%%%----------------------------------------------------------------------
%%% File    : ejabberd_websocket.erl
%%% Author  : Eric Cestari <ecestari@process-one.net>
%%% Purpose : XMPP Websocket support
%%% Created : 09-10-2010 by Eric Cestari <ecestari@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
%%%
%%%----------------------------------------------------------------------
-module (ejabberd_http_ws).

-author('ecestari@process-one.net').

-behaviour(gen_fsm).

% External exports
-export([
   start/1,
   start_link/1,
	 init/1,
	 handle_event/3,
	 handle_sync_event/4,
	 code_change/4,
	 handle_info/3,
	 terminate/3,
	 send/2,
	 setopts/2,
	 sockname/1, peername/1,
	 controlling_process/2,
	 become_controller/2,
	 close/1]).

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

-record(state, {
		socket,
		timeout,
		timer,
		input = "",
		waiting_input = false, %% {ReceiverPid, Tag}
		last_receiver,
		ws}).

%-define(DBGFSM, true).

-ifdef(DBGFSM).
-define(FSMOPTS, [{debug, [trace]}]).
-else.
-define(FSMOPTS, []).
-endif.

-define(WEBSOCKET_TIMEOUT, 300000).
%
%
%%%%----------------------------------------------------------------------
%%%% API
%%%%----------------------------------------------------------------------
start(WS) ->
    supervisor:start_child(ejabberd_wsloop_sup, [WS]).

start_link(WS) ->
    gen_fsm:start_link(?MODULE, [WS],?FSMOPTS).

send({http_ws, FsmRef, _IP}, Packet) ->
    gen_fsm:sync_send_all_state_event(FsmRef, {send, Packet}).

setopts({http_ws, FsmRef, _IP}, Opts) ->
    case lists:member({active, once}, Opts) of
	true ->
	    gen_fsm:send_all_state_event(FsmRef, {activate, self()});
	_ ->
	    ok
    end.

sockname(_Socket) ->
    {ok, {{0, 0, 0, 0}, 0}}.

peername({http_ws, _FsmRef, IP}) ->
    {ok, IP}.

controlling_process(_Socket, _Pid) ->
    ok.

become_controller(FsmRef, C2SPid) ->
    gen_fsm:send_all_state_event(FsmRef, {become_controller, C2SPid}).

close({http_ws, FsmRef, _IP}) ->
    catch gen_fsm:sync_send_all_state_event(FsmRef, close).    
    
%%% Internal


init([WS]) ->
    %% Read c2s options from the first ejabberd_c2s configuration in
    %% the config file listen section
    %% TODO: We should have different access and shaper values for
    %% each connector. The default behaviour should be however to use
    %% the default c2s restrictions if not defined for the current
    %% connector.
    Opts = ejabberd_c2s_config:get_c2s_limits(),

    WSTimeout = case ejabberd_config:get_local_option({websocket_timeout,
							     ?MYNAME}) of
			  %% convert seconds of option into milliseconds
			  Int when is_integer(Int) -> Int*1000;
			  undefined -> ?WEBSOCKET_TIMEOUT
		      end,
    
    Socket = {http_ws, self(), WS:get(ip)},
    ?DEBUG("Client connected through websocket ~p", [Socket]),
    ejabberd_socket:start(ejabberd_c2s, ?MODULE, Socket, Opts),
    Timer = erlang:start_timer(WSTimeout, self(), []),
    {ok, loop, #state{
		      socket = Socket,
		      timeout = WSTimeout,
		      timer = Timer,
		      ws = WS}}.

handle_event({activate, From}, StateName, StateData) ->
    case StateData#state.input of
	"" ->
	    {next_state, StateName,
	     StateData#state{waiting_input = {From, ok}}};
	Input ->
            Receiver = From,
	    Receiver ! {tcp, StateData#state.socket, list_to_binary(Input)},
	    {next_state, StateName, StateData#state{input = "",
						    waiting_input = false,
						    last_receiver = Receiver
						   }}
    end.

handle_sync_event({send, Packet}, _From, StateName, #state{ws = WS} = StateData) ->
    Packet2 = if
	    is_binary(Packet) ->
	        Packet;
	    true ->
	        list_to_binary(Packet)
        end,
    %?DEBUG("sending on websocket : ~p ", [Packet2]),
    WS:send(Packet2),
    {reply, ok, StateName, StateData};

handle_sync_event(close, From, _StateName, StateData)->
    {stop, normal, StateData}.

handle_info(closed, _StateName, StateData) ->
    {stop, normal,  StateData};
    
handle_info({browser, Packet}, StateName, StateData)->
    %?DEBUG("Received on websocket : ~p ", [Packet]),
    NPacket = unicode:characters_to_binary(Packet,latin1),
    NewState = case StateData#state.waiting_input of
		false ->
		    Input = [StateData#state.input|NPacket],
		    StateData#state{input = Input};
		{Receiver, _Tag} ->
		    Receiver ! {tcp, StateData#state.socket,NPacket},
		    cancel_timer(StateData#state.timer),
		    Timer = erlang:start_timer(StateData#state.timeout, self(), []),
        StateData#state{waiting_input = false,
				     last_receiver = Receiver,
				     timer = Timer}
	    end,
	   {next_state, StateName, NewState};
  

handle_info({timeout, Timer, _}, _StateName,
	    #state{timer = Timer} = StateData) ->
    {stop, normal, StateData};
    
handle_info(_, StateName, StateData) ->
    {next_state, StateName, StateData}.


code_change(_OldVsn, StateName, StateData, _Extra) ->
    {ok, StateName, StateData}.    
    
terminate(_Reason, _StateName, StateData) -> 
    case StateData#state.waiting_input of
	false ->
	    ok;
	{Receiver,_} ->
	    ?DEBUG("C2S Pid : ~p", [Receiver]),
	    Receiver ! {tcp_closed, StateData#state.socket }
    end,
    ok.

cancel_timer(Timer) ->
    erlang:cancel_timer(Timer),
    receive
	{timeout, Timer, _} ->
	    ok
    after 0 ->
	    ok
    end.