(***********************************************************************)
(*                                                                     *)
(*                               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.                                                        *)
(*                                                                     *)
(***********************************************************************)

INCLUDE "utils.ml"
INCLUDE "debug.ml"


module Make (T : Tree.S) =
struct

  let int (x : bool) : int = Obj.magic x
  let kint (x : Tree.NodeKind.t) : int = Obj.magic x
  let summary tree node is_first is_next fc ns =
    (int (ns != T.nil)) lor
      ((int (fc != T.nil)) lsl 1) lor
      ((int is_next) lsl 2) lor
      ((int is_first) lsl 3) lor
      ((kint (T.kind tree node)) lsl 4)

  let has_next_sibling summary : bool = Obj.magic (summary land 1)
  let has_first_child summary : bool = Obj.magic ((summary lsr 1) land 1)
  let is_next_sibling summary : bool = Obj.magic ((summary lsr 2) land 1)
  let is_first_child summary : bool = Obj.magic ((summary lsr 3) land 1)
  let kind summary : Tree.NodeKind.t  = Obj.magic (summary lsr 4)

  let dummy_set = StateSet.singleton State.dummy
  let dummy_trans_list =
    Ata.(TransList.cons
      (Transition.make (State.dummy, QNameSet.empty, Formula.false_))
      TransList.nil)

  module Run =
    struct
      open Bigarray
      type t = {
        mutable pass : int;
        auto : Ata.t;
        trans_cache : Ata.TransList.t Cache.N2.t;
        td_cache : StateSet.t Cache.N6.t;
        bu_cache : StateSet.t Cache.N6.t;
        mark_cache : (StateSet.t*StateSet.t*StateSet.t) Cache.N4.t;
      }

      let create a =
        {
          pass = 0;
          auto = a;
          trans_cache = Cache.N2.create dummy_trans_list;
          td_cache = Cache.N6.create dummy_set;
          bu_cache = Cache.N6.create dummy_set;
          mark_cache = Cache.N4.create (dummy_set,dummy_set,dummy_set);
        }
    end


  let eval_form phi node_summary f_set n_set p_set s_set =
    let rec loop phi =
      let open Boolean in
      match Ata.Formula.expr phi with
        False -> false
      | True -> true
      | Or (phi1, phi2) -> loop phi1 || loop phi2
      | And (phi1, phi2) -> loop phi1 && loop phi2
      | Atom (a, b) -> b == Ata.(
        match Atom.node a with
          Is_first_child -> is_first_child node_summary
        | Is_next_sibling -> is_next_sibling node_summary
        | Is k -> k == kind node_summary
        | Has_first_child -> has_first_child node_summary
        | Has_next_sibling -> has_next_sibling node_summary
        | Move (m, q) ->
          let set =
            match m with
              `First_child -> f_set
            | `Next_sibling -> n_set
            | `Parent
            | `Previous_sibling -> p_set
            | `Stay -> s_set
          in
          StateSet.mem q set
      )
    in
    loop phi


  let eval_trans_aux trans_list node_summary f_set n_set p_set s_set =
    let open Ata in
    TransList.fold (fun trs acc ->
      let q, _ , phi = Transition.node trs in
      if eval_form phi node_summary f_set n_set p_set s_set then
        StateSet.add q acc
      else
        acc) trans_list s_set

  let eval_trans trans_list node_summary f_set n_set p_set s_set =
    let rec loop old_s =

      let new_s =
        eval_trans_aux trans_list node_summary f_set n_set p_set old_s
      in
      if new_s == old_s then old_s else loop new_s
    in
    loop s_set

  let get_trans run tag set =
    let i = (tag.QName.id :> int) in
    let j = (set.StateSet.id :> int) in
    let res = Cache.N2.find run.Run.trans_cache i j in
    if res == dummy_trans_list then begin
      let res = Ata.get_trans run.Run.auto tag set in
      Cache.N2.add run.Run.trans_cache i j res;
      res
    end
    else
      res

  let eval_trans run cache set tag node_summary f_set n_set p_set s_set =
    let i = node_summary in
    let j = (tag.QName.id :> int) in
    let k = (f_set.StateSet.id :> int) in
    let l = (n_set.StateSet.id :> int) in
    let m = (p_set.StateSet.id :> int) in
    let n = (s_set.StateSet.id :> int) in
    let res = Cache.N6.find cache i j k l m n in
    if res == dummy_set then begin
      let trans_list = get_trans run tag set in
      let res = eval_trans trans_list node_summary f_set n_set p_set s_set in
      Cache.N6.add cache i j k l m n res;
      res
    end
    else res

  let auto_run run tree prev_nodes td_states bu_states exit_states _i =
    let exit_id = (exit_states.StateSet.id :> int) in
    let empty_sets = StateSet.(empty,empty,empty) in

    let mark_node front res node set f_set n_set =
      let i = (set.StateSet.id :> int) in
      let j = (f_set.StateSet.id :> int) in
      let k = (n_set.StateSet.id :> int) in
      let (mstates, _, _) as block =
        Cache.N4.find run.Run.mark_cache exit_id i j k
      in

      let mstates, ll, rr =
        if mstates == dummy_set then begin
        let r1 = StateSet.inter set exit_states in
        let r2 = StateSet.inter f_set exit_states in
        let r3 = StateSet.inter n_set exit_states in
        let r = r1,r2,r3 in
        Cache.N4.add run.Run.mark_cache exit_id i j k r;
        r
        end
        else block
      in
      if mstates != StateSet.empty then
        let block = mstates, ll, rr, node in
        if front then Sequence.push_front block res
        else Sequence.push_back block res
    in
    let rec loop res node is_first is_next parent_set =
      if node == T.nil then StateSet.empty else begin
        let set,lset,rset =
        if Sequence.is_empty prev_nodes then
          empty_sets
        else
          let set,lset,rset, node' = Sequence.peek prev_nodes in
          if node == node' then begin
            ignore (Sequence.pop prev_nodes);
            set,lset,rset
          end
          else
            empty_sets
        in
        let tag = T.tag tree node in
        let first_child = T.first_child tree node in
        let next_sibling = T.next_sibling tree node in
        let node_summary =
          summary tree node is_first is_next first_child next_sibling
        in
        let status1 =
          eval_trans run run.Run.td_cache td_states tag node_summary lset rset parent_set set
        in
        let fcs = loop res first_child true false status1 in
        let rres = Sequence.create () in
        let nss = loop rres next_sibling false true status1 in
        if bu_states == StateSet.empty then (* tail call *) begin
          mark_node true res node status1 fcs StateSet.empty;
          Sequence.append res rres;
          status1
        end else begin

          let status2 =
            eval_trans run run.Run.bu_cache bu_states tag node_summary fcs nss parent_set status1
          in
          if status2 != StateSet.empty then
            mark_node true res node status2 fcs nss;
          Sequence.append res rres;
          status2
        end;
      end
    in
    let res = Sequence.create () in
    ignore (loop res (T.root tree) false false StateSet.empty);
    res



  let prepare_run auto l =
    let res = Sequence.create () in
    let start = Ata.get_starting_states auto in
    Sequence.iter (fun n -> Sequence.push_back (start, StateSet.empty, StateSet.empty, n) res) l;
    res

let time f arg msg =
  let t1 = Unix.gettimeofday () in
  let r = f arg in
  let t2 = Unix.gettimeofday () in
  let time = (t2 -. t1) *. 1000. in
  Logger.msg `STATS "%s: %fms" msg time;
  r


  let main_eval auto tree nodes =
    let s_nodes = prepare_run auto nodes in
    let ranked_states = Ata.get_states_by_rank auto in
    let acc = ref s_nodes in
    let max_rank = Ata.get_max_rank auto in
    let run = Run.create auto in
    for i = 0 to max_rank do
      let open Ata in
      let { td; bu; exit } = ranked_states.(i) in
      run.Run.pass <- i;
      acc := auto_run run tree !acc td bu exit i;
    done;
    !acc


  let eval auto tree nodes =
    let res = main_eval auto tree nodes in
    let r = Sequence.create () in
    Sequence.iter (fun (_,_,_, n) -> Sequence.push_back n r) res;
    r


  let full_eval auto tree nodes =
    let res = main_eval auto tree nodes in
    let dummy = Sequence.create () in
    let cache = Cache.N1.create dummy in
    Sequence.iter (fun (set, _, _, n) ->
      StateSet.iter (fun q ->
        let qres = Cache.N1.find cache q in
        let qres =
          if qres == dummy then begin
            let s = Sequence.create () in
            Cache.N1.add cache q s;
            s
          end
          else qres
        in
        Sequence.push_back n qres) set )
      res;
    let l = StateSet.fold (fun q acc ->
      let res = Cache.N1.find cache q in
      (q, res) :: acc) (Ata.get_selecting_states auto) []
    in
    List.rev l

end