-module(opener_ffi).

-export([get_os/0, exec/2]).

get_os() ->
    case os:type() of
        {win32, _} ->
            nt;
        {unix, darwin} ->
            darwin;
        {unix, linux} ->
            linux;
        {_, _} ->
            unknown
    end.

exec(Command, Args) ->
  Command_ = binary_to_list(Command),
  Args_ = lists:map(fun(Arg) -> binary_to_list(Arg) end, Args),

  Name = {spawn_executable, os:find_executable(Command_)},

  Port = open_port(
           Name,
           [
            exit_status,
            binary,
            hide,
            stream,
            eof,
            stderr_to_stdout,
            {args, Args_}]),

  do_exec(Port, []).

%% Helper function to handle the execution of the command and collect output.
%%
%% @param Port The port used for communication with the external process.
%% @param Acc An accumulator for collecting output data.
%%
%% @return A tuple indicating success or failure of the command execution.
do_exec(Port, Acc) ->
  receive
    {Port, {data, Data}} ->
      do_exec(Port, [Data | Acc]);
    {Port, {exit_status, 0}} ->
      port_close(Port),
      {ok, list_to_binary(lists:reverse(Acc))};
    {Port, {exit_status, Code}} -> 
      port_close(Port),
      {error, {Code, list_to_binary(lists:reverse(Acc))}}
  end.