#55

backend/app/models/tag.rb

@@ -64,6 +64,7 @@ class Tag < ApplicationRecord
   validates :category, presence: true, inclusion: { in: Tag.categories.keys }
 
   validate :category_must_be_deerjikist_with_deerjikists
+  validate :tag_names_must_be_valid
 
   CATEGORY_PREFIXES = {
       'general:'    => :general,
@@ -77,10 +78,22 @@ class Tag < ApplicationRecord
       'mtr:'        => :material,
       'meta:'       => :meta }.freeze
 
-  def tag_name(language_code) = tag_names.find_by(language_code:, primary_flg: true)
+  SYSTEM_TAG_NAMES = ['タグ希望', 'bot操作', 'ニジラー情報不詳', '動画', 'ニコニコ', 'YouTube'].freeze
+
+  def tag_name language_code
+    if tag_names.loaded?
+      tag_names.find { _1.language_code == language_code && _1.primary_flg }
+    else
+      tag_names.find_by(language_code:, primary_flg: true)
+    end
+  end
   def name(language_code) = tag_name(language_code)&.name
   def wiki_page = tag_name('ja')&.wiki_page
 
+  def system?
+    tag_name('ja')&.name.in?(SYSTEM_TAG_NAMES)
+  end
+
   def deprecated? = deprecated_at?
 
   def has_wiki = wiki_page.present?
@@ -232,6 +245,7 @@ class Tag < ApplicationRecord
 
     tag = Tag.create!(tag_name_id: tn.id, category:)
     tn.update!(tag:)
+    tag.association(:tag_names).reset
 
     tag
   rescue ActiveRecord::RecordNotUnique
@@ -307,6 +321,14 @@ class Tag < ApplicationRecord
 
   private
 
+  def tag_names_must_be_valid
+    tag_names.each do |tag_name|
+      next if tag_name.valid?
+
+      tag_name.errors[:name].each { errors.add :name, _1 }
+    end
+  end
+
   def category_must_be_deerjikist_with_deerjikists
     if !(deerjikist?) && deerjikists.exists?
       errors.add :category, 'ニジラーと紐づいてゐるタグはニジラー・カテゴリである必要があります．'