require 'resque/plugins/multi_step_task/constantization'

module Resque
  module Plugins
    class MultiStepTask
      # Executes a single finalization job 
      class FinalizationJob
        extend Constantization

        # Handle job invocation
        def self.perform(task_id, job_module_name, *args)
          task = MultiStepTask.find(task_id)
          
          begin
            klass = constantize(job_module_name)
            klass.singleton_class.class_eval "def multi_step_task; @@task ||= MultiStepTask.find('#{task_id}'); end"
            klass.singleton_class.class_eval "def multi_step_task_id; @@task_id ||= '#{task_id}'; end"
            klass.perform(*args)
          rescue Exception
            logger.info("[Resque Multi-Step-Task] Incrementing failed_count: Finalization job #{job_module_name} failed for task id #{task_id} at #{Time.now} (args: #{args})")
            task.increment_failed_count
            raise
          end
          logger.info("[Resque Multi-Step-Task] Incrementing completed_count: Finalization job #{job_module_name} completed for task id #{task_id} at #{Time.now} (args: #{args})")          
          task.increment_completed_count

          if fin_job_info = task.redis.lpop('finalize_jobs')
            # Queue the next finalization job
            Resque::Job.create(task.queue_name, FinalizationJob, task.task_id, 
                               *Yajl::Parser.parse(fin_job_info))
          else
            # There is nothing left to do so cleanup.
            task.nuke
          end

        end
        
        def self.logger
          Resque::Plugins::MultiStepTask.logger
        end
      end
    end
  end
end