%%%----------------------------------------------------------------------
%%% File    : mod_register_refer.erl
%%% Author  : Michael Krause <mk@spline.de>
%%% Purpose : Refer Inband registrations to URL
%%% Created : 20 Oct 2013 by Michael Krause <mk@spline.de> 
%%%
%%%
%%% ejabberd, Copyright (C) 2002-2013   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
%%%
%%%----------------------------------------------------------------------

-module(mod_register_refer).
-author('mk@spline.de').

-behaviour(gen_mod).

-export( [ start/2,
	   stop/1,
	   stream_feature_register/2,
	   unauthenticated_iq_register/4 ] ).

-include("ejabberd.hrl").
-include("jlib.hrl").


start(Host, _Opts) ->
    ejabberd_hooks:add(c2s_stream_features, Host,
 		       ?MODULE, stream_feature_register, 50),
    ejabberd_hooks:add(c2s_unauthenticated_iq, Host,
 		       ?MODULE, unauthenticated_iq_register, 50).

stop(Host) ->
    ejabberd_hooks:delete(c2s_stream_features, Host,
 			  ?MODULE, stream_feature_register, 50),
    ejabberd_hooks:delete(c2s_unauthenticated_iq, Host,
			  ?MODULE, unauthenticated_iq_register, 50).

stream_feature_register(Acc, _Host) ->
	[{xmlelement, "register",
		[{"xmlns", ?NS_FEATURE_IQREGISTER}], []} | Acc].

unauthenticated_iq_register(_Acc, Server, #iq{xmlns = ?NS_REGISTER } = IQ, _IP) ->
    	?INFO_MSG("mod_register_refer: refering unauthenticated_iq_register ", []),
	jlib:iq_to_xml( process_iq(IQ, Server) ).
	

% protocol says, we may send a single instruction stanza to redirect
% TODO handle unregister requests as well?
process_iq(#iq{ lang = Lang } = IQ, Server) ->
	case gen_mod:get_module_opt(Server, ?MODULE, url, []) of
		[] -> 
			?WARNING_MSG("mod_register_refer: No URL given, check your ejabberd.cfg",[]),
			Url = "https://accounts.spline.de";
		[ReferUrl] ->	Url = ReferUrl
	end,
	IQ#iq{type = result,
	  sub_el = [{xmlelement,"query", [{"xmlns", "jabber:iq:register"}],
		       [ {xmlelement, "instructions", [],
		           [{xmlcdata, translate:translate(
			     	     Lang,
				     "Registration is handled at:"
				     "https://accounts.spline.de" )}]},
			 {xmlelement, "x", [{"xmlns","jabber:x:oob"}],
			  [{xmlelement, "url", [],
			    [{xmlcdata, Url }] }] }
		        ]}]}.