Fix #4016: Translated tags failing to find some tags.

* Normalize spaces to underscores when saving other names. Preserve case
  since case can be significant.

* Fix WikiPage#other_names_include to search case-insensitively (note:
  this prevents using the index).

* Fix sources to return the raw tags in `#tags` and the normalized tags
  in `#normalized_tags`. The normalized tags are the tags that will be
  matched against other names.

app/logical/sources/strategies/art_station.rb

@@ -72,7 +72,7 @@ module Sources::Strategies
 
     def tags
       api_response[:tags].to_a.map do |tag|
-        [tag.downcase.tr(" ", "_"), "https://www.artstation.com/search?q=" + CGI.escape(tag)]
+        [tag, "https://www.artstation.com/search?q=" + CGI.escape(tag)]
       end
     end
 

app/logical/sources/strategies/base.rb

@@ -178,8 +178,16 @@ module Sources
         (@tags || []).uniq
       end
 
+      def normalized_tags
+        tags.map { |tag, url| normalize_tag(tag) }.sort.uniq
+      end
+
+      def normalize_tag(tag)
+        WikiPage.normalize_other_name(tag).downcase
+      end
+
       def translated_tags
-        translated_tags = tags.map(&:first).flat_map(&method(:translate_tag)).uniq.sort
+        translated_tags = normalized_tags.flat_map(&method(:translate_tag)).uniq.sort
         translated_tags.reject { |tag| tag.category == Tag.categories.artist }
       end
 
@@ -240,6 +248,7 @@ module Sources
           :canonical_url => canonical_url,
           :normalized_for_artist_finder_url => normalize_for_artist_finder,
           :tags => tags,
+          :normalized_tags => normalized_tags,
           :translated_tags => translated_tags,
           :unique_id => unique_id,
           :artist_commentary => {

app/logical/sources/strategies/moebooru.rb

@@ -77,7 +77,7 @@ module Sources
 
       def tags
         api_response[:tags].to_s.split.map do |tag|
-          [tag.tr("_", " "), "https://#{site_name}/post?tags=#{CGI.escape(tag)}"]
+          [tag, "https://#{site_name}/post?tags=#{CGI.escape(tag)}"]
         end
       end
 

app/logical/sources/strategies/pixiv.rb

@@ -160,14 +160,16 @@ module Sources
       rescue PixivApiClient::BadIDError
         []
       end
-      memoize :tags
+
+      def normalize_tag(tag)
+        tag.gsub(/\d+users入り\z/i, "")
+      end
 
       def translate_tag(tag)
-        normalized_tag = tag.gsub(/\d+users入り\z/i, "")
-        translated_tags = super(normalized_tag)
+        translated_tags = super(tag)
 
-        if translated_tags.empty? && normalized_tag.include?("/")
-          translated_tags = normalized_tag.split("/").flat_map { |tag| super(tag) }
+        if translated_tags.empty? && tag.include?("/")
+          translated_tags = tag.split("/").flat_map { |tag| super(tag) }
         end
 
         translated_tags

app/logical/sources/strategies/tumblr.rb

@@ -105,12 +105,15 @@ module Sources::Strategies
 
     def tags
       post[:tags].to_a.map do |tag|
-        # normalize tags: space, underscore, and hyphen are equivalent in tumblr tags.
-        etag = tag.gsub(/[ _-]/, "_")
-        [etag, "https://tumblr.com/tagged/#{CGI.escape(etag)}"]
+        [tag, "https://tumblr.com/tagged/#{CGI.escape(tag)}"]
       end.uniq
     end
 
+    def normalize_tag(tag)
+      tag = tag.tr("-", "_")
+      super(tag)
+    end
+
     def dtext_artist_commentary_desc
       DText.from_html(artist_commentary_desc).strip
     end

app/models/wiki_page.rb

@@ -32,7 +32,9 @@ class WikiPage < ApplicationRecord
     end
 
     def other_names_include(name)
-      where("wiki_pages.other_names @> ARRAY[?]", name.unicode_normalize(:nfkc))
+      name = normalize_other_name(name).downcase
+      subquery = WikiPage.from("unnest(other_names) AS other_name").where("lower(other_name) = ?", name)
+      where(id: subquery)
     end
 
     def other_names_match(name)
@@ -146,7 +148,11 @@ class WikiPage < ApplicationRecord
   end
 
   def normalize_other_names
-    self.other_names = other_names.map { |name| name.unicode_normalize(:nfkc) }.uniq
+    self.other_names = other_names.map { |name| WikiPage.normalize_other_name(name) }.uniq
+  end
+
+  def self.normalize_other_name(name)
+    name.unicode_normalize(:nfkc).gsub(/[[:space:]]+/, " ").strip.tr(" ", "_")
   end
 
   def skip_secondary_validations=(value)