(* Copyright 2012 Tony Garnock-Jones <tonygarnockjones@gmail.com>. *)

(* This file is part of Hop. *)

(* Hop is free software: you can redistribute it and/or modify it *)
(* under the terms of the GNU General Public License as published by the *)
(* Free Software Foundation, either version 3 of the License, or (at your *)
(* option) any later version. *)

(* Hop is distributed in the hope that it will be useful, but *)
(* WITHOUT ANY WARRANTY; without even the implied warranty of *)
(* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU *)
(* General Public License for more details. *)

(* You should have received a copy of the GNU General Public License *)
(* along with Hop.  If not, see <http://www.gnu.org/licenses/>. *)

open Lwt
open Sexp

let mtx = Lwt_mutex.create ()
let write_to_log label body =
  Lwt_mutex.with_lock mtx (fun () ->
    try_lwt
      lwt () = Lwt_io.print label in
      lwt () = Lwt_io.print ": " in
      lwt () = output_sexp_human Lwt_io.stdout body in
      Lwt_io.printl ""
    with _ -> return ())

let hook = ref write_to_log

let info message args = (!hook) "info" (Arr (Sexp.str message :: args))
let warn message args = (!hook) "warn" (Arr (Sexp.str message :: args))
let error message args = (!hook) "error" (Arr (Sexp.str message :: args))