From 417284a9210cb8f6a3bcf9df41232e17c374da03 Mon Sep 17 00:00:00 2001
From: Evgeniy Khramtsov <ekhramtsov@process-one.net>
Date: Tue, 6 Sep 2016 17:55:18 +0300
Subject: [PATCH] Add get_subscribers command to list MUC subscribers

---
 src/mod_muc_admin.erl | 16 +++++++++++++++-
 src/mod_muc_room.erl  |  8 ++++++++
 2 files changed, 23 insertions(+), 1 deletion(-)

diff --git a/src/mod_muc_admin.erl b/src/mod_muc_admin.erl
index 76e90957e..9ceec7d5b 100644
--- a/src/mod_muc_admin.erl
+++ b/src/mod_muc_admin.erl
@@ -20,7 +20,7 @@
 	 change_room_option/4, get_room_options/2,
 	 set_room_affiliation/4, get_room_affiliations/2,
 	 web_menu_main/2, web_page_main/2, web_menu_host/3,
-	 subscribe_room/4, unsubscribe_room/2,
+	 subscribe_room/4, unsubscribe_room/2, get_subscribers/2,
 	 web_page_host/3, mod_opt_type/1, get_commands_spec/0]).
 
 -include("ejabberd.hrl").
@@ -163,6 +163,11 @@ get_commands_spec() ->
 			module = ?MODULE, function = unsubscribe_room,
 			args = [{user, binary}, {room, binary}],
 			result = {res, rescode}},
+     #ejabberd_commands{name = get_subscribers, tags = [muc_room],
+			desc = "List subscribers of a MUC conference",
+			module = ?MODULE, function = get_subscribers,
+			args = [{name, binary}, {service, binary}],
+			result = {subscribers, {list, {jid, string}}}},
      #ejabberd_commands{name = set_room_affiliation, tags = [muc_room],
 		       desc = "Change an affiliation in a MUC room",
 		       module = ?MODULE, function = set_room_affiliation,
@@ -955,6 +960,15 @@ unsubscribe_room(User, Room) ->
 	    throw({error, "Malformed room JID"})
     end.
 
+get_subscribers(Name, Host) ->
+    case get_room_pid(Name, Host) of
+	Pid when is_pid(Pid) ->
+	    {ok, JIDList} = gen_fsm:sync_send_all_state_event(Pid, get_subscribers),
+	    [jid:to_string(jid:remove_resource(J)) || J <- JIDList];
+	_ ->
+	    throw({error, "The room does not exist"})
+    end.
+
 make_opts(StateData) ->
     Config = StateData#state.config,
     [
diff --git a/src/mod_muc_room.erl b/src/mod_muc_room.erl
index e5ed4cc68..bdcb808a1 100644
--- a/src/mod_muc_room.erl
+++ b/src/mod_muc_room.erl
@@ -749,6 +749,14 @@ handle_sync_event({change_state, NewStateData}, _From,
 handle_sync_event({process_item_change, Item, UJID}, _From, StateName, StateData) ->
     NSD = process_item_change(Item, StateData, UJID),
     {reply, {ok, NSD}, StateName, NSD};
+handle_sync_event(get_subscribers, _From, StateName, StateData) ->
+    JIDs = dict:fold(
+	     fun(_, #user{is_subscriber = true, jid = J}, Acc) ->
+		     [J|Acc];
+		(_, _, Acc) ->
+		     Acc
+	     end, [], StateData#state.users),
+    {reply, {ok, JIDs}, StateName, StateData};
 handle_sync_event({muc_subscribe, From, Nick, Nodes}, _From,
 		  StateName, StateData) ->
     SubEl = #xmlel{name = <<"subscribe">>,