(*  Title:      Pure/Thy/thy_info.ML

     ID:         $Id$

     Author:     Markus Wenzel, TU Muenchen

 Main part of theory loader database, including handling of theory and

 file dependencies.

 *)

 signature BASIC_THY_INFO =

 sig

   val theory: string -> theory

 (*val use: string -> unit*)             (*exported later*)

   val time_use: string -> unit

   val touch_thy: string -> unit

   val use_thy: string -> unit

   val update_thy: string -> unit

   val remove_thy: string -> unit

   val time_use_thy: string -> unit

   val use_thy_only: string -> unit

   val update_thy_only: string -> unit

 end;

 signature THY_INFO =

 sig

   include BASIC_THY_INFO

   datatype action = Update | Outdate | Remove

   val str_of_action: action -> string

   val add_hook: (action -> string -> unit) -> unit

   val names: unit -> string list

   val known_thy: string -> bool

   val check_known_thy: string -> bool

   val if_known_thy: (string -> unit) -> string -> unit

   val lookup_theory: string -> theory option

   val get_theory: string -> theory

   val get_preds: string -> string list

   val loaded_files: string -> Path.T list

   val touch_child_thys: string -> unit

   val touch_all_thys: unit -> unit

   val load_file: bool -> Path.T -> unit

   val use: string -> unit

   val quiet_update_thy: bool -> string -> unit

   val pretend_use_thy_only: string -> unit

   val begin_theory: (Path.T option -> string -> string list ->

       (Path.T * bool) list -> theory -> theory) ->

     string -> string list -> (Path.T * bool) list -> bool -> theory

   val end_theory: theory -> theory

   val finish: unit -> unit

   val register_theory: theory -> unit

   val pretty_theory: theory -> Pretty.T

 end;

 structure ThyInfo: THY_INFO =

 struct

 (** theory loader actions and hooks **)

 datatype action = Update | Outdate | Remove;

 val str_of_action = fn Update => "Update" | Outdate => "Outdate" | Remove => "Remove";

 local

   val hooks = ref ([]: (action -> string -> unit) list);

 in

   fun add_hook f = hooks := f :: ! hooks;

   fun perform action name = List.app (fn f => (try (fn () => f action name) (); ())) (! hooks);

 end;

 (** thy database **)

 (* messages *)

 fun gen_msg txt [] = txt

   | gen_msg txt names = txt ^ " " ^ commas_quote names;

 fun loader_msg txt names = gen_msg ("Theory loader: " ^ txt) names;

 val show_path = space_implode " via " o map quote;

 fun cycle_msg names = loader_msg ("cyclic dependency of " ^ show_path names) [];

 (* derived graph operations *)

 fun add_deps name parents G = Graph.add_deps_acyclic (name, parents) G

   handle Graph.CYCLES namess => error (cat_lines (map cycle_msg namess));

 fun upd_deps name entry G =

   Library.foldl (fn (H, parent) => Graph.del_edge (parent, name) H) (G, Graph.imm_preds G name)

   |> Graph.map_node name (K entry);

 fun update_node name parents entry G =

   (if can (Graph.get_node G) name then upd_deps name entry G else Graph.new_node (name, entry) G)

   |> add_deps name parents;

 (* thy database *)

 type deps =

   {present: bool, outdated: bool,

     master: ThyLoad.master option, files: (Path.T * (Path.T * File.info) option) list};

 fun make_deps present outdated master files =

   {present = present, outdated = outdated, master = master, files = files}: deps;

 fun init_deps master files = SOME (make_deps false true master (map (rpair NONE) files));

 type thy = deps option * theory option;

 local

   val database = ref (Graph.empty: thy Graph.T);

 in

   fun get_thys () = ! database;

   val change_thys = Library.change database;

 end;

 (* access thy graph *)

 fun thy_graph f x = f (get_thys ()) x;

 (*theory names in topological order*)

 fun get_names () =

   let val G = get_thys ()

   in Graph.all_succs G (Graph.minimals G) end;

 (* access thy *)

 fun lookup_thy name =

   SOME (thy_graph Graph.get_node name) handle Graph.UNDEF _ => NONE;

 val known_thy = is_some o lookup_thy;

 fun check_known_thy name = known_thy name orelse (warning ("Unknown theory " ^ quote name); false);

 fun if_known_thy f name = if check_known_thy name then f name else ();

 fun get_thy name =

   (case lookup_thy name of

     SOME thy => thy

   | NONE => error (loader_msg "nothing known about theory" [name]));

 fun change_thy name f = (get_thy name; change_thys (Graph.map_node name f));

 (* access deps *)

 val lookup_deps = Option.map #1 o lookup_thy;

 val get_deps = #1 o get_thy;

 fun change_deps name f = change_thy name (fn (deps, x) => (f deps, x));

 fun is_finished name = is_none (get_deps name);

 fun get_files name = (case get_deps name of SOME {files, ...} => files | _ => []);

 fun loaded_files name =

   (case get_deps name of

     NONE => []

   | SOME {master, files, ...} =>

       (case master of SOME m => [#1 (ThyLoad.get_thy m)] | NONE => []) @

       (List.mapPartial (Option.map #1 o #2) files));

 fun get_preds name =

   (thy_graph Graph.imm_preds name) handle Graph.UNDEF _ =>

     error (loader_msg "nothing known about theory" [name]);

 (* pretty printing a theory *)

 local

 fun relevant_names names =

   let

     val (finished, unfinished) =

       List.filter (equal Context.draftN orf known_thy) names

       |> List.partition (not_equal Context.draftN andf is_finished);

   in (if not (null finished) then [List.last finished] else []) @ unfinished end;

 in

 fun pretty_theory thy =

   Pretty.str_list "{" "}" (relevant_names (Context.names_of thy));

 end;

 (* access theory *)

 fun lookup_theory name =

   (case lookup_thy name of

     SOME (_, SOME thy) => SOME thy

   | _ => NONE);

 fun get_theory name =

   (case lookup_theory name of

     (SOME theory) => theory

   | _ => error (loader_msg "undefined theory entry for" [name]));

 fun put_theory name theory = change_thy name (fn (deps, _) => (deps, SOME theory));

 (** thy operations **)

 (* maintain 'outdated' flag *)

 local

 fun is_outdated name =

   (case lookup_deps name of

     SOME (SOME {outdated, ...}) => outdated

   | _ => false);

 fun outdate_thy name =

   if is_finished name orelse is_outdated name then ()

   else (change_deps name (Option.map (fn {present, outdated = _, master, files} =>

     make_deps present true master files)); perform Outdate name);

 fun check_unfinished name =

   if is_finished name then (warning (loader_msg "tried to touch finished theory" [name]); NONE)

   else SOME name;

 in

 fun touch_thys names =

   List.app outdate_thy (thy_graph Graph.all_succs (List.mapPartial check_unfinished names));

 fun touch_thy name = touch_thys [name];

 fun touch_child_thys name = touch_thys (thy_graph Graph.imm_succs name);

 fun touch_all_thys () = List.app outdate_thy (get_names ());

 end;

 (* check 'finished' state *)

 fun check_unfinished fail name =

   if known_thy name andalso is_finished name then

     fail (loader_msg "cannot update finished theory" [name])

   else ();

 (* load_file *)

 val opt_path = Option.map (Path.dir o fst o ThyLoad.get_thy);

 fun opt_path' (d: deps option) = if_none (Option.map (opt_path o #master) d) NONE;

 fun opt_path'' d = if_none (Option.map opt_path' d) NONE;

 local

 fun provide path name info (deps as SOME {present, outdated, master, files}) =

      (if exists (equal path o #1) files then ()

       else warning (loader_msg "undeclared dependency of theory" [name] ^

         " on file: " ^ quote (Path.pack path));

       SOME (make_deps present outdated master (AList.update (op =) (path, SOME info) files)))

   | provide _ _ _ NONE = NONE;

 fun run_file path =

   (case Option.map Context.theory_name (Context.get_context ()) of

     NONE => (ThyLoad.load_file NONE path; ())

   | SOME name => (case lookup_deps name of

       SOME deps => change_deps name (provide path name

         (ThyLoad.load_file (opt_path' deps) path))

     | NONE => (ThyLoad.load_file NONE path; ())));

 in

 fun load_file time path =

   if time then

     let val name = Path.pack path in

       timeit (fn () =>

        (priority ("\n**** Starting file " ^ quote name ^ " ****");

         run_file path;

         priority ("**** Finished file " ^ quote name ^ " ****\n")))

     end

   else run_file path;

 val use = load_file false o Path.unpack;

 val time_use = load_file true o Path.unpack;

 end;

 (* load_thy *)

 fun required_by _ [] = ""

   | required_by s initiators = s ^ "(required by " ^ show_path (rev initiators) ^ ")";

 fun load_thy really ml time initiators dir name =

   let

     val _ =

       if really then priority ("Loading theory " ^ quote name ^ required_by " " initiators)

       else priority ("Registering theory " ^ quote name);

     val _ = touch_thy name;

     val master =

       if really then ThyLoad.load_thy dir name ml time

       else #1 (ThyLoad.deps_thy dir name ml);

     val files = get_files name;

     val missing_files = List.mapPartial (fn (path, NONE) => SOME (Path.pack path) | _ => NONE) files;

   in

     if null missing_files then ()

     else warning (loader_msg "unresolved dependencies of theory" [name] ^

       " on file(s): " ^ commas_quote missing_files);

     change_deps name (fn _ => SOME (make_deps true false (SOME master) files));

     perform Update name

   end;

 (* require_thy *)

 fun base_of_path s = Path.pack (Path.base (Path.unpack s));

 local

 fun load_deps ml dir name =

   let val (master, (parents, files)) = ThyLoad.deps_thy dir name ml

   in (SOME (init_deps (SOME master) files), parents) end;

 fun file_current master (_, NONE) = false

   | file_current master (path, info) =

       (info = ThyLoad.check_file (opt_path master) path);

 fun current_deps ml strict dir name =

   (case lookup_deps name of

     NONE => (false, load_deps ml dir name)

   | SOME deps =>

       let

         fun get_name s = (case opt_path'' (lookup_deps s) of NONE => s

           | SOME p => Path.pack (Path.append p (Path.basic s)));

         val same_deps = (NONE, map get_name (thy_graph Graph.imm_preds name))

       in

         (case deps of

           NONE => (true, same_deps)

         | SOME {present, outdated, master, files} =>

             if present andalso not strict then (true, same_deps)

             else

               let val master' = SOME (ThyLoad.check_thy dir name ml) in

                 if master <> master' then (false, load_deps ml dir name)

                 else (not outdated andalso forall (file_current master') files, same_deps)

               end)

       end);

 fun require_thy really ml time strict keep_strict initiators prfx (visited, str) =

   let

     val path = Path.expand (Path.unpack str);

     val name = Path.pack (Path.base path);

   in

     if name mem_string initiators then error (cycle_msg initiators) else ();

     if known_thy name andalso is_finished name orelse name mem_string visited then

       (visited, (true, name))

     else

       let

         val dir = Path.append prfx (Path.dir path);

         val req_parent = require_thy true true time (strict andalso keep_strict) keep_strict

           (name :: initiators);

         val (current, (new_deps, parents)) = current_deps ml strict dir name

           handle ERROR msg => cat_error msg

             (loader_msg "the error(s) above occurred while examining theory" [name] ^

               (if null initiators then "" else required_by "\n" initiators));

         val dir' = if_none (opt_path'' new_deps) dir;

         val (visited', parent_results) = foldl_map (req_parent dir') (name :: visited, parents);

         val thy = if not really then SOME (get_theory name) else NONE;

         val result =

           if current andalso forall fst parent_results then true

           else

             ((case new_deps of

               SOME deps => change_thys (update_node name (map base_of_path parents) (deps, thy))

             | NONE => ());

              load_thy really ml (time orelse ! Output.timing) initiators dir name;

              false);

       in (visited', (result, name)) end

   end;

 fun gen_use_thy' req prfx s =

   let val (_, (_, name)) = req [] prfx ([], s)

   in Context.context (get_theory name) end;

 fun gen_use_thy req = gen_use_thy' req Path.current;

 fun warn_finished f name = (check_unfinished warning name; f name);

 in

 val weak_use_thy         = gen_use_thy' (require_thy true true false false false);

 fun quiet_update_thy' ml = gen_use_thy' (require_thy true ml false true true);

 fun quiet_update_thy ml  = gen_use_thy (require_thy true ml false true true);

 val use_thy          = warn_finished (gen_use_thy (require_thy true true false true false));

 val time_use_thy     = warn_finished (gen_use_thy (require_thy true true true true false));

 val use_thy_only     = warn_finished (gen_use_thy (require_thy true false false true false));

 val update_thy       = warn_finished (gen_use_thy (require_thy true true false true true));

 val update_thy_only  = warn_finished (gen_use_thy (require_thy true false false true true));

 val pretend_use_thy_only = warn_finished (gen_use_thy (require_thy false false false true false));

 end;

 (* remove_thy *)

 fun remove_thy name =

   if is_finished name then error (loader_msg "cannot remove finished theory" [name])

   else

     let val succs = thy_graph Graph.all_succs [name] in

       priority (loader_msg "removing" succs);

       List.app (perform Remove) succs;

       change_thys (Graph.del_nodes succs)

     end;

 (* begin / end theory *)

 fun check_uses name uses =

   let val illegal = map (fn ext => Path.ext ext (Path.basic name)) ThyLoad.ml_exts in

     (case find_first (member (op =) illegal o Path.base o Path.expand o #1) uses of

       NONE => ()

     | SOME (path, _) => error ("Illegal use of theory ML file: " ^ quote (Path.pack path)))

   end;

 fun begin_theory present name parents uses int =

   let

     val bparents = map base_of_path parents;

     val dir' = opt_path'' (lookup_deps name);

     val dir = if_none dir' Path.current;

     val assert_thy = if int then quiet_update_thy' true dir else weak_use_thy dir;

     val _ = check_unfinished error name;

     val _ = List.app assert_thy parents;

     val _ = check_uses name uses;

     val theory = Theory.begin_theory name (map get_theory bparents);

     val deps =

       if known_thy name then get_deps name

       else (init_deps NONE (map #1 uses));   (*records additional ML files only!*)

     val uses_now = List.mapPartial (fn (x, true) => SOME x | _ => NONE) uses;

     val _ = change_thys (update_node name bparents (deps, SOME (Theory.copy theory)));

     val theory' = theory |> present dir' name bparents uses;

     val _ = put_theory name (Theory.copy theory');

     val ((), theory'') = Context.pass_theory theory' (List.app (load_file false)) uses_now;

     val _ = put_theory name (Theory.copy theory'');

   in theory'' end;

 fun end_theory theory =

   let

     val name = Context.theory_name theory;

     val theory' = Theory.end_theory theory;

   in put_theory name theory'; theory' end;

 (* finish all theories *)

 fun finish () = change_thys (Graph.map_nodes (fn (_, entry) => (NONE, entry)));

 (* register existing theories *)

 fun register_theory theory =

   let

     val name = Context.theory_name theory;

     val parents = Theory.parents_of theory;

     val parent_names = map Context.theory_name parents;

     fun err txt bads =

       error (loader_msg txt bads ^ "\n" ^ gen_msg "cannot register theory" [name]);

     val nonfinished = filter_out is_finished parent_names;

     fun get_variant (x, y_name) =

       if Theory.eq_thy (x, get_theory y_name) then NONE

       else SOME y_name;

     val variants = List.mapPartial get_variant (parents ~~ parent_names);

     fun register G =

       (Graph.new_node (name, (NONE, SOME theory)) G

         handle Graph.DUP _ => err "duplicate theory entry" [])

       |> add_deps name parent_names;

   in

     if not (null nonfinished) then err "non-finished parent theories" nonfinished

     else if not (null variants) then err "different versions of parent theories" variants

     else (change_thys register; perform Update name)

   end;

 val _ = register_theory ProtoPure.thy;

 (*final declarations of this structure*)

 val theory = get_theory;

 val names = get_names;

 end;

 structure BasicThyInfo: BASIC_THY_INFO = ThyInfo;

 open BasicThyInfo;