-module(countdown).
-export([init/0, reload/0]).
-export([tick/1]).  % so we can spawn this properly.

%% spawn a countdown process with a default start time of 10 seconds.
init() -> init(10).
init(Time) ->
    register(ticker, spawn(?MODULE, tick, [Time])).

tick(Time) when Time >= 0 ->
    io:format("Tick ~p~n", [Time]),
    timer:sleep(999),
    receive reload ->
        ?MODULE:tick(Time - 1)
    after 1 -> tick(Time - 1)
    end;
tick(_StartTime) ->
    io:format("Boom.~n", []),
    done.

reload() ->
    ticker ! reload.