINT_* constants in mess_data['extra'] in a serialized 'hints' dict.
+             Internal plugins can use directly addHint([HINT_* constant]).
+             Will set mess_data['extra']['history'] to 'skipped' when no store is requested and message is not saved in history."""))
+
+}
+
+NS_HINTS = u'urn:xmpp:hints'
+
+
+class XEP_0334(object):
+    HINT_NO_PERMANENT_STORE = u'no-permanent-store'
+    HINT_NO_STORE = u'no-store'
+    HINT_NO_COPY = u'no-copy'
+    HINT_STORE = u'store'
+    HINTS = (HINT_NO_PERMANENT_STORE, HINT_NO_STORE, HINT_NO_COPY, HINT_STORE)
+
+    def __init__(self, host):
+        log.info(_("Message Processing Hints plugin initialization"))
+        self.host = host
+        host.trigger.add("sendMessage", self.sendMessageTrigger)
+        host.trigger.add("MessageReceived", self.messageReceivedTrigger, priority=-1000)
+
+    def getHandler(self, client):
+        return XEP_0334_handler()
+
+    def addHint(self, mess_data, hint):
+        if hint == self.HINT_NO_COPY and not mess_data['to'].resource:
+            log.error(u"{hint} can only be used with full jids! Ignoring it.".format(hint=hint))
+            return
+        hints = mess_data.setdefault('hints', set())
+        if hint in self.HINTS:
+            hints.add(hint)
+        else:
+            log.error(u"Unknown hint: {}".format(hint))
+
+    def _sendPostXmlTreatment(self, mess_data):
+        if 'hints' in mess_data:
+            for hint in mess_data['hints']:
+                mess_data[u'xml'].addElement((NS_HINTS, hint))
+        return mess_data
+
+    def sendMessageTrigger(self, client, mess_data, pre_xml_treatments, post_xml_treatments):
+        """Add the hints element to the message to be sent"""
+        if u'hints' in mess_data[u'extra']:
+            for hint in data_format.dict2iter(u'hints', mess_data[u'extra'], pop=True):
+                self.addHint(hint)
+
+        post_xml_treatments.addCallback(self._sendPostXmlTreatment)
+        return True
+
+    def _receivedSkipHistory(self, mess_data):
+        mess_data[u'history'] = C.HISTORY_SKIP
+        return mess_data
+
+    def messageReceivedTrigger(self, client, message_elt, post_treat):
+        """Check for hints in the received message"""
+        for elt in message_elt.elements():
+            if elt.uri == NS_HINTS and elt.name in (self.HINT_NO_PERMANENT_STORE, self.HINT_NO_STORE):
+                log.debug(u"history will be skipped for this message, as requested")
+                post_treat.addCallback(self._receivedSkipHistory)
+                break
+        return True
+
+
+class XEP_0334_handler(XMPPHandler):
+    implements(iwokkel.IDisco)
+
+    def getDiscoInfo(self, requestor, target, nodeIdentifier=''):
+        return [disco.DiscoFeature(NS_HINTS)]
+
+    def getDiscoItems(self, requestor, target, nodeIdentifier=''):
+        return []