Check authentication on each request (#26)

Reviewed-on: #26

app/controllers/application_controller.rb

@@ -1,2 +1,3 @@
 class ApplicationController < ActionController::Base
+  include Authenticatable
 end

app/controllers/concerns/authenticatable.rb

@@ -0,0 +1,13 @@
+module Authenticatable
+  extend ActiveSupport::Concern
+
+  included do
+    before_action :authenticate_user
+  end
+
+  private
+
+  def authenticate_user
+    Current.user = User.find_by(id: session[:current_user_id]) || GuestUser.new
+  end
+end

app/models/current.rb

@@ -0,0 +1,3 @@
+class Current < ActiveSupport::CurrentAttributes
+  attribute :user
+end

app/models/guest_user.rb

@@ -0,0 +1,3 @@
+class GuestUser
+  def registered? = false
+end

app/models/user.rb

@@ -1,3 +1,5 @@
 class User < ApplicationRecord
   has_secure_password
+
+  def registered? = true
 end

app/views/layouts/application.html.erb

@@ -19,7 +19,11 @@
         <li class="mr-6"><%= link_to "Credit Card Bills", credit_card_bills_path, class: "text-white" %></li>
         <li class="mr-6"><%= link_to "Incomes", incomes_path, class: "text-white" %></li>
         <li class="mr-6"><%= link_to "Members", members_path, class: "text-white" %></li>
-        <li class="mr-6"><%= link_to "Log out", session_path, data: {turbo_method: :delete}, class: "text-white" %></li>
+        <% if Current.user.registered? %>
+          <li class="mr-6"><%= link_to "Log out", session_path, data: {turbo_method: :delete}, class: "text-white" %></li>
+        <% else %>
+          <li class="mr-6"><%= link_to "Log in", new_session_path, class: "text-white" %></li>
+        <% end %>
       </ul>
     </nav>