class BatchGenerateWeatherArtsWorker
  include Sidekiq::Worker

  GENERATION_INTERVAL = 24.hours
  MAX_DURATION = 50.minutes
  SLEEP_DURATION = 120.seconds

  def perform(*args)
    start_time = Time.current

    cities_to_process = get_eligible_cities

    cities_to_process.each do |city|
      break if Time.current - start_time > MAX_DURATION
      Rails.logger.info "Generating weather art for #{city.name}"

      GenerateWeatherArtWorker.perform_async(city.id)
      sleep SLEEP_DURATION
    end
  end

  private

  def get_eligible_cities
    cutoff_time = Time.current - GENERATION_INTERVAL

    City.active
        .joins("LEFT JOIN (
          SELECT city_id, MAX(created_at) as last_generation_time
          FROM weather_arts
          GROUP BY city_id
        ) latest_arts ON cities.id = latest_arts.city_id")
        .where("latest_arts.last_generation_time IS NULL OR latest_arts.last_generation_time < ?", cutoff_time)
        .order(:priority)
  end
end