(*  Title:      Pure/Isar/generic_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: bool -> 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

     (Context_Position.if_visible ctxt warning

       ("Additional type variable(s) in specification of " ^ Binding.print 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 (Mixfix.pretty_mixfix mx)));

       NoSyn);

 (* define *)

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

   let

     val thy = Proof_Context.theory_of lthy;

     val thy_ctxt = Proof_Context.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 = Raw_Simplifier.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 target_ctxt = Local_Theory.target_of lthy;

     val term_params =

       filter (Variable.is_fixed target_ctxt o #1) xs

       |> sort (Variable.fixed_ord target_ctxt o pairself #1)

       |> map Free;

     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 = Proof_Context.theory_of ctxt;

     val thy_ctxt = Proof_Context.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 (Raw_Simplifier.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 = Global_Theory.name_thm true true name (Thm.compress 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

       |> Global_Theory.name_thm false false name;

   in (result'', result) end;

 fun notes target_notes kind facts lthy =

   let

     val thy = Proof_Context.theory_of lthy;

     val facts' = facts

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

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

       |> Global_Theory.map_facts (import_export_proof lthy);

     val local_facts = Global_Theory.map_facts #1 facts';

     val global_facts = Global_Theory.map_facts #2 facts';

   in

     lthy

     |> target_notes kind global_facts local_facts

     |> Proof_Context.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 = Proof_Context.init_global (Proof_Context.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

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

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

   end;

 (** primitive theory operations **)

 fun theory_declaration syntax 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)

     |> Context.proof_map (Morphism.form 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 lthy ((b, U), mx));

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

     val ((_, def), lthy3) = lthy2

       |> Local_Theory.background_theory_result

         (Thm.add_def lthy2 false false (b_def, Logic.mk_equals (lhs, rhs)));

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

 fun theory_notes kind global_facts lthy =

   let

     val thy = Proof_Context.theory_of lthy;

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

   in

     lthy

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

     |> Local_Theory.target (Proof_Context.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;