%%%=============================================================================
%%% Copyright 2013-2014, Tobias Schlager <schlagert@github.com>
%%%
%%% Permission to use, copy, modify, and/or distribute this software for any
%%% purpose with or without fee is hereby granted, provided that the above
%%% copyright notice and this permission notice appear in all copies.
%%%
%%% THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
%%% WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
%%% MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
%%% ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
%%% WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
%%% ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
%%% OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
%%%
%%% @doc
%%% An implementation of the {@link bootstrap_protocol} providing UDP broadcast
%%% functionality.
%%% @end
%%%=============================================================================
-module(bootstrap_broadcast).

-behaviour(bootstrap_protocol).

%% bootstrap_protocol callbacks
-export([options/0, addresses/0]).

%%%=============================================================================
%%% bootstrap_protocol callbacks
%%%=============================================================================

%%------------------------------------------------------------------------------
%% @private
%%------------------------------------------------------------------------------
options() -> [{broadcast, true}].

%%------------------------------------------------------------------------------
%% @private
%%------------------------------------------------------------------------------
addresses() -> addresses(bootstrap_lib:get_env(broadcast_ip, undefined)).

%%%=============================================================================
%%% internal functions
%%%=============================================================================

%%------------------------------------------------------------------------------
%% @private
%%------------------------------------------------------------------------------
addresses(Addr = {_, _, _, _}) ->
    [Addr];
addresses(_) ->
    [A || {ok, Is} <- [inet:getifaddrs()],
          {_, L} <- Is,
          {broadaddr, A = {_, _, _, _}} <- L,
          lists:member(up, proplists:get_value(flags, L, []))].