(*  Title:      Pure/Isar/theory_target.ML

    ID:         $Id$

    Author:     Makarius

Common theory/locale/class targets.

*)

signature THEORY_TARGET =

sig

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

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

  val init: string option -> theory -> local_theory

  val init_cmd: xstring option -> theory -> local_theory

end;

structure TheoryTarget: THEORY_TARGET =

struct

(* context data *)

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

fun make_target target is_locale is_class =

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

structure Data = ProofDataFun

(

  type T = target;

  fun init _ = make_target "" false false;

);

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

(* pretty *)

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

  let

    val thy = ProofContext.theory_of ctxt;

    val target_name = (if is_class then "class " else "locale ") ^ Locale.extern thy target;

    val fixes = map (fn (x, T) => (x, SOME T, NoSyn)) (#1 (ProofContext.inferred_fixes ctxt));

    val assumes = map (fn A => (("", []), [(A, [])])) (map Thm.term_of (Assumption.assms_of ctxt));

    val elems =

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

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

  in

    Pretty.block [Pretty.str "theory", Pretty.brk 1, Pretty.str (Context.theory_name thy)] ::

     (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;

(* target declarations *)

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

  (if target = "" then Sign.naming_of (ProofContext.theory_of lthy)

   else ProofContext.naming_of (LocalTheory.target_of lthy))

  |> NameSpace.qualified_names;

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 = th''

      |> PureThy.name_thm true true ""

      |> Goal.close_result

      |> fold PureThy.tag_rule (ContextPosition.properties_of ctxt)

      |> PureThy.name_thm true true name;

    (*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 name;

  in (result'', result) end;

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

  let

    val thy = ProofContext.theory_of lthy;

    val full = LocalTheory.full_name lthy;

    val facts' = facts

      |> map (fn (a, bs) => (a, PureThy.burrow_fact (PureThy.name_multi (full (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_i kind global_facts #> snd

        #> Sign.restore_naming thy)

    |> is_locale ? LocalTheory.target (Locale.add_thmss target kind target_facts)

    |> ProofContext.qualified_names

    |> ProofContext.note_thmss_i kind local_facts

    ||> ProofContext.restore_naming lthy

  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 (prmode as (mode, _)) pos ((c, mx), rhs) phi =

  let

    val c' = Morphism.name phi c;

    val rhs' = Morphism.term phi rhs;

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

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

  in

    Context.mapping_result

      (Sign.add_abbrev PrintMode.internal pos legacy_arg)

      (ProofContext.add_abbrev PrintMode.internal pos arg)

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

        Type.similar_types (rhs, rhs') ?

          (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 ((c, T), mx) lthy =

  let

    val pos = ContextPosition.properties_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;

    val (const, lthy') = lthy |> LocalTheory.theory_result (Sign.declare_const pos (c, U, mx3));

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

  in

    lthy'

    |> is_locale ? term_syntax ta (locale_const Syntax.mode_default pos ((c, mx2), t))

    |> is_class ? class_target ta (Class.add_logical_const target pos ((c, mx1), t))

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

  end;

(* abbrev *)

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

  let

    val pos = ContextPosition.properties_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 pos (c, global_rhs))

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

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

            term_syntax ta (locale_const prmode pos ((c, mx2), lhs')) #>

            is_class ?

              class_target ta (Class.add_syntactic_const target prmode pos ((c, mx1), lhs'))

          end)

      else

        LocalTheory.theory

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

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

    |> ProofContext.add_abbrev PrintMode.internal pos (c, t) |> snd

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

  end;

(* define *)

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

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

  let

    val thy = ProofContext.theory_of lthy;

    val thy_ctxt = ProofContext.init thy;

    val name' = 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) ((c, T), mx);

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

    (*def*)

    val (global_def, lthy3) = lthy2

      |> LocalTheory.theory_result (Thm.add_def false (name', Logic.mk_equals (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;

(* axioms *)

fun axioms ta kind (vars, specs) lthy =

  let

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

    val expanded_props = map (Assumption.export_term lthy thy_ctxt) (maps snd specs);

    val xs = fold Term.add_frees expanded_props [];

    (*consts*)

    val (consts, lthy') = fold_map (declare_const ta (member (op =) xs)) vars lthy;

    val global_consts = map (Term.dest_Const o Term.head_of o Thm.term_of o Thm.rhs_of o #2) consts;

    (*axioms*)

    val hyps = map Thm.term_of (Assumption.assms_of lthy');

    fun axiom ((name, atts), props) thy = thy

      |> fold_map (Thm.add_axiom hyps) (PureThy.name_multi name props)

      |-> (fn ths => pair ((name, atts), [(ths, [])]));

  in

    lthy'

    |> fold Variable.declare_term expanded_props

    |> LocalTheory.theory (fold (fn c => Theory.add_deps "" c []) global_consts)

    |> LocalTheory.theory_result (fold_map axiom specs)

    |-> notes ta kind

    |>> pair (map #1 consts)

  end;

(* init and exit *)

fun begin target ctxt =

  let

    val thy = ProofContext.theory_of ctxt;

    val is_locale = target <> "";

    val is_class = Class.is_class thy target;

    val ta = Target {target = target, is_locale = is_locale, is_class = is_class};

  in

    ctxt

    |> Data.put ta

    |> is_class ? Class.init target

    |> LocalTheory.init (NameSpace.base target)

     {pretty = pretty ta,

      axioms = axioms ta,

      abbrev = abbrev ta,

      define = define ta,

      notes = notes ta,

      type_syntax = type_syntax ta,

      term_syntax = term_syntax ta,

      declaration = declaration ta,

      target_naming = target_naming ta,

      reinit = fn _ =>

        begin target o (if is_locale then Locale.init target else ProofContext.init),

      exit = LocalTheory.target_of}

  end;

fun init NONE thy = begin "" (ProofContext.init thy)

  | init (SOME target) thy = begin target (Locale.init target thy);

fun init_cmd (SOME "-") thy = init NONE thy

  | init_cmd target thy = init (Option.map (Locale.intern thy) target) thy;

end;