erlmld

-module(erlmld_sup).

-behaviour(supervisor).

%% API
-export([start_link/1]).
%% Supervisor callbacks
-export([init/1]).

%%====================================================================
%% API functions
%%====================================================================

start_link(Opts) ->
    Regname = regname(?MODULE, Opts),
    supervisor:start_link({local, Regname}, ?MODULE, [Regname, Opts]).

%%====================================================================
%% Supervisor callbacks
%%====================================================================

init([Regname,
      #{record_processor := RecordProcessor,
        record_processor_data := RecordProcessorData,
        listen_ip := ListenIP,
        listen_port := ListenPort,
        stream_type := StreamType} =
          Opts]) ->
    WorkerSupName = regname(erlmld_wrk_sup, Opts),
    AcceptorName = regname(erlmld_tcp_acceptor, Opts),
    RunnerName = regname(erlmld_runner, Opts),

    {ok, ListenSocket, ActualPort} = erlmld_tcp_acceptor:listen(ListenIP, ListenPort),
    error_logger:info_msg("~p listening on ~p~n", [Regname, ActualPort]),

    %% prepare MLD .properties file:
    {ok, PropertiesPathname} = erlmld_runner:build_properties(maps:put(port,
                                                                       ActualPort,
                                                                       Opts)),

    SupFlags = #{strategy => rest_for_one, intensity => 10, period => 10},

    StartWorker = fun (AcceptedSocket) ->
                          erlmld_wrk_sup:start_worker(WorkerSupName, AcceptedSocket)
                  end,

    WorkerSup = #{id => wrk_sup,
                  type => supervisor,
                  shutdown => infinity,
                  start =>
                      {erlmld_wrk_sup,
                       start_link,
                       [WorkerSupName, RecordProcessor, RecordProcessorData]}},

    TcpAcceptor = #{id => tcp_acceptor,
                    type => worker,
                    shutdown => brutal_kill,
                    start =>
                        {erlmld_tcp_acceptor,
                         start_link,
                         [AcceptorName, ListenSocket, StartWorker]}},

    MLDRunner = #{id => mld_runner,
                  type => worker,
                  shutdown => brutal_kill,
                  start =>
                      {erlmld_runner, start_link, [RunnerName, PropertiesPathname, StreamType]}},

    ChildSpecs = [WorkerSup, TcpAcceptor, MLDRunner],

    {ok, {SupFlags, ChildSpecs}}.

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

regname(Prefix, #{app_suffix := Suffix}) when Suffix /= undefined ->
    binary_to_atom(<<(atom_to_binary(Prefix, utf8))/binary,
                     "_",
                     (atom_to_binary(Suffix, utf8))/binary>>,
                   utf8);
regname(Prefix, _) ->
    Prefix.