(* Copyright (C) 2004, HELM Team.
 * 
 * This file is part of HELM, an Hypertextual, Electronic
 * Library of Mathematics, developed at the Computer Science
 * Department, University of Bologna, Italy.
 * 
 * HELM 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 2
 * of the License, or (at your option) any later version.
 * 
 * HELM 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 HELM; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston,
 * MA  02111-1307, USA.
 * 
 * For details, see the HELM World-Wide-Web page,
 * http://helm.cs.unibo.it/
 *)

let verbose = false

exception Failure of string
let fail msg = raise (Failure msg)

let constants_only uri = not (String.sub uri (String.length uri - 4) 4 = ".var")
let uri_predicate = ref constants_only

let uri_pred_of_conf tryvars varsprefix =
  if not tryvars then
    constants_only
  else
    let rex = Pcre.regexp ("^" ^ varsprefix) in
    (fun uri -> Pcre.pmatch ~rex uri)

module DisambiguateCallbacks =
 struct
  let interactive_user_uri_choice
   ~selection_mode ?ok ?enable_button_for_non_vars ~title ~msg ~id choices =
     List.filter !uri_predicate choices

  let interactive_interpretation_choice =
   let rec aux n =
    function
       [] -> []
     | _::tl -> n::(aux (n+1) tl)
   in
    aux 0

  let input_or_locate_uri ~title = fail "Unknown identifier"
 end

module Disambiguate' = DisambiguatingParser.Make (DisambiguateCallbacks)

let parse mqi_handle ?(uri_pred = constants_only) =
  uri_predicate := uri_pred;
  let empty_environment =
    DisambiguatingParser.EnvironmentP3.of_string
      DisambiguatingParser.EnvironmentP3.empty
  in
  let empty_context = [] in
  let empty_metasenv = [] in
  fun input ->
   List.map (fun (_,metasenv,term) -> metasenv,term)
    (Disambiguate'.disambiguate_term
      mqi_handle empty_context empty_metasenv input empty_environment)

let parse_pp mqi_handle ?uri_pred input = 
 List.map (fun (_,t) -> CicPp.ppterm t)
  (parse mqi_handle ?uri_pred input)