# Copyright (c) 2022 Contrast Security, Inc. See https://www.contrastsecurity.com/enduser-terms-0317a for more details.
# frozen_string_literal: true

module Contrast
  module Utils
    # this module extends HeadDumpUtil
    module HeadDumpExtend
      def log_enabled_warning
        control = Contrast::Utils::HeapDumpUtil.control
        dir    = control[:path]
        window = control[:window]
        count  = control[:count]
        delay  = control[:delay]
        clean  = control[:clean]

        logger.info(<<~WARNING)
          *****************************************************
          ********      HEAP DUMP HAS BEEN ENABLED     ********
          *** APPLICATION PROCESS WILL EXIT UPON COMPLETION ***
          *****************************************************

          Heap dump is a debugging tool that snapshots the entire
          state of the Ruby VM. It is an exceptionally expensive
          process, and should only be used to debug especially
          pernicious errors.

          It will write multiple memory snaphots, which are liable
          to be multiple gigabytes in size.
          They will be named "[unix timestamp]-heap.dump",
          e.g.: 1020304050-heap.dump

          It will then call Ruby `exit()`.

          If this is not your specific intent, you can (and should)
          disable this option in your Contrast config file.

          HEAP DUMP PARAMETERS:
          \t[write files to this directory]             dir:     #{ dir    }
          \t[wait this many seconds in between dumps]   window:  #{ window }
          \t[heap dump this many times]                 count:   #{ count  }
          \t[wait this many seconds into app lifetime]  delay:   #{ delay  }
          \t[perform gc pass before dump]               clean:   #{ clean  }

          *****************************************************
          ********        YOU HAVE BEEN WARNED         ********
          *****************************************************
        WARNING
      end

      def capture_heap_dump
        control = Contrast::Utils::HeapDumpUtil.control
        dir    = control[:path]
        window = control[:window]
        count  = control[:count]
        clean  = control[:clean]
        logger.info('HEAP DUMP MAIN LOOP')
        ObjectSpace.trace_object_allocations_start
        count.times do |i|
          logger.info('STARTING HEAP DUMP PASS', current_pass: i, max: count)
          snapshot_heap(dir, clean)
          logger.info('FINISHING HEAP DUMP PASS', current_pass: i, max: count)
          sleep(window)
        end
      ensure
        ObjectSpace.trace_object_allocations_stop
        logger.info('*****************************************************')
        logger.info('********        HEAP DUMP HAS CONCLUDED      ********')
        logger.info('***     APPLICATION PROCESS WILL EXIT SHORTLY     ***')
        logger.info('*****************************************************')
        exit # rubocop:disable Rails/Exit We weren't kidding!
      end
    end
  end
end