-module(active_echo_protocol).
-behaviour(ranch_protocol).
-export([start_link/3]).
-export([init/3]).
start_link(Ref, Transport, Opts) ->
Pid = spawn_link(?MODULE, init, [Ref, Transport, Opts]),
{ok, Pid}.
init(Ref, Transport, _Opts = []) ->
{ok, Socket} = ranch:handshake(Ref),
loop(Socket, Transport).
loop(Socket, Transport) ->
{OK, Closed, Error, _Passive} = Transport:messages(),
Transport:setopts(Socket, [{active, once}]),
receive
{OK, Socket, Data} ->
Transport:send(Socket, Data),
loop(Socket, Transport);
{Closed, Socket} ->
ok;
{Error, Socket, _} ->
ok = Transport:close(Socket)
end.