Add `popular-enabled` option

This is similar to the removed `top-enabled` option but for the Popular feed.
The instance needs to be restarted if the feed was enabled.

Editing admin options on the preferences page is also fixed.

The handling of the feed pages now only happens in a single place.

Instead of redirecting:
  - The Top feed now displays a message that it was removed from Invidious.
  - The Popular feed now displays a message that it was disabled if it was.

src/invidious.cr

@@ -162,13 +162,16 @@ end
 Invidious::Jobs.register Invidious::Jobs::RefreshChannelsJob.new(PG_DB, logger, config)
 Invidious::Jobs.register Invidious::Jobs::RefreshFeedsJob.new(PG_DB, logger, config)
 Invidious::Jobs.register Invidious::Jobs::SubscribeToFeedsJob.new(PG_DB, logger, config, HMAC_KEY)
-Invidious::Jobs.register Invidious::Jobs::PullPopularVideosJob.new(PG_DB)
 Invidious::Jobs.register Invidious::Jobs::UpdateDecryptFunctionJob.new
 
 if config.statistics_enabled
   Invidious::Jobs.register Invidious::Jobs::StatisticsRefreshJob.new(PG_DB, config, SOFTWARE)
 end
 
+if config.popular_enabled
+  Invidious::Jobs.register Invidious::Jobs::PullPopularVideosJob.new(PG_DB)
+end
+
 if config.captcha_key
   Invidious::Jobs.register Invidious::Jobs::BypassCaptchaJob.new(logger, config)
 end
@@ -1140,13 +1143,20 @@ end
 
 get "/feed/top" do |env|
   locale = LOCALES[env.get("preferences").as(Preferences).locale]?
-  env.redirect "/"
+
+  message = translate(locale, "The Top feed has been removed from Invidious.")
+  templated "message"
 end
 
 get "/feed/popular" do |env|
   locale = LOCALES[env.get("preferences").as(Preferences).locale]?
 
-  templated "popular"
+  if config.popular_enabled
+    templated "popular"
+  else
+    message = translate(locale, "The Popular feed has been disabled by the administrator.")
+    templated "message"
+  end
 end
 
 get "/feed/trending" do |env|
@@ -2210,6 +2220,12 @@ get "/api/v1/popular" do |env|
 
   env.response.content_type = "application/json"
 
+  if !config.popular_enabled
+    error_message = {"error" => "Administrator has disabled this endpoint."}.to_json
+    env.response.status_code = 400
+    next error_message
+  end
+
   JSON.build do |json|
     json.array do
       popular_videos.each do |video|
@@ -2223,7 +2239,8 @@ get "/api/v1/top" do |env|
   locale = LOCALES[env.get("preferences").as(Preferences).locale]?
 
   env.response.content_type = "application/json"
-  "[]"
+  env.response.status_code = 400
+  {"error" => "The Top feed has been removed from Invidious."}.to_json
 end
 
 get "/api/v1/channels/:ucid" do |env|

src/invidious/helpers/helpers.cr

@@ -60,7 +60,7 @@ struct ConfigPreferences
   end
 end
 
-struct Config
+class Config
   include YAML::Serializable
 
   property channel_threads : Int32                 # Number of threads to use for crawling videos from channels (for updating subscriptions)
@@ -71,6 +71,7 @@ struct Config
   property hmac_key : String?                      # HMAC signing key for CSRF tokens and verifying pubsub subscriptions
   property domain : String?                        # Domain to be used for links to resources on the site where an absolute URL is required
   property use_pubsub_feeds : Bool | Int32 = false # Subscribe to channels using PubSubHubbub (requires domain, hmac_key)
+  property popular_enabled : Bool = true
   property captcha_enabled : Bool = true
   property login_enabled : Bool = true
   property registration_enabled : Bool = true

src/invidious/routes/home.cr

@@ -5,30 +5,24 @@ class Invidious::Routes::Home < Invidious::Routes::BaseRoute
     user = env.get? "user"
 
     case preferences.default_home
-    when ""
-      templated "empty"
     when "Popular"
-      templated "popular"
+      env.redirect "/feed/popular"
     when "Trending"
       env.redirect "/feed/trending"
     when "Subscriptions"
       if user
         env.redirect "/feed/subscriptions"
       else
-        templated "popular"
+        env.redirect "/feed/popular"
       end
     when "Playlists"
       if user
         env.redirect "/view_all_playlists"
       else
-        templated "popular"
+        env.redirect "/feed/popular"
       end
     else
       templated "empty"
     end
   end
-
-  private def popular_videos
-    Jobs::PullPopularVideosJob::POPULAR_VIDEOS.get
-  end
 end

src/invidious/routes/user_preferences.cr

@@ -154,6 +154,10 @@ class Invidious::Routes::UserPreferences < Invidious::Routes::BaseRoute
         end
         config.default_user_preferences.feed_menu = admin_feed_menu
 
+        popular_enabled = env.params.body["popular_enabled"]?.try &.as(String)
+        popular_enabled ||= "off"
+        config.popular_enabled = popular_enabled == "on"
+
         captcha_enabled = env.params.body["captcha_enabled"]?.try &.as(String)
         captcha_enabled ||= "off"
         config.captcha_enabled = captcha_enabled == "on"

src/invidious/views/message.ecr

@@ -0,0 +1,12 @@
+<% content_for "header" do %>
+<meta name="description" content="<%= translate(locale, "An alternative front-end to YouTube") %>">
+<title>
+    Invidious
+</title>
+<% end %>
+
+<%= rendered "components/feed_menu" %>
+
+<p>
+    <%= message %>
+</p>

src/invidious/views/preferences.ecr

@@ -227,6 +227,12 @@
                     <% end %>
                 </div>
 
+                <div class="pure-control-group">
+                    <label for="popular_enabled"><%= translate(locale, "Popular enabled: ") %></label>
+                    <input name="popular_enabled" id="popular_enabled" type="checkbox" <% if config.popular_enabled %>checked<% end %>>
+                </div>
+
+
                 <div class="pure-control-group">
                     <label for="captcha_enabled"><%= translate(locale, "CAPTCHA enabled: ") %></label>
                     <input name="captcha_enabled" id="captcha_enabled" type="checkbox" <% if config.captcha_enabled %>checked<% end %>>