am-kantox/kantox-chronoscope

module Kantox
  module Chronoscope
    # Dummy module to be used in production-like environments.
    module Generic
      COLOR_VIVID   = "\033[#{Kantox::Chronoscope.kungfuig.colors!.vivid || '01;38;05;226'}m".freeze
      COLOR_PALE    = "\033[#{Kantox::Chronoscope.kungfuig.colors!.pale || '01;38;05;178'}m".freeze
      COLOR_WARN    = "\033[#{Kantox::Chronoscope.kungfuig.colors!.warn || '01;38;05;173'}m".freeze
      LOGGER        = Kantox::Chronoscope.kungfuig.logger && Kernel.const_get(Kantox::Chronoscope.kungfuig.logger).new ||
                      Kernel.const_defined?(:Rails) && ::Rails.logger ||
                      Logger.new(STDOUT)

      LANG          = Kantox::Chronoscope.kungfuig.lang || :en
      I18N          = Kantox::Chronoscope.kungfuig.i18n!.public_send("#{LANG}!")
      BM_DELIMITER  = (I18N.bm_delimiter || ' :: ').to_s.freeze
      ARROW         = (I18N.arrow || '  ⇒  ').to_s.freeze
      METHOD_LABEL  = (I18N.name || 'method').freeze
      TIMES_LABEL   = (I18N.times || 'times').freeze
      AVERAGE_LABEL = (I18N.average || 'average').freeze
      TOTAL_LABEL   = (I18N.total || 'total').freeze

      COLOR_NONE    = "\033[0m".freeze
      DEFAULT_TAG   = 'N/A'.freeze
      LOGGER_TAG    = 'CHRONOS'.freeze

      @@chronoscope_data = {}
      @@★ = []

      # rubocop:disable Style/MethodName
      # rubocop:disable Metrics/MethodLength
      # rubocop:disable Metrics/AbcSize

      def ⌚(arg = DEFAULT_TAG, log = false)
        return (@@chronoscope_data[arg.to_s] = nil) unless block_given? # pass no block to reset

        result = nil # needed for it to be defined in this scope
        @@chronoscope_data[arg.to_s] ||= { count: 0, total: 0, stack: @@★.dup }
        @@★.unshift arg.to_s
        begin
          (Benchmark.measure { result = yield }).tap do |bm|
            @@chronoscope_data[arg.to_s][:count] += 1
            @@chronoscope_data[arg.to_s][:total] += bm.real
            LOGGER.debug log_bm arg, bm if log
          end
          result
        rescue => e
          LOGGER.debug log_problem arg, e
          yield # re-try without any wrappers. If it will raise anyway— fine
        ensure
          @@★.shift
        end
      end
      alias watch ⌚

      # FIXME: total currently adds up all calls, including nested
      #        I am not sure if it is correct ot not, so leaving it for now
      def ⌛(cleanup: true, count: 18, log: true) # Yes, 18 is my fave number)
        return if @@chronoscope_data.empty?

        log_report(count).tap do |log_hash|
          LOGGER.debug(log_hash[:string]) if log
          log_hash[:data] = @@chronoscope_data.map { |k, v| [k, v.dup] }.to_h
          @@chronoscope_data.clear if cleanup
        end
      end
      alias harvest ⌛

      def log_bm(arg, bm)
        [
          "  #{COLOR_PALE}[#{LOGGER_TAG}] #{arg}#{COLOR_NONE}",
          BM_DELIMITER,
          "#{COLOR_PALE}#{@@chronoscope_data[arg.to_s][:count]}#{COLOR_NONE}",
          BM_DELIMITER,
          "#{COLOR_VIVID}#{(@@chronoscope_data[arg.to_s][:total] / @@chronoscope_data[arg.to_s][:count]).round(3)}#{COLOR_NONE}",
          BM_DELIMITER,
          "#{COLOR_PALE}#{@@chronoscope_data[arg.to_s][:total].round(3)}#{COLOR_NONE}",
          bm.to_s
        ].join(' ').strip
      end

      def log_problem(arg, e)
        [
          "  #{COLOR_WARN}[#{LOGGER_TAG}] #{arg}#{COLOR_NONE} #{BM_DELIMITER} threw “#{COLOR_WARN}#{e.message}#{COLOR_NONE}”",
          e.backtrace.map { |s| "#{COLOR_WARN}#{s}#{COLOR_NONE}" }
        ].join("#{$/}⮩\t")
      end

      def log_report(count)
        count = @@chronoscope_data.size if count <= 0

        delim_label = [" ⇓⇓ [#{LOGGER_TAG}] ⇓⇓ ", " ⇑⇑ [#{LOGGER_TAG}] ⇑⇑ "].map do |label|
          delim = '—' * ((log_width - label.length) / 2)
          "#{COLOR_PALE}#{delim}#{label}#{delim}#{COLOR_NONE}"
        end

        method_len = [@@chronoscope_data.keys.max_by(&:length).length, 5].max + 2
        times_len = [TIMES_LABEL.length, 6].max
        average_len = [AVERAGE_LABEL.length, 8].max
        total = @@chronoscope_data.values.map { |v| v[:total] }.inject(:+).round(5)

        as_string = [
          '',
          delim_label.first,
          [
            METHOD_LABEL.rjust(method_len, ' '),
            ARROW,
            TIMES_LABEL.rjust(times_len, ' '),
            BM_DELIMITER,
            AVERAGE_LABEL.ljust(average_len, ' '),
            BM_DELIMITER,
            TOTAL_LABEL
          ].join,
          (@@chronoscope_data.sort_by { |_, v| -v[:total] }.take(count).map do |what, bms|
            [
              "#{COLOR_PALE}#{what.rjust(method_len, ' ')}#{COLOR_NONE}",
              ARROW,
              "#{COLOR_VIVID}#{bms[:count].to_s.rjust(times_len, ' ')}#{COLOR_NONE}",
              BM_DELIMITER,
              "#{COLOR_VIVID}#{(bms[:total] / bms[:count]).round(5).to_s.ljust(average_len, ' ')}#{COLOR_NONE}",
              BM_DELIMITER,
              "#{COLOR_VIVID}#{bms[:total].round(5)}#{COLOR_NONE}"
            ].join
          end),
          "#{COLOR_PALE}#{'—' * log_width}#{COLOR_NONE}",
          [
            "#{COLOR_VIVID}#{'total'.rjust(method_len, ' ')}#{COLOR_NONE}#{ARROW}",
            ' ' * (times_len + average_len + 2 * BM_DELIMITER.length),
            "#{COLOR_VIVID}#{total}#{COLOR_NONE}"
          ].join,
          delim_label.last
        ].flatten.join($/)

        { data: @@chronoscope_data, string: as_string }
      end

      def log_width
        ($stdin.winsize.last.nonzero? || 90) - 10
      rescue
        80
      end

      protected :log_problem, :log_bm, :log_report, :log_width
      # rubocop:enable Metrics/AbcSize
      # rubocop:enable Metrics/MethodLength
      # rubocop:enable Style/MethodName

      def inject(top = nil)
        top ||= Object
        top.send :prepend, Kantox::Chronoscope::Generic
      end
      module_function :inject
    end
  end
end