defmodule SNet.Addr do

  def get_if_inet4 do
    {:ok, ifs} = :inet.getifaddrs
    for {_, opts} <- ifs,
        {:addr, addr} <- opts,
        tuple_size(addr) == 4,
        addr != {127,0,0,1}
    do
      addr
    end
  end

  def get_pub_inet4 do
    Application.ensure_all_started(:inets)
    Application.ensure_all_started(:ssl)
    {:ok, {_, _, body}} = :httpc.request('http://api.ipify.org')
    {:ok, addr} = :inet.parse_address body
    addr
  end

  def get_all_inet4 do
    addrset = for x <- get_if_inet4(), into: %MapSet{}, do: x
    addrset = MapSet.put(addrset, get_pub_inet4())
    MapSet.to_list addrset
  end

  def is_local?({:inet, ip, port}) do
    port == Application.get_env(:shard, :port) and (ip == {127,0,0,1} or ip in get_if_inet4())
  end
end