From 3ae4797848e0846291b11f286a6b8747a308164f Mon Sep 17 00:00:00 2001
From: Pablo Polvorin <pablo.polvorin@process-one.net>
Date: Mon, 19 Sep 2011 15:43:20 -0300
Subject: [PATCH] Command to moderate short term muc history (part of
 EJABS-1733)

ejabberdctl moderate_room_history test@conference.domain.com nick

removes from short term storage all messages on
room test@conference.domain.com from nick "nick", so new user
joining the room don't get these ones.

Return the number of messages removed.
---
 src/ejabberd_admin.erl       |  7 ++++++-
 src/mod_muc/mod_muc.erl      | 16 +++++++++++++++-
 src/mod_muc/mod_muc_room.erl | 16 +++++++++++++++-
 3 files changed, 36 insertions(+), 3 deletions(-)

diff --git a/src/ejabberd_admin.erl b/src/ejabberd_admin.erl
index fd4a3d149..cd8da85d4 100644
--- a/src/ejabberd_admin.erl
+++ b/src/ejabberd_admin.erl
@@ -203,7 +203,12 @@ commands() ->
      #ejabberd_commands{name = install_fallback, tags = [mnesia],
 			desc = "Install the database from a fallback file",
 			module = ?MODULE, function = install_fallback_mnesia,
-			args = [{file, string}], result = {res, restuple}}
+			args = [{file, string}], result = {res, restuple}},
+     #ejabberd_commands{name = moderate_room_history, tags = [server],
+	     		desc = "Clean messages from the short-term MUC storage",
+			module = mod_muc, function = moderate_room_history,
+			args = [{room, string}, {nick, string}],
+			result = {res, restuple}}
     ].
 
 
diff --git a/src/mod_muc/mod_muc.erl b/src/mod_muc/mod_muc.erl
index 13eba7615..d8116dc3c 100644
--- a/src/mod_muc/mod_muc.erl
+++ b/src/mod_muc/mod_muc.erl
@@ -47,7 +47,8 @@
 	 migrate/3,
 	 get_vh_rooms/1,
          is_broadcasted/1,
-	 can_use_nick/3]).
+	 can_use_nick/3,
+ 	 moderate_room_history/2]).
 
 %% gen_server callbacks
 -export([init/1, handle_call/3, handle_cast/2, handle_info/2,
@@ -99,6 +100,19 @@ stop(Host) ->
     gen_server:call(Proc, stop),
     supervisor:delete_child(ejabberd_sup, Proc).
 
+
+moderate_room_history(RoomStr, Nick) ->
+	Room = jlib:string_to_jid(RoomStr),
+	Name = Room#jid.luser,
+	Host = Room#jid.lserver,
+	case mnesia:dirty_read(muc_online_room, {Name, Host}) of
+		[] ->
+			{error, not_found};
+		[R] ->
+		    	Pid = R#muc_online_room.pid,
+			mod_muc_room:moderate_room_history(Pid, Nick)
+	end.
+
 %% This function is called by a room in three situations:
 %% A) The owner of the room destroyed it
 %% B) The only participant of a temporary room leaves it
diff --git a/src/mod_muc/mod_muc_room.erl b/src/mod_muc/mod_muc_room.erl
index 87c29667b..ef20792bf 100644
--- a/src/mod_muc/mod_muc_room.erl
+++ b/src/mod_muc/mod_muc_room.erl
@@ -40,7 +40,8 @@
 	 start/7,
 	 start/2,
 	 migrate/3,
-	 route/4]).
+	 route/4,
+ 	moderate_room_history/2]).
 
 %% gen_fsm callbacks
 -export([init/1,
@@ -112,6 +113,9 @@ start_link(StateName, StateData) ->
 migrate(FsmRef, Node, After) ->
     erlang:send_after(After, FsmRef, {migrate, Node}).
 
+moderate_room_history(FsmRef, Nick) ->
+	?GEN_FSM:sync_send_all_state_event(FsmRef, {moderate_room_history, Nick}).
+
 %%%----------------------------------------------------------------------
 %%% Callback functions from gen_fsm
 %%%----------------------------------------------------------------------
@@ -623,6 +627,13 @@ handle_event(_Event, StateName, StateData) ->
 %%          {stop, Reason, NewStateData}                          |
 %%          {stop, Reason, Reply, NewStateData}
 %%----------------------------------------------------------------------
+handle_sync_event({moderate_room_history, Nick}, _From, StateName, #state{history = History} = StateData) ->
+	NewHistory = lqueue_filter(fun({FromNick, _TSPacket, _HaveSubject, _Timestamp, _Size}) -> 
+				FromNick /= Nick 
+		end, History),
+	Moderated = History#lqueue.len - NewHistory#lqueue.len,
+	{reply, {ok, integer_to_list(Moderated)}, StateName, StateData#state{history = NewHistory}};
+
 handle_sync_event({get_disco_item, JID, Lang}, _From, StateName, StateData) ->
     Reply = get_roomdesc_reply(JID, StateData,
 			       get_roomdesc_tail(StateData, Lang)),
@@ -2260,6 +2271,9 @@ lqueue_cut(Q, N) ->
 lqueue_to_list(#lqueue{queue = Q1}) ->
     queue:to_list(Q1).
 
+lqueue_filter(F, #lqueue{queue = Q1} = LQ) ->
+	Q2 = queue:filter(F, Q1),
+	LQ#lqueue{queue = Q2, len = queue:len(Q2)}.
 
 add_message_to_history(FromNick, FromJID, Packet, StateData) ->
     HaveSubject = case xml:get_subtag(Packet, "subject") of