Process Manager Event

process_manager_event.rb

class CapturingProcess < ApplicationJob
  prepend RailsEventStore::AsyncHandler

  class State < ActiveRecord::Base
    self.table_name = "capturing_process_state"
    serialize :data

    def self.get_by_order_number(order_number)
      transaction do
        lock.find_or_create_by(order_number: order_number).tap do |s|
          s.data ||= {auth: false, shipped: false, completed: false}
          yield s
          s.save!
        end
      end
    end
  end

  def perform(event)
    State.get_by_order_number(event.data.fetch(:order_number)) do |state|
      case event
        when Orders::OrderShipped
          state.data[:shipped] = true
        when Payments::PaymentAuthorized
          state.data[:auth] = true
        else
          raise ArgumentError
      end
      if trigger_command?(state)
        PaymentsService.new.call(
          CapturePaymentCommand.new(order_number: state.order_number)
        )
        state.data[:completed] = true
      end
    end
  end

  private

  def trigger_command?(state)
    state.data[:auth] && state.data[:shipped] && !state.data[:completed]
  end
end