# Copyright (c) 2013 AppNeta, Inc.
# All rights reserved.

module Oboe
  ##
  # Methods to act on, manipulate or investigate an X-Trace
  # value
  module XTrace
    class << self
      ##
      #  Oboe::XTrace.valid?
      #
      #  Perform basic validation on a potential X-Trace ID
      #
      def valid?(xtrace)
        # Shouldn't be nil
        return false unless xtrace

        # The X-Trace ID shouldn't be an initialized empty ID
        return false if (xtrace =~ /^1b0000000/i) == 0

        # Valid X-Trace IDs have a length of 58 bytes and start with '1b'
        return false unless xtrace.length == 58 && (xtrace =~ /^1b/i) == 0

        true
      rescue StandardError => e
        Oboe.logger.debug e.message
        Oboe.logger.debug e.backtrace
        false
      end

      ##
      # Oboe::XTrace.task_id
      #
      # Extract and return the task_id portion of an X-Trace ID
      #
      def task_id(xtrace)
        return nil unless Oboe::XTrace.valid?(xtrace)

        xtrace[2..41]
      rescue StandardError => e
        Oboe.logger.debug e.message
        Oboe.logger.debug e.backtrace
        return nil
      end
    end
  end
end