(*  Title:      Pure/Isar/theory_target.ML

    Author:     Makarius

Common theory/locale/class/instantiation/overloading targets.

*)

signature THEORY_TARGET =

sig

  val peek: local_theory -> {target: string, new_locale: bool, is_locale: bool,

    is_class: bool, instantiation: string list * (string * sort) list * sort,

    overloading: (string * (string * typ) * bool) list}

  val init: string option -> theory -> local_theory

  val begin: string -> Proof.context -> local_theory

  val context: xstring -> theory -> local_theory

  val instantiation: string list * (string * sort) list * sort -> theory -> local_theory

  val overloading: (string * (string * typ) * bool) list -> theory -> local_theory

  val overloading_cmd: (string * string * bool) list -> theory -> local_theory

end;

structure TheoryTarget: THEORY_TARGET =

struct

(* new locales *)

fun locale_extern new_locale x = 

  if new_locale then NewLocale.extern x else Locale.extern x;

fun locale_add_type_syntax new_locale x =

  if new_locale then NewLocale.add_type_syntax x else Locale.add_type_syntax x;

fun locale_add_term_syntax new_locale x =

  if new_locale then NewLocale.add_term_syntax x else Locale.add_term_syntax x;

fun locale_add_declaration new_locale x =

  if new_locale then NewLocale.add_declaration x else Locale.add_declaration x;

fun locale_add_thmss new_locale x =

  if new_locale then NewLocale.add_thmss x else Locale.add_thmss x;

fun locale_init new_locale x =

  if new_locale then NewLocale.init x else Locale.init x;

fun locale_intern new_locale x =

  if new_locale then NewLocale.intern x else Locale.intern x;

(* context data *)

datatype target = Target of {target: string, new_locale: bool, is_locale: bool,

  is_class: bool, instantiation: string list * (string * sort) list * sort,

  overloading: (string * (string * typ) * bool) list};

fun make_target target new_locale is_locale is_class instantiation overloading =

  Target {target = target, new_locale = new_locale, is_locale = is_locale,

    is_class = is_class, instantiation = instantiation, overloading = overloading};

val global_target = make_target "" false false false ([], [], []) [];

structure Data = ProofDataFun

(

  type T = target;

  fun init _ = global_target;

);

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

(* pretty *)

fun pretty_thy ctxt target is_locale is_class =

  let

    val thy = ProofContext.theory_of ctxt;

    val target_name = (if is_class then "class " else "locale ") ^ locale_extern is_class 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.assms_of ctxt);

    val elems =

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

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

  in

    if target = "" then []

    else if null elems then [Pretty.str target_name]

    else [Pretty.big_list (target_name ^ " =")

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

  end;

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

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

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

    (if not (null overloading) then [Overloading.pretty ctxt]

     else if not (null (#1 instantiation)) then [Class.pretty_instantiation ctxt]

     else pretty_thy ctxt target is_locale is_class);

(* target declarations *)

fun target_decl add (Target {target, new_locale, ...}) d lthy =

  let

    val d' = Morphism.transform (LocalTheory.target_morphism lthy) d;

    val d0 = Morphism.form d';

  in

    if target = "" then

      lthy

      |> LocalTheory.theory (Context.theory_map d0)

      |> LocalTheory.target (Context.proof_map d0)

    else

      lthy

      |> LocalTheory.target (add new_locale target d')

  end;

val type_syntax = target_decl locale_add_type_syntax;

val term_syntax = target_decl locale_add_term_syntax;

val declaration = target_decl locale_add_declaration;

fun class_target (Target {target, ...}) f =

  LocalTheory.raw_theory f #>

  LocalTheory.target (Class.refresh_syntax target);

(* notes *)

fun import_export_proof ctxt (name, raw_th) =

  let

    val thy = ProofContext.theory_of ctxt;

    val thy_ctxt = ProofContext.init 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') = LocalDefs.export ctxt thy_ctxt th;

    val concl_conv = MetaSimplifier.rewrite true defs (Thm.cprop_of th);

    val assms = map (MetaSimplifier.rewrite_rule defs o Thm.assume) (Assumption.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 Position.none 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 (TermSubst.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 => LocalDefs.trans_props ctxt [res, Thm.symmetric concl_conv])

      |> Goal.norm_result

      |> PureThy.name_thm false false Position.none name;

  in (result'', result) end;

fun note_local kind facts ctxt =

  ctxt

  |> ProofContext.qualified_names

  |> ProofContext.note_thmss_i kind facts

  ||> ProofContext.restore_naming ctxt;

fun notes (Target {target, is_locale, new_locale, ...}) kind facts lthy =

  let

    val thy = ProofContext.theory_of lthy;

    val facts' = facts

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

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

      |> PureThy.map_facts (import_export_proof lthy);

    val local_facts = PureThy.map_facts #1 facts'

      |> Attrib.map_facts (Attrib.attribute_i thy);

    val target_facts = PureThy.map_facts #1 facts'

      |> is_locale ? Element.facts_map (Element.morph_ctxt (LocalTheory.target_morphism lthy));

    val global_facts = PureThy.map_facts #2 facts'

      |> Attrib.map_facts (if is_locale then K I else Attrib.attribute_i thy);

  in

    lthy |> LocalTheory.theory

      (Sign.qualified_names

        #> PureThy.note_thmss_grouped kind (LocalTheory.group_of lthy) global_facts #> snd

        #> Sign.restore_naming thy)

    |> not is_locale ? LocalTheory.target (note_local kind global_facts #> snd)

    |> is_locale ? LocalTheory.target (locale_add_thmss new_locale target kind target_facts)

    |> note_local kind local_facts

  end;

(* declare_const *)

fun fork_mixfix (Target {is_locale, is_class, ...}) mx =

  if not is_locale then (NoSyn, NoSyn, mx)

  else if not is_class then (NoSyn, mx, NoSyn)

  else (mx, NoSyn, NoSyn);

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

  let

    val b' = Morphism.binding phi b;

    val rhs' = Morphism.term phi rhs;

    val legacy_arg = (b', Term.close_schematic_term (Logic.legacy_varify rhs'));

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

    val similar_body = Type.similar_types (rhs, rhs');

    (* FIXME workaround based on educated guess *)

    val (prefix', _) = Binding.dest b';

    val class_global = Binding.base_name b = Binding.base_name b'

      andalso not (null prefix')

      andalso (fst o snd o split_last) prefix' = Class.class_prefix target;

  in

    not (is_class andalso (similar_body orelse class_global)) ?

      (Context.mapping_result

        (fn thy => thy |> 

          Sign.no_base_names

          |> Sign.add_abbrev PrintMode.internal tags legacy_arg

          ||> Sign.restore_naming thy)

        (ProofContext.add_abbrev PrintMode.internal tags arg)

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

          similar_body ?

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

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

  end;

fun declare_const (ta as Target {target, is_locale, is_class, ...}) depends ((b, T), mx) lthy =

  let

    val c = Binding.base_name b;

    val tags = LocalTheory.group_position_of lthy;

    val xs = filter depends (#1 (ProofContext.inferred_fixes (LocalTheory.target_of lthy)));

    val U = map #2 xs ---> T;

    val (mx1, mx2, mx3) = fork_mixfix ta mx;

    fun syntax_error c = error ("Illegal mixfix syntax for overloaded constant " ^ quote c);

    val declare_const =

      (case Class.instantiation_param lthy c of

        SOME c' =>

          if mx3 <> NoSyn then syntax_error c'

          else LocalTheory.theory_result (AxClass.declare_overloaded (c', U))

            ##> Class.confirm_declaration c

        | NONE =>

            (case Overloading.operation lthy c of

              SOME (c', _) =>

                if mx3 <> NoSyn then syntax_error c'

                else LocalTheory.theory_result (Overloading.declare (c', U))

                  ##> Overloading.confirm c

            | NONE => LocalTheory.theory_result (Sign.declare_const tags ((b, U), mx3))));

    val (const, lthy') = lthy |> declare_const;

    val t = Term.list_comb (const, map Free xs);

  in

    lthy'

    |> is_locale ? term_syntax ta (locale_const ta Syntax.mode_default tags ((b, mx2), t))

    |> is_class ? class_target ta (Class.declare target tags ((c, mx1), t))

    |> LocalDefs.add_def ((b, NoSyn), t)

  end;

(* abbrev *)

fun abbrev (ta as Target {target, is_locale, is_class, ...}) prmode ((b, mx), t) lthy =

  let

    val c = Binding.base_name b;

    val tags = LocalTheory.group_position_of lthy;

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

    val target_ctxt = LocalTheory.target_of lthy;

    val (mx1, mx2, mx3) = fork_mixfix ta mx;

    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 global_rhs =

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

  in

    lthy |>

     (if is_locale then

        LocalTheory.theory_result (Sign.add_abbrev PrintMode.internal tags (b, global_rhs))

        #-> (fn (lhs, _) =>

          let val lhs' = Term.list_comb (Logic.unvarify lhs, xs) in

            term_syntax ta (locale_const ta prmode tags ((b, mx2), lhs')) #>

            is_class ? class_target ta (Class.abbrev target prmode tags ((c, mx1), t'))

          end)

      else

        LocalTheory.theory

          (Sign.add_abbrev (#1 prmode) tags (b, global_rhs) #-> (fn (lhs, _) =>

           Sign.notation true prmode [(lhs, mx3)])))

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

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

  end;

(* define *)

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

    kind ((b, mx), ((name, atts), rhs)) lthy =

  let

    val thy = ProofContext.theory_of lthy;

    val thy_ctxt = ProofContext.init thy;

    val c = Binding.base_name b;

    val name' = Binding.map_base (Thm.def_name_optional c) name;

    val (rhs', rhs_conv) =

      LocalDefs.export_cterm lthy thy_ctxt (Thm.cterm_of thy rhs) |>> Thm.term_of;

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

    val T = Term.fastype_of rhs;

    (*const*)

    val ((lhs, local_def), lthy2) = lthy |> declare_const ta (member (op =) xs) ((b, T), mx);

    val (_, lhs') = Logic.dest_equals (Thm.prop_of local_def);

    (*def*)

    val define_const =

      (case Overloading.operation lthy c of

        SOME (_, checked) =>

          (fn name => fn (Const (c, _), rhs) => Overloading.define checked name (c, rhs))

      | NONE =>

          if is_none (Class.instantiation_param lthy c)

          then (fn name => fn eq => Thm.add_def false false (name, Logic.mk_equals eq))

          else (fn name => fn (Const (c, _), rhs) => AxClass.define_overloaded name (c, rhs)));

    val (global_def, lthy3) = lthy2

      |> LocalTheory.theory_result (define_const (Binding.base_name name') (lhs', rhs'));

    val def = LocalDefs.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

      |> notes ta kind [((name', atts), [([def], [])])];

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

(* init *)

local

fun init_target _ NONE = global_target

  | init_target thy (SOME target) =

      make_target target (NewLocale.test_locale thy (NewLocale.intern thy target))

      true (Class.is_class thy target) ([], [], []) [];

fun init_ctxt (Target {target, new_locale, is_locale, is_class, instantiation, overloading}) =

  if not (null (#1 instantiation)) then Class.init_instantiation instantiation

  else if not (null overloading) then Overloading.init overloading

  else if not is_locale then ProofContext.init

  else if not is_class then locale_init new_locale target

  else Class.init target;

fun init_lthy (ta as Target {target, instantiation, overloading, ...}) =

  Data.put ta #>

  LocalTheory.init (NameSpace.base target)

   {pretty = pretty ta,

    abbrev = abbrev ta,

    define = define ta,

    notes = notes ta,

    type_syntax = type_syntax ta,

    term_syntax = term_syntax ta,

    declaration = declaration ta,

    reinit = fn lthy => init_lthy_ctxt ta (ProofContext.theory_of lthy),

    exit = LocalTheory.target_of o

      (if not (null (#1 instantiation)) then Class.conclude_instantiation

       else if not (null overloading) then Overloading.conclude

       else I)}

and init_lthy_ctxt ta = init_lthy ta o init_ctxt ta;

fun gen_overloading prep_const raw_ops thy =

  let

    val ctxt = ProofContext.init thy;

    val ops = raw_ops |> map (fn (name, const, checked) =>

      (name, Term.dest_Const (prep_const ctxt const), checked));

  in thy |> init_lthy_ctxt (make_target "" false false false ([], [], []) ops) end;

in

fun init target thy = init_lthy_ctxt (init_target thy target) thy;

fun begin target ctxt = init_lthy (init_target (ProofContext.theory_of ctxt) (SOME target)) ctxt;

fun context "-" thy = init NONE thy

  | context target thy = init (SOME (locale_intern

      (NewLocale.test_locale thy (NewLocale.intern thy target)) thy target)) thy;

fun instantiation arities = init_lthy_ctxt (make_target "" false false false arities []);

val overloading = gen_overloading (fn ctxt => Syntax.check_term ctxt o Const);

val overloading_cmd = gen_overloading Syntax.read_term;

end;

end;