feat: improve city selection for weather arts generation

- Introduce `get_recent_cities` to filter out cities that have been recently generated weather arts.
- Update `select_cities` method to exclude recent cities from the selection process, ensuring diversity in the generated arts.
- Modify the `select_countries` method to maintain its functionality while integrating recent city filtering.

This update enhances the system's ability to select active cities efficiently, reducing redundancy and improving the variety of generated weather arts by avoiding recent candidates.

app/workers/batch_generate_weather_arts_worker.rb

@@ -15,7 +15,8 @@ class BatchGenerateWeatherArtsWorker
     remaining_slots = [ remaining_slots, PER_RUN_GENERATION_LIMIT ].min
 
     countries_to_process = select_countries
-    cities_to_process = select_cities(countries_to_process, remaining_slots)&.shuffle
+    recent_cities = get_recent_cities
+    cities_to_process = select_cities(recent_cities, countries_to_process, remaining_slots)&.shuffle
     print_cities_list(cities_to_process, start_time)
 
     skipped_cities = []
@@ -39,6 +40,16 @@ class BatchGenerateWeatherArtsWorker
 
   private
 
+  def get_recent_cities
+    cutoff_time = Time.current - GENERATION_INTERVAL
+    City.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 < ?", cutoff_time)
+  end
+
   def calculate_remaining_slots
     today_generations = WeatherArt
                           .where("DATE(created_at) = ?", Date.today)
@@ -50,9 +61,6 @@ class BatchGenerateWeatherArtsWorker
   end
 
   def select_countries
-    cutoff_time = Time.current - GENERATION_INTERVAL
-
-
     Country.all.select do |country|
       timezone_info = country.timezones.present? ? JSON.parse(country.timezones).first : { "zoneName" => "UTC" }
       local_time = Time.current.in_time_zone(ActiveSupport::TimeZone[timezone_info["zoneName"]])
@@ -60,10 +68,12 @@ class BatchGenerateWeatherArtsWorker
     end
   end
 
-  def select_cities(countries, limit)
+  def select_cities(recent_city, countries, limit)
+    cutoff_time = Time.current - GENERATION_INTERVAL
     Rails.logger.debug "Select Cities with limit: #{limit}, in #{countries.size} countries."
-    # 第一阶段：筛选 active 城市
+    # 第一阶段：筛选 active 城市, 排除最近生成过的城市
-    active_cities = City.where(active: true, country_id: countries.map(&:id)).limit(limit).to_a
+    active_cities = City.where.not(id: recent_city.pluck(:id))
+                        .where(active: true, country_id: countries.map(&:id)).limit(limit).to_a
     selected = active_cities.first(limit)
     remaining = limit - selected.size
     Rails.logger.debug "Step1: Selected #{selected.size} cities with active city."
@@ -79,17 +89,17 @@ class BatchGenerateWeatherArtsWorker
     Rails.logger.debug "Step2: Selected #{remaining_every_country_count} cities in every country"
 
     select_countries.each do |country|
-      c = City.where.not(id: select_countries.pluck(:id))
+      c = City.where.not(id: recent_city.pluck(:id))
-                      .where(country_id: country.id)
+              .where.not(id: select_countries.pluck(:id))
-                      .order(Arel.sql("RANDOM()"))
+              .where(country_id: country.id)
-                      .first(remaining_every_country_count)
+              .order(Arel.sql("RANDOM()"))
+              .first(remaining_every_country_count)
       if c.any? # 检查是否有有效的城市
         Rails.logger.debug "== Selected city [#{c.first.name}] in country: [#{country.name}]"
         selected << c
       else
         Rails.logger.debug "== No valid cities found in country: [#{country.name}]"
       end
-      selected << c
     end
     Rails.logger.debug "Finished selected #{selected.size} cities."
     selected