(*  Title:      Pure/Isar/theory_target.ML

    Author:     Makarius

    Author:     Florian Haftmann, TU Muenchen

Common target infrastructure.

*)

signature GENERIC_TARGET =

sig

  val define: (((binding * typ) * mixfix) * (binding * term)

    -> term list * term list -> local_theory -> (term * thm) * local_theory)

    -> (binding * mixfix) * (Attrib.binding * term) -> local_theory

    -> (term * (string * thm)) * local_theory

  val notes: (string

    -> (Attrib.binding * (thm list * Args.src list) list) list

    -> (Attrib.binding * (thm list * Args.src list) list) list

    -> local_theory -> local_theory)

    -> string -> (Attrib.binding * (thm list * Args.src list) list) list

    -> local_theory -> (string * thm list) list * local_theory

  val abbrev: (string * bool -> binding * mixfix -> term * term

    -> term list -> local_theory -> local_theory)

    -> string * bool -> (binding * mixfix) * term -> local_theory

    -> (term * term) * local_theory

  val theory_declaration: declaration -> local_theory -> local_theory

  val theory_foundation: ((binding * typ) * mixfix) * (binding * term)

    -> term list * term list -> local_theory -> (term * thm) * local_theory

  val theory_notes: string -> (Attrib.binding * (thm list * Args.src list) list) list

    -> local_theory -> local_theory

  val theory_abbrev: Syntax.mode -> (binding * mixfix) * term

    -> local_theory -> local_theory

end;

structure Generic_Target: GENERIC_TARGET =

struct

(** lifting primitive to target operations **)

(* mixfix syntax *)

fun check_mixfix ctxt (b, extra_tfrees) mx =

  if null extra_tfrees then mx

  else

    (warning

      ("Additional type variable(s) in specification of " ^ Binding.str_of b ^ ": " ^

        commas (map (Syntax.string_of_typ ctxt o TFree) (sort_wrt #1 extra_tfrees)) ^

        (if mx = NoSyn then ""

         else "\nDropping mixfix syntax " ^ Pretty.string_of (Syntax.pretty_mixfix mx)));

      NoSyn);

(* define *)

fun define foundation ((b, mx), ((proto_b_def, atts), rhs)) lthy =

  let

    val thy = ProofContext.theory_of lthy;

    val thy_ctxt = ProofContext.init_global thy;

    val b_def = Thm.def_binding_optional b proto_b_def;

    (*term and type parameters*)

    val crhs = Thm.cterm_of thy rhs;

    val (defs, rhs') = Local_Defs.export_cterm lthy thy_ctxt crhs ||> Thm.term_of;

    val rhs_conv = MetaSimplifier.rewrite true defs crhs;

    val xs = Variable.add_fixed (Local_Theory.target_of lthy) rhs' [];

    val T = Term.fastype_of rhs;

    val tfreesT = Term.add_tfreesT T (fold (Term.add_tfreesT o #2) xs []);

    val extra_tfrees = rev (subtract (op =) tfreesT (Term.add_tfrees rhs []));

    val mx' = check_mixfix lthy (b, extra_tfrees) mx;

    val type_params = map (Logic.mk_type o TFree) extra_tfrees;

    val term_params =

      rev (Variable.fixes_of (Local_Theory.target_of lthy))

      |> map_filter (fn (_, x) =>

        (case AList.lookup (op =) xs x of

          SOME T => SOME (Free (x, T))

        | NONE => NONE));

    val params = type_params @ term_params;

    val U = map Term.fastype_of params ---> T;

    (*foundation*)

    val ((lhs', global_def), lthy2) = foundation

      (((b, U), mx'), (b_def, rhs')) (type_params, term_params) lthy;

    (*local definition*)

    val ((lhs, local_def), lthy3) = lthy2

      |> Local_Defs.add_def ((b, NoSyn), lhs');

    val def = Local_Defs.trans_terms lthy3

      [(*c == global.c xs*)     local_def,

       (*global.c xs == rhs'*)  global_def,

       (*rhs' == rhs*)          Thm.symmetric rhs_conv];

    (*note*)

    val ([(res_name, [res])], lthy4) = lthy3

      |> Local_Theory.notes_kind "" [((b_def, atts), [([def], [])])];

  in ((lhs, (res_name, res)), lthy4) end;

(* notes *)

fun import_export_proof ctxt (name, raw_th) =

  let

    val thy = ProofContext.theory_of ctxt;

    val thy_ctxt = ProofContext.init_global thy;

    val certT = Thm.ctyp_of thy;

    val cert = Thm.cterm_of thy;

    (*export assumes/defines*)

    val th = Goal.norm_result raw_th;

    val (defs, th') = Local_Defs.export ctxt thy_ctxt th;

    val assms = map (MetaSimplifier.rewrite_rule defs o Thm.assume)

      (Assumption.all_assms_of ctxt);

    val nprems = Thm.nprems_of th' - Thm.nprems_of th;

    (*export fixes*)

    val tfrees = map TFree (Thm.fold_terms Term.add_tfrees th' []);

    val frees = map Free (Thm.fold_terms Term.add_frees th' []);

    val (th'' :: vs) = (th' :: map (Drule.mk_term o cert) (map Logic.mk_type tfrees @ frees))

      |> Variable.export ctxt thy_ctxt

      |> Drule.zero_var_indexes_list;

    (*thm definition*)

    val result = PureThy.name_thm true true name th'';

    (*import fixes*)

    val (tvars, vars) =

      chop (length tfrees) (map (Thm.term_of o Drule.dest_term) vs)

      |>> map Logic.dest_type;

    val instT = map_filter (fn (TVar v, T) => SOME (v, T) | _ => NONE) (tvars ~~ tfrees);

    val inst = filter (is_Var o fst) (vars ~~ frees);

    val cinstT = map (pairself certT o apfst TVar) instT;

    val cinst = map (pairself (cert o Term.map_types (Term_Subst.instantiateT instT))) inst;

    val result' = Thm.instantiate (cinstT, cinst) result;

    (*import assumes/defines*)

    val assm_tac = FIRST' (map (fn assm => Tactic.compose_tac (false, assm, 0)) assms);

    val result'' =

      (case SINGLE (Seq.INTERVAL assm_tac 1 nprems) result' of

        NONE => raise THM ("Failed to re-import result", 0, [result'])

      | SOME res => Local_Defs.contract ctxt defs (Thm.cprop_of th) res)

      |> Goal.norm_result

      |> PureThy.name_thm false false name;

  in (result'', result) end;

fun notes target_notes kind facts lthy =

  let

    val thy = ProofContext.theory_of lthy;

    val facts' = facts

      |> map (fn (a, bs) => (a, PureThy.burrow_fact (PureThy.name_multi

          (Local_Theory.full_name lthy (fst a))) bs))

      |> PureThy.map_facts (import_export_proof lthy);

    val local_facts = PureThy.map_facts #1 facts';

    val global_facts = PureThy.map_facts #2 facts';

  in

    lthy

    |> target_notes kind global_facts local_facts

    |> ProofContext.note_thmss kind (Attrib.map_facts (Attrib.attribute_i thy) local_facts)

  end;

(* abbrev *)

fun abbrev target_abbrev prmode ((b, mx), t) lthy =

  let

    val thy_ctxt = ProofContext.init_global (ProofContext.theory_of lthy);

    val target_ctxt = Local_Theory.target_of lthy;

    val t' = Assumption.export_term lthy target_ctxt t;

    val xs = map Free (rev (Variable.add_fixed target_ctxt t' []));

    val u = fold_rev lambda xs t';

    val extra_tfrees =

      subtract (op =) (Term.add_tfreesT (Term.fastype_of u) []) (Term.add_tfrees u []);

    val mx' = check_mixfix lthy (b, extra_tfrees) mx;

    val global_rhs =

      singleton (Variable.export_terms (Variable.declare_term u target_ctxt) thy_ctxt) u;

  in

    lthy

    |> target_abbrev prmode (b, mx') (global_rhs, t') xs

    |> ProofContext.add_abbrev Print_Mode.internal (b, t) |> snd

    |> Local_Defs.fixed_abbrev ((b, NoSyn), t)

  end;

(** primitive theory operations **)

fun theory_declaration decl lthy =

  let

    val global_decl = Morphism.form

      (Morphism.transform (Local_Theory.global_morphism lthy) decl);

  in

    lthy

    |> Local_Theory.background_theory (Context.theory_map global_decl)

    |> Local_Theory.target (Context.proof_map global_decl)

  end;

fun theory_foundation (((b, U), mx), (b_def, rhs)) (type_params, term_params) lthy =

  let

    val (const, lthy2) = lthy |> Local_Theory.background_theory_result

      (Sign.declare_const ((b, U), mx));

    val lhs = list_comb (const, type_params @ term_params);

    val ((_, def), lthy3) = lthy2 |> Local_Theory.background_theory_result

      (Thm.add_def false false (b_def, Logic.mk_equals (lhs, rhs)));

  in ((lhs, def), lthy3) end;

fun theory_notes kind global_facts lthy =

  let

    val thy = ProofContext.theory_of lthy;

    val global_facts' = Attrib.map_facts (Attrib.attribute_i thy) global_facts;

  in

    lthy

    |> Local_Theory.background_theory (PureThy.note_thmss kind global_facts' #> snd)

    |> Local_Theory.target (ProofContext.note_thmss kind global_facts' #> snd)

  end;

fun theory_abbrev prmode ((b, mx), t) =

  Local_Theory.background_theory

    (Sign.add_abbrev (#1 prmode) (b, t) #->

      (fn (lhs, _) => Sign.notation true prmode [(lhs, mx)]));

end;