From 02451e4caa4e39700d93e65b4d10f856c9f91a8f Mon Sep 17 00:00:00 2001
From: miteruzo <miteruzo@naver.com>
Date: Sun, 11 Oct 2026 01:32:46 +0900
Subject: [PATCH] #425

---
 .../app/controllers/wiki_pages_controller.rb  | 11 +++--
 backend/app/services/tag_group_operation.rb   | 45 +++++++++++++++++++
 backend/spec/tasks/nico_export_spec.rb        |  8 ++--
 3 files changed, 56 insertions(+), 8 deletions(-)

diff --git a/backend/app/controllers/wiki_pages_controller.rb b/backend/app/controllers/wiki_pages_controller.rb
index d993dc3..a9245bf 100644
--- a/backend/app/controllers/wiki_pages_controller.rb
+++ b/backend/app/controllers/wiki_pages_controller.rb
@@ -11,7 +11,8 @@ class WikiPagesController < ApplicationController
     tag_groups = TagGroup.all
     if title.present?
       pattern = "%#{ ApplicationRecord.sanitize_sql_like(title) }%"
-      descriptions = descriptions.joins(tag: :tag_names)
+      descriptions =
+          descriptions.joins(tag: :tag_names)
           .where(tag_names: { language_code: 'ja', primary_flg: true })
           .where('tag_names.name LIKE ?', pattern).limit(20)
       tag_groups = tag_groups.where(
@@ -55,9 +56,11 @@ class WikiPagesController < ApplicationController
 
     return render_wiki_page_by_tag_description tag_description if tag_description
 
-    page = WikiPage.joins(:tag_name)
-                   .includes(tag_name: :tag)
-                   .find_by(tag_name: { name: title })
+    page =
+        WikiPage
+        .joins(:tag_name)
+        .includes(tag_name: :tag)
+        .find_by(tag_name: { name: title })
 
     render_wiki_page_or_404 page
   end
diff --git a/backend/app/services/tag_group_operation.rb b/backend/app/services/tag_group_operation.rb
index cd26c5c..905773b 100644
--- a/backend/app/services/tag_group_operation.rb
+++ b/backend/app/services/tag_group_operation.rb
@@ -27,6 +27,8 @@ class TagGroupOperation
       group.lock!
       old_name = group.name
       attributes = prepare!(group:, name:, description:, members:, placements:)
+      next [group, nil] if unchanged?(group, attributes)
+
       group.update!(name: attributes.fetch(:name),
                     description: attributes.fetch(:description),
                     version_no: group.version_no + 1,
@@ -66,6 +68,49 @@ class TagGroupOperation
   end
   private_class_method :prepare!
 
+  def self.unchanged?(group, attributes)
+    unless (group.name_in_database == attributes.fetch(:name) &&
+            group.description_in_database == attributes.fetch(:description))
+      return false
+    end
+
+    members = TagGroupTag.where(tag_group_id: group.id).pluck(:tag_id)
+        .map { { 'tag_id' => _1 } }
+    members.concat(TagGroupGroup.where(tag_group_id: group.id)
+        .pluck(:child_tag_group_id).map { { 'tag_group_id' => _1 } })
+    requested_members = attributes.fetch(:members).map do |member|
+      member.except('version_no')
+    end
+    return false unless members.to_set == requested_members.to_set
+
+    rows = TagGroupPlacement.where(tag_group_id: group.id).order(:position)
+        .group_by(&:parent_position)
+    build = lambda do |parent_position|
+      rows.fetch(parent_position, []).map do |row|
+        node = if row.tag_id
+          { 'tag_id' => row.tag_id }
+        elsif row.child_tag_group_id
+          { 'tag_group_id' => row.child_tag_group_id }
+        else
+          { 'section_name' => row.section_name, 'description' => row.description }
+        end
+        node.merge('children' => build.call(row.position))
+      end
+    end
+    build.call(nil) == comparable_placements(attributes.fetch(:placements))
+  end
+  private_class_method :unchanged?
+
+  def self.comparable_placements(nodes)
+    nodes.map do |node|
+      result = node.dup
+      result['description'] = node['description'] if node.key?('section_name')
+      result['children'] = comparable_placements(node.fetch('children'))
+      result
+    end
+  end
+  private_class_method :comparable_placements
+
   def self.normalize_members(record, members)
     invalid!(record, :members, 'members は配列で指定してください．') unless members.is_a?(Array)
 
diff --git a/backend/spec/tasks/nico_export_spec.rb b/backend/spec/tasks/nico_export_spec.rb
index 0221f99..93aa770 100644
--- a/backend/spec/tasks/nico_export_spec.rb
+++ b/backend/spec/tasks/nico_export_spec.rb
@@ -18,8 +18,8 @@ RSpec.describe 'nico:export' do
   before do
     task.reenable
 
-    allow(ENV).to receive(:fetch).with('MYSQL_USER').and_return('mysql-user')
-    allow(ENV).to receive(:fetch).with('MYSQL_PASS').and_return('mysql-pass')
+    allow(ENV).to receive(:fetch).with('NIZIKA_NICO_MYSQL_USER').and_return('mysql-user')
+    allow(ENV).to receive(:fetch).with('NIZIKA_NICO_MYSQL_PASS').and_return('mysql-pass')
     allow(ENV).to receive(:fetch).with('NIZIKA_NICO_PATH').and_return('/srv/nizika-nico')
   end
 
@@ -33,8 +33,8 @@ RSpec.describe 'nico:export' do
       expect(Open3).to receive(:capture3) do |env, *args, **kwargs|
         expect(env).to eq(
           {
-            'MYSQL_USER' => 'mysql-user',
-            'MYSQL_PASS' => 'mysql-pass',
+            'NIZIKA_NICO_MYSQL_USER' => 'mysql-user',
+            'NIZIKA_NICO_MYSQL_PASS' => 'mysql-pass',
           },
         )