# encoding: utf-8

require 'active_support/concern'

module DynoScaler
  module Workers
    module Resque
      extend ActiveSupport::Concern

      included do
        class_attribute :scale_up_enabled
        class_attribute :scale_down_enabled

        enable_scaling_up
        enable_scaling_down
      end

      module ClassMethods
        def after_perform_scale_down(*args)
          info = ::Resque.info
          working = info[:working] > 0 ? info[:working] - 1 : 0
          info.merge!(working: working) # we are not working anymore

          dyno_scaler_manager.scale_down(info) if scale_down_enabled?
        rescue StandardError => e
          $stderr.puts "Could not scale down workers: #{e}"
        end

        def after_enqueue_scale_up(*args)
          if scale_up_enabled?
            if DynoScaler.configuration.async?
              DynoScaler.configuration.async.call(::Resque.info.merge(action: :scale_up))
            else
              dyno_scaler_manager.scale_up(::Resque.info)
            end
          end
        rescue StandardError => e
          $stderr.puts "Could not scale up workers: #{e}"
        end

        def enable_scaling_up
          self.scale_up_enabled = true
        end

        def enable_scaling_down
          self.scale_down_enabled = true
        end

        def disable_scaling_up
          self.scale_up_enabled = false
        end

        def disable_scaling_down
          self.scale_down_enabled = false
        end

        private
          def dyno_scaler_manager
            @manager ||= DynoScaler::Manager.new
          end
      end
    end
  end
end