%%% Copyright (c) 2014 Eric des Courtis <eric.des.courtis@benbria.ca>
%%%
%%% Permission is hereby granted, free of charge, to any person obtaining a copy
%%% of this software and associated documentation files (the "Software"), to deal
%%% in the Software without restriction, including without limitation the rights
%%% to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
%%% copies of the Software, and to permit persons to whom the Software is
%%% furnished to do so, subject to the following conditions:
%%%
%%% The above copyright notice and this permission notice shall be included in
%%% all copies or substantial portions of the Software.
%%%
%%% THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
%%% IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
%%% FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
%%% AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
%%% LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
%%% OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
%%% THE SOFTWARE.

%% For backwards compatibility with old iconv implementations
%% create a gen_server which does nothing except start and stop.

-module(iconv_null_srv).
-author("Eric des Courtis").

-behaviour(gen_server).

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

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

-define(SERVER, ?MODULE).

-record(state, {}).

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

%%--------------------------------------------------------------------
%% @doc
%% Starts the server
%%
%% @end
%%--------------------------------------------------------------------
-spec(start() ->
  {ok, Pid :: pid()} | ignore | {error, Reason :: term()}).
start() ->
  gen_server:start({local, ?SERVER}, ?MODULE, [], []).


%%--------------------------------------------------------------------
%% @doc
%% Starts the server
%%
%% @end
%%--------------------------------------------------------------------
-spec(start_link() ->
  {ok, Pid :: pid()} | ignore | {error, Reason :: term()}).
start_link() ->
  gen_server:start_link({local, ?SERVER}, ?MODULE, [], []).

%%--------------------------------------------------------------------
%% @doc
%% Stops the server
%%
%% @end
%%--------------------------------------------------------------------
-spec(stop() ->
  ok | {error, Reason :: term()}).
stop() ->
  gen_server:call(?SERVER, stop).


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

%%--------------------------------------------------------------------
%% @private
%% @doc
%% Initializes the server
%%
%% @spec init(Args) -> {ok, State} |
%%                     {ok, State, Timeout} |
%%                     ignore |
%%                     {stop, Reason}
%% @end
%%--------------------------------------------------------------------
-spec(init(Args :: term()) ->
  {ok, State :: #state{}} | {ok, State :: #state{}, timeout() | hibernate} |
  {stop, Reason :: term()} | ignore).
init([]) ->
  {ok, #state{}}.

%%--------------------------------------------------------------------
%% @private
%% @doc
%% Handling call messages
%%
%% @end
%%--------------------------------------------------------------------
-spec(handle_call(Request :: term(), From :: {pid(), Tag :: term()},
    State :: #state{}) ->
  {reply, Reply :: term(), NewState :: #state{}} |
  {reply, Reply :: term(), NewState :: #state{}, timeout() | hibernate} |
  {noreply, NewState :: #state{}} |
  {noreply, NewState :: #state{}, timeout() | hibernate} |
  {stop, Reason :: term(), Reply :: term(), NewState :: #state{}} |
  {stop, Reason :: term(), NewState :: #state{}}).
handle_call(stop, _From, State) ->
  {stop, normal, ok, State};
handle_call(_Request, _From, State) ->
  {reply, ok, State}.

%%--------------------------------------------------------------------
%% @private
%% @doc
%% Handling cast messages
%%
%% @end
%%--------------------------------------------------------------------
-spec(handle_cast(Request :: term(), State :: #state{}) ->
  {noreply, NewState :: #state{}} |
  {noreply, NewState :: #state{}, timeout() | hibernate} |
  {stop, Reason :: term(), NewState :: #state{}}).
handle_cast(_Request, 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
%%--------------------------------------------------------------------
-spec(handle_info(Info :: timeout() | term(), State :: #state{}) ->
  {noreply, NewState :: #state{}} |
  {noreply, NewState :: #state{}, timeout() | hibernate} |
  {stop, Reason :: term(), NewState :: #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
%%--------------------------------------------------------------------
-spec(terminate(Reason :: (normal | shutdown | {shutdown, term()} | term()),
    State :: #state{}) -> term()).
terminate(_Reason, _State) ->
  ok.

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

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