# Copyright (c) 2021 Contrast Security, Inc. See https://www.contrastsecurity.com/enduser-terms-0317a for more details.
# frozen_string_literal: true

require 'ougai'
require 'contrast/utils/object_share'
require 'contrast/utils/thread_tracker'

module Contrast
  module Logger
    # Our format for the Ougai logger allowing for custom log format that
    # extends the behavior of the default Ougai logger
    class Format < Ougai::Formatters::Bunyan
      LOG_TRACKER = Contrast::Utils::ThreadTracker.new
      # Our override of the _call method to add in the extra data that we want,
      # based on
      # https://github.com/tilfin/ougai/blob/1fe4fc2587be8eabc47d36dc57ee2814f8a0162b/lib/ougai/formatters/bunyan.rb#L26
      # By default, it adds:
      #   name: progname || @app_name,
      #   hostname: @hostname,
      #   pid: $$,
      #   level: to_level(severity),
      #   time: time,
      #   v: 0
      # and we add the fields from #format_hash
      def _call severity, time, progname, data
        super(severity,
              time,
              progname,
              format_hash.merge(data)
        )
      end

      private

      # The extra values to add to the Bunyan hash.
      # @return [Hash{Symbol => Object}] the extra data to log
      def format_hash
        thread_hash.merge(request_hash)
      end

      # Because this is unique per thread, we'll create it once and then store
      # it, rather than create a new hash on every log call during the request.
      def thread_hash
        hash = LOG_TRACKER.get(:logging_hash)
        unless hash
          hash = { thread_id: Thread.current.object_id }
          LOG_TRACKER.set(:logging_hash, hash)
        end
        hash
      end

      NO_REQUEST_HASH = { request_id: -1 }.cs__freeze
      def request_hash
        @request_tracker_defined ||= defined?(Contrast::Agent) && defined?(Contrast::Agent::REQUEST_TRACKER)
        return NO_REQUEST_HASH unless @request_tracker_defined

        Contrast::Agent::REQUEST_TRACKER&.current&.logging_hash || NO_REQUEST_HASH
      end
    end
  end
end