(***********************************************************************)
(*                                                                     *)
(*                               TAToo                                 *)
(*                                                                     *)
(*                   Lucca Hirschi, LRI UMR8623                        *)
(*                   Université Paris-Sud & CNRS                       *)
(*                                                                     *)
(*  Copyright 2010-2012 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.                                                        *)
(*                                                                     *)
(***********************************************************************)

INCLUDE "utils.ml"

module Node  =
struct
  type t = int
  let hash n = n
  let compare = (-)
  let equal = (=)
end
  
module NodeHash = Hashtbl.Make (Node)
  
type t = (StateSet.t*StateSet.t) NodeHash.t
(** Map from nodes to query and recognizing states *)
(* Note that we do not consider nil nodes *)

exception Oracle_fail
exception Over_max_fail
exception Max_fail


(* Hash Consign modules *)

module type Oracle_fixpoint =
sig
  type t = StateSet.t*StateSet.t*StateSet.t*((StateSet.elt*Formula.t) list)*QName.t
  val equal : t -> t -> bool
  val hash : t -> int
end

type dStateS = StateSet.t*StateSet.t
module type Run_fixpoint =
sig
  type t = dStateS*dStateS*dStateS*(State.t*Formula.t) list*QName.t
  val equal : t -> t -> bool
  val hash : t -> int
end
    
module Oracle_fixpoint : Oracle_fixpoint = struct
  type t =
      StateSet.t*StateSet.t*StateSet.t*((StateSet.elt*Formula.t) list)*QName.t
  let equal (s,l,r,list,t) (s',l',r',list',t') = StateSet.equal s s' &&
    StateSet.equal l l' && StateSet.equal r r' && QName.equal t t'
  let hash (s,l,r,list,t) =
    HASHINT4(StateSet.hash s, StateSet.hash l, StateSet.hash r, QName.hash t)
end
  
let dequal (x,y) (x',y') = StateSet.equal x x' && StateSet.equal y y'
let dhash (x,y) = HASHINT2(StateSet.hash x, StateSet.hash y)
module Run_fixpoint : Run_fixpoint = struct
  type t = dStateS*dStateS*dStateS*(State.t*Formula.t) list*QName.t
  let equal (s,l,r,list,t) (s',l',r',list',t') = dequal s s' &&
    dequal l l' && dequal r r' && QName.equal t t'
  let hash (s,l,r,list,t) =
    HASHINT4(dhash s, dhash l, dhash r, QName.hash t)
end

module HashOracle = Hashtbl.Make(Oracle_fixpoint)
module HashRun = Hashtbl.Make(Run_fixpoint)

(* Mapped sets for leaves *)
let map_leaf asta = (Asta.bot_states_s asta, StateSet.empty)

(* Build the Oracle *)
let rec bu_oracle asta run tree tnode hashOracle=
  let node = Tree.preorder tree tnode in
  if Tree.is_leaf tree tnode
  then
    if tnode == Tree.nil
    then ()
    else NodeHash.add run node (map_leaf asta)
  else
    let tfnode = Tree.first_child_x tree tnode
    and tnnode = Tree.next_sibling tree tnode in
    let fnode,nnode =                            (* their preorders *)
      (Tree.preorder tree tfnode, Tree.preorder tree tnnode) in
    begin
      bu_oracle asta run tree tfnode hashOracle;
      bu_oracle asta run tree tnnode hashOracle;
      (* add states which satisfy a transition *)
      let rec result set qfr qnr flag = function
        | [] -> set,flag
        | (q,form) :: tl ->
          if Formula.eval_form (set,qfr,qnr) form (* evaluates the formula*)
          then
            if StateSet.mem q set
            then result set qfr qnr 0 tl
            else result (StateSet.add q set) qfr qnr 1 tl
          else result set qfr qnr 0 tl in
      (* compute the fixed point of states of node *)
      let rec fix_point set_i qfr qnr list_tr t =
        try HashOracle.find hashOracle (set_i, qfr, qnr, list_tr, t)
        with _ -> 
          let set,flag = result set_i qfr qnr 0 list_tr in
          HashOracle.add hashOracle (set_i,qfr,qnr,list_tr,t) (set);
          if flag = 0
          then set
          else fix_point set qfr qnr list_tr t in
      let q_rec n =                     (* compute the set for child/sibling *)
        try NodeHash.find run n
        with Not_found -> map_leaf asta in
      let (_,qfr),(_,qnr) = q_rec fnode,q_rec nnode (* computed in rec call *)
      and lab = Tree.tag tree tnode in
      let _,list_tr = Asta.transitions_lab asta lab in (*only reco. tran.*)     
     NodeHash.add run node (StateSet.empty,
                            fix_point StateSet.empty qfr qnr list_tr lab)
    end

(* Build the over-approx. of the maximal run *)
let rec bu_over_max asta run tree tnode hashRun =
  if (Tree.is_leaf tree tnode)      (* BU_oracle has already created the map *)
  then
    ()
  else
    let tfnode = Tree.first_child_x tree tnode
    and tnnode = Tree.next_sibling tree tnode in
    begin
      bu_over_max asta run tree tfnode hashRun;
      bu_over_max asta run tree tnnode hashRun;
      let (fnode,nnode) =
        (Tree.preorder tree tfnode, Tree.preorder tree tnnode)
      and node = Tree.preorder tree tnode in          
      let q_rec n =
        try NodeHash.find run n
        with Not_found -> map_leaf asta in
      let qf,qn = q_rec fnode,q_rec nnode in
      let lab = Tree.tag tree tnode in
      let list_tr,_ = Asta.transitions_lab asta lab (* only take query st. *)
      and _,resultr = try NodeHash.find run node
        with _ -> raise Over_max_fail in      
      let rec result set flag = function
        | [] -> if flag = 0 then set else result set 0 list_tr
        | (q,form) :: tl ->
          if StateSet.mem q set
          then result set 0 tl
          else if Formula.infer_form (set,resultr) qf qn form
               then result (StateSet.add q set) 1 tl
               else result set 0 tl in
      let result_set = result StateSet.empty 0 list_tr in
      (* we keep the old recognizing states set *)
      NodeHash.replace run node (result_set, resultr)
    end


(* Build the maximal run *)
let rec tp_max asta run tree tnode hashRun =
  if (Tree.is_leaf tree tnode)      (* BU_oracle has already created the map *)
  then
    ()
  else
    let node = Tree.preorder tree tnode
    and tfnode = Tree.first_child_x tree tnode
    and tnnode = Tree.next_sibling tree tnode in
    let (fnode,nnode) =
      (Tree.preorder tree tfnode, Tree.preorder tree tnnode) in
    begin
      if tnode == Tree.root tree        (* we must intersect with top states *)
      then let setq,_  = try NodeHash.find run node
        with _ -> raise Max_fail in
           NodeHash.replace run node
             ((StateSet.inter (Asta.top_states_s asta) setq),StateSet.empty)
      else ();
      let q_rec n =
        try NodeHash.find run n
        with Not_found -> map_leaf asta in
      let qf,qn = q_rec fnode,q_rec nnode in
      let lab = Tree.tag tree tnode in
      let list_tr,_ = Asta.transitions_lab asta lab in (* only take query. *)
      let (self_q,self_r) = try NodeHash.find run node
        with Not_found -> raise Max_fail in

      (* We must compute again accepting states from self transitions since
         previous calls of tp_max may remove them *)
      let rec result_q self_q queue = function (* for initializing the queue *)
        | [] -> self_q,queue
        | (q,form) :: tl ->
          if (StateSet.mem q self_q)
          then begin 
            let q_cand,_,_ = Formula.st form in
            StateSet.iter (fun x -> Queue.push x queue) q_cand;
            result_q (StateSet.add q self_q) queue tl;
          end
          else result_q self_q queue tl
      and result_st_q self_q queue flag = function (*for computing the fixed p*)
        | [] -> flag,queue
        | form :: tl ->
          if Formula.infer_form (self_q,self_r) qf qn form
          then begin 
            let q_cand,_,_ = Formula.st form in
            StateSet.iter (fun x -> Queue.push x queue) q_cand;
            result_st_q self_q queue 1 tl;
          end
          else result_st_q self_q queue flag tl in
      let rec comp_acc_self self_q_i queue = (* compute the fixed point *)
        if Queue.is_empty queue
        then self_q_i
        else
          let q = Queue.pop queue in
          let list_q,_ = Asta.transitions_st_lab asta q lab in
          let flag,queue = result_st_q self_q_i queue 0 list_q in
          let self_q = if flag = 1 then StateSet.add q self_q_i else self_q_i in
          comp_acc_self self_q queue in
      
      let self,queue_init = result_q self_q (Queue.create()) list_tr in
      let self_q = comp_acc_self self_q queue_init in
      NodeHash.replace run node (self_q,self_r);
      (* From now, the correct set of states is mapped to node! *)
      let rec result = function
        | [] -> []
        | (q,form) :: tl ->
          if (StateSet.mem q self) &&  (* infers & trans. can start here *)
            (Formula.infer_form (self_q,self_r) qf qn form)
          then form :: (result tl)
          else result tl in      
      let list_form = result list_tr in (* tran. candidates *)
      (* compute states occuring in transition candidates *)
      let rec add_st (ql,qr) = function
        | [] -> ql,qr
        | f :: tl -> let sqs,sql,sqr = Formula.st f in
                     let ql' = StateSet.union sql ql
                     and qr' = StateSet.union sqr qr in
                     add_st (ql',qr') tl in
      let ql,qr = add_st (StateSet.empty, StateSet.empty) list_form in
      let qfq,qfr = try NodeHash.find run fnode
        with | _ -> map_leaf asta
      and qnq,qnr = try NodeHash.find run nnode
        with | _ -> map_leaf asta in
      begin
        if tfnode == Tree.nil || Tree.is_attribute tree tnode
        then ()
        else NodeHash.replace run fnode (StateSet.inter qfq ql,qfr);
        if tnnode == Tree.nil || Tree.is_attribute tree tnode
        then ()
        else NodeHash.replace run nnode (StateSet.inter qnq qr,qnr);
        (* indeed we delete all states from self transitions!  *)
        tp_max asta run tree tfnode hashRun;
        tp_max asta run tree tnnode hashRun;
      end;
    end
        
let compute tree asta =
  let flag = 2 in                       (* debug  *)
  let size_tree = 10000 in              (* todo (Tree.size ?) *)
  let size_hcons_O = 1000 in            (* todo size Hashtbl *)
  let size_hcons_M = 1000 in            (* todo size Hashtbl *)
  let map = NodeHash.create size_tree in
  let hashOracle = HashOracle.create(size_hcons_O) in
  bu_oracle asta map tree (Tree.root tree) hashOracle;
  HashOracle.clear hashOracle;
  if flag > 0 then begin
    let hashRun = HashRun.create(size_hcons_M) in
    bu_over_max asta map tree (Tree.root tree) hashRun;
    if flag = 2
    then
      tp_max asta map tree (Tree.root tree) hashRun
    else ();
    HashRun.clear hashRun;
  end
  else ();
  map

let selected_nodes tree asta =
  let run = compute tree asta in
  NodeHash.fold
    (fun key set acc ->
      if not(StateSet.is_empty
               (StateSet.inter (fst set) (Asta.selec_states asta)))
      then key :: acc
      else acc)
    run []

let print fmt run =
  let print_d_set fmt (s_1,s_2) =
    Format.fprintf fmt "(%a,%a)"
      StateSet.print s_1 StateSet.print s_2 in
  let print_map fmt run =
    let pp = Format.fprintf fmt in
    if NodeHash.length run = 0
    then Format.fprintf fmt "ø"
    else
      NodeHash.iter (fun cle set -> pp "|  %i->%a  @ " cle print_d_set set)
        run in
  let print_box fmt run =
    let pp = Format.fprintf fmt in
    pp "@[<hov 0>@.  # Mapping:@.   @[<hov 0>%a@]@]"
      print_map run
  in
  Format.fprintf fmt "@[<hov 0>##### RUN #####@, %a@]@." print_box run