open Format

type t = string
type level = int

let loggers = [ "parsing";
                "indexing";
                "top-down-run";
		"top-down-approx";
		"result-set";
		"level2-jit";
		"res-jit";
		"twopass";
		"transition";
		"bottom-up" ]
let active_loggers : (t, int) Hashtbl.t = Hashtbl.create 17
let margin = List.fold_left (fun m l -> max m (String.length l)) 0 loggers
let available () = loggers

let is_logger s = List.mem s loggers
let level s = try Hashtbl.find active_loggers s with Not_found -> 0
let is_active s = Hashtbl.mem active_loggers s
let activate s lvl = if not (is_active s) then Hashtbl.add active_loggers s lvl
let deactivate s = Hashtbl.remove active_loggers s

let logger_output = ref err_formatter
let set_output f = logger_output := f

let log t l fmt =
  if l <= level t
  then begin
    pp_open_hovbox !logger_output (margin + 3);
    fprintf !logger_output "%-.*s : " margin t;
    kfprintf (fun _ ->
      pp_close_box !logger_output ();
      fprintf !logger_output "@?@\n";
    ) !logger_output fmt
  end
  else
    ifprintf !logger_output fmt

let print ppf fmt =
  fprintf ppf fmt

let _verbose = ref false
let set_verbose b = _verbose := b
let msg ppf fmt =
  if !_verbose
  then fprintf ppf fmt
  else ifprintf ppf fmt

let start_msg ppf s =
  msg ppf "@[%s" s

let end_msg ppf s =
  msg ppf "@]%s@?" s

let verbose a b = msg a b