#22 完了

backend/app/controllers/application_controller.rb

@@ -1,2 +1,16 @@
 class ApplicationController < ActionController::API
+  before_action :authenticate_user
+
+  def current_user
+    @current_user
+  end
+
+  private
+
+  def authenticate_user
+    code = request.headers['X-Transfer-Code'] || request.headers['HTTP_X_TRANSFER_CODE']
+    @current_user = User.find_by inheritance_code: code
+      Rails.logger.info("X-Transfer-Code: #{request.headers['X-Transfer-Code']}")
+  Rails.logger.info("current_user: #{@current_user&.id}")
+  end
 end

backend/app/controllers/posts_controller.rb

@@ -24,7 +24,10 @@ class PostsController < ApplicationController
   # GET /posts/1
   def show
     @post = Post.includes(:tags).find(params[:id])
-    render json: @post.as_json(include: { tags: { only: [:id, :name, :category] } })
+    viewed = current_user&.viewed?(@post)
+    render json: (@post
+                  .as_json(include: { tags: { only: [:id, :name, :category] } })
+                  .merge(viewed: viewed))
   end
 
   # POST /posts
@@ -38,6 +41,20 @@ class PostsController < ApplicationController
     end
   end
 
+  def viewed
+    return head :unauthorized unless current_user
+
+    current_user.viewed_posts << Post.find(params[:id])
+    head :no_content
+  end
+
+  def unviewed
+    return head :unauthorized unless current_user
+
+    current_user.viewed_posts.delete(Post.find(params[:id]))
+    head :no_content
+  end
+
   # PATCH/PUT /posts/1
   def update
     if @post.update(post_params)