(*  Title:      HOL/Tools/ATP_Manager/atp_manager.ML

    Author:     Fabian Immler, TU Muenchen

    Author:     Makarius

Central manager component for ATP threads.

*)

signature ATP_MANAGER =

sig

  type problem =

   {with_full_types: bool,

    subgoal: int,

    goal: Proof.context * (thm list * thm),

    axiom_clauses: (thm * (string * int)) list option,

    filtered_clauses: (thm * (string * int)) list option}

  val problem_of_goal: bool -> int -> Proof.context * (thm list * thm) -> problem

  type prover_result =

   {success: bool,

    message: string,

    theorem_names: string list,

    runtime: int,

    proof: string,

    internal_thm_names: string Vector.vector,

    filtered_clauses: (thm * (string * int)) list}

  type prover = int -> problem -> prover_result

  val atps: string Unsynchronized.ref

  val get_atps: unit -> string list

  val timeout: int Unsynchronized.ref

  val full_types: bool Unsynchronized.ref

  val kill: unit -> unit

  val info: unit -> unit

  val messages: int option -> unit

  val add_prover: string * prover -> theory -> theory

  val get_prover: theory -> string -> prover option

  val print_provers: theory -> unit

  val sledgehammer: string list -> Proof.state -> unit

end;

structure ATP_Manager : ATP_MANAGER =

struct

(** problems, results, and provers **)

type problem =

 {with_full_types: bool,

  subgoal: int,

  goal: Proof.context * (thm list * thm),

  axiom_clauses: (thm * (string * int)) list option,

  filtered_clauses: (thm * (string * int)) list option};

fun problem_of_goal with_full_types subgoal goal : problem =

 {with_full_types = with_full_types,

  subgoal = subgoal,

  goal = goal,

  axiom_clauses = NONE,

  filtered_clauses = NONE};

type prover_result =

 {success: bool,

  message: string,

  theorem_names: string list,  (*relevant theorems*)

  runtime: int,  (*user time of the ATP, in milliseconds*)

  proof: string,

  internal_thm_names: string Vector.vector,

  filtered_clauses: (thm * (string * int)) list};

type prover = int -> problem -> prover_result;

(** preferences **)

val message_store_limit = 20;

val message_display_limit = 5;

val atps = Unsynchronized.ref "e spass remote_vampire";

fun get_atps () = String.tokens (Symbol.is_ascii_blank o String.str) (! atps);

val timeout = Unsynchronized.ref 60;

val full_types = Unsynchronized.ref false;

val _ =

  ProofGeneralPgip.add_preference Preferences.category_proof

    (Preferences.string_pref atps

      "ATP: provers" "Default automatic provers (separated by whitespace)");

val _ =

  ProofGeneralPgip.add_preference Preferences.category_proof

    (Preferences.int_pref timeout

      "ATP: timeout" "ATPs will be interrupted after this time (in seconds)");

val _ =

  ProofGeneralPgip.add_preference Preferences.category_proof

    (Preferences.bool_pref full_types

      "ATP: full types" "ATPs will use full type information");

(** thread management **)

(* data structures over threads *)

structure Thread_Heap = Heap

(

  type elem = Time.time * Thread.thread;

  fun ord ((a, _), (b, _)) = Time.compare (a, b);

);

fun lookup_thread xs = AList.lookup Thread.equal xs;

fun delete_thread xs = AList.delete Thread.equal xs;

fun update_thread xs = AList.update Thread.equal xs;

(* state of thread manager *)

type state =

 {manager: Thread.thread option,

  timeout_heap: Thread_Heap.T,

  active: (Thread.thread * (Time.time * Time.time * string)) list,

  cancelling: (Thread.thread * (Time.time * string)) list,

  messages: string list,

  store: string list};

fun make_state manager timeout_heap active cancelling messages store : state =

  {manager = manager, timeout_heap = timeout_heap, active = active,

    cancelling = cancelling, messages = messages, store = store};

val global_state = Synchronized.var "atp_manager"

  (make_state NONE Thread_Heap.empty [] [] [] []);

(* unregister ATP thread *)

fun unregister message thread = Synchronized.change global_state

  (fn state as {manager, timeout_heap, active, cancelling, messages, store} =>

    (case lookup_thread active thread of

      SOME (_, _, description) =>

        let

          val active' = delete_thread thread active;

          val cancelling' = (thread, (Time.now (), description)) :: cancelling;

          val message' = description ^ "\n" ^ message;

          val messages' = message' :: messages;

          val store' = message' ::

            (if length store <= message_store_limit then store

             else #1 (chop message_store_limit store));

        in make_state manager timeout_heap active' cancelling' messages' store' end

    | NONE => state));

(* main manager thread -- only one may exist *)

val min_wait_time = Time.fromMilliseconds 300;

val max_wait_time = Time.fromSeconds 10;

fun print_new_messages () =

  let val msgs = Synchronized.change_result global_state

    (fn {manager, timeout_heap, active, cancelling, messages, store} =>

      (messages, make_state manager timeout_heap active cancelling [] store))

  in

    if null msgs then ()

    else priority ("Sledgehammer: " ^ space_implode "\n\n" msgs)

  end;

fun check_thread_manager () = Synchronized.change global_state

  (fn state as {manager, timeout_heap, active, cancelling, messages, store} =>

    if (case manager of SOME thread => Thread.isActive thread | NONE => false) then state

    else let val manager = SOME (Toplevel.thread false (fn () =>

      let

        fun time_limit timeout_heap =

          (case try Thread_Heap.min timeout_heap of

            NONE => Time.+ (Time.now (), max_wait_time)

          | SOME (time, _) => time);

        (*action: find threads whose timeout is reached, and interrupt cancelling threads*)

        fun action {manager, timeout_heap, active, cancelling, messages, store} =

          let val (timeout_threads, timeout_heap') =

            Thread_Heap.upto (Time.now (), Thread.self ()) timeout_heap;

          in

            if null timeout_threads andalso null cancelling

            then NONE

            else

              let

                val _ = List.app (SimpleThread.interrupt o #1) cancelling;

                val cancelling' = filter (Thread.isActive o #1) cancelling;

                val state' = make_state manager timeout_heap' active cancelling' messages store;

              in SOME (map #2 timeout_threads, state') end

          end;

      in

        while Synchronized.change_result global_state

          (fn state as {timeout_heap, active, cancelling, messages, store, ...} =>

            if null active andalso null cancelling andalso null messages

            then (false, make_state NONE timeout_heap active cancelling messages store)

            else (true, state))

        do

          (Synchronized.timed_access global_state (SOME o time_limit o #timeout_heap) action

            |> these

            |> List.app (unregister "Interrupted (reached timeout)");

            print_new_messages ();

            (*give threads some time to respond to interrupt*)

            OS.Process.sleep min_wait_time)

      end))

    in make_state manager timeout_heap active cancelling messages store end);

(* register ATP thread *)

fun register birth_time death_time (thread, desc) =

 (Synchronized.change global_state

    (fn {manager, timeout_heap, active, cancelling, messages, store} =>

      let

        val timeout_heap' = Thread_Heap.insert (death_time, thread) timeout_heap;

        val active' = update_thread (thread, (birth_time, death_time, desc)) active;

        val state' = make_state manager timeout_heap' active' cancelling messages store;

      in state' end);

  check_thread_manager ());

(** user commands **)

(* kill *)

fun kill () = Synchronized.change global_state

  (fn {manager, timeout_heap, active, cancelling, messages, store} =>

    let

      val killing = map (fn (th, (_, _, desc)) => (th, (Time.now (), desc))) active;

      val state' = make_state manager timeout_heap [] (killing @ cancelling) messages store;

    in state' end);

(* info *)

fun seconds time = string_of_int (Time.toSeconds time) ^ "s";

fun info () =

  let

    val {active, cancelling, ...} = Synchronized.value global_state;

    val now = Time.now ();

    fun running_info (_, (birth_time, death_time, desc)) =

      "Running: " ^ seconds (Time.- (now, birth_time)) ^ " -- " ^

        seconds (Time.- (death_time, now)) ^ " to live:\n" ^ desc;

    fun cancelling_info (_, (deadth_time, desc)) =

      "Trying to interrupt thread since " ^ seconds (Time.- (now, deadth_time)) ^ ":\n" ^ desc;

    val running =

      if null active then "No ATPs running."

      else space_implode "\n\n" ("Running ATPs:" :: map running_info active);

    val interrupting =

      if null cancelling then ""

      else

        space_implode "\n\n"

          ("Trying to interrupt the following ATPs:" :: map cancelling_info cancelling);

  in writeln (running ^ "\n" ^ interrupting) end;

fun messages opt_limit =

  let

    val limit = the_default message_display_limit opt_limit;

    val {store, ...} = Synchronized.value global_state;

    val header =

      "Recent ATP messages" ^

        (if length store <= limit then ":" else " (" ^ string_of_int limit ^ " displayed):");

  in writeln (space_implode "\n\n" (header :: #1 (chop limit store))) end;

(** The Sledgehammer **)

(* named provers *)

fun err_dup_prover name = error ("Duplicate prover: " ^ quote name);

structure Provers = Theory_Data

(

  type T = (prover * stamp) Symtab.table;

  val empty = Symtab.empty;

  val extend = I;

  fun merge data : T = Symtab.merge (eq_snd op =) data

    handle Symtab.DUP dup => err_dup_prover dup;

);

fun add_prover (name, prover) thy =

  Provers.map (Symtab.update_new (name, (prover, stamp ()))) thy

    handle Symtab.DUP dup => err_dup_prover dup;

fun get_prover thy name =

  Option.map #1 (Symtab.lookup (Provers.get thy) name);

fun print_provers thy = Pretty.writeln

  (Pretty.strs ("external provers:" :: sort_strings (Symtab.keys (Provers.get thy))));

(* start prover thread *)

fun start_prover name birth_time death_time i proof_state =

  (case get_prover (Proof.theory_of proof_state) name of

    NONE => warning ("Unknown external prover: " ^ quote name)

  | SOME prover =>

      let

        val {context = ctxt, facts, goal} = Proof.goal proof_state;

        val desc =

          "external prover " ^ quote name ^ " for subgoal " ^ string_of_int i ^ ":\n" ^

            Syntax.string_of_term ctxt (Thm.term_of (Thm.cprem_of goal i));

        val _ = Toplevel.thread true (fn () =>

          let

            val _ = register birth_time death_time (Thread.self (), desc);

            val problem = problem_of_goal (! full_types) i (ctxt, (facts, goal));

            val message = #message (prover (! timeout) problem)

              handle Sledgehammer_HOL_Clause.TRIVIAL =>   (* FIXME !? *)

                  "Empty clause: Try this command: " ^ Markup.markup Markup.sendback "apply metis"

                | ERROR msg => ("Error: " ^ msg);

            val _ = unregister message (Thread.self ());

          in () end);

      in () end);

(* sledghammer for first subgoal *)

fun sledgehammer names proof_state =

  let

    val provers = if null names then get_atps () else names;

    val birth_time = Time.now ();

    val death_time = Time.+ (birth_time, Time.fromSeconds (! timeout));

    val _ = kill ();   (*RACE wrt. other invocations of sledgehammer*)

    val _ = List.app (fn name => start_prover name birth_time death_time 1 proof_state) provers;

  in () end;

end;