(*  Title:      Pure/Isar/theory_target.ML

    ID:         $Id$

    Author:     Makarius

Common theory/locale targets.

*)

signature THEORY_TARGET =

sig

  val peek: local_theory -> string option

  val fork_mixfix: bool -> bool -> mixfix -> mixfix * mixfix

  val begin: bool -> bstring -> Proof.context -> local_theory

  val init: xstring option -> theory -> local_theory

  val init_i: string option -> theory -> local_theory

end;

structure TheoryTarget: THEORY_TARGET =

struct

(** locale targets **)

(* context data *)

structure Data = ProofDataFun

(

  val name = "Isar/theory_target";

  type T = string option;

  fun init _ = NONE;

  fun print _ _ = ();

);

val _ = Context.add_setup Data.init;

val peek = Data.get;

(* pretty *)

fun pretty loc ctxt =

  let

    val thy = ProofContext.theory_of ctxt;

    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

    if loc = "" then

      [Pretty.block

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

          Pretty.str " =", Pretty.brk 1, ThyInfo.pretty_theory thy]]

    else if null elems then [Pretty.str ("locale " ^ Locale.extern thy loc)]

    else

      [Pretty.big_list ("locale " ^ Locale.extern thy loc ^ " =")

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

  end;

(* consts *)

fun fork_mixfix is_class is_loc mx =

  let

    val mx' = Syntax.unlocalize_mixfix mx;

    val mx1 = if is_class orelse (is_loc andalso mx = mx') then NoSyn else mx';

    val mx2 = if is_loc then mx else NoSyn;

  in (mx1, mx2) end;

fun internal_abbrev prmode ((c, mx), t) =

  LocalTheory.term_syntax (ProofContext.target_abbrev prmode ((c, mx), t)) #>

  ProofContext.add_abbrev Syntax.internalM (c, t) #> snd;

fun consts is_class is_loc depends decls lthy =

  let

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

    fun const ((c, T), mx) thy =

      let

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

        val t = Term.list_comb (Const (Sign.full_name thy c, U), map Free xs);

        val (mx1, mx2) = fork_mixfix is_class is_loc mx;

        val thy' = Sign.add_consts_authentic [(c, U, mx1)] thy;

      in (((c, mx2), t), thy') end;

    val (abbrs, lthy') = lthy |> LocalTheory.theory_result (fold_map const decls);

    val defs = map (apsnd (pair ("", []))) abbrs;

  in

    lthy'

    |> is_loc ? fold (internal_abbrev Syntax.default_mode) abbrs

    |> LocalDefs.add_defs defs |>> map (apsnd snd)

  end;

(* abbrev *)

fun occ_params ctxt ts =

  #1 (ProofContext.inferred_fixes ctxt)

  |> filter (member (op =) (fold (Variable.add_fixed ctxt) ts []));

fun abbrev is_class is_loc prmode ((raw_c, mx), raw_t) lthy =

  let

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

    val target = LocalTheory.target_of lthy;

    val target_morphism = LocalTheory.target_morphism lthy;

    val c = Morphism.name target_morphism raw_c;

    val t = Morphism.term target_morphism raw_t;

    val xs = map Free (occ_params target [t]);

    val u = fold_rev Term.lambda xs t;

    val U = Term.fastype_of u;

    val u' = singleton (Variable.export_terms (Variable.declare_term u target) thy_ctxt) u;

    val ((lhs as Const (full_c, _), rhs), lthy1) = lthy

      |> LocalTheory.theory_result (Sign.add_abbrev (#1 prmode) (c, u'));

    val (mx1, mx2) = fork_mixfix is_class is_loc mx;

  in

    lthy1

    |> LocalTheory.theory (Sign.add_notation prmode [(lhs, mx1)])

    |> is_loc ? internal_abbrev prmode ((c, mx2), Term.list_comb (Const (full_c, U), xs))

    |> ProofContext.local_abbrev (c, rhs)

  end;

(* defs *)

local

fun expand_term ctxt t =

  let

    val thy = ProofContext.theory_of ctxt;

    val thy_ctxt = ProofContext.init thy;

    val ct = Thm.cterm_of thy t;

    val (defs, ct') = LocalDefs.export ctxt thy_ctxt (Drule.mk_term ct) ||> Drule.dest_term;

  in (Thm.term_of ct', MetaSimplifier.rewrite true defs ct) end;

fun add_def (name, prop) =

  Theory.add_defs_i false false [(name, prop)] #>

  (fn thy => (Drule.unvarify (Thm.get_axiom_i thy (Sign.full_name thy name)), thy));

in

fun defs kind args lthy0 =

  let

    fun def ((c, mx), ((name, atts), rhs)) lthy1 =

      let

        val (rhs', rhs_conv) = expand_term lthy0 rhs;

        val xs = Variable.add_fixed (LocalTheory.target_of lthy0) rhs' [];

        val ([(lhs, lhs_def)], lthy2) = lthy1

          |> LocalTheory.consts (member (op =) xs) [((c, Term.fastype_of rhs), mx)];

        val lhs' = #2 (Logic.dest_equals (Thm.prop_of lhs_def));

        val name' = Thm.def_name_optional c name;

        val (def, lthy3) = lthy2

          |> LocalTheory.theory_result (add_def (name', Logic.mk_equals (lhs', rhs')));

        val eq = LocalDefs.trans_terms lthy3

          [(*c == loc.c xs*) lhs_def,

           (*lhs' == rhs'*)  def,

           (*rhs' == rhs*)   Thm.symmetric rhs_conv];

      in ((lhs, ((name', atts), [([eq], [])])), lthy3) end;

    val ((lhss, facts), lthy') = lthy0 |> fold_map def args |>> split_list;

    val (res, lthy'') = lthy' |> LocalTheory.notes kind facts;

  in (lhss ~~ map (apsnd the_single) res, lthy'') end;

end;

(* axioms *)

local

fun add_axiom hyps (name, prop) thy =

  let

    val name' = if name = "" then "axiom_" ^ serial_string () else name;

    val prop' = Logic.list_implies (hyps, prop);

    val thy' = thy |> Theory.add_axioms_i [(name', prop')];

    val axm = Drule.unvarify (Thm.get_axiom_i thy' (Sign.full_name thy' name'));

    val prems = map (Thm.assume o Thm.cterm_of thy') hyps;

  in (Drule.implies_elim_list axm prems, thy') end;

in

fun axioms kind specs lthy =

  let

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

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

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

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

  in

    lthy

    |> fold (fold Variable.declare_term o snd) specs

    |> LocalTheory.theory_result (fold_map axiom specs)

    |-> LocalTheory.notes kind

  end;

end;

(* 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 (Drule.fold_terms Term.add_tfrees th' []);

    val frees = map Free (Drule.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

      |> 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 loc kind facts lthy =

  let

    val is_loc = loc <> "";

    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_loc ? Element.facts_map (Element.morph_ctxt (LocalTheory.target_morphism lthy));

    val global_facts = PureThy.map_facts #2 facts'

      |> Attrib.map_facts (if is_loc 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_loc ? LocalTheory.target (Locale.add_thmss loc kind target_facts)

    |> ProofContext.set_stmt true

    |> ProofContext.qualified_names

    |> ProofContext.note_thmss_i kind local_facts

    ||> ProofContext.restore_naming lthy

    ||> ProofContext.restore_stmt lthy

  end;

(* target declarations *)

fun target_decl _ "" f =

      LocalTheory.theory (Context.theory_map (f Morphism.identity)) #>

      LocalTheory.target (Context.proof_map (f Morphism.identity))

  | target_decl add loc f = LocalTheory.target (add loc f);

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_morphism loc lthy =

  ProofContext.export_morphism lthy (LocalTheory.target_of lthy) $>

  Morphism.thm_morphism Goal.norm_result;

fun target_name loc lthy =

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

   else ProofContext.naming_of (LocalTheory.target_of lthy))

  |> NameSpace.qualified_names

  |> NameSpace.full;

(* init and exit *)

fun begin is_class loc =

  let val is_loc = loc <> "" in

    Data.put (if is_loc then SOME loc else NONE) #>

    LocalTheory.init (NameSpace.base loc)

     {pretty = pretty loc,

      consts = consts is_class is_loc,

      axioms = axioms,

      abbrev = abbrev is_class is_loc,

      defs = defs,

      notes = notes loc,

      type_syntax = type_syntax loc,

      term_syntax = term_syntax loc,

      declaration = declaration loc,

      target_morphism = target_morphism loc,

      target_name = target_name loc,

      reinit = fn _ =>

        begin is_class loc o (if is_loc then Locale.init loc else ProofContext.init),

      exit = LocalTheory.target_of}

  end;

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

  | init_i (SOME loc) thy =

      begin (can (Sign.certify_class thy) loc)  (* FIXME approximation *)

        loc (Locale.init loc thy);

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

  | init loc thy = init_i (Option.map (Locale.intern thy) loc) thy;

end;