%% Copyright (c) 2019-2021, Jan Uhlig <[email protected]>
%%
%% 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.
-module(ranch_server_proxy).
-behavior(gen_server).
-export([start_link/0]).
-export([init/1]).
-export([handle_call/3]).
-export([handle_cast/2]).
-export([handle_info/2]).
-export([code_change/3]).
-spec start_link() -> {ok, pid()} | {error, term()}.
start_link() ->
gen_server:start_link(?MODULE, [], []).
-spec init([]) -> {ok, pid()} | {stop, term()}.
init([]) ->
case wait_ranch_server(50) of
{ok, Monitor} ->
{ok, Monitor, hibernate};
{error, Reason} ->
{stop, Reason}
end.
-spec handle_call(_, _, reference()) -> {noreply, reference(), hibernate}.
handle_call(_, _, Monitor) ->
{noreply, Monitor, hibernate}.
-spec handle_cast(_, reference()) -> {noreply, reference(), hibernate}.
handle_cast(_, Monitor) ->
{noreply, Monitor, hibernate}.
-spec handle_info(term(), reference()) -> {noreply, reference(), hibernate} | {stop, term(), reference()}.
handle_info({'DOWN', Monitor, process, _, Reason}, Monitor) ->
{stop, Reason, Monitor};
handle_info(_, Monitor) ->
{noreply, Monitor, hibernate}.
-spec code_change(term() | {down, term()}, reference(), term()) -> {ok, reference()}.
code_change(_, Monitor, _) ->
{ok, Monitor}.
wait_ranch_server(N) ->
case whereis(ranch_server) of
undefined when N > 0 ->
receive after 100 -> ok end,
wait_ranch_server(N - 1);
undefined ->
{error, noproc};
Pid ->
Monitor = monitor(process, Pid),
{ok, Monitor}
end.
