%%--------------------------------------------------------------------
%% Copyright (c) 2020-2021 EMQ Technologies Co., Ltd. All Rights Reserved.
%%
%% Licensed under the Apache License, Version 2.0 (the "License");
%% you may not use this file except in compliance with the License.
%% You may obtain a copy of the License at
%%
%%     http://www.apache.org/licenses/LICENSE-2.0
%%
%% Unless required by applicable law or agreed to in writing, software
%% distributed under the License is distributed on an "AS IS" BASIS,
%% WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
%% See the License for the specific language governing permissions and
%% limitations under the License.
%%--------------------------------------------------------------------

-module(emqx_coap_timer).

-include("emqx_coap.hrl").

-export([ cancel_timer/1
        , start_timer/2
        , restart_timer/1
        , kick_timer/1
        , is_timeout/1
        , get_timer_length/1
        ]).

-record(timer_state, {interval, kickme, tref, message}).

-define(LOG(Level, Format, Args),
        emqx_logger:Level("CoAP-Timer: " ++ Format, Args)).

cancel_timer(#timer_state{tref = TRef}) when is_reference(TRef) ->
    catch erlang:cancel_timer(TRef),
    ok;
cancel_timer(_) ->
    ok.

kick_timer(State=#timer_state{kickme = false}) ->
    State#timer_state{kickme = true};
kick_timer(State=#timer_state{kickme = true}) ->
    State.

start_timer(Sec, Msg) ->
    ?LOG(debug, "emqx_coap_timer:start_timer ~p", [Sec]),
    TRef = erlang:send_after(timer:seconds(Sec), self(), Msg),
    #timer_state{interval = Sec, kickme = false, tref = TRef, message = Msg}.

restart_timer(State=#timer_state{interval = Sec, message = Msg}) ->
    ?LOG(debug, "emqx_coap_timer:restart_timer ~p", [Sec]),
    TRef = erlang:send_after(timer:seconds(Sec), self(), Msg),
    State#timer_state{kickme = false, tref = TRef}.

is_timeout(#timer_state{kickme = Bool}) ->
    not Bool.

get_timer_length(#timer_state{interval = Interval}) ->
    Interval.