%% Copyright (C) 2013 Wildfire Games.
%% This file is part of 0 A.D.
%%
%% 0 A.D. 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.
%%
%% 0 A.D. 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 0 A.D.  If not, see <http://www.gnu.org/licenses/>.

-module(mod_ipstamp).

-behaviour(gen_mod).

-include("ejabberd.hrl").

-export([start/2, stop/1, on_filter_packet/1]).

%% Domain on which run the ejabberd server
-define (Domain, "lobby.wildfiregames.com").

%% Login of the Xpartamupp jabber client
%% TODO: It would be nice to get this from the module options.
-define (XpartamuppLogin, "wfgbot").

start(_Host, _Opts) ->
    ?INFO_MSG("mod_ipstamp starting", []),
    ejabberd_hooks:add(filter_packet, global, ?MODULE, on_filter_packet, 50),
    ok.

stop(_Host) ->
    ?INFO_MSG("mod_ipstamp stopping", []),
    ejabberd_hooks:delete(filter_packet, global, ?MODULE, on_filter_packet, 50),
    ok.

on_filter_packet({From, To, Packet} = Input) ->
    {_,SElement,LPacketInfo,LPacketQuery} = Packet,
    {_,SFrom,_,_,_,_,_} = From,
    {_,STo,_,_,_,_,_} = To,
    %% We only want to do something for the bot
    if STo == ?XpartamuppLogin ->
      if SElement == "iq" ->
        %% Get iq type (get/set/result...). 
        {_, SType} = lists:keyfind("type",1,LPacketInfo),
        if SType == "set" ->
          %% Get the sender's IP for later.
          Info = ejabberd_sm:get_user_info(SFrom,[?Domain],"0ad"),
          {ip, {Ploc, _Port}} = lists:keyfind(ip, 1, Info),
          SIp = inet_parse:ntoa(Ploc),
          %% Get XMLNS and message body (we assume the first xml element contains the xmlns).
          {_,_,LXmlns,LBody} = lists:keyfind(xmlelement,1,LPacketQuery),
          {_,SXmlns} = lists:keyfind("xmlns",1,LXmlns),
          %% Insert IP into game registration requests.
          if SXmlns == "jabber:iq:gamelist" ->
            {_,_,_,LCommand} = lists:keyfind("command",2,LBody),
            {_,SCommand} = lists:keyfind(xmlcdata,1,LCommand),
            if SCommand == <<"register">> ->
                {_,_,KGame,_} = lists:keyfind("game",2,LBody),
                ?INFO_MSG(string:concat("Inserting IP into game registration stanza: ",SIp), []),
                {From,To,{xmlelement,"iq",LPacketInfo,[
                  {xmlelement,"query",[{"xmlns","jabber:iq:gamelist"}],[
                    {xmlelement,"game",lists:keyreplace("ip",1,KGame,{"ip",SIp}),[]},
                    {xmlelement,"command",[],[{xmlcdata,<<"register">>}]}
                    ]
                  }
                ]}};
            true ->
              Input
            end;
          true ->
            Input
          end;
        true ->
          Input
        end;
      true ->
        Input 
      end;
    true ->
      Input
    end.