(*
 * Copyright (c) 2017 - present Facebook, Inc.
 * All rights reserved.
 *
 * This source code is licensed under the BSD style license found in the
 * LICENSE file in the root directory of this source tree. An additional grant
 * of patent rights can be found in the PATENTS file in the same directory.
 *)
open! IStd

let reportdiff ~current_report:current_report_fname ~previous_report:previous_report_fname =
  let load_report filename_opt : Jsonbug_t.report =
    let empty_report = [] in
    Option.value_map
      ~f:(fun filename -> Jsonbug_j.report_of_string (In_channel.read_all filename))
      ~default:empty_report filename_opt
  in
  let current_report = load_report current_report_fname in
  let previous_report = load_report previous_report_fname in
  let diff =
    let unfiltered_diff = Differential.of_reports ~current_report ~previous_report in
    if Config.filtering then
      let file_renamings =
        match Config.file_renamings with
        | Some f
         -> DifferentialFilters.FileRenamings.from_json_file f
        | None
         -> DifferentialFilters.FileRenamings.empty
      in
      let interesting_paths =
        Option.map
          ~f:(fun fname ->
            List.map ~f:(SourceFile.create ~warn_on_error:false) (In_channel.read_lines fname))
          Config.differential_filter_files
      in
      DifferentialFilters.do_filter unfiltered_diff file_renamings
        ~skip_duplicated_types:Config.skip_duplicated_types ~interesting_paths
    else unfiltered_diff
  in
  let out_path = Config.results_dir ^/ "differential" in
  Unix.mkdir_p out_path ; Differential.to_files diff out_path