autocomplete: recognize Japanese tags in autocomplete.

Allowing typing Japanese tags in autocomplete. For example, typing 東方
in autocomplete will be completed to the touhou tag. Typing ぶくぶ will
complete to the bkub tag.

This works using wiki page and artist other names. Effectively, any name
listed as an other name in a wiki or artist page will be treated like an
alias for autocomplete purposes. This is limited to non-ASCII other names,
to prevent English other names from interfering with regular tag searches.

app/logical/autocomplete_service.rb

@@ -72,8 +72,11 @@ class AutocompleteService
       results = results.uniq.sort_by { |r| [r[:antecedent].length, -r[:post_count]] }.take(limit)
     elsif string.include?("*")
       results = tag_matches(string)
+      results = tag_other_name_matches(string) if results.blank?
     else
-      results = tag_matches(string + "*")
+      string += "*"
+      results = tag_matches(string)
+      results = tag_other_name_matches(string) if results.blank?
       results = tag_autocorrect_matches(string) if results.blank?
     end
 
@@ -81,6 +84,8 @@ class AutocompleteService
   end
 
   def tag_matches(string)
+    return [] if string =~ /[^[:ascii:]]/
+
     name_matches = Tag.nonempty.name_matches(string).order(post_count: :desc).limit(limit)
     alias_matches = Tag.nonempty.alias_matches(string).order(post_count: :desc).limit(limit)
     union = "((#{name_matches.to_sql}) UNION (#{alias_matches.to_sql})) AS tags"
@@ -100,6 +105,7 @@ class AutocompleteService
   end
 
   def tag_autocorrect_matches(string)
+    string = string.delete("*")
     tags = Tag.nonempty.autocorrect_matches(string).limit(limit)
 
     tags.map do |tag|
@@ -107,6 +113,21 @@ class AutocompleteService
     end
   end
 
+  def tag_other_name_matches(string)
+    return [] unless string =~ /[^[:ascii:]]/
+
+    artists = Artist.undeleted.any_other_name_like(string)
+    wikis = WikiPage.undeleted.other_names_match(string)
+    tags = Tag.where(name: wikis.select(:title)).or(Tag.where(name: artists.select(:name)))
+    tags = tags.nonempty.order(post_count: :desc).limit(limit).includes(:wiki_page, :artist)
+
+    tags.map do |tag|
+      other_names = tag.artist&.other_names.to_a + tag.wiki_page&.other_names.to_a
+      antecedent = other_names.find { |other_name| other_name.ilike?(string) }
+      { type: "tag", label: tag.pretty_name, value: tag.name, category: tag.category, post_count: tag.post_count, antecedent: antecedent }
+    end
+  end
+
   def autocomplete_metatag(metatag, value)
     results = case metatag.to_sym
     when :user, :approver, :commenter, :comm, :noter, :noteupdater, :commentaryupdater,

app/models/wiki_page.rb

@@ -45,7 +45,7 @@ class WikiPage < ApplicationRecord
 
     def other_names_match(name)
       if name =~ /\*/
-        subquery = WikiPage.from("unnest(other_names) AS other_name").where_ilike("other_name", name)
+        subquery = WikiPage.from("unnest(other_names) AS other_name").where_ilike("other_name", normalize_other_name(name))
         where(id: subquery)
       else
         other_names_include(name)

test/unit/autocomplete_service_test.rb

@@ -97,6 +97,33 @@ class AutocompleteServiceTest < ActiveSupport::TestCase
         assert_autocomplete_includes("mole_under_eye", "~/mue", :tag_query)
       end
 
+      should "autocomplete tags from wiki and artist other names" do
+        create(:tag, name: "touhou")
+        create(:tag, name: "bkub", category: Tag.categories.artist)
+        create(:wiki_page, title: "touhou", other_names: %w[東方 东方 동방])
+        create(:artist, name: "bkub", other_names: %w[大川ぶくぶ フミンバイン])
+
+        assert_autocomplete_equals(["touhou"], "東", :tag_query)
+        assert_autocomplete_equals(["touhou"], "东", :tag_query)
+        assert_autocomplete_equals(["touhou"], "동", :tag_query)
+
+        assert_autocomplete_equals(["touhou"], "*東*", :tag_query)
+        assert_autocomplete_equals(["touhou"], "東*", :tag_query)
+        assert_autocomplete_equals([], "*東", :tag_query)
+
+        assert_autocomplete_equals(["touhou"], "*方*", :tag_query)
+        assert_autocomplete_equals(["touhou"], "*方", :tag_query)
+        assert_autocomplete_equals([], "方", :tag_query)
+
+        assert_autocomplete_equals(["bkub"], "*大*", :tag_query)
+        assert_autocomplete_equals(["bkub"], "大", :tag_query)
+        assert_autocomplete_equals([], "*大", :tag_query)
+
+        assert_autocomplete_equals(["bkub"], "*川*", :tag_query)
+        assert_autocomplete_equals([], "*川", :tag_query)
+        assert_autocomplete_equals([], "川", :tag_query)
+      end
+
       should "autocomplete wildcard searches" do
         create(:tag, name: "mole", post_count: 150)
         create(:tag, name: "mole_under_eye", post_count: 100)