(*

     Title:      HOL/Mutabelle/mutabelle_extra.ML

     Author:     Stefan Berghofer, Jasmin Blanchette, Lukas Bulwahn, TU Muenchen

     Invokation of Counterexample generators

 *)

 signature MUTABELLE_EXTRA =

 sig

 val take_random : int -> 'a list -> 'a list

 datatype outcome = GenuineCex | PotentialCex | NoCex | Donno | Timeout | Error

 type timing = (string * int) list

 type mtd = string * (theory -> term -> outcome * (timing * (int * Quickcheck.report list) list option))

 type mutant_subentry = term * (string * (outcome * (timing * Quickcheck.report option))) list

 type detailed_entry = string * bool * term * mutant_subentry list

 type subentry = string * int * int * int * int * int * int

 type entry = string * bool * subentry list

 type report = entry list

 val quickcheck_mtd : string -> mtd

 (*

 val refute_mtd : mtd

 val nitpick_mtd : mtd

 *)

 val freezeT : term -> term

 val thms_of : bool -> theory -> thm list

 val string_for_report : report -> string

 val write_report : string -> report -> unit

 val mutate_theorems_and_write_report :

   theory -> mtd list -> thm list -> string -> unit

 val random_seed : real Unsynchronized.ref

 end;

 structure MutabelleExtra : MUTABELLE_EXTRA =

 struct

 (* Own seed; can't rely on the Isabelle one to stay the same *)

 val random_seed = Unsynchronized.ref 1.0;

 (* mutation options *)

 val max_mutants = 4

 val num_mutations = 1

 (* soundness check: *)

 val max_mutants = 1

 val num_mutations = 0

 (* quickcheck options *)

 (*val quickcheck_generator = "SML"*)

 val iterations = 10

 val size = 5

 exception RANDOM;

 fun rmod x y = x - y * Real.realFloor (x / y);

 local

   val a = 16807.0;

   val m = 2147483647.0;

 in

 fun random () = CRITICAL (fn () =>

   let val r = rmod (a * ! random_seed) m

   in (random_seed := r; r) end);

 end;

 fun random_range l h =

   if h < l orelse l < 0 then raise RANDOM

   else l + Real.floor (rmod (random ()) (real (h - l + 1)));

 datatype outcome = GenuineCex | PotentialCex | NoCex | Donno | Timeout | Error

 type timing = (string * int) list

 type mtd = string * (theory -> term -> outcome * (timing * (int * Quickcheck.report list) list option))

 type mutant_subentry = term * (string * (outcome * (timing * Quickcheck.report option))) list

 type detailed_entry = string * bool * term * mutant_subentry list

 type subentry = string * int * int * int * int * int * int

 type entry = string * bool * subentry list

 type report = entry list

 fun inst_type insts (Type (s, Ts)) = Type (s, map (inst_type insts) Ts)

   | inst_type insts T = the_default HOLogic.intT (AList.lookup op = insts T)

 fun preprocess thy insts t = Object_Logic.atomize_term thy

  (map_types (inst_type insts) (Mutabelle.freeze t));

 fun invoke_quickcheck quickcheck_generator thy t =

   TimeLimit.timeLimit (Time.fromSeconds (! Auto_Counterexample.time_limit))

       (fn _ =>

           case Quickcheck.gen_test_term (ProofContext.init thy) true true (SOME quickcheck_generator)

                                     size iterations (preprocess thy [] t) of

             (NONE, (time_report, report)) => (NoCex, (time_report, report))

           | (SOME _, (time_report, report)) => (GenuineCex, (time_report, report))) ()

   handle TimeLimit.TimeOut => (Timeout, ([("timelimit", !Auto_Counterexample.time_limit)], NONE))

 fun quickcheck_mtd quickcheck_generator =

   ("quickcheck_" ^ quickcheck_generator, invoke_quickcheck quickcheck_generator)

   (*

 fun invoke_refute thy t =

   let

     val res = MyRefute.refute_term thy [] t

     val _ = priority ("Refute: " ^ res)

   in

     case res of

       "genuine" => GenuineCex

     | "likely_genuine" => GenuineCex

     | "potential" => PotentialCex

     | "none" => NoCex

     | "unknown" => Donno

     | _ => Error

   end

   handle MyRefute.REFUTE (loc, details) =>

          (error ("Unhandled Refute error (" ^ quote loc ^ "): " ^ details ^

                    "."))

 val refute_mtd = ("refute", invoke_refute)

 *)

 (*

 open Nitpick_Util

 open Nitpick_Rep

 open Nitpick_Nut

 fun invoke_nitpick thy t =

   let

     val ctxt = ProofContext.init thy

     val state = Proof.init ctxt

   in

     let

       val (res, _) = Nitpick.pick_nits_in_term state (Nitpick_Isar.default_params thy []) false [] t

       val _ = priority ("Nitpick: " ^ res)

     in

       case res of

         "genuine" => GenuineCex

       | "likely_genuine" => GenuineCex

       | "potential" => PotentialCex

       | "none" => NoCex

       | "unknown" => Donno

       | _ => Error

     end

     handle ARG (loc, details) =>

            (error ("Bad argument(s) to " ^ quote loc ^ ": " ^ details ^ "."))

          | BAD (loc, details) =>

            (error ("Internal error (" ^ quote loc ^ "): " ^ details ^ "."))

          | LIMIT (_, details) =>

            (warning ("Limit reached: " ^ details ^ "."); Donno)

          | NOT_SUPPORTED details =>

            (warning ("Unsupported case: " ^ details ^ "."); Donno)

          | NUT (loc, us) =>

            (error ("Invalid nut" ^ plural_s_for_list us ^

                    " (" ^ quote loc ^ "): " ^

                   commas (map (string_for_nut ctxt) us) ^ "."))

          | REP (loc, Rs) =>

            (error ("Invalid representation" ^ plural_s_for_list Rs ^

                    " (" ^ quote loc ^ "): " ^

                    commas (map string_for_rep Rs) ^ "."))

          | TERM (loc, ts) =>

            (error ("Invalid term" ^ plural_s_for_list ts ^

                    " (" ^ quote loc ^ "): " ^

                    commas (map (Syntax.string_of_term ctxt) ts) ^ "."))

          | TYPE (loc, Ts, ts) =>

            (error ("Invalid type" ^ plural_s_for_list Ts ^

                    (if null ts then

                       ""

                     else

                       " for term" ^ plural_s_for_list ts ^ " " ^

                       commas (map (quote o Syntax.string_of_term ctxt) ts)) ^

                    " (" ^ quote loc ^ "): " ^

                    commas (map (Syntax.string_of_typ ctxt) Ts) ^ "."))

          | Kodkod.SYNTAX (_, details) =>

            (warning ("Ill-formed Kodkodi output: " ^ details ^ "."); Error)

          | Refute.REFUTE (loc, details) =>

            (error ("Unhandled Refute error (" ^ quote loc ^ "): " ^ details ^

                    "."))

          | Exn.Interrupt => raise Exn.Interrupt

          | _ => (priority ("Unknown error in Nitpick"); Error)

   end

 val nitpick_mtd = ("nitpick", invoke_nitpick)

 *)

 val comms = [@{const_name "op ="}, @{const_name "op |"}, @{const_name "op &"}]

 val forbidden =

  [(* (@{const_name "power"}, "'a"), *)

   (*(@{const_name induct_equal}, "'a"),

   (@{const_name induct_implies}, "'a"),

   (@{const_name induct_conj}, "'a"),*)

   (@{const_name "undefined"}, "'a"),

   (@{const_name "default"}, "'a"),

   (@{const_name "dummy_pattern"}, "'a::{}") (*,

   (@{const_name "uminus"}, "'a"),

   (@{const_name "Nat.size"}, "'a"),

   (@{const_name "Groups.abs"}, "'a") *)]

 val forbidden_thms =

  ["finite_intvl_succ_class",

   "nibble"]

 val forbidden_consts =

  [@{const_name nibble_pair_of_char}]

 fun is_forbidden_theorem (s, th) =

   let val consts = Term.add_const_names (prop_of th) [] in

     exists (fn s' => s' mem space_explode "." s) forbidden_thms orelse

     exists (fn s' => s' mem forbidden_consts) consts orelse

     length (space_explode "." s) <> 2 orelse

     String.isPrefix "type_definition" (List.last (space_explode "." s)) orelse

     String.isSuffix "_def" s orelse

     String.isSuffix "_raw" s

   end

 fun is_forbidden_mutant t =

   let val consts = Term.add_const_names t [] in

     exists (String.isPrefix "Nitpick") consts orelse

     exists (String.isSubstring "_sumC") consts (* internal function *)

   end

 fun is_executable_term thy t = can (TimeLimit.timeLimit (Time.fromMilliseconds 2000) (Quickcheck.test_term

  (ProofContext.init thy) false (SOME "SML") 1 0)) (preprocess thy [] t)

 fun is_executable_thm thy th = is_executable_term thy (prop_of th)

 val freezeT =

   map_types (map_type_tvar (fn ((a, i), S) =>

     TFree (if i = 0 then a else a ^ "_" ^ string_of_int i, S)))

 fun thms_of all thy =

   filter

     (fn th => (all orelse Context.theory_name (theory_of_thm th) = Context.theory_name thy)

       (* andalso is_executable_thm thy th *))

     (map snd (filter_out is_forbidden_theorem (Mutabelle.all_unconcealed_thms_of thy)))

 val count = length oo filter o equal

 fun take_random 0 _ = []

   | take_random _ [] = []

   | take_random n xs =

     let val j = random_range 0 (length xs - 1) in

       Library.nth xs j :: take_random (n - 1) (nth_drop j xs)

     end

 fun cpu_time description f =

   let

     val start = start_timing ()

     val result = Exn.capture f ()

     val time = Time.toMilliseconds (#cpu (end_timing start))

   in (Exn.release result, (description, time)) end

 fun safe_invoke_mtd thy (mtd_name, invoke_mtd) t =

   let

     val _ = priority ("Invoking " ^ mtd_name)

     val ((res, (timing, reports)), time) = cpu_time "total time"

       (fn () => case try (invoke_mtd thy) t of

           SOME (res, (timing, reports)) => (res, (timing, reports))

         | NONE => (priority ("**** PROBLEMS WITH " ^ Syntax.string_of_term_global thy t);

            (Error , ([], NONE))))

     val _ = priority (" Done")

   in (res, (time :: timing, reports)) end

 (* theory -> term list -> mtd -> subentry *)

 (*

 fun test_mutants_using_one_method thy mutants (mtd_name, invoke_mtd) =

   let

      val res = map (safe_invoke_mtd thy (mtd_name, invoke_mtd)) mutants

   in

     (mtd_name, count GenuineCex res, count PotentialCex res, count NoCex res,

      count Donno res, count Timeout res, count Error res)

   end

 fun create_entry thy thm exec mutants mtds =

   (Thm.get_name thm, exec, map (test_mutants_using_one_method thy mutants) mtds)

 *)

 fun create_detailed_entry thy thm exec mutants mtds =

   let

     fun create_mutant_subentry mutant = (mutant,

       map (fn (mtd_name, invoke_mtd) =>

         (mtd_name, safe_invoke_mtd thy (mtd_name, invoke_mtd) mutant)) mtds)

   in

     (Thm.get_name thm, exec, prop_of thm, map create_mutant_subentry mutants)

   end

 (* (theory -> thm -> bool -> term list -> mtd list -> 'a) -> theory -> mtd list -> thm -> 'a *)

 fun mutate_theorem create_entry thy mtds thm =

   let

     val pp = Syntax.pp_global thy

     val exec = is_executable_thm thy thm

     val _ = priority (if exec then "EXEC" else "NOEXEC")

     val mutants =

           (if num_mutations = 0 then

              [Thm.prop_of thm]

            else

              Mutabelle.mutate_mix (Thm.prop_of thm) thy comms forbidden

                                   num_mutations)

              |> filter_out is_forbidden_mutant

     val mutants =

       if exec then

         let

           val _ = priority ("BEFORE PARTITION OF " ^

                             Int.toString (length mutants) ^ " MUTANTS")

           val (execs, noexecs) = List.partition (is_executable_term thy) (take_random (20 * max_mutants) mutants)

           val _ = tracing ("AFTER PARTITION (" ^ Int.toString (length execs) ^

                            " vs " ^ Int.toString (length noexecs) ^ ")")

         in

           execs @ take_random (Int.max (0, max_mutants - length execs)) noexecs

         end

       else

         mutants

     val mutants = mutants

           |> take_random max_mutants

           |> map Mutabelle.freeze |> map freezeT

 (*          |> filter (not o is_forbidden_mutant) *)

           |> List.mapPartial (try (Sign.cert_term thy))

     val _ = map (fn t => priority ("MUTANT: " ^ Pretty.string_of (Pretty.term pp t))) mutants

   in

     create_entry thy thm exec mutants mtds

   end

 (* theory -> mtd list -> thm list -> report *)

 val mutate_theorems = map ooo mutate_theorem

 fun string_of_outcome GenuineCex = "GenuineCex"

   | string_of_outcome PotentialCex = "PotentialCex"

   | string_of_outcome NoCex = "NoCex"

   | string_of_outcome Donno = "Donno"

   | string_of_outcome Timeout = "Timeout"

   | string_of_outcome Error = "Error"

 fun string_of_mutant_subentry thy thm_name (t, results) =

   "mutant: " ^ Syntax.string_of_term_global thy t ^ "\n" ^

   space_implode "; "

     (map (fn (mtd_name, (outcome, timing)) => mtd_name ^ ": " ^ string_of_outcome outcome) results) ^

   "\n"

 fun string_of_mutant_subentry' thy thm_name (t, results) =

   let

     fun string_of_report (Quickcheck.Report {iterations = i, raised_match_errors = e,

       satisfied_assms = s, positive_concl_tests = p}) =

       "errors: " ^ string_of_int e ^ "; conclusion tests: " ^ string_of_int p

     fun string_of_reports NONE = ""

       | string_of_reports (SOME reports) =

         cat_lines (map (fn (size, [report]) =>

           "size " ^ string_of_int size ^ ": " ^ string_of_report report) (rev reports))

     fun string_of_mtd_result (mtd_name, (outcome, (timing, reports))) =

       mtd_name ^ ": " ^ string_of_outcome outcome ^ "; " ^

       space_implode "; " (map (fn (s, t) => (s ^ ": " ^ string_of_int t)) timing)

       ^ "\n" ^ string_of_reports reports

   in

     "mutant of " ^ thm_name ^ ":\n" ^ cat_lines (map string_of_mtd_result results)

   end

 fun string_of_detailed_entry thy (thm_name, exec, t, mutant_subentries) = 

    thm_name ^ " " ^ (if exec then "[exe]" else "[noexe]") ^ ": " ^

    Syntax.string_of_term_global thy t ^ "\n" ^

    cat_lines (map (string_of_mutant_subentry' thy thm_name) mutant_subentries) ^ "\n"

 (* subentry -> string *)

 fun string_for_subentry (mtd_name, genuine_cex, potential_cex, no_cex, donno,

                          timeout, error) =

   "    " ^ mtd_name ^ ": " ^ Int.toString genuine_cex ^ "+ " ^

   Int.toString potential_cex ^ "= " ^ Int.toString no_cex ^ "- " ^

   Int.toString donno ^ "? " ^ Int.toString timeout ^ "T " ^

   Int.toString error ^ "!"

 (* entry -> string *)

 fun string_for_entry (thm_name, exec, subentries) =

   thm_name ^ " " ^ (if exec then "[exe]" else "[noexe]") ^ ":\n" ^

   cat_lines (map string_for_subentry subentries) ^ "\n"

 (* report -> string *)

 fun string_for_report report = cat_lines (map string_for_entry report)

 (* string -> report -> unit *)

 fun write_report file_name =

   File.write (Path.explode file_name) o string_for_report

 (* theory -> mtd list -> thm list -> string -> unit *)

 fun mutate_theorems_and_write_report thy mtds thms file_name =

   let

     val _ = priority "Starting Mutabelle..."

     val path = Path.explode file_name

     (* for normal report: *)

     (*val (gen_create_entry, gen_string_for_entry) = (create_entry, string_for_entry)*)

     (*for detailled report: *)

     val (gen_create_entry, gen_string_for_entry) =

       (create_detailed_entry, string_of_detailed_entry thy)

   in

     File.write path (

     "Mutation options = "  ^

       "max_mutants: " ^ string_of_int max_mutants ^

       "; num_mutations: " ^ string_of_int num_mutations ^ "\n" ^

     "QC options = " ^

       (*"quickcheck_generator: " ^ quickcheck_generator ^ ";*)

       "size: " ^ string_of_int size ^

       "; iterations: " ^ string_of_int iterations ^ "\n");

     map (File.append path o gen_string_for_entry o mutate_theorem gen_create_entry thy mtds) thms;

     ()

   end

 end;