class Kuroko2::JobSchedule

def self.launch_scheduled_jobs!(time_from, time_to)
  includes(job_definition: :job_suspend_schedules).find_each do |schedule|
    definition = schedule.job_definition
    suspend_times = schedule.suspend_times(time_from, time_to)
    schedule.scheduled_times(time_from, time_to).each do |time|
      if definition.suspended?
        Kuroko2.logger.info("Skipped suspended \"##{definition.id} #{definition.name}\" that is scheduled at #{I18n.l(time, format: :short)} by `#{schedule.cron}`")
      elsif suspend_times.include?(time)
        Kuroko2.logger.info("Skipped schedule suspended \"##{definition.id} #{definition.name}\" that is scheduled at #{I18n.l(time, format: :short)} by `#{schedule.cron}`")
      else
        launched_by = "\"##{definition.id} #{definition.name}\" that is scheduled at #{I18n.l(time, format: :short)} by `#{schedule.cron}`"
        definition.create_instance(launched_by: launched_by)
      end
    end
  end
end

def has_suspend_schedules?
  job_definition && !job_definition.job_suspend_schedules.empty?
end

def next(now = Time.current)
  return if suspended_all?
  next_time = Chrono::Iterator.new(self.cron, now: now).next
  suspend_times = suspend_times(next_time, next_time)
  if suspend_times.include?(next_time)
    self.next(next_time)
  else
    next_time
  end
end

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

def suspend_times(time_from, time_to)
  if has_suspend_schedules?
    job_definition.job_suspend_schedules.
      map { |schedule| schedule.suspend_times(time_from, time_to) }.flatten.uniq
  else
    []
  end
end

def suspended_all?
  return false unless has_suspend_schedules?
  launch_schedule = Chrono::Schedule.new(cron)
  schedule = CHRONO_SCHEDULE_METHODS.each_with_object({}) do |method, h|
    h[method] = launch_schedule.public_send(method)
  end
  job_definition.job_suspend_schedules.each do |suspend_schedule_model|
    suspend_schedule = Chrono::Schedule.new(suspend_schedule_model.cron)
    CHRONO_SCHEDULE_METHODS.each do |method|
      schedule[method] -= suspend_schedule.public_send(method)
    end
    # 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 suspend_schedule.wdays? && suspend_schedule.days?
      case
      when launch_schedule.wdays? && !launch_schedule.days?
        schedule[:days] = []
      when !launch_schedule.wdays? && launch_schedule.days?
        schedule[:wdays] = []
      end
    end
  end
  schedule.values.all?(&:empty?)
end

def validate_cron_schedule
  if CRON_FORMAT === cron
    self.next
  end
  nil
rescue Chrono::Fields::Base::InvalidField => e
  errors.add(:cron, "has invalid field: #{e.message}")
end