A task timer based on rufus-scheduler, added logger and start/shutdown feature

task_scheduler

require 'rufus-scheduler'

module Clipper

  class TaskScheduler

    def initialize(logger)
      @scheduler = build_scheduler(logger)
      @scheduled_tasks = []
      @running = false
      @logger = logger
    end

    def add_periodic_task(period_time, &block)
      job = Rufus::Scheduler::IntervalJob.new(@scheduler, "#{period_time}s", {}, block)
      @scheduled_tasks << job
      @scheduler.start_job(job) if running?
    end

    def add_task(delay_time, &block)
      job = Rufus::Scheduler::InJob.new(@scheduler, "#{delay_time}s", {}, block)
      @scheduled_tasks << job
      @scheduler.start_job(job) if running?
    end

    def start!
      unless @running
        @scheduled_tasks.each do |job|
          @scheduler.start_job(job)
        end
        @logger.info("TaskScheduler started")
      end
    end

    def running?
      return @running
    end

    def shutdown
      @logger.info("TaskScheduler starts shuting down")
      @scheduler.shutdown
      @logger.info("TaskScheduler has shut down")
    end

    private 

    def build_scheduler(logger)
      unless logger.respond_to? :puts
        logger.define_singleton_method(:puts){ |error| self.error(error) }
      end

      scheduler = Rufus::Scheduler.new
      scheduler.define_singleton_method(:start_job) do |job|
        if job.is_a? Rufus::Scheduler::InJob
          #hacked into Rufus::Scheduler::InJob to reset its @next_time
          in_time = job.next_time - job.scheduled_at
          job.instance_variable_set(:@next_time,Time.now + in_time)
        end
        @jobs.push(job)
      end
      return scheduler
    end

  end

end