%%--------------------------------------------------------------------
%% Copyright (c) 2019 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(esockd_dtls_acceptor_sup).

-behaviour(supervisor).

-export([start_link/3]).

-export([ start_acceptor/2
        , count_acceptors/1
        ]).

-export([init/1]).

start_link(Opts, MFA, LimitFun) ->
    supervisor:start_link(?MODULE, [Opts, MFA, LimitFun]).

-spec(start_acceptor(pid(), inet:socket()) -> {ok, pid()} | {error, term()}).
start_acceptor(Sup, LSock) ->
    supervisor:start_child(Sup, [LSock]).

count_acceptors(Sup) ->
    proplists:get_value(active, supervisor:count_children(Sup), 0).

init([Opts, MFA, LimitFun]) ->
    SupFlags = #{strategy => simple_one_for_one,
                 intensity => 0,
                 period => 1
                },
    Acceptor = #{id => acceptor,
                 start => {esockd_dtls_acceptor, start_link, [self(), Opts, MFA, LimitFun]},
                 restart => transient,
                 shutdown => brutal_kill,
                 type => worker,
                 modules => [esockd_dtls_acceptor]
                },
    {ok, {SupFlags, [Acceptor]}}.