type args = { debug : bool; file_name : string option }

let parse_args () : args =
  let usage_msg = "mlox [--debug] [<file>]" in
  let debug = ref false in
  let anon = ref [] in
  let anon_fun s = anon := s :: !anon in
  let spec = [ ("--debug", Arg.Set debug, "Debug mode") ] in
  let () = Arg.parse spec anon_fun usage_msg in
  let debug = !debug in
  let file_and_args = List.rev !anon in
  let file_name = List.nth_opt file_and_args 0 in
  { debug; file_name }

let () =
  let { debug; file_name } = parse_args () in
  match file_name with
  | None -> Lox.runRepl ~debug ()
  | Some file_name -> (
      (* Printf.printf "Running script %s\n" path; *)
      let ic = open_in file_name in
      let source = In_channel.input_all ic in
      match Lox.run ~debug source with
      | Error e ->
          Lox.Error.print_error e;
          exit 1
      | Ok () -> exit 0)