-module(radiate).
-compile([no_auto_import, nowarn_unused_vars]).

-export([new/0, add_dir/2, on_reload/2, start/1]).
-export_type([no_directories/0, has_directories/0, builder/1, module_/0, what/0]).

-type no_directories() :: any().

-type has_directories() :: any().

-opaque builder(HNN) :: {builder, list(binary()), list(fun((binary()) -> nil))} |
    {gleam_phantom, HNN}.

-type module_() :: any().

-type what() :: any().

-spec new() -> builder(no_directories()).
new() ->
    {builder, [], []}.

-spec add_dir(builder(any()), binary()) -> builder(has_directories()).
add_dir(Builder, Dir) ->
    {builder, [Dir | erlang:element(2, Builder)], erlang:element(3, Builder)}.

-spec on_reload(builder(HNS), fun((binary()) -> nil)) -> builder(HNS).
on_reload(Builder, Callback) ->
    {builder,
        erlang:element(2, Builder),
        [Callback | erlang:element(3, Builder)]}.

-spec start(builder(has_directories())) -> {ok,
        gleam@erlang@process:subject(filespy:change())} |
    {error, gleam@otp@actor:start_error()}.
start(Builder) ->
    _pipe = filespy:new(),
    _pipe@1 = filespy:add_dirs(_pipe, erlang:element(2, Builder)),
    _pipe@3 = filespy:set_handler(_pipe@1, fun(Path, Event) -> case Event of
                closed ->
                    case gleam@string:ends_with(Path, <<".gleam"/utf8>>) of
                        true ->
                            Build_result = shellout:command(
                                <<"gleam"/utf8>>,
                                [<<"build"/utf8>>],
                                <<"."/utf8>>,
                                []
                            ),
                            case Build_result of
                                {ok, _} ->
                                    Mods = code:modified_modules(),
                                    gleam@list:each(Mods, fun code:purge/1),
                                    _ = code:atomic_load(Mods),
                                    gleam@list:each(
                                        erlang:element(3, Builder),
                                        fun(Callback) -> Callback(Path) end
                                    ),
                                    nil;

                                {error, {_, Message}} ->
                                    _pipe@2 = Message,
                                    gleam@io:print_error(_pipe@2)
                            end;

                        _ ->
                            nil
                    end;

                _ ->
                    nil
            end end),
    filespy:start(_pipe@3).