%% Minimal distribution helpers for the gleamtk POC.
-module(gleamtk_ffi).
-export([
    ping/1,
    send_to/3,
    register_name/1,
    self_pid/0,
    node_name/0,
    nodes/0,
    receive_any/1,
    atom/1,
    tuple2_atom_binary/2,
    tuple2_atom_int/2,
    hello_with_self/0
]).

%% Gleam PingResult constructors → atoms pong | pang
ping(Node) when is_atom(Node) ->
    net_adm:ping(Node).

%% Gleam Nil → atom nil
send_to(Name, Node, Msg) when is_atom(Name), is_atom(Node) ->
    {Name, Node} ! Msg,
    nil.

%% Gleam Result(Nil, Nil) → {ok, nil} | {error, nil}
register_name(Name) when is_atom(Name) ->
    case catch erlang:register(Name, self()) of
        true ->
            {ok, nil};
        {'EXIT', _} ->
            case erlang:whereis(Name) of
                Pid when Pid =:= self() -> {ok, nil};
                _ -> {error, nil}
            end
    end.

self_pid() -> self().

node_name() -> node().

nodes() -> nodes(connected).

%% Gleam Result(Term, Nil) → {ok, Msg} | {error, nil}
receive_any(TimeoutMs) when is_integer(TimeoutMs), TimeoutMs >= 0 ->
    receive
        Msg -> {ok, Msg}
    after TimeoutMs ->
        {error, nil}
    end.

atom(Bin) when is_binary(Bin) ->
    binary_to_atom(Bin, utf8).

tuple2_atom_binary(AtomBin, Str) when is_binary(AtomBin), is_binary(Str) ->
    {binary_to_atom(AtomBin, utf8), Str}.

tuple2_atom_int(AtomBin, N) when is_binary(AtomBin), is_integer(N) ->
    {binary_to_atom(AtomBin, utf8), N}.

%% `{hello, self()}` so the foreign node can SEND replies to our pid.
hello_with_self() ->
    {hello, self()}.