(*  Title:      Pure/Isar/named_target.ML

    Author:     Makarius

    Author:     Florian Haftmann, TU Muenchen

Targets for theory, locale and class.

*)

signature NAMED_TARGET =

sig

  val init: (local_theory -> local_theory) -> 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,

    before_exit: local_theory -> local_theory};

fun make_target target is_locale is_class before_exit =

  Target {target = target, is_locale = is_locale, is_class = is_class,

    before_exit = before_exit};

fun named_target _ "" before_exit = make_target "" false false before_exit

  | named_target thy locale before_exit =

      if Locale.defined thy locale

      then make_target locale true (Class.is_class thy locale) before_exit

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

structure Data = Proof_Data

(

  type T = target option;

  fun init _ = NONE;

);

val peek =

  Data.get #> Option.map (fn Target {target, is_locale, is_class, ...} =>

    {target = target, is_locale = is_locale, is_class = is_class});

(* 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 before_exit target thy =

  let

    val ta = named_target thy target before_exit;

  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 o before_exit}

  end;

val theory_init = init I "";

fun reinit lthy =

  (case Data.get lthy of

    SOME (Target {target, before_exit, ...}) => init before_exit target o Local_Theory.exit_global

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

fun context_cmd "-" thy = init I "" thy

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

end;