#422

backend/app/controllers/tag_descriptions_controller.rb

@@ -0,0 +1,74 @@
+class TagDescriptionsController < ApplicationController
+  def show
+    description = TagDescription.find_by(tag_id: params[:id], language_code: 'ja')
+    return head :not_found unless description
+
+    render json: representation(description)
+  end
+
+  def show_by_title
+    tag_name = TagName.find_by(language_code: 'ja', name: params[:name].to_s.strip)
+    description = tag_name&.tag && TagDescription.find_by(tag: tag_name.tag, language_code: 'ja')
+    return head :not_found unless description
+
+    render json: representation(description)
+  end
+
+  def create
+    return head :unauthorized unless current_user
+    return head :forbidden unless current_user.gte_member?
+
+    body = params[:body].to_s
+    return render_unprocessable_entity('本文は必須です．', field: :body) if body.blank?
+
+    tag = Tag.find_by(id: params[:id])
+    return head :not_found unless tag
+
+    if TagDescription.exists?(tag:, language_code: 'ja')
+      return render_unprocessable_entity('説明はすでに存在します．')
+    end
+
+    TagDescriptionOperation.create!(tag:, body:, created_by_user: current_user)
+    description = TagDescription.find_by!(tag:, language_code: 'ja')
+
+    render json: representation(description), status: :created
+  rescue ActiveRecord::RecordInvalid => e
+    render_validation_error e.record
+  rescue ActiveRecord::RecordNotUnique
+    render_record_not_unique
+  end
+
+  def update
+    return head :unauthorized unless current_user
+    return head :forbidden unless current_user.gte_member?
+
+    body = params[:body].to_s
+    return render_unprocessable_entity('本文は必須です．', field: :body) if body.blank?
+
+    description = TagDescription.find_by(tag_id: params[:id], language_code: 'ja')
+    return head :not_found unless description
+
+    page = WikiPage.find(description.id)
+    TagDescriptionOperation.update!(
+        description:, page:, body:, updated_by_user: current_user)
+    description.reload
+
+    render json: representation(description)
+  rescue ActiveRecord::RecordInvalid => e
+    render_validation_error e.record
+  end
+
+  private
+
+  def representation description
+    description.as_json(only: [
+        :tag_id,
+        :language_code,
+        :body,
+        :version_no,
+        :created_by_user_id,
+        :updated_by_user_id,
+        :created_at,
+        :updated_at])
+  end
+end