(* 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/
 *)

exception Not_implemented of string
let not_implemented feature = raise (Not_implemented feature)

  (** exceptions whose content should be presented to the user *)
exception Failure of string
let error s = raise (Failure s)
let warning s = prerr_endline ("MATITA WARNING:\t" ^ s)
let debug_print s =
  if BuildTimeConf.debug then prerr_endline ("MATITA DEBUG:\t" ^ s)

exception No_proof  (** no current proof is available *)

let untitled_con_uri = UriManager.uri_of_string "cic:/untitled.con"
let untitled_def_uri = UriManager.uri_of_string "cic:/untitled.ind"

class type observer =
  (* "observer" pattern *)
  object
    method update: unit -> unit
  end

class subject =
  (* "observer" pattern *)
  object
    val mutable observers = []
    method attach (o: observer) = observers <- o :: observers
    method detach (o: observer) =
      observers <- List.filter (fun o' -> o' != o) observers
    method notify () = List.iter (fun o -> o#update ()) observers
  end

class type command =
  (* "command" pattern *)
  object
    method execute: unit -> unit
    method undo: unit -> unit
  end

class type parserr =  (* "parser" is a keyword :-( *)
  object
    method parseTerm:     char Stream.t -> DisambiguateTypes.term
    method parseTactic:   char Stream.t -> DisambiguateTypes.tactic
    method parseTactical: char Stream.t -> DisambiguateTypes.tactical
    method parseCommand:  char Stream.t -> DisambiguateTypes.command
    method parseScript:   char Stream.t -> DisambiguateTypes.script
  end

class type disambiguator =
  object
    method parserr: parserr
    method setParserr: parserr -> unit

    method env: DisambiguateTypes.environment
    method setEnv: DisambiguateTypes.environment -> unit

      (* TODO Zack: as long as matita doesn't support MDI inteface,
      * disambiguateTerm will return a single term *)
      (** @param env disambiguation environment. If this parameter is given the
      * disambiguator act statelessly, that is internal disambiguation status
      * want be changed but only returned. If this parameter is not given the
      * internal one will be used and updated with the disambiguation status
      * resulting from the disambiguation *)
    method disambiguateTerm:
      ?context:Cic.context -> ?metasenv:Cic.metasenv ->
      ?env:DisambiguateTypes.environment ->
        char Stream.t ->
          (DisambiguateTypes.environment * Cic.metasenv * Cic.term)
      (** @param env @see disambiguateTerm above *)
    method disambiguateTermAst:
      ?context:Cic.context -> ?metasenv:Cic.metasenv ->
      ?env:DisambiguateTypes.environment ->
        DisambiguateTypes.term ->
          (DisambiguateTypes.environment * Cic.metasenv * Cic.term)
  end

class type proofStatus =
  object
    inherit subject

      (** {3 properties} *)

    method proof: ProofEngineTypes.proof
    method setProof: ProofEngineTypes.proof -> unit

    method goal: ProofEngineTypes.goal option
    method setGoal: ProofEngineTypes.goal option -> unit

      (** @raise MatitaTypes.No_proof *)
    method status: ProofEngineTypes.status (* proof, goal *)
    method setStatus: ProofEngineTypes.status -> unit

      (** {3 actions} *)

    (** return a pair of "xml" (as defined in Xml module) representing the *
     * current proof type and body, respectively *)
    method toXml: Xml.token Stream.t * Xml.token Stream.t
    method toString: string
  end

class type proof =
  object
      (** {3 status} *)
    method status: proofStatus
    method setStatus: proofStatus -> unit
  end

type proof_handler =
  { get_proof: unit -> proof; (* return current proof or fail *)
    set_proof: proof option -> unit;  (* set a proof option as current proof *)
    has_proof: unit -> bool;  (* check if a current proof is available or not *)
    new_proof: proof -> unit; (* as a set_proof but takes care also to register
                              observers *)
    quit: unit -> unit
  }

  (** interpreter for toplevel phrases given via console *)
class type interpreter =
  object
    method evalPhrase: string -> unit
  end

(** {2 shorthands} *)

type namer = ProofEngineTypes.mk_fresh_name_type

type choose_uris_callback =
  selection_mode:[`MULTIPLE|`SINGLE] ->
  ?title:string -> ?msg:string -> ?nonvars_button:bool ->
  string list ->
    string list

type choose_interp_callback = (string * string) list list -> int list