(***********************************************************************)
(*                                                                     *)
(*                               TAToo                                 *)
(*                                                                     *)
(*                     Kim Nguyen, LRI UMR8623                         *)
(*                   Université Paris-Sud & CNRS                       *)
(*                                                                     *)
(*  Copyright 2010-2013 Université Paris-Sud and Centre National de la *)
(*  Recherche Scientifique. All rights reserved.  This file is         *)
(*  distributed under the terms of the GNU Lesser General Public       *)
(*  License, with the special exception on linking described in file   *)
(*  ../LICENSE.                                                        *)
(*                                                                     *)
(***********************************************************************)

(*
  Time-stamp: <Last modified on 2013-03-15 18:32:22 CET by Kim Nguyen>
*)

INCLUDE "utils.ml"
open Format
open Utils

module Make (T : Tree.Sig.S) :
  sig
    val eval : Ata.t -> T.t -> T.node -> T.node list
  end
 = struct


IFDEF HTMLTRACE
  THEN
DEFINE TRACE(e) = (e)
  ELSE
DEFINE TRACE(e) = ()
END



  type cache = StateSet.t Cache.N1.t
  let get c t n = Cache.N1.find c (T.preorder t n)

  let set c t n v = Cache.N1.add c (T.preorder t n) v


  let top_down_run auto tree node cache _i =
    let redo = ref false in
    let rec loop node =
      if node != T.nil then begin
        let parent = T.parent tree node in
        let fc = T.first_child tree node in
        let ns = T.next_sibling tree node in
        let tag = T.tag tree node in
        let states0 = get cache tree node in
        let trans0 = Ata.get_trans auto tag auto.Ata.states in
        let () =
          TRACE(Html.trace (T.preorder tree node) _i "Pre States: %a<br/>Pre Trans: %a<br/>"
                  StateSet.print states0 (Ata.TransList.print ~sep:"<br/>") trans0)
        in
        let ps = get cache tree parent in
        let fcs = get cache tree fc in
        let nss = get cache tree ns in
        let is_left = node == T.first_child tree parent
        and is_right = node == T.next_sibling tree parent
        and has_left = fc != T.nil
        and has_right = ns != T.nil
        and kind = T.kind tree node
        in
        let trans1, states1 =
          Ata.eval_trans auto trans0
            fcs nss ps states0
            is_left is_right has_left has_right kind
        in
        let () =
          TRACE(Html.trace (T.preorder tree node) _i "TD States: %a<br/>TD Trans: %a<br/>" StateSet.print states1 (Ata.TransList.print ~sep:"<br/>") trans1)
        in
        if states1 != states0 then set cache tree node states1;
        let () = loop fc in
        let fcs1 = get cache tree fc in
        let trans2, states2 =
          Ata.eval_trans auto trans1
            fcs1 nss ps states1
            is_left is_right has_left has_right kind
        in
        let () =
          TRACE(Html.trace (T.preorder tree node) _i "Left BU States: %a<br/>Left BU Trans: %a<br/>" StateSet.print states2 (Ata.TransList.print ~sep:"<br/>") trans2)
        in
        if states2 != states1 then set cache tree node states2;
        let () = loop ns in
        let _trans3, states3 =
          Ata.eval_trans auto trans2
            fcs1 (get cache tree ns) ps states2
            is_left is_right has_left has_right kind
        in
        let () =
          TRACE(Html.trace (T.preorder tree node) _i "Right BU States: %a<br/>Right BU Trans: %a<br/>" StateSet.print states3 (Ata.TransList.print ~sep:"<br/>") _trans3)
        in
        if states3 != states2 then set cache tree node states3;
        if states0 != states3 && (not !redo) then redo := true
      end
    in
    loop node;
    !redo

  let get_results auto tree node cache =
    let rec loop node acc =
      if node == T.nil then acc
      else
        let acc0 = loop (T.next_sibling tree node) acc in
        let acc1 = loop (T.first_child tree node) acc0 in

        if StateSet.intersect (get cache tree node) auto.Ata.selection_states then
          node::acc1
        else
          acc1
    in
    loop node []

  let eval auto tree node =
    let cache = Cache.N1.create StateSet.empty in
    let redo = ref true in
    let iter = ref 0 in
    Ata.reset auto;
    while !redo do
      redo := top_down_run auto tree node cache !iter;
      incr iter;
    done;
    let r = get_results auto tree node cache in
    TRACE(Html.gen_trace (module T : Tree.Sig.S with type t = T.t) (tree));
    r

end