-module(active_sh).

-export([
  reduce/0,
  run/1,
  sh/1,
  sh/3,
  exe/1
]).


% {status,code,msg} = :active_sh.exe(String.to_charlist("mix compile"))

reduce() ->
  fun({_, Chunk}, Acc) ->
    [Chunk|Acc]
  end.

run(Args) ->
  erlang:open_port({spawn_executable, os:find_executable("sh")},
    [stream, in, out, eof, use_stdio, stderr_to_stdout, binary, exit_status,
     {args, ["-c", Args]}, {cd, erlang:element(2, file:get_cwd())}, {env, []}]).

sh(Port) -> sh(Port, reduce(), []).
sh(Port, Fun, Acc) ->
  receive
    {Port, {exit_status, Status}} -> {done, Status, erlang:iolist_to_binary(lists:reverse(Acc))};
    {Port, {data, {eol, Line}}}   -> sh(Port, Fun, Fun({eol,   Line}, Acc));
    {Port, {data, {noeol, Line}}} -> sh(Port, Fun, Fun({noeol, Line}, Acc));
    {Port, {data, Data}}          -> sh(Port, Fun, Fun({data,Data}, Acc))
  end.

exe(X) -> sh(run(X)).