5#random podcast by day (#21)

app/controllers/home_controller.rb

@@ -2,7 +2,7 @@ class HomeController < ApplicationController
   allow_unauthenticated_access
 
   def index
-    @random_podcast = Podcast.offset(rand(Podcast.count)).first # TODO: use cron
+    @random_podcast = Podcast.random_by_day
     @last_podcast = Podcast.last
   end
 end

app/models/podcast.rb

@@ -4,4 +4,13 @@ class Podcast < ApplicationRecord
 
   validates :title, presence: true
   validates :title, length: { minimum: 2 }
+
+  def self.random_by_day
+    return unless exists?
+
+    cached_random_podcast_id = Rails.cache.fetch("random_podcast_id", expires_in: 1.days) do
+      offset(rand(Podcast.count)).first.id
+    end
+    find_by(id: cached_random_podcast_id)
+  end
 end

app/views/home/_list.html.erb

@@ -1,7 +1,11 @@
 <% if Podcast.any? %>
   <div class="card-group">
     <div class="card">
-      <img src="https://mir-s3-cdn-cf.behance.net/project_modules/max_1200/9abc28136491393.61fa8bcfee8ce.png" class="card-img-top" alt="...">
+      <% if @last_podcast.photo.attached? %>
+        <%= image_tag @last_podcast.photo, class: "card-img-top", alt: "last podcast" %>
+      <% else %>
+        <img src="https://mir-s3-cdn-cf.behance.net/project_modules/max_1200/9abc28136491393.61fa8bcfee8ce.png" class="card-img-top" alt="last podcast">
+      <% end %>     
       <div class="card-body">
         <h5 class="card-title">
           <%= link_to @last_podcast.title, @last_podcast,
@@ -14,8 +18,12 @@
         <small class="text-body-secondary"><%= @last_podcast.created_at %></small>
       </div>
     </div>
-    <div class="card">
-      <img src="https://mir-s3-cdn-cf.behance.net/project_modules/max_1200/c4c965136491393.6336af6811b4b.jpg" class="card-img-top" alt="...">
+    <div class="card" id="random_podcast">
+      <% if @random_podcast.photo.attached? %>
+        <%= image_tag @random_podcast.photo, class: "card-img-top", alt: "random podcast" %>
+      <% else %>
+        <img src="https://mir-s3-cdn-cf.behance.net/project_modules/max_1200/c4c965136491393.6336af6811b4b.jpg" class="card-img-top" alt="random podcast">
+      <% end %>
       <div class="card-body">
         <h5 class="card-title">
           <%= link_to @random_podcast.title, @random_podcast,

spec/features/home_page_spec.rb

@@ -5,6 +5,38 @@
     10.times { FactoryBot.create(:podcast) }
   end
 
+  context "random podcast" do
+    # connect the cache to the tests only in this block
+    let(:memory_store) { ActiveSupport::Cache.lookup_store(:memory_store) }
+    let(:cache) { Rails.cache }
+
+    before do
+      allow(Rails).to receive(:cache).and_return(memory_store)
+      Rails.cache.clear
+    end
+
+    scenario "by default" do
+      visit root_path
+
+      random_podcast_id = Rails.cache.read("random_podcast_id")
+
+      expect(random_podcast_id).to be_present
+      expect(Podcast.exists?(id: random_podcast_id)).to be_truthy
+      expect(page).to have_selector("#random_podcast")
+    end
+
+    scenario "forced" do
+      Rails.cache.write("random_podcast_id", 6, expires_in: 1.days)
+      visit root_path
+
+      random_podcast_id = Rails.cache.read("random_podcast_id")
+
+      expect(random_podcast_id).to eq(6)
+      expect(Podcast.exists?(id: 6)).to be_truthy
+      expect(page).to have_selector("#random_podcast")
+    end
+  end
+
   context do
     before { visit root_path }