jabber_mirror: Dynamically join and leave MUCs

For personal mirrors, this means that the mirror should join all Jabber rooms
corresponding to their Zulip subscriptions.  For the public mirror, this means
that the mirror should join all Jabber rooms corresponding to Zulip streams that
end in "/xmpp".

(imported from commit 16ed9e3deee7e02b2ae0dd79925f0ed5c4acd044)

bots/jabber_mirror.py

@@ -53,7 +53,7 @@ def room_to_stream(room):
     return str(room).rpartition("@")[0] + "/xmpp"
 
 def stream_to_room(stream):
-    return stream.rpartition("/xmpp")[0]
+    return stream.lower().rpartition("/xmpp")[0]
 
 def jid_to_zulip(jid):
     return "%s@%s" % (str(jid).rpartition("@")[0], options.zulip_domain)
@@ -64,7 +64,8 @@ class JabberToZulipBot(ClientXMPP):
         jid = "%s@%s/jabber_mirror" % (nick, domain)
         ClientXMPP.__init__(self, jid, password)
         self.password = password
-        self.rooms = rooms
+        self.rooms = set()
+        self.rooms_to_join = rooms
         self.add_event_handler("session_start", self.session_start)
         self.add_event_handler("message", self.message)
         self.password = password
@@ -85,10 +86,25 @@ class JabberToZulipBot(ClientXMPP):
     def session_start(self, event):
         self.get_roster()
         self.send_presence()
-        for room in self.rooms:
+        for room in self.rooms_to_join:
+            self.join_muc(room)
+
+    def join_muc(self, room):
+        if room in self.rooms:
+            return
+        logging.debug("Joining " + room)
+        self.rooms.add(room)
         muc_jid = room + "@" + options.conference_domain
         self.plugin['xep_0045'].joinMUC(muc_jid, self.nick)
 
+    def leave_muc(self, room):
+        if room not in self.rooms:
+            return
+        logging.debug("Leaving " + room)
+        self.rooms.remove(room)
+        muc_jid = room + "@" + options.conference_domain
+        self.plugin['xep_0045'].leaveMUC(muc_jid, self.nick)
+
     def message(self, msg):
         try:
             if msg["type"] == "groupchat":
@@ -154,19 +170,23 @@ class ZulipToJabberBot(object):
     def set_jabber_client(self, client):
         self.jabber = client
 
-    def process_message(self, event):
-        try:
-            if event['type'] != 'message':
-                return
+    def process_event(self, event):
+        if event['type'] == 'message':
             message = event["message"]
             if message['sender_email'] != self.client.email:
                 return
+
+            try:
                 if message['type'] == 'stream':
                     self.stream_message(message)
                 elif message['type'] == 'private':
                     self.private_message(message)
             except:
                 logging.exception("Exception forwarding Zulip => Jabber")
+        elif event['type'] == 'subscription':
+            self.process_subscription(event)
+        elif event['type'] == 'stream':
+            self.process_stream(event)
 
     def stream_message(self, msg):
         stream = msg['display_recipient']
@@ -196,6 +216,30 @@ class ZulipToJabberBot(object):
             outgoing['thread'] = u'\u1B80'
             outgoing.send()
 
+    def process_subscription(self, event):
+        if event['op'] == 'add':
+            streams = [s['name'].lower() for s in event['subscriptions']]
+            streams = [s for s in streams if s.endswith("/xmpp")]
+            for stream in streams:
+                self.jabber.join_muc(stream_to_room(stream))
+        if event['op'] == 'remove':
+            streams = [s['name'].lower() for s in event['subscriptions']]
+            streams = [s for s in streams if s.endswith("/xmpp")]
+            for stream in streams:
+                self.jabber.leave_muc(stream_to_room(stream))
+
+    def process_stream(self, event):
+        if event['op'] == 'occupy':
+            streams = [s['name'].lower() for s in event['streams']]
+            streams = [s for s in streams if s.endswith("/xmpp")]
+            for stream in streams:
+                self.jabber.join_muc(stream_to_room(stream))
+        if event['op'] == 'vacate':
+            streams = [s['name'].lower() for s in event['streams']]
+            streams = [s for s in streams if s.endswith("/xmpp")]
+            for stream in streams:
+                self.jabber.leave_muc(stream_to_room(stream))
+
 def get_rooms(zulip):
     if options.mode == 'public':
         stream_infos = zulip.client.get_streams()['streams']
@@ -286,13 +330,16 @@ user and mirrors messages sent to Jabber rooms to Zulip.'''.replace("\n", " "))
     xmpp.set_zulip_client(zulip)
     zulip.set_jabber_client(xmpp)
 
-    if options.mode == 'public':
-        xmpp.process(block=True)
-    else:
     xmpp.process(block=False)
+    if options.mode == 'public':
+        event_types = ['stream']
+    else:
+        event_types = ['message', 'subscription']
+
     try:
         logging.info("Connecting to Zulip.")
-            zulip.client.call_on_each_event(zulip.process_message)
+        zulip.client.call_on_each_event(zulip.process_event,
+                                        event_types=event_types)
     except BaseException as e:
         logging.exception("Exception in main loop")
         xmpp.abort()