(* Copyright (C) 2000, 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://cs.unibo.it/helm/.
 *)

(******************************************************************************)
(*                                                                            *)
(*                               PROJECT HELM                                 *)
(*                                                                            *)
(*                Claudio Sacerdoti Coen <sacerdot@cs.unibo.it>               *)
(*                                 24/01/2000                                 *)
(*                                                                            *)
(* This is the main (top level) module of a parser for cic objects from xml   *)
(* files to the internal representation. It uses the modules cicParser2       *)
(* (objects level) and cicParser3 (terms level)                               *)
(*                                                                            *)
(******************************************************************************)

exception Getter_failure of string * string
exception Parser_failure of string

  (** tries to recover from a parse error caused by the parsing of a getter
  * error message (e.g. Key_not_found exception). Unfortunately we have to
  * re-parse xml document to extract exception data *)
let try_recover exn filename =
  let rc = ref None in
  (try
    let entity_manager =
      Pxp_ev_parser.create_entity_manager ~is_document:true
        PxpHelmConf.pxp_config (Pxp_types.from_file filename)
    in
    let pull_parser =
      Pxp_ev_parser.create_pull_parser PxpHelmConf.pxp_config
        (`Entry_document []) entity_manager
    in
    let rec find_exn p =
      match p () with
      | None -> ()
      | Some (Pxp_types.E_start_tag ("html", attrs, _, _)) ->
          let exn = List.assoc "helm:exception" attrs in
          let arg =
            try List.assoc "helm:exception_arg" attrs with Not_found -> ""
          in
          rc := Some (Getter_failure (exn, arg))
      | _ -> find_exn p
    in
    find_exn pull_parser
  with _ -> raise (Parser_failure (Printexc.to_string exn)));
  match !rc with
  | None -> raise (Parser_failure (Printexc.to_string exn))
  | Some exn -> raise exn

let parse_document filename =
  try
    Pxp_tree_parser.parse_document_entity PxpHelmConf.pxp_config
      (Pxp_types.from_file ~alt:[PxpUrlResolver.url_resolver] filename)
      CicParser3.domspec
  with exn ->
    raise (try_recover exn filename)

(* given the filename of an xml file of a cic object it returns its internal *)
(* representation.                                                           *)
let annobj_of_xml filename filenamebody =
  let root, rootbody =
    let doc = parse_document filename in
    let docroot = doc#root in
     match filenamebody with
        None -> docroot,None
      | Some filename ->
         let docbody = parse_document filename in
         docroot,Some docbody#root
  in
   CicParser2.get_term root rootbody

let obj_of_xml filename filenamebody =
 Deannotate.deannotate_obj (annobj_of_xml filename filenamebody)