DEV: Normalize locales that are similar (e.g. en and en_GB) so they do not get translated (#1495)

This commit
- normalizes locales like en_GB and variants to en. With this, the feature will not translate en_GB posts to en (or similarly pt_BR to pt_PT)
- consolidates whether the feature is enabled in `DiscourseAi::Translation.enabled?`
- similarly for backfill in  `DiscourseAi::Translation.backfill_enabled?`
  - turns off backfill if `ai_translation_backfill_max_age_days` is 0 to keep true to what it says. Set it to a high number to backfill everything

app/jobs/regular/detect_translate_post.rb

@@ -6,8 +6,7 @@ module Jobs
     sidekiq_options retry: false
 
     def execute(args)
-      return if !SiteSetting.discourse_ai_enabled
-      return if !SiteSetting.ai_translation_enabled
+      return if !DiscourseAi::Translation.enabled?
       return if args[:post_id].blank?
 
       post = Post.find_by(id: args[:post_id])
@@ -36,12 +35,14 @@ module Jobs
         end
       end
 
+      return if detected_locale.blank?
       locales = SiteSetting.content_localization_supported_locales.split("|")
       return if locales.blank?
 
       locales.each do |locale|
-        next if locale == detected_locale
-        next if post.post_localizations.exists?(locale:)
+        next if DiscourseAi::Translation::LocaleNormalizer.is_same?(locale, detected_locale)
+        regionless_locale = locale.split("_").first
+        next if post.post_localizations.where("locale LIKE ?", "#{regionless_locale}%").exists?
 
         begin
           DiscourseAi::Translation::PostLocalizer.localize(post, locale)

app/jobs/regular/detect_translate_topic.rb

@@ -6,8 +6,7 @@ module Jobs
     sidekiq_options retry: false
 
     def execute(args)
-      return if !SiteSetting.discourse_ai_enabled
-      return if !SiteSetting.ai_translation_enabled
+      return if !DiscourseAi::Translation.enabled?
       return if args[:topic_id].blank?
 
       topic = Topic.find_by(id: args[:topic_id])
@@ -34,12 +33,14 @@ module Jobs
         end
       end
 
+      return if detected_locale.blank?
       locales = SiteSetting.content_localization_supported_locales.split("|")
       return if locales.blank?
 
       locales.each do |locale|
-        next if locale == detected_locale
-        next if topic.topic_localizations.exists?(locale:)
+        next if DiscourseAi::Translation::LocaleNormalizer.is_same?(locale, detected_locale)
+        regionless_locale = locale.split("_").first
+        next if topic.topic_localizations.where("locale LIKE ?", "#{regionless_locale}%").exists?
 
         begin
           DiscourseAi::Translation::TopicLocalizer.localize(topic, locale)

app/jobs/regular/localize_categories.rb

@@ -6,21 +6,17 @@ module Jobs
     sidekiq_options retry: false
 
     def execute(args)
+      return if !DiscourseAi::Translation.enabled?
+
       limit = args[:limit]
       raise Discourse::InvalidParameters.new(:limit) if limit.nil?
       return if limit <= 0
-
-      return if !SiteSetting.discourse_ai_enabled
-      return if !SiteSetting.ai_translation_enabled
       locales = SiteSetting.content_localization_supported_locales.split("|")
-      return if locales.blank?
 
       categories = Category.where("locale IS NOT NULL")
-
       if SiteSetting.ai_translation_backfill_limit_to_public_content
         categories = categories.where(read_restricted: false)
       end
-
       categories = categories.order(:id).limit(limit)
       return if categories.empty?
 
@@ -33,6 +29,7 @@ module Jobs
         missing_locales = locales - existing_locales - [category.locale]
         missing_locales.each do |locale|
           break if remaining_limit <= 0
+          next if DiscourseAi::Translation::LocaleNormalizer.is_same?(locale, category.locale)
 
           begin
             DiscourseAi::Translation::CategoryLocalizer.localize(category, locale)

app/jobs/regular/localize_posts.rb

@@ -9,23 +9,25 @@ module Jobs
       limit = args[:limit]
       raise Discourse::InvalidParameters.new(:limit) if limit.blank? || limit <= 0
 
-      return if !SiteSetting.discourse_ai_enabled
-      return if !SiteSetting.ai_translation_enabled
+      return if !DiscourseAi::Translation.backfill_enabled?
 
       locales = SiteSetting.content_localization_supported_locales.split("|")
-      return if locales.blank?
-
       locales.each do |locale|
+        base_locale = locale.split("_").first
         posts =
           Post
             .joins(
-              "LEFT JOIN post_localizations pl ON pl.post_id = posts.id AND pl.locale = #{ActiveRecord::Base.connection.quote(locale)}",
+              "LEFT JOIN post_localizations pl ON pl.post_id = posts.id AND pl.locale LIKE '#{base_locale}%'",
+            )
+            .where(
+              "posts.created_at > ?",
+              SiteSetting.ai_translation_backfill_max_age_days.days.ago,
             )
             .where(deleted_at: nil)
             .where("posts.user_id > 0")
             .where.not(raw: [nil, ""])
             .where.not(locale: nil)
-            .where.not(locale: locale)
+            .where("posts.locale NOT LIKE '#{base_locale}%'")
             .where("pl.id IS NULL")
 
         posts = posts.joins(:topic)
@@ -46,14 +48,6 @@ module Jobs
             )
         end
 
-        if SiteSetting.ai_translation_backfill_max_age_days > 0
-          posts =
-            posts.where(
-              "posts.created_at > ?",
-              SiteSetting.ai_translation_backfill_max_age_days.days.ago,
-            )
-        end
-
         posts = posts.order(updated_at: :desc).limit(limit)
 
         next if posts.empty?

app/jobs/regular/localize_topics.rb

@@ -9,22 +9,24 @@ module Jobs
       limit = args[:limit]
       raise Discourse::InvalidParameters.new(:limit) if limit.blank? || limit <= 0
 
-      return if !SiteSetting.discourse_ai_enabled
-      return if !SiteSetting.ai_translation_enabled
+      return if !DiscourseAi::Translation.backfill_enabled?
 
       locales = SiteSetting.content_localization_supported_locales.split("|")
-      return if locales.blank?
-
       locales.each do |locale|
+        base_locale = locale.split("_").first
         topics =
           Topic
             .joins(
-              "LEFT JOIN topic_localizations tl ON tl.topic_id = topics.id AND tl.locale = #{ActiveRecord::Base.connection.quote(locale)}",
+              "LEFT JOIN topic_localizations tl ON tl.topic_id = topics.id AND tl.locale LIKE '#{base_locale}%'",
+            )
+            .where(
+              "topics.created_at > ?",
+              SiteSetting.ai_translation_backfill_max_age_days.days.ago,
             )
             .where(deleted_at: nil)
             .where("topics.user_id > 0")
             .where.not(locale: nil)
-            .where.not(locale: locale)
+            .where("topics.locale NOT LIKE '#{base_locale}%'")
             .where("tl.id IS NULL")
 
         if SiteSetting.ai_translation_backfill_limit_to_public_content
@@ -43,14 +45,6 @@ module Jobs
             )
         end
 
-        if SiteSetting.ai_translation_backfill_max_age_days > 0
-          topics =
-            topics.where(
-              "topics.created_at > ?",
-              SiteSetting.ai_translation_backfill_max_age_days.days.ago,
-            )
-        end
-
         topics = topics.order(updated_at: :desc).limit(limit)
 
         next if topics.empty?

app/jobs/scheduled/categories_locale_detection_backfill.rb

@@ -7,10 +7,7 @@ module Jobs
     cluster_concurrency 1
 
     def execute(args)
-      return if !SiteSetting.discourse_ai_enabled
-      return if !SiteSetting.ai_translation_enabled
-      limit = SiteSetting.ai_translation_backfill_hourly_rate
-      return if limit == 0
+      return if !DiscourseAi::Translation.backfill_enabled?
 
       categories = Category.where(locale: nil)
 
@@ -18,6 +15,7 @@ module Jobs
         categories = categories.where(read_restricted: false)
       end
 
+      limit = SiteSetting.ai_translation_backfill_hourly_rate
       categories = categories.limit(limit)
       return if categories.empty?
 

app/jobs/scheduled/category_localization_backfill.rb

@@ -6,11 +6,8 @@ module Jobs
     cluster_concurrency 1
 
     def execute(args)
-      return if !SiteSetting.discourse_ai_enabled
-      return if !SiteSetting.ai_translation_enabled
-      return if SiteSetting.content_localization_supported_locales.blank?
+      return if !DiscourseAi::Translation.backfill_enabled?
       limit = SiteSetting.ai_translation_backfill_hourly_rate
-      return if limit == 0
 
       Jobs.enqueue(:localize_categories, limit:)
     end

app/jobs/scheduled/post_localization_backfill.rb

@@ -6,10 +6,8 @@ module Jobs
     cluster_concurrency 1
 
     def execute(args)
-      return if !SiteSetting.discourse_ai_enabled
-      return if !SiteSetting.ai_translation_enabled
+      return if !DiscourseAi::Translation.backfill_enabled?
 
-      return if SiteSetting.content_localization_supported_locales.blank?
       limit = SiteSetting.ai_translation_backfill_hourly_rate / (60 / 5) # this job runs in 5-minute intervals
       return if limit == 0
 

app/jobs/scheduled/posts_locale_detection_backfill.rb

@@ -7,16 +7,16 @@ module Jobs
     cluster_concurrency 1
 
     def execute(args)
-      return if !SiteSetting.discourse_ai_enabled
-      return if !SiteSetting.ai_translation_enabled
+      return if !DiscourseAi::Translation.backfill_enabled?
+
       limit = SiteSetting.ai_translation_backfill_hourly_rate / (60 / 5) # this job runs in 5-minute intervals
-      return if limit == 0
 
       posts =
         Post
           .where(locale: nil)
           .where(deleted_at: nil)
           .where("posts.user_id > 0")
+          .where("posts.created_at > ?", SiteSetting.ai_translation_backfill_max_age_days.days.ago)
           .where.not(raw: [nil, ""])
 
       if SiteSetting.ai_translation_backfill_limit_to_public_content
@@ -33,14 +33,6 @@ module Jobs
           )
       end
 
-      if SiteSetting.ai_translation_backfill_max_age_days > 0
-        posts =
-          posts.where(
-            "posts.created_at > ?",
-            SiteSetting.ai_translation_backfill_max_age_days.days.ago,
-          )
-      end
-
       posts = posts.order(updated_at: :desc).limit(limit)
       return if posts.empty?
 

app/jobs/scheduled/topic_localization_backfill.rb

@@ -6,13 +6,9 @@ module Jobs
     cluster_concurrency 1
 
     def execute(args)
-      return if !SiteSetting.discourse_ai_enabled
-      return if !SiteSetting.ai_translation_enabled
+      return if !DiscourseAi::Translation.backfill_enabled?
 
-      return if SiteSetting.content_localization_supported_locales.blank?
       limit = SiteSetting.ai_translation_backfill_hourly_rate / (60 / 5) # this job runs in 5-minute intervals
-      return if limit == 0
-
       Jobs.enqueue(:localize_topics, limit:)
     end
   end

app/jobs/scheduled/topics_locale_detection_backfill.rb

@@ -7,12 +7,15 @@ module Jobs
     cluster_concurrency 1
 
     def execute(args)
-      return if !SiteSetting.discourse_ai_enabled
-      return if !SiteSetting.ai_translation_enabled
-      limit = SiteSetting.ai_translation_backfill_hourly_rate / (60 / 5) # this job runs in 5-minute intervals
-      return if limit == 0
+      return if !DiscourseAi::Translation.backfill_enabled?
 
-      topics = Topic.where(locale: nil, deleted_at: nil).where("topics.user_id > 0")
+      limit = SiteSetting.ai_translation_backfill_hourly_rate / (60 / 5) # this job runs in 5-minute intervals
+
+      topics =
+        Topic
+          .where(locale: nil, deleted_at: nil)
+          .where("topics.user_id > 0")
+          .where("topics.created_at > ?", SiteSetting.ai_translation_backfill_max_age_days.days.ago)
 
       if SiteSetting.ai_translation_backfill_limit_to_public_content
         topics =
@@ -28,14 +31,6 @@ module Jobs
           )
       end
 
-      if SiteSetting.ai_translation_backfill_max_age_days > 0
-        topics =
-          topics.where(
-            "topics.created_at > ?",
-            SiteSetting.ai_translation_backfill_max_age_days.days.ago,
-          )
-      end
-
       topics = topics.order(updated_at: :desc).limit(limit)
       return if topics.empty?
 

config/locales/server.en.yml

@@ -122,7 +122,7 @@ en:
     ai_translation_model: "The model to use for translation. This model must support translation. Personas can override this setting."
     ai_translation_backfill_limit_to_public_content: "When enabled, only content in public categories will be translated. When disabled, content in group PMs and private categories will also be sent for translation."
     ai_translation_max_post_length: "The maximum length of a post to be translated. Posts longer than this will not be translated."
-    ai_translation_backfill_max_age_days: "The maximum age of a post and topic to be translated. Posts and topics older than this will not be translated."
+    ai_translation_backfill_max_age_days: "The maximum age of a post and topic to be translated. Posts and topics older than this will not be translated. 0 disables backfilling, but will not disable translation of new posts."
 
   reviewables:
     reasons:

lib/translation.rb

@@ -0,0 +1,16 @@
+# frozen_string_literal: true
+
+module DiscourseAi
+  module Translation
+    def self.enabled?
+      SiteSetting.discourse_ai_enabled && SiteSetting.ai_translation_enabled &&
+        SiteSetting.ai_translation_model.present? &&
+        SiteSetting.content_localization_supported_locales.present?
+    end
+
+    def self.backfill_enabled?
+      enabled? && SiteSetting.ai_translation_backfill_hourly_rate > 0 &&
+        SiteSetting.ai_translation_backfill_max_age_days > 0
+    end
+  end
+end

lib/translation/entry_point.rb

@@ -5,19 +5,19 @@ module DiscourseAi
     class EntryPoint
       def inject_into(plugin)
         plugin.on(:post_created) do |post|
-          if SiteSetting.discourse_ai_enabled && SiteSetting.ai_translation_enabled
+          if DiscourseAi::Translation.enabled?
             Jobs.enqueue(:detect_translate_post, post_id: post.id)
           end
         end
 
         plugin.on(:topic_created) do |topic|
-          if SiteSetting.discourse_ai_enabled && SiteSetting.ai_translation_enabled
+          if DiscourseAi::Translation.enabled?
             Jobs.enqueue(:detect_translate_topic, topic_id: topic.id)
           end
         end
 
         plugin.on(:post_edited) do |post, topic_changed|
-          if SiteSetting.discourse_ai_enabled && SiteSetting.ai_translation_enabled && topic_changed
+          if DiscourseAi::Translation.enabled? && topic_changed
             Jobs.enqueue(:detect_translate_topic, topic_id: post.topic_id)
           end
         end

lib/translation/locale_normalizer.rb

@@ -15,6 +15,13 @@ module DiscourseAi
         locale
       end
 
+      def self.is_same?(locale1, locale2)
+        return true if locale1 == locale2
+        locale1 = locale1.gsub("-", "_").downcase
+        locale2 = locale2.gsub("-", "_").downcase
+        locale1.split("_").first == locale2.split("_").first
+      end
+
       private
 
       def self.i18n_pairs

spec/jobs/regular/detect_translate_post_spec.rb

@@ -32,9 +32,9 @@ describe Jobs::DetectTranslatePost do
   end
 
   it "detects locale" do
-    SiteSetting.discourse_ai_enabled = true
-    DiscourseAi::Translation::PostLocaleDetector.expects(:detect_locale).with(post).once
-    DiscourseAi::Translation::PostLocalizer.expects(:localize).twice
+    allow(DiscourseAi::Translation::PostLocaleDetector).to receive(:detect_locale).with(
+      post,
+    ).and_return("zh_CN")
 
     job.execute({ post_id: post.id })
   end
@@ -42,21 +42,21 @@ describe Jobs::DetectTranslatePost do
   it "skips locale detection when post has a locale" do
     post.update!(locale: "en")
     DiscourseAi::Translation::PostLocaleDetector.expects(:detect_locale).with(post).never
-    DiscourseAi::Translation::PostLocalizer.expects(:localize).with(post, "ja").once
 
     job.execute({ post_id: post.id })
   end
 
   it "skips bot posts" do
     post.update!(user: Discourse.system_user)
+    DiscourseAi::Translation::PostLocaleDetector.expects(:detect_locale).never
     DiscourseAi::Translation::PostLocalizer.expects(:localize).never
 
     job.execute({ post_id: post.id })
   end
 
-  it "does not translate when no target languages are configured" do
+  it "skips locale detection when no target languages are configured" do
     SiteSetting.content_localization_supported_locales = ""
-    DiscourseAi::Translation::PostLocaleDetector.expects(:detect_locale).with(post).returns("en")
+    DiscourseAi::Translation::PostLocaleDetector.expects(:detect_locale).never
     DiscourseAi::Translation::PostLocalizer.expects(:localize).never
 
     job.execute({ post_id: post.id })
@@ -72,7 +72,16 @@ describe Jobs::DetectTranslatePost do
 
   it "skips translating if the post is already localized" do
     post.update(locale: "en")
-    Fabricate(:post_localization, post: post, locale: "ja")
+    Fabricate(:post_localization, post:, locale: "ja")
+
+    DiscourseAi::Translation::PostLocalizer.expects(:localize).never
+
+    job.execute({ post_id: post.id })
+  end
+
+  it "does not translate to language of similar variant" do
+    post.update(locale: "en_GB")
+    Fabricate(:post_localization, post: post, locale: "ja_JP")
 
     DiscourseAi::Translation::PostLocalizer.expects(:localize).never
 

spec/jobs/regular/detect_translate_topic_spec.rb

@@ -33,7 +33,9 @@ describe Jobs::DetectTranslateTopic do
 
   it "detects locale" do
     SiteSetting.discourse_ai_enabled = true
-    DiscourseAi::Translation::TopicLocaleDetector.expects(:detect_locale).with(topic).once
+    allow(DiscourseAi::Translation::TopicLocaleDetector).to receive(:detect_locale).with(
+      topic,
+    ).and_return("zh_CN")
     DiscourseAi::Translation::TopicLocalizer.expects(:localize).twice
 
     job.execute({ topic_id: topic.id })
@@ -54,9 +56,9 @@ describe Jobs::DetectTranslateTopic do
     job.execute({ topic_id: topic.id })
   end
 
-  it "does not translate when no target languages are configured" do
+  it "does not get locale or translate when no target languages are configured" do
     SiteSetting.content_localization_supported_locales = ""
-    DiscourseAi::Translation::TopicLocaleDetector.expects(:detect_locale).with(topic).returns("en")
+    DiscourseAi::Translation::TopicLocaleDetector.expects(:detect_locale).never
     DiscourseAi::Translation::TopicLocalizer.expects(:localize).never
 
     job.execute({ topic_id: topic.id })
@@ -78,6 +80,15 @@ describe Jobs::DetectTranslateTopic do
     job.execute({ topic_id: topic.id })
   end
 
+  it "does not translate to language of similar variant" do
+    topic.update(locale: "en_GB")
+    Fabricate(:topic_localization, topic:, locale: "ja_JP")
+
+    DiscourseAi::Translation::PostLocalizer.expects(:localize).never
+
+    job.execute({ topic_id: topic.id })
+  end
+
   it "handles translation errors gracefully" do
     topic.update(locale: "en")
     DiscourseAi::Translation::TopicLocalizer.expects(:localize).raises(

spec/jobs/regular/localize_categories_spec.rb

@@ -15,7 +15,7 @@ describe Jobs::LocalizeCategories do
       SiteSetting.public_send("ai_translation_model=", "custom:#{fake_llm.id}")
     end
     SiteSetting.ai_translation_enabled = true
-    SiteSetting.content_localization_supported_locales = "pt|zh_CN"
+    SiteSetting.content_localization_supported_locales = "pt_BR|zh_CN"
 
     Jobs.run_immediately!
   end
@@ -65,7 +65,7 @@ describe Jobs::LocalizeCategories do
 
     DiscourseAi::Translation::CategoryLocalizer
       .expects(:localize)
-      .with(is_a(Category), "pt")
+      .with(is_a(Category), "pt_BR")
       .times(number_of_categories)
     DiscourseAi::Translation::CategoryLocalizer
       .expects(:localize)
@@ -92,7 +92,10 @@ describe Jobs::LocalizeCategories do
   it "skips categories that already have localizations" do
     localize_all_categories("pt", "zh_CN")
 
-    DiscourseAi::Translation::CategoryLocalizer.expects(:localize).with(is_a(Category), "pt").never
+    DiscourseAi::Translation::CategoryLocalizer
+      .expects(:localize)
+      .with(is_a(Category), "pt_BR")
+      .never
     DiscourseAi::Translation::CategoryLocalizer
       .expects(:localize)
       .with(is_a(Category), "zh_CN")
@@ -107,7 +110,8 @@ describe Jobs::LocalizeCategories do
     category1 = Fabricate(:category, name: "First", description: "First description", locale: "en")
     DiscourseAi::Translation::CategoryLocalizer
       .expects(:localize)
-      .with(category1, "pt")
+      .with(category1, "pt_BR")
+      .once
       .raises(StandardError.new("API error"))
     DiscourseAi::Translation::CategoryLocalizer.expects(:localize).with(category1, "zh_CN").once
 

spec/jobs/regular/localize_posts_spec.rb

@@ -13,6 +13,8 @@ describe Jobs::LocalizePosts do
     end
     SiteSetting.ai_translation_enabled = true
     SiteSetting.content_localization_supported_locales = locales.join("|")
+    SiteSetting.ai_translation_backfill_hourly_rate = 100
+    SiteSetting.ai_translation_backfill_max_age_days = 100
   end
 
   it "does nothing when translator is disabled" do
@@ -36,6 +38,13 @@ describe Jobs::LocalizePosts do
     job.execute({ limit: 10 })
   end
 
+  it "does nothing when ai_translation_backfill_hourly_rate is 0" do
+    SiteSetting.ai_translation_backfill_hourly_rate = 0
+    DiscourseAi::Translation::PostLocalizer.expects(:localize).never
+
+    job.execute({ limit: 10 })
+  end
+
   it "does nothing when there are no posts to translate" do
     Post.destroy_all
     DiscourseAi::Translation::PostLocalizer.expects(:localize).never
@@ -43,20 +52,9 @@ describe Jobs::LocalizePosts do
     job.execute({ limit: 10 })
   end
 
-  it "skips posts that already have localizations" do
-    Post.all.each do |post|
-      Fabricate(:post_localization, post:, locale: "en")
-      Fabricate(:post_localization, post:, locale: "ja")
-    end
-    DiscourseAi::Translation::PostLocalizer.expects(:localize).never
-
-    job.execute({ limit: 10 })
-  end
-
   it "skips bot posts" do
-    post.update!(user: Discourse.system_user)
-    DiscourseAi::Translation::PostLocalizer.expects(:localize).with(post, "en").never
-    DiscourseAi::Translation::PostLocalizer.expects(:localize).with(post, "ja").never
+    post.update!(locale: "es", user: Discourse.system_user)
+    DiscourseAi::Translation::PostLocalizer.expects(:localize).never
 
     job.execute({ limit: 10 })
   end
@@ -90,7 +88,7 @@ describe Jobs::LocalizePosts do
       job.execute({ limit: 10 })
     end
 
-    it "scenario 2: returns post with locale 'es' if localizations for en/ja/de do not exist" do
+    it "scenario 2: localizes post with locale 'es' when localizations for en/ja/de do not exist" do
       post = Fabricate(:post, locale: "es")
 
       DiscourseAi::Translation::PostLocalizer.expects(:localize).with(post, "en").once
@@ -100,7 +98,7 @@ describe Jobs::LocalizePosts do
       job.execute({ limit: 10 })
     end
 
-    it "scenario 3: returns post with locale 'en' if ja/de localization does not exist" do
+    it "scenario 3: localizes post with locale 'en' when ja/de localization do not exist" do
       post = Fabricate(:post, locale: "en")
 
       DiscourseAi::Translation::PostLocalizer.expects(:localize).with(post, "ja").once
@@ -110,13 +108,32 @@ describe Jobs::LocalizePosts do
       job.execute({ limit: 10 })
     end
 
-    it "scenario 4: skips post with locale 'en' if 'ja' localization already exists" do
+    it "scenario 4: skips post with locale 'en' if all localizations exist" do
       post = Fabricate(:post, locale: "en")
       Fabricate(:post_localization, post: post, locale: "ja")
+      Fabricate(:post_localization, post: post, locale: "de")
 
-      DiscourseAi::Translation::PostLocalizer.expects(:localize).with(post, "en").never
-      DiscourseAi::Translation::PostLocalizer.expects(:localize).with(post, "ja").never
-      DiscourseAi::Translation::PostLocalizer.expects(:localize).with(post, "de").once
+      DiscourseAi::Translation::PostLocalizer.expects(:localize).never
+
+      job.execute({ limit: 10 })
+    end
+
+    it "scenario 5: skips posts that already have localizations in similar language variant" do
+      post = Fabricate(:post, locale: "en")
+      Fabricate(:post_localization, post: post, locale: "ja_JP")
+      Fabricate(:post_localization, post: post, locale: "de_DE")
+
+      DiscourseAi::Translation::PostLocalizer.expects(:localize).never
+
+      job.execute({ limit: 10 })
+    end
+
+    it "scenario 6: skips posts with variant 'en_GB' when localizations for ja/de exist" do
+      post = Fabricate(:post, locale: "en_GB")
+      Fabricate(:post_localization, post: post, locale: "ja_JP")
+      Fabricate(:post_localization, post: post, locale: "de_DE")
+
+      DiscourseAi::Translation::PostLocalizer.expects(:localize).never
 
       job.execute({ limit: 10 })
     end
@@ -201,8 +218,8 @@ describe Jobs::LocalizePosts do
       job.execute({ limit: 10 })
     end
 
-    it "processes all posts when setting is disabled" do
-      SiteSetting.ai_translation_backfill_max_age_days = 0
+    it "processes all posts when setting is large" do
+      SiteSetting.ai_translation_backfill_max_age_days = 1000
 
       DiscourseAi::Translation::PostLocalizer.expects(:localize).with(new_post, "ja").once
 

spec/jobs/regular/localize_topics_spec.rb

@@ -13,6 +13,8 @@ describe Jobs::LocalizeTopics do
     end
     SiteSetting.ai_translation_enabled = true
     SiteSetting.content_localization_supported_locales = locales.join("|")
+    SiteSetting.ai_translation_backfill_hourly_rate = 100
+    SiteSetting.ai_translation_backfill_max_age_days = 100
   end
 
   it "does nothing when translator is disabled" do
@@ -116,13 +118,22 @@ describe Jobs::LocalizeTopics do
       job.execute({ limit: 10 })
     end
 
-    it "scenario 4: skips topic with locale 'en' if 'ja' localization already exists" do
+    it "scenario 4: skips topic with locale 'en' if all localizations exist" do
       topic = Fabricate(:topic, locale: "en")
       Fabricate(:topic_localization, topic: topic, locale: "ja")
+      Fabricate(:topic_localization, topic: topic, locale: "de")
 
-      DiscourseAi::Translation::TopicLocalizer.expects(:localize).with(topic, "en").never
-      DiscourseAi::Translation::TopicLocalizer.expects(:localize).with(topic, "ja").never
-      DiscourseAi::Translation::TopicLocalizer.expects(:localize).with(topic, "de").once
+      DiscourseAi::Translation::TopicLocalizer.expects(:localize).never
+
+      job.execute({ limit: 10 })
+    end
+
+    it "scenario 5: skips topic that already have localizations in similar language variant" do
+      topic = Fabricate(:topic, locale: "en")
+      Fabricate(:topic_localization, topic: topic, locale: "ja_JP")
+      Fabricate(:topic_localization, topic: topic, locale: "de_DE")
+
+      DiscourseAi::Translation::TopicLocalizer.expects(:localize).never
 
       job.execute({ limit: 10 })
     end
@@ -205,8 +216,8 @@ describe Jobs::LocalizeTopics do
       job.execute({ limit: 10 })
     end
 
-    it "processes all topics when setting is disabled" do
-      SiteSetting.ai_translation_backfill_max_age_days = 0
+    it "processes all topics when setting is more than the post age" do
+      SiteSetting.ai_translation_backfill_max_age_days = 100
 
       DiscourseAi::Translation::TopicLocalizer.expects(:localize).with(new_topic, "en").once
       DiscourseAi::Translation::TopicLocalizer.expects(:localize).with(new_topic, "ja").once

spec/jobs/scheduled/categories_locale_detection_backfill_spec.rb

@@ -11,6 +11,7 @@ describe Jobs::CategoriesLocaleDetectionBackfill do
     end
     SiteSetting.ai_translation_enabled = true
     SiteSetting.ai_translation_backfill_hourly_rate = 100
+    SiteSetting.content_localization_supported_locales = "en"
   end
 
   it "does nothing when AI is disabled" do

spec/jobs/scheduled/posts_locale_detection_backfill_spec.rb

@@ -11,6 +11,7 @@ describe Jobs::PostsLocaleDetectionBackfill do
     end
     SiteSetting.ai_translation_enabled = true
     SiteSetting.ai_translation_backfill_hourly_rate = 100
+    SiteSetting.content_localization_supported_locales = "en"
   end
 
   it "does nothing when translator is disabled" do
@@ -137,8 +138,8 @@ describe Jobs::PostsLocaleDetectionBackfill do
       job.execute({})
     end
 
-    it "processes all posts when setting is disabled" do
-      SiteSetting.ai_translation_backfill_max_age_days = 0
+    it "processes all posts when setting is large" do
+      SiteSetting.ai_translation_backfill_max_age_days = 100
 
       # other posts
       DiscourseAi::Translation::PostLocaleDetector.expects(:detect_locale).at_least_once

spec/jobs/scheduled/topics_locale_detection_backfill_spec.rb

@@ -11,6 +11,7 @@ describe Jobs::TopicsLocaleDetectionBackfill do
     end
     SiteSetting.ai_translation_enabled = true
     SiteSetting.ai_translation_backfill_hourly_rate = 100
+    SiteSetting.content_localization_supported_locales = "en"
   end
 
   it "does nothing when translator is disabled" do
@@ -148,8 +149,8 @@ describe Jobs::TopicsLocaleDetectionBackfill do
       job.execute({ limit: 10 })
     end
 
-    it "processes all topics when setting is disabled" do
-      SiteSetting.ai_translation_backfill_max_age_days = 0
+    it "processes all topics when setting is large" do
+      SiteSetting.ai_translation_backfill_max_age_days = 100
 
       DiscourseAi::Translation::TopicLocaleDetector.expects(:detect_locale).with(new_topic).once
       DiscourseAi::Translation::TopicLocaleDetector.expects(:detect_locale).with(old_topic).once

spec/lib/translation/entry_point_spec.rb

@@ -7,6 +7,7 @@ describe DiscourseAi::Translation::EntryPoint do
       SiteSetting.public_send("ai_translation_model=", "custom:#{fake_llm.id}")
     end
     SiteSetting.ai_translation_enabled = true
+    SiteSetting.content_localization_supported_locales = "en"
   end
 
   describe "upon post process cooked" do
@@ -56,6 +57,13 @@ describe DiscourseAi::Translation::EntryPoint do
     fab!(:post) { Fabricate(:post, post_number: 1) }
     fab!(:non_first_post) { Fabricate(:post, post_number: 2) }
 
+    before do
+      SiteSetting.discourse_ai_enabled = true
+      Fabricate(:fake_model).tap do |fake_llm|
+        SiteSetting.public_send("ai_translation_model=", "custom:#{fake_llm.id}")
+      end
+    end
+
     it "enqueues detect topic locale and translate topic job" do
       SiteSetting.ai_translation_enabled = true
       topic = post.topic

spec/lib/translation/locale_normalizer_spec.rb

@@ -1,6 +1,7 @@
 # frozen_string_literal: true
 
 describe DiscourseAi::Translation::LocaleNormalizer do
+  describe ".normalize_to_i18n" do
     it "matches input locales to i18n locales" do
       expect(described_class.normalize_to_i18n("en-GB")).to eq("en_GB")
       expect(described_class.normalize_to_i18n("en")).to eq("en")
@@ -11,4 +12,31 @@ describe DiscourseAi::Translation::LocaleNormalizer do
     it "converts dashes to underscores" do
       expect(described_class.normalize_to_i18n("a-b")).to eq("a_b")
     end
+  end
+
+  describe "#is_same?" do
+    it "returns true for the same locale" do
+      expect(described_class.is_same?("en", "en")).to be true
+    end
+
+    it "returns true for locales with different cases" do
+      expect(described_class.is_same?("en", "EN")).to be true
+    end
+
+    it "returns true for locales with different separators" do
+      expect(described_class.is_same?("en-US", "en_US")).to be true
+    end
+
+    it "returns false for different locales" do
+      expect(described_class.is_same?("en", "ja")).to be false
+    end
+
+    it "returns true for locales with the same base language" do
+      expect(described_class.is_same?("zh-CN", "zh_TW")).to be true
+    end
+
+    it "returns false for completely different locales" do
+      expect(described_class.is_same?("en", "ja")).to be false
+    end
+  end
 end