class Kuroko2::JobSuspendSchedule

def suspend_times(time_from, time_to)
  it = Chrono::Iterator.new(cron, now: time_from - 1)
  suspend_times = []
  loop do
    next_time = it.next
    if next_time <= time_to
      suspend_times << next_time
    else
      break
    end
  end
  suspend_times.map(&:in_time_zone)
end

def validate_cron_schedule
  if Kuroko2::JobSchedule::CRON_FORMAT === cron
    suspend_schedule = Chrono::Schedule.new(cron)
    if job_definition.job_schedules.empty?
      errors.add(:cron, "needs job schedules")
    else
      schedule = job_definition.job_schedules.each_with_object({}) do |launch_schedule_model, h|
        launch_schedule = Chrono::Schedule.new(launch_schedule_model.cron)
        Kuroko2::JobSchedule::CHRONO_SCHEDULE_METHODS.each do |method|
          h[method] ||= []
          suspend_schedule_list = suspend_schedule.public_send(method)
          # https://linux.die.net/man/5/crontab
          # > Note: The day of a command's execution can be specified by two fields
          # >  day of month, and day of week. If both fields are restricted (ie, aren't *),
          # >  the command will be run when either field matches the current time.
          # >  For example, "30 4 1,15 * 5" would cause a command to be run at 4:30 am
          # >  on the 1st and 15th of each month, plus every Friday.
          if launch_schedule.wdays? && launch_schedule.days?
            if (method == :wdays && suspend_schedule.wdays? && !suspend_schedule.days?) || (method == :days && !suspend_schedule.wdays? && suspend_schedule.days?)
              suspend_schedule_list = []
            end
          end
          h[method] |= launch_schedule.public_send(method) - suspend_schedule_list
        end
      end
      if schedule.values.all?(&:empty?)
        errors.add(:cron, "suspends all launched schedules")
      end
    end
  end
rescue Chrono::Fields::Base::InvalidField => e
  errors.add(:cron, "has invalid field: #{e.message}")
end