(***********************************************************************)
(*                                                                     *)
(*                               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 2013-03-14 11:12:24 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

  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

  module Info = struct
    type t = { is_left : bool;
               is_right : bool;
               has_left : bool;
               has_right : bool;
               kind : Tree.Common.NodeKind.t;
             }
    let equal a b = a = b
    let hash  a = Hashtbl.hash a
  end

  module NodeInfo = Hcons.Make(Info)

  let eval_form phi node_info fcs nss ps ss =
    let open NodeInfo in
    let open Info in
    let rec loop phi =
      begin match Ata.SFormula.expr phi with
        Formula.True -> true
      | Formula.False -> false
      | Formula.Atom a ->
          let p, b, q = Ata.Atom.node a in
          let pos =
            let open Ata in
                match p with
                | First_child -> StateSet.mem q fcs
                | Next_sibling ->  StateSet.mem q nss
                | Parent | Previous_sibling -> StateSet.mem q ps
                | Stay -> StateSet.mem q ss
                | Is_first_child -> node_info.node.is_left
                | Is_next_sibling -> node_info.node.is_right
                | Is k -> k == node_info.node.kind
                | Has_first_child -> node_info.node.has_left
                | Has_next_sibling -> node_info.node.has_right
            in
            if Ata.is_move p && (not b) then
              eprintf "Warning: Invalid negative atom %a" Ata.Atom.print a;
            b == pos
      | Formula.And(phi1, phi2) -> loop phi1 && loop phi2
      | Formula.Or (phi1, phi2) -> loop phi1 || loop phi2
      end
    in
    loop phi

  let eval_trans cache ltrs node_info fcs nss ps ss =
    let j = (node_info.NodeInfo.id :> int)
    and k = (fcs.StateSet.id :> int)
    and l = (nss.StateSet.id :> int)
    and m = (ps.StateSet.id :> int) in
  let rec loop ltrs ss =
    let i = (ltrs.Ata.TransList.id :> int)
    and n = (ss.StateSet.id :> int) in
    let (new_ltrs, new_ss) as res =
      let res = Cache.N6.find cache i j k l m n in
      if res == Cache.N6.dummy cache then
        let res =
          Ata.TransList.fold (fun trs (acct, accs) ->
            let q, _, phi = Ata.Transition.node trs in
            if StateSet.mem q accs then (acct, accs) else
              if eval_form phi node_info fcs nss ps accs then
                (acct, StateSet.add q accs)
              else
                (Ata.TransList.cons trs acct, accs)
          ) ltrs (Ata.TransList.nil, ss)
        in
        Cache.N6.add cache i j k l m n res; res
      else
        res
    in
    if new_ss == ss then res else
      loop new_ltrs new_ss
  in
  loop ltrs ss

  let top_down_run auto tree node cache trans_cache2 trans_cache6  _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 =
          let trs =
            Cache.N2.find trans_cache2
              (tag.QName.id :> int) (auto.Ata.states.StateSet.id :> int)
          in
          if trs == Cache.N2.dummy trans_cache2 then
            let trs = Ata.get_trans auto auto.Ata.states tag in
            (Cache.N2.add
              trans_cache2
              (tag.QName.id :> int)
              (auto.Ata.states.StateSet.id :> int) trs; trs)
          else trs
        in
        let ps = get cache tree parent in
        let fcs = get cache tree fc in
        let nss = get cache tree ns in
        let node_info = NodeInfo.make
          (Info.({ is_left = node == T.first_child tree parent;
                   is_right = node == T.next_sibling tree parent;
                   has_left = fc != T.nil;
                   has_right = ns != T.nil;
                   kind = T.kind tree node }))
        in
        let trans1, states1 =
          eval_trans trans_cache6 trans0 node_info fcs nss ps states0
        in
        if states1 != states0 then set cache tree node states1;
        let () = loop fc in
        let fcs1 = get cache tree fc in
        let trans2, states2 =
          eval_trans trans_cache6 trans1 node_info fcs1 nss ps states1
        in
        if states2 != states1 then set cache tree node states2;
        let () = loop ns in
        let _, states3 =
          eval_trans trans_cache6 trans2 node_info fcs1 (get cache tree ns) ps states2
        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 (T.size tree) StateSet.empty in
    let redo = ref true in
    let iter = ref 0 in
    let dummy2 = Ata.TransList.cons
      (Ata.Transition.make (State.dummy,QNameSet.empty, Ata.SFormula.false_))
      Ata.TransList.nil
    in
    let dummy6 = (dummy2, StateSet.empty) in
    let trans_cache6 = Cache.N6.create 17 dummy6 in
    let trans_cache2 = Cache.N2.create 17 dummy2 in
    let () = at_exit (fun () ->
      let num_phi = ref 0 in
      let num_trans = ref 0 in
      Cache.N6.iteri (fun _ _ _ _ _ _ _ b  -> if not b then incr num_phi) trans_cache6;
      Cache.N2.iteri (fun _ _ _ b -> if not b then incr num_trans) trans_cache2;
      Format.eprintf "PROFILE:materialized %i transitions and %i configurations\n@." !num_trans !num_phi
    )
    in
    while !redo do
      redo := top_down_run auto tree node cache trans_cache2 trans_cache6 !iter;
      incr iter;
    done;
    get_results auto tree node cache

end