(*
 * Copyright (c) 2009-2013, Monoidics ltd.
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *)

open! IStd
module F = Format

module Stats = struct
  type t =
    { failure_kind: SymOp.failure_kind option
          (** what type of failure stopped the analysis (if any) *)
    ; symops: int  (** Number of SymOp's throughout the whole analysis of the function *)
    ; mutable nodes_visited: IntSet.t  (** Nodes visited *) }

  let empty = {failure_kind= None; symops= 0; nodes_visited= IntSet.empty}

  let is_visited stats node_id = IntSet.mem node_id stats.nodes_visited

  let add_visited stats node_id = stats.nodes_visited <- IntSet.add node_id stats.nodes_visited

  let nb_visited {nodes_visited} = IntSet.cardinal nodes_visited

  let update ?(add_symops = 0) ?failure_kind stats =
    let symops = stats.symops + add_symops in
    let failure_kind = match failure_kind with None -> stats.failure_kind | some -> some in
    {stats with symops; failure_kind}


  let failure_kind {failure_kind} = failure_kind

  let symops {symops} = symops

  let pp_failure_kind_opt fmt failure_kind_opt =
    match failure_kind_opt with
    | Some failure_kind ->
        SymOp.pp_failure_kind fmt failure_kind
    | None ->
        F.pp_print_string fmt "NONE"


  let failure_kind_to_string {failure_kind} = F.asprintf "%a" pp_failure_kind_opt failure_kind

  let pp fmt {failure_kind; symops} =
    F.fprintf fmt "FAILURE:%a SYMOPS:%d@\n" pp_failure_kind_opt failure_kind symops
end

module Status = struct
  type t =
    | Pending  (** the summary has been created by the procedure has not been analyzed yet *)
    | Analyzed  (** the analysis of the procedure is finished *)

  let to_string = function Pending -> "Pending" | Analyzed -> "Analyzed"

  let pp fmt status = F.pp_print_string fmt (to_string status)

  let is_analyzed = function Analyzed -> true | _ -> false
end

include struct
  (* ignore dead modules added by @@deriving fields *)
  [@@@warning "-60"]

  type t =
    { payloads: Payloads.t
    ; mutable sessions: int
    ; stats: Stats.t
    ; status: Status.t
    ; proc_desc: Procdesc.t
    ; err_log: Errlog.t
    ; mutable callee_pnames: Typ.Procname.Set.t }
  [@@deriving fields]
end

let poly_fields =
  PolyFields.(make Fields.map_poly ~subfields:[S (Fields.payloads, Payloads.poly_fields)])


let get_status summary = summary.status

let get_proc_desc summary = summary.proc_desc

let get_attributes summary = Procdesc.get_attributes summary.proc_desc

let get_proc_name summary = (get_attributes summary).ProcAttributes.proc_name

let get_ret_type summary = (get_attributes summary).ProcAttributes.ret_type

let get_formals summary = (get_attributes summary).ProcAttributes.formals

let get_err_log summary = summary.err_log

let get_loc summary = (get_attributes summary).ProcAttributes.loc

let pp_errlog fmt err_log =
  F.fprintf fmt "ERRORS: @[<h>%a@]@\n%!" Errlog.pp_errors err_log ;
  F.fprintf fmt "WARNINGS: @[<h>%a@]" Errlog.pp_warnings err_log


let pp_signature fmt summary =
  let pp_formal fmt (p, typ) = F.fprintf fmt "%a %a" (Typ.pp_full Pp.text) typ Mangled.pp p in
  F.fprintf fmt "%a %a(%a)" (Typ.pp_full Pp.text) (get_ret_type summary) Typ.Procname.pp
    (get_proc_name summary) (Pp.seq ~sep:", " pp_formal) (get_formals summary)


let get_signature summary = F.asprintf "%a" pp_signature summary

let pp_no_stats_specs fmt summary =
  F.fprintf fmt "%a@\n" pp_signature summary ;
  F.fprintf fmt "%a@\n" Status.pp summary.status


let pp_text fmt summary =
  pp_no_stats_specs fmt summary ;
  F.fprintf fmt "%a@\n%a%a" pp_errlog (get_err_log summary) Stats.pp summary.stats
    (Payloads.pp Pp.text) summary.payloads


let pp_html source fmt summary =
  F.pp_force_newline fmt () ;
  Io_infer.Html.with_color Black pp_no_stats_specs fmt summary ;
  F.fprintf fmt "<br />%a<br />@\n" Stats.pp summary.stats ;
  Errlog.pp_html source [] fmt (get_err_log summary) ;
  Io_infer.Html.pp_hline fmt () ;
  F.fprintf fmt "<LISTING>@\n" ;
  Payloads.pp (Pp.html Black) fmt summary.payloads ;
  F.fprintf fmt "</LISTING>@\n"


module OnDisk = struct
  open PolyVariantEqual

  type cache = t Typ.Procname.Hash.t

  let cache : cache = Typ.Procname.Hash.create 128

  let clear_cache () = Typ.Procname.Hash.clear cache

  let remove_from_cache pname = Typ.Procname.Hash.remove cache pname

  (** Add the summary to the table for the given function *)
  let add (proc_name : Typ.Procname.t) (summary : t) : unit =
    Typ.Procname.Hash.replace cache proc_name summary


  let specs_filename pname =
    let pname_file = Typ.Procname.to_filename pname in
    pname_file ^ Config.specs_files_suffix


  (** Return the path to the .specs file for the given procedure in the current results directory *)
  let specs_filename_of_procname pname =
    DB.Results_dir.path_to_filename DB.Results_dir.Abs_root
      [Config.specs_dir_name; specs_filename pname]


  (** paths to the .specs file for the given procedure in the current spec libraries *)
  let specs_library_filename specs_dir pname =
    DB.filename_from_string (Filename.concat specs_dir (specs_filename pname))


  (** paths to the .specs file for the given procedure in the models folder *)
  let specs_models_filename pname =
    DB.filename_from_string (Filename.concat Config.models_dir (specs_filename pname))


  let has_model pname =
    BackendStats.incr_summary_has_model_queries () ;
    Sys.file_exists (DB.filename_to_string (specs_models_filename pname)) = `Yes


  let summary_serializer : t Serialization.serializer =
    Serialization.create_serializer Serialization.Key.summary


  (** Load procedure summary from the given file *)
  let load_from_file specs_file =
    BackendStats.incr_summary_file_try_load () ;
    let opt = Serialization.read_from_file summary_serializer specs_file in
    if Option.is_some opt then BackendStats.incr_summary_read_from_disk () ;
    opt


  (** Load procedure summary for the given procedure name and update spec table *)
  let load_summary_to_spec_table =
    let rec or_load_summary_libs specs_dirs proc_name summ_opt =
      match (summ_opt, specs_dirs) with
      | Some _, _ | _, [] ->
          summ_opt
      | None, specs_dir :: specs_dirs ->
          load_from_file (specs_library_filename specs_dir proc_name)
          |> or_load_summary_libs specs_dirs proc_name
    in
    let load_summary_ziplibs zip_specs_filename =
      let zip_specs_path = Filename.concat Config.specs_dir_name zip_specs_filename in
      ZipLib.load summary_serializer zip_specs_path
    in
    let or_from f_load f_filenames proc_name summ_opt =
      match summ_opt with Some _ -> summ_opt | None -> f_load (f_filenames proc_name)
    in
    fun proc_name ->
      let summ_opt =
        load_from_file (specs_filename_of_procname proc_name)
        |> or_from load_from_file specs_models_filename proc_name
        |> or_from load_summary_ziplibs specs_filename proc_name
        |> or_load_summary_libs Config.specs_library proc_name
      in
      Option.iter ~f:(add proc_name) summ_opt ;
      summ_opt


  let get proc_name =
    match Typ.Procname.Hash.find cache proc_name with
    | summary ->
        BackendStats.incr_summary_cache_hits () ;
        Some summary
    | exception Caml.Not_found ->
        BackendStats.incr_summary_cache_misses () ;
        load_summary_to_spec_table proc_name


  (** Check if the procedure is from a library:
    It's not defined, and there is no spec file for it. *)
  let proc_is_library proc_attributes =
    if not proc_attributes.ProcAttributes.is_defined then
      match get proc_attributes.ProcAttributes.proc_name with None -> true | Some _ -> false
    else false


  (** Try to find the attributes for a defined proc.
    First look at specs (to get attributes computed by analysis)
    then look at the attributes table.
    If no attributes can be found, return None.
*)
  let proc_resolve_attributes proc_name =
    match get proc_name with
    | Some summary ->
        Some (get_attributes summary)
    | None ->
        Attributes.load proc_name


  (** Save summary for the procedure into the spec database *)
  let store (summ : t) =
    let final_summary = {summ with status= Status.Analyzed} in
    let proc_name = get_proc_name final_summary in
    (* Make sure the summary in memory is identical to the saved one *)
    add proc_name final_summary ;
    Serialization.write_to_file summary_serializer
      (specs_filename_of_procname proc_name)
      ~data:final_summary


  let reset proc_desc =
    let summary =
      { sessions= 0
      ; payloads= Payloads.empty
      ; stats= Stats.empty
      ; status= Status.Pending
      ; proc_desc
      ; err_log= Errlog.empty ()
      ; callee_pnames= Typ.Procname.Set.empty }
    in
    Typ.Procname.Hash.replace cache (Procdesc.get_proc_name proc_desc) summary ;
    summary


  let dummy =
    let dummy_attributes =
      ProcAttributes.default (SourceFile.invalid __FILE__) Typ.Procname.empty_block
    in
    let dummy_proc_desc = Procdesc.from_proc_attributes dummy_attributes in
    reset dummy_proc_desc


  let reset_all ~filter () =
    let reset proc_name =
      let filename = specs_filename_of_procname proc_name in
      BackendStats.incr_summary_file_try_load () ;
      Serialization.read_from_file summary_serializer filename
      |> Option.iter ~f:(fun summary ->
             BackendStats.incr_summary_read_from_disk () ;
             let blank_summary = reset summary.proc_desc in
             Serialization.write_to_file summary_serializer filename ~data:blank_summary )
    in
    Procedures.get_all ~filter () |> List.iter ~f:reset
end

module SummaryValue = struct
  type nonrec t = t option

  let label = "summary"
end

module SummaryServer = Memcached.Make (SummaryValue)