%%%----------------------------------------------------------------------
%%% File    : mod_roster_log.erl
%%% Author  : Badlop <badlop@process-one.net>
%%% Purpose : Log and watch roster changes
%%% Created : 24 May 2010 by Badlop <badlop@process-one.net>
%%%
%%%
%%% ejabberd, Copyright (C) 2002-2010   ProcessOne
%%%
%%% This program is free software; you can redistribute it and/or
%%% modify it under the terms of the GNU General Public License as
%%% published by the Free Software Foundation; either version 2 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
%%% General Public License for more details.
%%%
%%% You should have received a copy of the GNU General Public License
%%% along with this program; if not, write to the Free Software
%%% Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
%%% 02111-1307 USA
%%%
%%%----------------------------------------------------------------------

%%% This module logs any roster changes in ejabberd.cfg
%%% If you configure the option 'watchers', it will also send messages:
%%% {modules, [
%%%  {mod_roster_log, [{watchers, ["admin1@example.org", "sadmin@localhost"]}]},
%%%

-module(mod_roster_log).

-behaviour(gen_mod).

-export([start/2, stop/1,
	 in_subscription/6,
	 out_subscription/4
	]).

-include("ejabberd.hrl").
-include("jlib.hrl").
-include("mod_roster.hrl").
-include("web/ejabberd_http.hrl").
-include("web/ejabberd_web_admin.hrl").


start(Host, _Opts) ->
    ejabberd_hooks:add(roster_in_subscription, Host,
		       ?MODULE, in_subscription, 50),
    ejabberd_hooks:add(roster_out_subscription, Host,
		       ?MODULE, out_subscription, 50).

stop(Host) ->
    ejabberd_hooks:delete(roster_in_subscription, Host,
			  ?MODULE, in_subscription, 50),
    ejabberd_hooks:delete(roster_out_subscription, Host,
			  ?MODULE, out_subscription, 50).

in_subscription(_, User, Server, JID, Type, Reason) ->
    process_subscription(in, User, Server, JID, Type, Reason).

out_subscription(User, Server, JID, Type) ->
    process_subscription(out, User, Server, JID, Type, []).

process_subscription(Direction, User, Server, JID, Type, _Reason) ->
    LServer = jlib:nameprep(Server),
    FromType = case lists:member(LServer, ?MYHOSTS) of true -> local; false -> remote end,
    ToType = case lists:member(JID#jid.lserver, ?MYHOSTS) of true -> local; false -> remote end,
    DoMessage = case {FromType, Direction, ToType} of
		    {local, out, local} -> true;
		    {local, in, local} -> false;
		    _ -> true
		end,
    {Arrow1, Arrow2} = case Direction of
			   out -> {"==", "===>"};
			   in -> {"<===", "=="}
		       end,
    case DoMessage of
	true ->
	    Data = {User,Server, Arrow1,Type,Arrow2, JID#jid.luser,JID#jid.lserver},
	    {TimeString, TextString} = build_notifications(Data),
	    ?INFO_MSG(TextString, []),
	    send_notifications(Server, TimeString++TextString),
	    ok;
	false ->
	    ok
    end.

%%%
%%% Message to watchers
%%%

build_notifications({User,Server, Arrow1,Type,Arrow2, ToUser, ToServer}) ->
    TextString = io_lib:format(
		   "~s@~s ~s ~p ~s ~s@~s",
		   [User,Server, Arrow1,Type,Arrow2, ToUser, ToServer]),
    {"["++get_time_string()++"] ", TextString}.

get_time_string() -> write_time(erlang:localtime()).
%% Function copied from ejabberd_logger_h.erl and customized
write_time({{Y,Mo,D},{H,Mi,S}}) ->
    io_lib:format("~w-~.2.0w-~.2.0w ~.2.0w:~.2.0w:~.2.0w",
		  [Y, Mo, D, H, Mi, S]).

%% Copied from mod_register.erl
send_notifications(Host, BodyString) ->
    case gen_mod:get_module_opt(Host, ?MODULE, watchers, []) of
	[] -> ok;
	JIDs when is_list(JIDs) ->
	    lists:foreach(
	      fun(S) ->
		      case jlib:string_to_jid(S) of
			  error -> ok;
			  JID ->
			      ejabberd_router:route(
				jlib:make_jid("", Host, ""),
				JID,
				{xmlelement, "message", [{"type", "chat"}],
				 [{xmlelement, "body", [],
				   [{xmlcdata, BodyString}]}]})
		      end
	      end, JIDs);
	_ ->
	    ok
    end.