FIX: Customizing missing pluralized translations didn't work

app/controllers/admin/site_texts_controller.rb

@@ -27,13 +27,9 @@ class Admin::SiteTextsController < Admin::AdminController
       extras[:recommended] = true
       results = self.class.preferred_keys.map { |k| record_for(k) }
     else
-      results = []
-      translations = I18n.search(query, overridden: overridden)
-      translations.each do |k, v|
-        results << record_for(k, v)
-      end
+      results = find_translations(query, overridden)
 
-      unless translations.empty?
+      if results.any?
         extras[:regex] = I18n::Backend::DiscourseI18n.create_search_regexp(query, as_string: true)
       end
 
@@ -110,20 +106,70 @@ class Admin::SiteTextsController < Admin::AdminController
 
   protected
 
-  def record_for(k, value = nil)
-    if k.ends_with?("_MF")
-      ovr = TranslationOverride.where(translation_key: k, locale: I18n.locale).pluck(:value)
-      value = ovr[0] if ovr.present?
+  def record_for(key, value = nil)
+    if key.ends_with?("_MF")
+      override = TranslationOverride.where(translation_key: key, locale: I18n.locale).pluck(:value)
+      value = override&.first
     end
 
-    value ||= I18n.t(k)
-    { id: k, value: value }
+    value ||= I18n.t(key)
+    { id: key, value: value }
   end
 
+  PLURALIZED_REGEX = /(.*)\.(zero|one|two|few|many|other)$/
+
   def find_site_text
-    raise Discourse::NotFound unless I18n.exists?(params[:id])
-    raise Discourse::InvalidAccess.new(nil, nil, custom_message: 'email_template_cant_be_modified') if self.class.restricted_keys.include?(params[:id])
-    record_for(params[:id])
+    if self.class.restricted_keys.include?(params[:id])
+      raise Discourse::InvalidAccess.new(nil, nil, custom_message: 'email_template_cant_be_modified')
+    end
+
+    if I18n.exists?(params[:id]) || TranslationOverride.exists?(locale: I18n.locale, translation_key: params[:id])
+      return record_for(params[:id])
+    end
+
+    if PLURALIZED_REGEX.match(params[:id])
+      value = fix_plural_keys($1, {}).fetch($2.to_sym)
+      return record_for(params[:id], value) if value
+    end
+
+    raise Discourse::NotFound
   end
 
+  def find_translations(query, overridden)
+    translations = Hash.new { |hash, key| hash[key] = {} }
+
+    I18n.search(query, overridden: overridden).each do |key, value|
+      if PLURALIZED_REGEX.match(key)
+        translations[$1][$2] = value
+      else
+        translations[key] = value
+      end
+    end
+
+    results = []
+
+    translations.each do |key, value|
+      if value&.is_a?(Hash)
+        value = fix_plural_keys(key, value)
+        value.each do |plural_key, plural_value|
+          results << record_for("#{key}.#{plural_key}", plural_value)
+        end
+      else
+        results << record_for(key, value)
+      end
+    end
+
+    results
+  end
+
+  def fix_plural_keys(key, value)
+    value = value.with_indifferent_access
+    plural_keys = I18n.t('i18n.plural.keys')
+    return value if value.keys.size == plural_keys.size && plural_keys.all? { |k| value.key?(k) }
+
+    fallback_value = I18n.t(key, locale: :en)
+    plural_keys.map do |k|
+      [k, value[k] || fallback_value[k] || fallback_value[:other]]
+    end.to_h
+  end
 end