(*  Title:      Pure/Isar/theory_target.ML

     Author:     Makarius

     Author:     Florian Haftmann, TU Muenchen

 Targets for theory, locale and class.

 *)

 signature NAMED_TARGET =

 sig

   val init: string -> theory -> local_theory

   val theory_init: theory -> local_theory

   val reinit: local_theory -> local_theory -> local_theory

   val context_cmd: xstring -> theory -> local_theory

   val peek: local_theory -> {target: string, is_locale: bool, is_class: bool} option

 end;

 structure Named_Target: NAMED_TARGET =

 struct

 (* context data *)

 datatype target = Target of {target: string, is_locale: bool, is_class: bool};

 fun named_target _ "" = Target {target = "", is_locale = false, is_class = false}

   | named_target thy locale =

       if Locale.defined thy locale

       then Target {target = locale, is_locale = true, is_class = Class.is_class thy locale}

       else error ("No such locale: " ^ quote locale);

 structure Data = Proof_Data

 (

   type T = target option;

   fun init _ = NONE;

 );

 val peek = Option.map (fn Target args => args) o Data.get;

 (* generic declarations *)

 fun locale_declaration locale {syntax, pervasive} decl lthy =

   let

     val add = if syntax then Locale.add_syntax_declaration else Locale.add_declaration;

     val locale_decl = Morphism.transform (Local_Theory.target_morphism lthy) decl;

   in

     lthy

     |> pervasive ? Generic_Target.theory_declaration decl

     |> Local_Theory.target (add locale locale_decl)

   end;

 fun target_declaration (Target {target, ...}) {syntax, pervasive} =

   if target = "" then Generic_Target.theory_declaration

   else locale_declaration target {syntax = syntax, pervasive = pervasive};

 (* consts in locales *)

 fun locale_const (Target {target, is_class, ...}) (prmode as (mode, _)) ((b, mx), rhs) phi =

   let

     val b' = Morphism.binding phi b;

     val rhs' = Morphism.term phi rhs;

     val arg = (b', Term.close_schematic_term rhs');

     val same_shape = Term.aconv_untyped (rhs, rhs');

     (* FIXME workaround based on educated guess *)

     val prefix' = Binding.prefix_of b';

     val is_canonical_class = is_class andalso

       (Binding.eq_name (b, b')

         andalso not (null prefix')

         andalso List.last prefix' = (Class.class_prefix target, false)

       orelse same_shape);

   in

     not is_canonical_class ?

       (Context.mapping_result

         (Sign.add_abbrev Print_Mode.internal arg)

         (ProofContext.add_abbrev Print_Mode.internal arg)

       #-> (fn (lhs' as Const (d, _), _) =>

           same_shape ?

             (Context.mapping

               (Sign.revert_abbrev mode d) (ProofContext.revert_abbrev mode d) #>

              Morphism.form (ProofContext.target_notation true prmode [(lhs', mx)]))))

   end;

 fun locale_const_declaration (ta as Target {target, ...}) prmode arg =

   locale_declaration target {syntax = true, pervasive = false} (locale_const ta prmode arg);

 (* define *)

 fun locale_foundation ta (((b, U), mx), (b_def, rhs)) (type_params, term_params) =

   Generic_Target.theory_foundation (((b, U), NoSyn), (b_def, rhs)) (type_params, term_params)

   #-> (fn (lhs, def) => locale_const_declaration ta Syntax.mode_default ((b, mx), lhs)

     #> pair (lhs, def))

 fun class_foundation (ta as Target {target, ...})

     (((b, U), mx), (b_def, rhs)) (type_params, term_params) =

   Generic_Target.theory_foundation (((b, U), NoSyn), (b_def, rhs)) (type_params, term_params)

   #-> (fn (lhs, def) => locale_const_declaration ta Syntax.mode_default ((b, NoSyn), lhs)

     #> Class.const target ((b, mx), (type_params, lhs))

     #> pair (lhs, def))

 fun target_foundation (ta as Target {is_locale, is_class, ...}) =

   if is_class then class_foundation ta

   else if is_locale then locale_foundation ta

   else Generic_Target.theory_foundation;

 (* notes *)

 fun locale_notes locale kind global_facts local_facts lthy =

   let

     val global_facts' = Attrib.map_facts (K I) global_facts;

     val local_facts' = Element.facts_map

       (Element.morph_ctxt (Local_Theory.target_morphism lthy)) local_facts;

   in

     lthy

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

     |> Local_Theory.target (Locale.add_thmss locale kind local_facts')

   end

 fun target_notes (Target {target, is_locale, ...}) =

   if is_locale then locale_notes target

   else fn kind => fn global_facts => fn _ => Generic_Target.theory_notes kind global_facts;

 (* abbrev *)

 fun locale_abbrev ta prmode ((b, mx), t) xs =

   Local_Theory.background_theory_result

     (Sign.add_abbrev Print_Mode.internal (b, t)) #->

       (fn (lhs, _) => locale_const_declaration ta prmode

         ((b, mx), Term.list_comb (Logic.unvarify_global lhs, xs)));

 fun target_abbrev (ta as Target {target, is_locale, is_class, ...})

     prmode (b, mx) (global_rhs, t') xs lthy =

   if is_locale then

     lthy

     |> locale_abbrev ta prmode ((b, if is_class then NoSyn else mx), global_rhs) xs

     |> is_class ? Class.abbrev target prmode ((b, mx), t')

   else

     lthy

     |> Generic_Target.theory_abbrev prmode ((b, mx), global_rhs);

 (* pretty *)

 fun pretty (Target {target, is_locale, is_class, ...}) ctxt =

   let

     val thy = ProofContext.theory_of ctxt;

     val target_name =

       [Pretty.command (if is_class then "class" else "locale"),

         Pretty.str (" " ^ Locale.extern thy target)];

     val fixes = map (fn (x, T) => (Binding.name x, SOME T, NoSyn))

       (#1 (ProofContext.inferred_fixes ctxt));

     val assumes = map (fn A => (Attrib.empty_binding, [(Thm.term_of A, [])]))

       (Assumption.all_assms_of ctxt);

     val elems =

       (if null fixes then [] else [Element.Fixes fixes]) @

       (if null assumes then [] else [Element.Assumes assumes]);

     val body_elems =

       if not is_locale then []

       else if null elems then [Pretty.block target_name]

       else [Pretty.block (Pretty.fbreaks (Pretty.block (target_name @ [Pretty.str " ="]) ::

         map (Pretty.chunks o Element.pretty_ctxt ctxt) elems))];

   in

     Pretty.block [Pretty.command "theory", Pretty.brk 1,

       Pretty.str (Context.theory_name (ProofContext.theory_of ctxt))] :: body_elems

   end;

 (* init *)

 fun init_context (Target {target, is_locale, is_class}) =

   if not is_locale then ProofContext.init_global

   else if not is_class then Locale.init target

   else Class.init target;

 fun init target thy =

   let

     val ta = named_target thy target;

   in

     thy

     |> init_context ta

     |> Data.put (SOME ta)

     |> Local_Theory.init NONE (Long_Name.base_name target)

        {define = Generic_Target.define (target_foundation ta),

         notes = Generic_Target.notes (target_notes ta),

         abbrev = Generic_Target.abbrev (target_abbrev ta),

         declaration = fn pervasive => target_declaration ta

           {syntax = false, pervasive = pervasive},

         syntax_declaration = fn pervasive => target_declaration ta

           {syntax = true, pervasive = pervasive},

         pretty = pretty ta,

         exit = Local_Theory.target_of}

   end;

 val theory_init = init "";

 fun reinit lthy =

   (case peek lthy of

     SOME {target, ...} => init target o Local_Theory.exit_global

   | NONE => error "Not in a named target");

 fun context_cmd "-" thy = init "" thy

   | context_cmd target thy = init (Locale.intern thy target) thy;

 end;