-module(interface_server2).
-behaviour(gen_server).
-compile(export_all).
-record(interface_state, {port, lsock, buffer}).

process_data([13,10], State) ->
    exec_call(State),
    New_state = State#interface_state{buffer = []},
    New_state;

process_data(RawData, State) ->
    Buffer = State#interface_state.buffer,
    New_state = State#interface_state{buffer = Buffer ++ RawData},
    New_state.


args_to_terms(RawArgs) ->
    {ok, Toks, _Line} = erl_scan:string("[" ++ RawArgs ++ "]. ", 1),
    {ok, Args} = erl_parse:parse_term(Toks),
    Args.

exec_call(State) ->
    Socket = State#interface_state.lsock,
    Buffer = State#interface_state.buffer,
    {match, [XMod, XFun, XArgs]} = re:run(Buffer, "^([^\s]+):([^\s]+)\\(\s*(.*)\s*\\)$", [{capture, [1, 2, 3], list}]),
    Mod = list_to_atom(XMod),
    Fun = list_to_atom(XFun),
    Args = args_to_terms(XArgs),
    io:format("~p:~p~w~n", [Mod, Fun, Args]),
    Result = apply(Mod, Fun, Args),
    gen_tcp:send(Socket, io_lib:fwrite("~p~n", [Result])),
    io:format("~w~n", [Result]).


start_link(Port) -> gen_server:start_link({local, ?MODULE}, ?MODULE, [Port], []).

init([Port]) -> 
    {ok, LSock} = gen_tcp:listen(Port, [{active, true}]),
    {ok, #interface_state{port = Port, lsock = LSock, buffer=[]}, 0}.

handle_info({tcp, _Socket, RawData}, State) ->
    New_state = process_data(RawData, State),
    {noreply, New_state};
    
handle_info(timeout, #interface_state{lsock = LSock} = State) ->
    {ok, _Sock} = gen_tcp:accept(LSock),
    {noreply, State}.

handle_cast(stop, State) -> {stop, normal, State}.

%handle_call(_Request, _From, State) -> {reply, Reply, State}.
%handle_cast(_Msg, State) -> {noreply, State}.
%handle_info(_Info, State) -> {noreply, State}.
terminate(_Reason, _State) -> ok.
code_change(_OldVsn, State, _Extra) -> {ok, State}.