%%%----------------------------------------------------------------------
%%% File    : ejabberd_local.erl
%%% Author  : Alexey Shchepin <alexey@sevcom.net>
%%% Purpose : Route local packets
%%% Created : 30 Nov 2002 by Alexey Shchepin <alexey@sevcom.net>
%%% Id      : $Id$
%%%----------------------------------------------------------------------

-module(ejabberd_local).
-author('alexey@sevcom.net').
-vsn('$Revision$ ').

-behaviour(gen_server).

%% API
-export([start_link/0]).

-export([route/3,
	 register_iq_handler/4,
	 register_iq_handler/5,
	 unregister_iq_handler/2,
	 refresh_iq_handlers/0,
	 bounce_resource_packet/3
	]).

%% gen_server callbacks
-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
	 terminate/2, code_change/3]).

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

-record(state, {}).

-define(IQTABLE, local_iqtable).

%%====================================================================
%% API
%%====================================================================
%%--------------------------------------------------------------------
%% Function: start_link() -> {ok,Pid} | ignore | {error,Error}
%% Description: Starts the server
%%--------------------------------------------------------------------
start_link() ->
    gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).

process_iq(From, To, Packet) ->
    IQ = jlib:iq_query_info(Packet),
    case IQ of
	#iq{xmlns = XMLNS} ->
	    Host = To#jid.lserver,
	    case ets:lookup(?IQTABLE, {XMLNS, Host}) of
		[{_, Module, Function}] ->
		    ResIQ = Module:Function(From, To, IQ),
		    if
			ResIQ /= ignore ->
			    ejabberd_router:route(
			      To, From, jlib:iq_to_xml(ResIQ));
			true ->
			    ok
		    end;
		[{_, Module, Function, Opts}] ->
		    gen_iq_handler:handle(Host, Module, Function, Opts,
					  From, To, IQ);
		[] ->
		    Err = jlib:make_error_reply(
			    Packet, ?ERR_FEATURE_NOT_IMPLEMENTED),
		    ejabberd_router:route(To, From, Err)
	    end;
	reply ->
	    ok;
	_ ->
	    Err = jlib:make_error_reply(Packet, ?ERR_BAD_REQUEST),
	    ejabberd_router:route(To, From, Err),
	    ok
    end.

route(From, To, Packet) ->
    case catch do_route(From, To, Packet) of
	{'EXIT', Reason} ->
	    ?ERROR_MSG("~p~nwhen processing: ~p",
		       [Reason, {From, To, Packet}]);
	_ ->
	    ok
    end.

register_iq_handler(Host, XMLNS, Module, Fun) ->
    ejabberd_local ! {register_iq_handler, Host, XMLNS, Module, Fun}.

register_iq_handler(Host, XMLNS, Module, Fun, Opts) ->
    ejabberd_local ! {register_iq_handler, Host, XMLNS, Module, Fun, Opts}.

unregister_iq_handler(Host, XMLNS) ->
    ejabberd_local ! {unregister_iq_handler, Host, XMLNS}.

refresh_iq_handlers() ->
    ejabberd_local ! refresh_iq_handlers.

bounce_resource_packet(From, To, Packet) ->
    Err = jlib:make_error_reply(Packet, ?ERR_ITEM_NOT_FOUND),
    ejabberd_router:route(To, From, Err),
    stop.

%%====================================================================
%% gen_server callbacks
%%====================================================================

%%--------------------------------------------------------------------
%% Function: init(Args) -> {ok, State} |
%%                         {ok, State, Timeout} |
%%                         ignore               |
%%                         {stop, Reason}
%% Description: Initiates the server
%%--------------------------------------------------------------------
init([]) ->
    lists:foreach(
      fun(Host) ->
	      ejabberd_router:register_route(Host, {apply, ?MODULE, route}),
	      ejabberd_hooks:add(local_send_to_resource_hook, Host,
				 ?MODULE, bounce_resource_packet, 100)
      end, ?MYHOSTS),
    catch ets:new(?IQTABLE, [named_table, public]),
    {ok, #state{}}.

%%--------------------------------------------------------------------
%% Function: %% handle_call(Request, From, State) -> {reply, Reply, State} |
%%                                      {reply, Reply, State, Timeout} |
%%                                      {noreply, State} |
%%                                      {noreply, State, Timeout} |
%%                                      {stop, Reason, Reply, State} |
%%                                      {stop, Reason, State}
%% Description: Handling call messages
%%--------------------------------------------------------------------
handle_call(_Request, _From, State) ->
    Reply = ok,
    {reply, Reply, State}.

%%--------------------------------------------------------------------
%% Function: handle_cast(Msg, State) -> {noreply, State} |
%%                                      {noreply, State, Timeout} |
%%                                      {stop, Reason, State}
%% Description: Handling cast messages
%%--------------------------------------------------------------------
handle_cast(_Msg, State) ->
    {noreply, State}.

%%--------------------------------------------------------------------
%% Function: handle_info(Info, State) -> {noreply, State} |
%%                                       {noreply, State, Timeout} |
%%                                       {stop, Reason, State}
%% Description: Handling all non call/cast messages
%%--------------------------------------------------------------------
handle_info({route, From, To, Packet}, State) ->
    case catch do_route(From, To, Packet) of
	{'EXIT', Reason} ->
	    ?ERROR_MSG("~p~nwhen processing: ~p",
		       [Reason, {From, To, Packet}]);
	_ ->
	    ok
    end,
    {noreply, State};
handle_info({register_iq_handler, Host, XMLNS, Module, Function}, State) ->
    ets:insert(?IQTABLE, {{XMLNS, Host}, Module, Function}),
    catch mod_disco:register_feature(Host, XMLNS),
    {noreply, State};
handle_info({register_iq_handler, Host, XMLNS, Module, Function, Opts}, State) ->
    ets:insert(?IQTABLE, {{XMLNS, Host}, Module, Function, Opts}),
    catch mod_disco:register_feature(Host, XMLNS),
    {noreply, State};
handle_info({unregister_iq_handler, Host, XMLNS}, State) ->
    case ets:lookup(?IQTABLE, {XMLNS, Host}) of
	[{_, Module, Function, Opts}] ->
	    gen_iq_handler:stop_iq_handler(Module, Function, Opts);
	_ ->
	    ok
    end,
    ets:delete(?IQTABLE, {XMLNS, Host}),
    catch mod_disco:unregister_feature(Host, XMLNS),
    {noreply, State};
handle_info(refresh_iq_handlers, State) ->
    lists:foreach(
      fun(T) ->
	      case T of
		  {{XMLNS, Host}, _Module, _Function, _Opts} ->
		      catch mod_disco:register_feature(Host, XMLNS);
		  {{XMLNS, Host}, _Module, _Function} ->
		      catch mod_disco:register_feature(Host, XMLNS);
		  _ ->
		      ok
	      end
      end, ets:tab2list(?IQTABLE)),
    {noreply, State};
handle_info(_Info, State) ->
    {noreply, State}.

%%--------------------------------------------------------------------
%% Function: terminate(Reason, State) -> void()
%% Description: This function is called by a gen_server when it is about to
%% terminate. It should be the opposite of Module:init/1 and do any necessary
%% cleaning up. When it returns, the gen_server terminates with Reason.
%% The return value is ignored.
%%--------------------------------------------------------------------
terminate(_Reason, _State) ->
    ok.

%%--------------------------------------------------------------------
%% Func: code_change(OldVsn, State, Extra) -> {ok, NewState}
%% Description: Convert process state when code is changed
%%--------------------------------------------------------------------
code_change(_OldVsn, State, _Extra) ->
    {ok, State}.

%%--------------------------------------------------------------------
%%% Internal functions
%%--------------------------------------------------------------------
do_route(From, To, Packet) ->
    ?DEBUG("local route~n\tfrom ~p~n\tto ~p~n\tpacket ~P~n",
	   [From, To, Packet, 8]),
    if
	To#jid.luser /= "" ->
	    ejabberd_sm:route(From, To, Packet);
	To#jid.lresource == "" ->
	    {xmlelement, Name, _Attrs, _Els} = Packet,
	    case Name of
		"iq" ->
		    process_iq(From, To, Packet);
		"message" ->
		    ok;
		"presence" ->
		    ok;
		_ ->
		    ok
	    end;
	true ->
	    {xmlelement, _Name, Attrs, _Els} = Packet,
	    case xml:get_attr_s("type", Attrs) of
		"error" -> ok;
		"result" -> ok;
		_ ->
		    ejabberd_hooks:run(local_send_to_resource_hook,
				       To#jid.lserver,
				       [From, To, Packet])
	    end
	end.