handle_asynchronously, delay with sidekiq, make sidekiq work with instance methods

generic_job.rb

class GenericJob
  include Sidekiq::Job

  def perform(klass, id, undelayed_method, *args)
    object = klass.constantize.find(id)
    object.send(undelayed_method, *args)
  end
end

report.rb

class Report
  include Sidekiq_Dj
  
  def generate(*args)
    # code hidden
  end
  handle_asynchronously :generate, queue: :critical
end

sidekiq_dj.rb

module Sidekiq_Dj
    extend ActiveSupport::Concern

    included do
      def delay(options={})
        Delayer.new(self, options)
      end
    end

    class_methods do
      def handle_asynchronously(method, options={})
        delayed_method = "#{method}_delayed"
        undelayed_method = "#{method}_undelayed"

        define_method("#{delayed_method}") do |*args|
          if self.is_a?(Class)
            raise ArgumentError, "Sidekiq_Dj extension doesn't work with class methods."
          end
          delay(options).send(undelayed_method, *args)
        end

        alias_method undelayed_method, method
        alias_method method, delayed_method
      end
    end

    class Delayer
      def initialize(target, options)
        @target = target
        @options = options
      end

      def method_missing(method, *args)
        GenericJob.set(@options).perform_async(@target.class.to_s, @target.id, method, *stringify_hash_keys(args))
      end

      def stringify_hash_keys(args)
        args.map do |arg|
          case arg
          when Hash
            arg.deep_stringify_keys
          when Array
            stringify_hash_keys(arg)
          else
            arg
          end
        end
      end
    end
  end