%%%-------------------------------------------------------------------
%% @doc eota_streams top level supervisor.
%% @end
%%%-------------------------------------------------------------------

-module(eredis_streams_sup).

-behaviour(supervisor).

-include_lib("eunit/include/eunit.hrl").

-export([start_link/0]).
-export([init/1]).
-export([add_stream/1]).

-define(SERVER, ?MODULE).

start_link() -> supervisor:start_link({local, ?SERVER}, ?MODULE, []).

init([]) ->
  SupFlags = #{strategy => one_for_one, intensity => 10, period => 1},
  ChildSpecs = gen_stream_sups_specs(streams(), []),
  {ok, {SupFlags, ChildSpecs}}.


add_stream(Declaration) ->
  ChildSpec = hd(gen_stream_sups_specs([Declaration], [])),
  supervisor:start_child(?MODULE, ChildSpec).

%% internal functions

gen_stream_sups_specs([], Specs) -> Specs;

gen_stream_sups_specs([Stream | Streams], Specs) ->
  NewSpecs = [stream_sup_spec(Stream) | Specs],
  gen_stream_sups_specs(Streams, NewSpecs).


stream_sup_spec(#{name := StreamName} = Stream) ->
  #{
    id => {eredis_streams_stream_sup, StreamName},
    start => {eredis_streams_stream_sup, start_link, [Stream]},
    restart => permanent,
    shutdown => infinity,
    type => supervisor,
    modules => [eredis_streams_stream_sup]
  }.

streams() -> application:get_env(eredis_streams, streams, []).