app/lib/delivery_failure_tracker.rb

   1 # frozen_string_literal: true
   2
   3 class DeliveryFailureTracker
   4   FAILURE_DAYS_THRESHOLD = 7
   5
   6   def initialize(url_or_host)
   7     @host = url_or_host.start_with?('https://') || url_or_host.start_with?('http://') ? Addressable::URI.parse(url_or_host).normalized_host : url_or_host
   8   end
   9
  10   def track_failure!
  11     Redis.current.sadd(exhausted_deliveries_key, today)
  12     UnavailableDomain.create(domain: @host) if reached_failure_threshold?
  13   end
  14
  15   def track_success!
  16     Redis.current.del(exhausted_deliveries_key)
  17     UnavailableDomain.find_by(domain: @host)&.destroy
  18   end
  19
  20   def days
  21     Redis.current.scard(exhausted_deliveries_key) || 0
  22   end
  23
  24   def available?
  25     !UnavailableDomain.where(domain: @host).exists?
  26   end
  27
  28   alias reset! track_success!
  29
  30   class << self
  31     def without_unavailable(urls)
  32       unavailable_domains_map = Rails.cache.fetch('unavailable_domains') { UnavailableDomain.pluck(:domain).index_with(true) }
  33
  34       urls.reject do |url|
  35         host = Addressable::URI.parse(url).normalized_host
  36         unavailable_domains_map[host]
  37       end
  38     end
  39
  40     def available?(url)
  41       new(url).available?
  42     end
  43
  44     def reset!(url)
  45       new(url).reset!
  46     end
  47   end
  48
  49   private
  50
  51   def exhausted_deliveries_key
  52     "exhausted_deliveries:#{@host}"
  53   end
  54
  55   def today
  56     Time.now.utc.strftime('%Y%m%d')
  57   end
  58
  59   def reached_failure_threshold?
  60     days >= FAILURE_DAYS_THRESHOLD
  61   end
  62 end