(*  Title:      HOL/Tools/Sledgehammer/sledgehammer.ML

    Author:     Fabian Immler, TU Muenchen

    Author:     Makarius

    Author:     Jasmin Blanchette, TU Muenchen

Sledgehammer's heart.

*)

signature SLEDGEHAMMER =

sig

  type failure = ATP_Systems.failure

  type locality = Sledgehammer_Filter.locality

  type relevance_override = Sledgehammer_Filter.relevance_override

  type fol_formula = Sledgehammer_Translate.fol_formula

  type minimize_command = Sledgehammer_Reconstruct.minimize_command

  type params =

    {blocking: bool,

     debug: bool,

     verbose: bool,

     overlord: bool,

     atps: string list,

     full_types: bool,

     explicit_apply: bool,

     relevance_thresholds: real * real,

     max_relevant: int option,

     isar_proof: bool,

     isar_shrink_factor: int,

     timeout: Time.time,

     expect: string}

  type problem =

    {state: Proof.state,

     goal: thm,

     subgoal: int,

     axioms: (term * ((string * locality) * fol_formula) option) list,

     only: bool}

  type prover_result =

    {outcome: failure option,

     message: string,

     pool: string Symtab.table,

     used_thm_names: (string * locality) list,

     atp_run_time_in_msecs: int,

     output: string,

     tstplike_proof: string,

     axiom_names: (string * locality) list vector,

     conjecture_shape: int list list}

  type prover = params -> minimize_command -> problem -> prover_result

  val dest_dir : string Config.T

  val problem_prefix : string Config.T

  val measure_run_time : bool Config.T

  val kill_atps: unit -> unit

  val running_atps: unit -> unit

  val messages: int option -> unit

  val get_prover_fun : theory -> string -> prover

  val run_sledgehammer :

    params -> bool -> int -> relevance_override -> (string -> minimize_command)

    -> Proof.state -> bool * Proof.state

  val setup : theory -> theory

end;

structure Sledgehammer : SLEDGEHAMMER =

struct

open ATP_Problem

open ATP_Proof

open ATP_Systems

open Metis_Clauses

open Sledgehammer_Util

open Sledgehammer_Filter

open Sledgehammer_Translate

open Sledgehammer_Reconstruct

(** The Sledgehammer **)

(* Identifier to distinguish Sledgehammer from other tools using

   "Async_Manager". *)

val das_Tool = "Sledgehammer"

fun kill_atps () = Async_Manager.kill_threads das_Tool "ATPs"

fun running_atps () = Async_Manager.running_threads das_Tool "ATPs"

val messages = Async_Manager.thread_messages das_Tool "ATP"

(** problems, results, provers, etc. **)

type params =

  {blocking: bool,

   debug: bool,

   verbose: bool,

   overlord: bool,

   atps: string list,

   full_types: bool,

   explicit_apply: bool,

   relevance_thresholds: real * real,

   max_relevant: int option,

   isar_proof: bool,

   isar_shrink_factor: int,

   timeout: Time.time,

   expect: string}

type problem =

  {state: Proof.state,

   goal: thm,

   subgoal: int,

   axioms: (term * ((string * locality) * fol_formula) option) list,

   only: bool}

type prover_result =

  {outcome: failure option,

   message: string,

   pool: string Symtab.table,

   used_thm_names: (string * locality) list,

   atp_run_time_in_msecs: int,

   output: string,

   tstplike_proof: string,

   axiom_names: (string * locality) list vector,

   conjecture_shape: int list list}

type prover = params -> minimize_command -> problem -> prover_result

(* configuration attributes *)

val (dest_dir, dest_dir_setup) =

  Attrib.config_string "sledgehammer_dest_dir" (K "")

  (* Empty string means create files in Isabelle's temporary files directory. *)

val (problem_prefix, problem_prefix_setup) =

  Attrib.config_string "sledgehammer_problem_prefix" (K "prob")

val (measure_run_time, measure_run_time_setup) =

  Attrib.config_bool "sledgehammer_measure_run_time" (K false)

fun with_path cleanup after f path =

  Exn.capture f path

  |> tap (fn _ => cleanup path)

  |> Exn.release

  |> tap (after path)

(* generic TPTP-based provers *)

(* Important messages are important but not so important that users want to see

   them each time. *)

val important_message_keep_factor = 0.1

fun prover_fun auto atp_name

        {exec, required_execs, arguments, has_incomplete_mode, proof_delims,

         known_failures, default_max_relevant, explicit_forall,

         use_conjecture_for_hypotheses}

        ({debug, verbose, overlord, full_types, explicit_apply,

          max_relevant, isar_proof, isar_shrink_factor, timeout, ...} : params)

        minimize_command ({state, goal, subgoal, axioms, only} : problem) =

  let

    val ctxt = Proof.context_of state

    val (_, hyp_ts, concl_t) = strip_subgoal goal subgoal

    val axioms = axioms |> not only

                          ? take (the_default default_max_relevant max_relevant)

    val the_dest_dir = if overlord then getenv "ISABELLE_HOME_USER"

                       else Config.get ctxt dest_dir

    val the_problem_prefix = Config.get ctxt problem_prefix

    val problem_file_name =

      Path.basic ((if overlord then "prob_" ^ atp_name

                   else the_problem_prefix ^ serial_string ())

                  ^ "_" ^ string_of_int subgoal)

    val problem_path_name =

      if the_dest_dir = "" then

        File.tmp_path problem_file_name

      else if File.exists (Path.explode the_dest_dir) then

        Path.append (Path.explode the_dest_dir) problem_file_name

      else

        error ("No such directory: " ^ quote the_dest_dir ^ ".")

    val measure_run_time = verbose orelse Config.get ctxt measure_run_time

    val command = Path.explode (getenv (fst exec) ^ "/" ^ snd exec)

    (* write out problem file and call prover *)

    fun command_line complete timeout probfile =

      let

        val core = File.shell_path command ^ " " ^ arguments complete timeout ^

                   " " ^ File.shell_path probfile

      in

        (if measure_run_time then "TIMEFORMAT='%3R'; { time " ^ core ^ " ; }"

         else "exec " ^ core) ^ " 2>&1"

      end

    fun split_time s =

      let

        val split = String.tokens (fn c => str c = "\n");

        val (output, t) = s |> split |> split_last |> apfst cat_lines;

        fun as_num f = f >> (fst o read_int);

        val num = as_num (Scan.many1 Symbol.is_ascii_digit);

        val digit = Scan.one Symbol.is_ascii_digit;

        val num3 = as_num (digit ::: digit ::: (digit >> single));

        val time = num --| Scan.$$ "." -- num3 >> (fn (a, b) => a * 1000 + b);

        val as_time = the_default 0 o Scan.read Symbol.stopper time o explode;

      in (output, as_time t) end;

    fun run_on probfile =

      case filter (curry (op =) "" o getenv o fst) (exec :: required_execs) of

        (home_var, _) :: _ =>

        error ("The environment variable " ^ quote home_var ^ " is not set.")

      | [] =>

        if File.exists command then

          let

            fun run complete timeout =

              let

                val command = command_line complete timeout probfile

                val ((output, msecs), res_code) =

                  bash_output command

                  |>> (if overlord then

                         prefix ("% " ^ command ^ "\n% " ^ timestamp () ^ "\n")

                       else

                         I)

                  |>> (if measure_run_time then split_time else rpair 0)

                val (tstplike_proof, outcome) =

                  extract_tstplike_proof_and_outcome complete res_code

                      proof_delims known_failures output

              in (output, msecs, tstplike_proof, outcome) end

            val readable_names = debug andalso overlord

            val (problem, pool, conjecture_offset, axiom_names) =

              prepare_problem ctxt readable_names explicit_forall full_types

                              explicit_apply hyp_ts concl_t axioms

            val ss = tptp_strings_for_atp_problem use_conjecture_for_hypotheses

                                                  problem

            val _ = File.write_list probfile ss

            val conjecture_shape =

              conjecture_offset + 1 upto conjecture_offset + length hyp_ts + 1

              |> map single

            val run_twice = has_incomplete_mode andalso not auto

            val timer = Timer.startRealTimer ()

            val result =

              run false (if run_twice then

                           Time.fromMilliseconds

                                         (2 * Time.toMilliseconds timeout div 3)

                         else

                           timeout)

              |> run_twice

                 ? (fn (_, msecs0, _, SOME _) =>

                       run true (Time.- (timeout, Timer.checkRealTimer timer))

                       |> (fn (output, msecs, tstplike_proof, outcome) =>

                              (output, msecs0 + msecs, tstplike_proof, outcome))

                     | result => result)

          in ((pool, conjecture_shape, axiom_names), result) end

        else

          error ("Bad executable: " ^ Path.implode command ^ ".")

    (* If the problem file has not been exported, remove it; otherwise, export

       the proof file too. *)

    fun cleanup probfile =

      if the_dest_dir = "" then try File.rm probfile else NONE

    fun export probfile (_, (output, _, _, _)) =

      if the_dest_dir = "" then

        ()

      else

        File.write (Path.explode (Path.implode probfile ^ "_proof")) output

    val ((pool, conjecture_shape, axiom_names),

         (output, msecs, tstplike_proof, outcome)) =

      with_path cleanup export run_on problem_path_name

    val (conjecture_shape, axiom_names) =

      repair_conjecture_shape_and_axiom_names output conjecture_shape

                                              axiom_names

    val important_message =

      if random () <= important_message_keep_factor then

        extract_important_message output

      else

        ""

    val banner = if auto then "Sledgehammer found a proof"

                 else "Try this command"

    val (message, used_thm_names) =

      case outcome of

        NONE =>

        proof_text isar_proof

            (pool, debug, isar_shrink_factor, ctxt, conjecture_shape)

            (banner, full_types, minimize_command, tstplike_proof, axiom_names,

             goal, subgoal)

        |>> (fn message =>

                message ^ (if verbose then

                             "\nATP real CPU time: " ^ string_of_int msecs ^

                             " ms."

                           else

                             "") ^

                (if important_message <> "" then

                   "\n\nImportant message from Dr. Geoff Sutcliffe:\n" ^

                   important_message

                 else

                   ""))

      | SOME failure => (string_for_failure failure, [])

  in

    {outcome = outcome, message = message, pool = pool,

     used_thm_names = used_thm_names, atp_run_time_in_msecs = msecs,

     output = output, tstplike_proof = tstplike_proof,

     axiom_names = axiom_names, conjecture_shape = conjecture_shape}

  end

fun get_prover_fun thy name = prover_fun false name (get_prover thy name)

fun run_prover (params as {blocking, debug, verbose, max_relevant, timeout,

                           expect, ...})

               auto i n minimize_command (problem as {state, goal, axioms, ...})

               (prover as {default_max_relevant, ...}, atp_name) =

  let

    val ctxt = Proof.context_of state

    val birth_time = Time.now ()

    val death_time = Time.+ (birth_time, timeout)

    val max_relevant = the_default default_max_relevant max_relevant

    val num_axioms = Int.min (length axioms, max_relevant)

    val desc =

      "ATP " ^ quote atp_name ^

      (if verbose then

         " with " ^ string_of_int num_axioms ^ " fact" ^ plural_s num_axioms

       else

         "") ^

      " on " ^ (if n = 1 then "goal" else "subgoal " ^ string_of_int i) ^ ":" ^

      (if blocking then

         ""

       else

         "\n" ^ Syntax.string_of_term ctxt (Thm.term_of (Thm.cprem_of goal i)))

    fun go () =

      let

        fun really_go () =

          prover_fun auto atp_name prover params (minimize_command atp_name)

                     problem

          |> (fn {outcome, message, ...} =>

                 (if is_some outcome then "none" else "some", message))

        val (outcome_code, message) =

          if debug then

            really_go ()

          else

            (really_go ()

             handle ERROR message => ("unknown", "Error: " ^ message ^ "\n")

                  | exn => ("unknown", "Internal error:\n" ^

                                       ML_Compiler.exn_message exn ^ "\n"))

        val _ =

          if expect = "" orelse outcome_code = expect then

            ()

          else if blocking then

            error ("Unexpected outcome: " ^ quote outcome_code ^ ".")

          else

            warning ("Unexpected outcome: " ^ quote outcome_code ^ ".");

      in (outcome_code = "some", message) end

  in

    if auto then

      let val (success, message) = TimeLimit.timeLimit timeout go () in

        (success, state |> success ? Proof.goal_message (fn () =>

             Pretty.chunks [Pretty.str "", Pretty.mark Markup.hilite

                 (Pretty.str message)]))

      end

    else if blocking then

      let val (success, message) = TimeLimit.timeLimit timeout go () in

        List.app priority

                 (Async_Manager.break_into_chunks [desc ^ "\n" ^ message]);

        (success, state)

      end

    else

      (Async_Manager.launch das_Tool birth_time death_time desc (snd o go);

       (false, state))

  end

val auto_max_relevant_divisor = 2

fun run_sledgehammer (params as {blocking, atps, full_types,

                                 relevance_thresholds, max_relevant, ...})

                     auto i (relevance_override as {only, ...}) minimize_command

                     state =

  if null atps then

    error "No ATP is set."

  else case subgoal_count state of

    0 => (priority "No subgoal!"; (false, state))

  | n =>

    let

      val _ = Proof.assert_backward state

      val thy = Proof.theory_of state

      val _ = () |> not blocking ? kill_atps

      val _ = if auto then () else priority "Sledgehammering..."

      val provers = map (`(get_prover thy)) atps

      fun go () =

        let

          val {context = ctxt, facts = chained_ths, goal} = Proof.goal state

          val (_, hyp_ts, concl_t) = strip_subgoal goal i

          val max_max_relevant =

            case max_relevant of

              SOME n => n

            | NONE =>

              0 |> fold (Integer.max o #default_max_relevant o fst) provers

                |> auto ? (fn n => n div auto_max_relevant_divisor)

          val axioms =

            relevant_facts ctxt full_types relevance_thresholds

                           max_max_relevant relevance_override chained_ths

                           hyp_ts concl_t

          val problem =

            {state = state, goal = goal, subgoal = i,

             axioms = map (prepare_axiom ctxt) axioms, only = only}

          val run_prover = run_prover params auto i n minimize_command problem

        in

          if auto then

            fold (fn prover => fn (true, state) => (true, state)

                                | (false, _) => run_prover prover)

                 provers (false, state)

          else

            (if blocking then Par_List.map else map) run_prover provers

            |> exists fst |> rpair state

        end

    in if blocking then go () else Future.fork (tap go) |> K (false, state) end

val setup =

  dest_dir_setup

  #> problem_prefix_setup

  #> measure_run_time_setup

end;