%%%-------------------------------------------------------------------
%%% @author Heinz Nikolaus Gies <heinz@licenser.net>
%%% @copyright (C) 2013, Heinz Nikolaus Gies
%%% @doc
%%%
%%% @end
%%% Created : 25 Jan 2013 by Heinz Nikolaus Gies <heinz@licenser.net>
%%%-------------------------------------------------------------------
-module(libchunter_console_server).

-behaviour(gen_server).

%% API
-export([start_link/4,
         console/4]).

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

-define(SERVER, ?MODULE).

-record(state, {socket, proc}).

%%%===================================================================
%%% API
%%%===================================================================

%%--------------------------------------------------------------------
%% @doc
%% Starts the server
%%
%% @spec start_link() -> {ok, Pid} | ignore | {error, Error}
%% @end
%%--------------------------------------------------------------------
start_link(Server, Port, VM, From) ->
    gen_server:start_link(?MODULE, [Server, Port, VM, From], []).

console(Server, Port, VM, Proc) ->
    supervisor:start_child(libchunter_console_sup, [Server, Port, VM, Proc]).

send(Console, Data) ->
    gen_server:cast(Console, {send, Data}).

close(Console) ->
    gen_server:cast(Console, close).

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

%%--------------------------------------------------------------------
%% @private
%% @doc
%% Initializes the server
%%
%% @spec init(Args) -> {ok, State} |
%%                     {ok, State, Timeout} |
%%                     ignore |
%%                     {stop, Reason}
%% @end
%%--------------------------------------------------------------------
init([Server, Port, VM, Proc]) ->
    case gen_tcp:connect(Server, Port, [binary, {active, true}, {packet, 4}],
                         100) of
        {ok, Socket} ->
            ok = gen_tcp:send(Socket, term_to_binary({console, VM})),
            {ok, #state{socket = Socket, proc = Proc}};
        _ ->
            {stop, connection_failed}
    end.

%%--------------------------------------------------------------------
%% @private
%% @doc
%% Handling call messages
%%
%% @spec handle_call(Request, From, State) ->
%%                                   {reply, Reply, State} |
%%                                   {reply, Reply, State, Timeout} |
%%                                   {noreply, State} |
%%                                   {noreply, State, Timeout} |
%%                                   {stop, Reason, Reply, State} |
%%                                   {stop, Reason, State}
%% @end
%%--------------------------------------------------------------------
handle_call(_Request, _From, State) ->
    Reply = ok,
    {reply, Reply, State}.

%%--------------------------------------------------------------------
%% @private
%% @doc
%% Handling cast messages
%%
%% @spec handle_cast(Msg, State) -> {noreply, State} |
%%                                  {noreply, State, Timeout} |
%%                                  {stop, Reason, State}
%% @end
%%--------------------------------------------------------------------
handle_cast({send, Data}, State = #state{socket = Socket}) ->
    gen_tcp:send(Socket, Data),
    {noreply, State};

handle_cast(close, State) ->
    {stop, normal, State};

handle_cast(_Msg, State) ->
    {noreply, State}.

%%--------------------------------------------------------------------
%% @private
%% @doc
%% Handling all non call/cast messages
%%
%% @spec handle_info(Info, State) -> {noreply, State} |
%%                                   {noreply, State, Timeout} |
%%                                   {stop, Reason, State}
%% @end
%%--------------------------------------------------------------------

handle_info({tcp, _Socket, Data}, State = #state{proc = Proc}) ->
    Proc ! {data, Data},
    {noreply, State};

handle_info({tcp_closed, _Socket}, State = #state{proc = Proc}) ->
    Proc ! closed,
    {noreply, State};

handle_info(_Info, State) ->
    {noreply, State}.

%%--------------------------------------------------------------------
%% @private
%% @doc
%% 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.
%%
%% @spec terminate(Reason, State) -> void()
%% @end
%%--------------------------------------------------------------------
terminate(_Reason, _State) ->
    ok.

%%--------------------------------------------------------------------
%% @private
%% @doc
%% Convert process state when code is changed
%%
%% @spec code_change(OldVsn, State, Extra) -> {ok, NewState}
%% @end
%%--------------------------------------------------------------------
code_change(_OldVsn, State, _Extra) ->
    {ok, State}.

%%%===================================================================
%%% Internal functions
%%%===================================================================