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

-export([register/3, unregister/2, find/2, start/0]).
-export_type([message/2, record/1, errors/0]).

-opaque message(GVS, GVT) :: {register, GVS, gleam@erlang@process:subject(GVT)} |
    {unregister, GVS} |
    {find,
        gleam@erlang@process:subject({ok, gleam@erlang@process:subject(GVT)} |
            {error, errors()}),
        GVS}.

-type record(GVU) :: {record,
        gleam@erlang@process:subject(GVU),
        gleam@erlang@process:process_monitor()}.

-type errors() :: not_found.

-spec register(
    gleam@erlang@process:subject(message(GWD, GWE)),
    GWD,
    gleam@erlang@process:subject(GWE)
) -> nil.
register(Registry, Name, Subject) ->
    gleam@erlang@process:send(Registry, {register, Name, Subject}).

-spec unregister(gleam@erlang@process:subject(message(GWH, any())), GWH) -> nil.
unregister(Registry, Name) ->
    gleam@erlang@process:send(Registry, {unregister, Name}).

-spec find(gleam@erlang@process:subject(message(GWJ, GWK)), GWJ) -> {ok,
        gleam@erlang@process:subject(GWK)} |
    {error, errors()}.
find(Registry, Name) ->
    gleam@erlang@process:call(
        Registry,
        fun(Self) -> {find, Self, Name} end,
        100
    ).

-spec handle_message(message(GWO, GWP), gleam@map:map_(GWO, record(GWP))) -> gleam@otp@actor:next(message(GWO, any()), gleam@map:map_(GWO, record(GWP))).
handle_message(Message, State) ->
    case Message of
        {register, Name, Subject} ->
            Monitor = begin
                _pipe = Subject,
                _pipe@1 = gleam@erlang@process:subject_owner(_pipe),
                gleam@erlang@process:monitor_process(_pipe@1)
            end,
            State@1 = gleam@map:insert(State, Name, {record, Subject, Monitor}),
            Handle_down = fun(_) -> {unregister, Name} end,
            Handle_process_down = begin
                _pipe@2 = gleam_erlang_ffi:new_selector(),
                gleam@erlang@process:selecting_process_down(
                    _pipe@2,
                    Monitor,
                    Handle_down
                )
            end,
            _pipe@3 = gleam@otp@actor:continue(State@1),
            gleam@otp@actor:with_selector(_pipe@3, Handle_process_down);

        {unregister, Name@1} ->
            case gleam@map:get(State, Name@1) of
                {ok, {record, _, Monitor@1}} ->
                    gleam_erlang_ffi:demonitor(Monitor@1),
                    State@2 = gleam@map:delete(State, Name@1),
                    gleam@otp@actor:continue(State@2);

                {error, nil} ->
                    gleam@otp@actor:continue(State)
            end;

        {find, Client, Name@2} ->
            case gleam@map:get(State, Name@2) of
                {ok, {record, Subject@1, _}} ->
                    gleam@erlang@process:send(Client, {ok, Subject@1}),
                    gleam@otp@actor:continue(State);

                {error, nil} ->
                    gleam@erlang@process:send(Client, {error, not_found}),
                    gleam@otp@actor:continue(State)
            end
    end.

-spec start() -> {ok, gleam@erlang@process:subject(message(any(), any()))} |
    {error, gleam@otp@actor:start_error()}.
start() ->
    gleam@otp@actor:start(gleam@map:new(), fun handle_message/2).