(************************************************************************)
(*         *   The Coq Proof Assistant / The Coq Development Team       *)
(*  v      *   INRIA, CNRS and contributors - Copyright 1999-2018       *)
(* <O___,, *       (see CREDITS file for the list of authors)           *)
(*   \VV/  **************************************************************)
(*    //   *    This file is distributed under the terms of the         *)
(*         *     GNU Lesser General Public License Version 2.1          *)
(*         *     (see LICENSE file for the text of the license)         *)
(************************************************************************)

open Util
open Locus
open Misctypes
open Genredexpr
open Stdarg
open Extraargs
open Names

DECLARE PLUGIN "ltac_plugin"

(** Basic tactics *)

TACTIC EXTEND reflexivity
  [ "reflexivity" ] -> [ Tactics.intros_reflexivity ]
END

TACTIC EXTEND exact
  [ "exact" casted_constr(c) ] -> [ Tactics.exact_no_check c ]
END

TACTIC EXTEND assumption
  [ "assumption" ] -> [ Tactics.assumption ]
END

TACTIC EXTEND etransitivity
  [ "etransitivity" ] -> [ Tactics.intros_transitivity None ]
END

TACTIC EXTEND cut
  [ "cut" constr(c) ] -> [ Tactics.cut c ]
END

TACTIC EXTEND exact_no_check
  [ "exact_no_check" constr(c) ] -> [ Tactics.exact_no_check c ]
END

TACTIC EXTEND vm_cast_no_check
  [ "vm_cast_no_check" constr(c) ] -> [ Tactics.vm_cast_no_check c ]
END

TACTIC EXTEND native_cast_no_check
  [ "native_cast_no_check" constr(c) ] -> [ Tactics.native_cast_no_check c ]
END

TACTIC EXTEND casetype
  [ "casetype" constr(c) ] -> [ Tactics.case_type c ]
END

TACTIC EXTEND elimtype
  [ "elimtype" constr(c) ] -> [ Tactics.elim_type c ]
END

TACTIC EXTEND lapply
  [ "lapply" constr(c) ] -> [ Tactics.cut_and_apply c ]
END

TACTIC EXTEND transitivity
  [ "transitivity" constr(c) ] -> [ Tactics.intros_transitivity (Some c) ]
END

(** Left *)

TACTIC EXTEND left
  [ "left" ] -> [ Tactics.left_with_bindings false NoBindings ]
END

TACTIC EXTEND eleft
  [ "eleft" ] -> [ Tactics.left_with_bindings true NoBindings ]
END

TACTIC EXTEND left_with
  [ "left" "with" bindings(bl) ] -> [
    Tacticals.New.tclDELAYEDWITHHOLES false bl (fun bl -> Tactics.left_with_bindings false bl)
  ]
END

TACTIC EXTEND eleft_with
  [ "eleft" "with" bindings(bl) ] -> [
    Tacticals.New.tclDELAYEDWITHHOLES true bl (fun bl -> Tactics.left_with_bindings true bl)
  ]
END

(** Right *)

TACTIC EXTEND right
  [ "right" ] -> [ Tactics.right_with_bindings false NoBindings ]
END

TACTIC EXTEND eright
  [ "eright" ] -> [ Tactics.right_with_bindings true NoBindings ]
END

TACTIC EXTEND right_with
  [ "right" "with" bindings(bl) ] -> [
    Tacticals.New.tclDELAYEDWITHHOLES false bl (fun bl -> Tactics.right_with_bindings false bl)
  ]
END

TACTIC EXTEND eright_with
  [ "eright" "with" bindings(bl) ] -> [
    Tacticals.New.tclDELAYEDWITHHOLES true bl (fun bl -> Tactics.right_with_bindings true bl)
  ]
END

(** Constructor *)

TACTIC EXTEND constructor
  [ "constructor" ] -> [ Tactics.any_constructor false None ]
| [ "constructor" int_or_var(i) ] -> [
    Tactics.constructor_tac false None i NoBindings
  ]
| [ "constructor" int_or_var(i) "with" bindings(bl) ] -> [
    let tac bl = Tactics.constructor_tac false None i bl in
    Tacticals.New.tclDELAYEDWITHHOLES false bl tac
  ]
END

TACTIC EXTEND econstructor
  [ "econstructor" ] -> [ Tactics.any_constructor true None ]
| [ "econstructor" int_or_var(i) ] -> [
    Tactics.constructor_tac true None i NoBindings
  ]
| [ "econstructor" int_or_var(i) "with" bindings(bl) ] -> [
    let tac bl = Tactics.constructor_tac true None i bl in
    Tacticals.New.tclDELAYEDWITHHOLES true bl tac
  ]
END

(** Specialize *)

TACTIC EXTEND specialize
  [ "specialize" constr_with_bindings(c) ] -> [
    Tacticals.New.tclDELAYEDWITHHOLES false c (fun c -> Tactics.specialize c None)
  ]
| [ "specialize" constr_with_bindings(c) "as" intropattern(ipat) ] -> [
    Tacticals.New.tclDELAYEDWITHHOLES false c (fun c -> Tactics.specialize c (Some ipat))
  ]
END

TACTIC EXTEND symmetry
  [ "symmetry" ] -> [ Tactics.intros_symmetry {onhyps=Some[];concl_occs=AllOccurrences} ]
END

TACTIC EXTEND symmetry_in
| [ "symmetry" "in" in_clause(cl) ] -> [ Tactics.intros_symmetry cl ]
END

(** Split *)

let rec delayed_list = function
| [] -> fun _ sigma -> (sigma, [])
| x :: l ->
  fun env sigma ->
    let (sigma, x) = x env sigma in
    let (sigma, l) = delayed_list l env sigma in
    (sigma, x :: l)

TACTIC EXTEND split
  [ "split" ] -> [ Tactics.split_with_bindings false [NoBindings] ]
END

TACTIC EXTEND esplit
  [ "esplit" ] -> [ Tactics.split_with_bindings true [NoBindings] ]
END

TACTIC EXTEND split_with
  [ "split" "with" bindings(bl) ] -> [
    Tacticals.New.tclDELAYEDWITHHOLES false bl (fun bl -> Tactics.split_with_bindings false [bl])
  ]
END

TACTIC EXTEND esplit_with
  [ "esplit" "with" bindings(bl) ] -> [
    Tacticals.New.tclDELAYEDWITHHOLES true bl (fun bl -> Tactics.split_with_bindings true [bl])
  ]
END

TACTIC EXTEND exists
  [ "exists" ] -> [ Tactics.split_with_bindings false [NoBindings] ]
| [ "exists" ne_bindings_list_sep(bll, ",") ] -> [
    Tacticals.New.tclDELAYEDWITHHOLES false (delayed_list bll) (fun bll -> Tactics.split_with_bindings false bll)
  ]
END

TACTIC EXTEND eexists
  [ "eexists" ] -> [ Tactics.split_with_bindings true [NoBindings] ]
| [ "eexists" ne_bindings_list_sep(bll, ",") ] -> [
    Tacticals.New.tclDELAYEDWITHHOLES true (delayed_list bll) (fun bll -> Tactics.split_with_bindings true bll)
  ]
END

(** Intro *)

TACTIC EXTEND intros_until
  [ "intros" "until" quantified_hypothesis(h) ] -> [ Tactics.intros_until h ]
END

TACTIC EXTEND intro
| [ "intro" ] -> [ Tactics.intro_move None MoveLast ]
| [ "intro" ident(id) ] -> [ Tactics.intro_move (Some id) MoveLast ]
| [ "intro" ident(id) "at" "top" ] -> [ Tactics.intro_move (Some id) MoveFirst ]
| [ "intro" ident(id) "at" "bottom" ] -> [ Tactics.intro_move (Some id) MoveLast ]
| [ "intro" ident(id) "after" hyp(h) ] -> [ Tactics.intro_move (Some id) (MoveAfter h) ]
| [ "intro" ident(id) "before" hyp(h) ] -> [ Tactics.intro_move (Some id) (MoveBefore h) ]
| [ "intro" "at" "top" ] -> [ Tactics.intro_move None MoveFirst ]
| [ "intro" "at" "bottom" ] -> [ Tactics.intro_move None MoveLast ]
| [ "intro" "after" hyp(h) ] -> [ Tactics.intro_move None (MoveAfter h) ]
| [ "intro" "before" hyp(h) ] -> [ Tactics.intro_move None (MoveBefore h) ]
END

(** Move *)

TACTIC EXTEND move
  [ "move" hyp(id) "at" "top" ] -> [ Tactics.move_hyp id MoveFirst ]
| [ "move" hyp(id) "at" "bottom" ] -> [ Tactics.move_hyp id MoveLast ]
| [ "move" hyp(id) "after" hyp(h) ] -> [ Tactics.move_hyp id (MoveAfter h) ]
| [ "move" hyp(id) "before" hyp(h) ] -> [ Tactics.move_hyp id (MoveBefore h) ]
END

(** Rename *)

TACTIC EXTEND rename
| [ "rename" ne_rename_list_sep(ids, ",") ] -> [ Tactics.rename_hyp ids ]
END

(** Revert *)

TACTIC EXTEND revert
  [ "revert" ne_hyp_list(hl) ] -> [ Tactics.revert hl ]
END

(** Simple induction / destruct *)

let simple_induct h =
  Tacticals.New.tclTHEN (Tactics.intros_until h)
    (Tacticals.New.onLastHyp Tactics.simplest_elim)

TACTIC EXTEND simple_induction
  [ "simple" "induction" quantified_hypothesis(h) ] -> [ simple_induct h ]
END

let simple_destruct h =
  Tacticals.New.tclTHEN (Tactics.intros_until h)
    (Tacticals.New.onLastHyp Tactics.simplest_case)

TACTIC EXTEND simple_destruct
  [ "simple" "destruct" quantified_hypothesis(h) ] -> [ simple_destruct h ]
END

(** Double induction *)

TACTIC EXTEND double_induction
  [ "double" "induction" quantified_hypothesis(h1) quantified_hypothesis(h2) ] ->
  [ Elim.h_double_induction h1 h2 ]
END

(* Admit *)

TACTIC EXTEND admit
 [ "admit" ] -> [ Proofview.give_up ]
END

(* Fix *)

TACTIC EXTEND fix
  [ "fix" natural(n) ] -> [ Tactics.fix None n ]
| [ "fix" ident(id) natural(n) ] -> [ Tactics.fix (Some id) n ]
END

(* Cofix *)

TACTIC EXTEND cofix
  [ "cofix" ] -> [ Tactics.cofix None ]
| [ "cofix" ident(id) ] -> [ Tactics.cofix (Some id) ]
END

(* Clear *)

TACTIC EXTEND clear
  [ "clear" hyp_list(ids) ] -> [
    if List.is_empty ids then Tactics.keep []
    else Tactics.clear ids
  ]
| [ "clear" "-" ne_hyp_list(ids) ] -> [ Tactics.keep ids ]
END

(* Clearbody *)

TACTIC EXTEND clearbody
  [ "clearbody" ne_hyp_list(ids) ] -> [ Tactics.clear_body ids ]
END

(* Generalize dependent *)

TACTIC EXTEND generalize_dependent
  [ "generalize" "dependent" constr(c) ] -> [ Tactics.generalize_dep c ]
END

(* Table of "pervasives" macros tactics (e.g. auto, simpl, etc.) *)

open Tacexpr

let initial_atomic () =
  let nocl = {onhyps=Some[];concl_occs=AllOccurrences} in
  let iter (s, t) =
    let body = TacAtom (Loc.tag t) in
    Tacenv.register_ltac false false (Names.Id.of_string s) body
  in
  let () = List.iter iter
      [ "red", TacReduce(Red false,nocl);
        "hnf", TacReduce(Hnf,nocl);
        "simpl", TacReduce(Simpl (Redops.all_flags,None),nocl);
        "compute", TacReduce(Cbv Redops.all_flags,nocl);
        "intros", TacIntroPattern (false,[]);
      ]
  in
  let iter (s, t) = Tacenv.register_ltac false false (Names.Id.of_string s) t in
  List.iter iter
      [ "idtac",TacId [];
        "fail", TacFail(TacLocal,ArgArg 0,[]);
        "fresh", TacArg(Loc.tag @@ TacFreshId [])
      ]

let () = Mltop.declare_cache_obj initial_atomic "ltac_plugin"

(* First-class Ltac access to primitive blocks *)

let initial_name s = { mltac_plugin = "ltac_plugin"; mltac_tactic = s; }
let initial_entry s = { mltac_name = initial_name s; mltac_index = 0; }

let register_list_tactical name f =
  let tac args ist = match args with
  | [v] ->
    begin match Tacinterp.Value.to_list v with
    | None -> Tacticals.New.tclZEROMSG (Pp.str "Expected a list")
    | Some tacs ->
      let tacs = List.map (fun tac -> Tacinterp.tactic_of_value ist tac) tacs in
      f tacs
    end
  | _ -> assert false
  in
  Tacenv.register_ml_tactic (initial_name name) [|tac|]

let () = register_list_tactical "first" Tacticals.New.tclFIRST
let () = register_list_tactical "solve" Tacticals.New.tclSOLVE

let initial_tacticals () =
  let idn n = Id.of_string (Printf.sprintf "_%i" n) in
  let varn n = Reference (ArgVar (CAst.make (idn n))) in
  let iter (s, t) = Tacenv.register_ltac false false (Id.of_string s) t in
  List.iter iter [
    "first", TacFun ([Name (idn 0)], TacML (None, (initial_entry "first", [varn 0])));
    "solve", TacFun ([Name (idn 0)], TacML (None, (initial_entry "solve", [varn 0])));
  ]

let () = Mltop.declare_cache_obj initial_tacticals "ltac_plugin"