%%% --------------------------------------------------------------------
%%% BSD 3-Clause License
%%%
%%% Copyright (c) 2016-2017, Pouriya Jahanbakhsh
%%% (pouriya.jahanbakhsh@gmail.com)
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%%% --------------------------------------------------------------------
%% @author  Pouriya Jahanbakhsh <pouriya.jahanbakhsh@gmail.com>
%% @version
%% @hidden
%% ---------------------------------------------------------------------


-module(sockerl_server_connection_sup).
-author("pouriya.jahanbakhsh@gmail.com").


%% ---------------------------------------------------------------------
%% Exports:





%% API:
-export([start_link/3
        ,add/2
        ,fetch/1]).





%% 'director' export:
-export([init/1]).





%% ---------------------------------------------------------------------
%% Internal functions:





-spec
start_link(module(), term(), sockerl_types:start_options()) ->
    sockerl_types:start_return().
%% @doc
%%      starts and links connection supervisor for keeping other
%%      connection supervisor(s).
%% @end
start_link(Mod, InitArg ,Opts) ->
    director:start_link(?MODULE, {Mod, InitArg, Opts}).







-spec
add(sockerl_types:name(), term()) ->
    sockerl_types:start_return().
%% @doc
%%      adds new supervisor to connection supervisor.
%% @end
add(RootSup, Id) ->
    director:start_child(RootSup
                        ,#{plan => []
                         ,count => 0
                         ,id => Id
                         ,append => true}).







-spec
fetch(sockerl_types:name()) ->
    [] | [{sockerl_types:socket(), pid()}].
%% @doc
%%      fetch all available connections from supervisors.
%% @end
fetch(RootSup) ->
    concat([sockerl_connector_sup:fetch(Pid)
           || {_Id, Pid} <- director:get_pids(RootSup)]).





%% ---------------------------------------------------------------------
%% 'director' callback:





%% @hidden
init({Mod, InitArg, Opts}) ->
    {ok
    ,[]
    ,#{start => {sockerl_connector_sup
                ,start_link
                ,[Mod, InitArg, Opts]}
      ,plan => [stop]
      ,type => supervisor
      ,count => 1}}.





%% ---------------------------------------------------------------------
%% Internal functions:





concat(List) ->
    concat(List, []).







concat([[Elem|List3]|List], List2) ->
    concat([List3|List], [Elem|List2]);
concat([[]|List], List2) ->
    concat(List, List2);
concat([], List2) ->
    List2.