Allow automatic instance redirect to be turned off

Instead the "switch invidious instance" link would bring users to
redirect.invidious.io

src/invidious/helpers/helpers.cr

@@ -44,6 +44,7 @@ struct ConfigPreferences
   property quality_dash : String = "auto"
   property default_home : String? = "Popular"
   property feed_menu : Array(String) = ["Popular", "Trending", "Subscriptions", "Playlists"]
+  property automatic_instance_redirect : Bool = true
   property related_videos : Bool = true
   property sort : String = "published"
   property speed : Float32 = 1.0_f32

src/invidious/routes/misc.cr

@@ -37,8 +37,13 @@ class Invidious::Routes::Misc < Invidious::Routes::BaseRoute
   end
 
   def cross_instance_redirect(env)
-    instance_url = fetch_random_instance
     referer = get_referer(env)
+
+    if !env.get("preferences").as(Preferences).automatic_instance_redirect
+      return env.redirect("https://redirect.invidious.io#{referer}")
+    end
+
+    instance_url = fetch_random_instance
     env.redirect "https://#{instance_url}#{referer}"
   end
 end

src/invidious/routes/preferences.cr

@@ -92,6 +92,10 @@ class Invidious::Routes::PreferencesRoute < Invidious::Routes::BaseRoute
       end
     end
 
+    automatic_instance_redirect = env.params.body["automatic_instance_redirect"]?.try &.as(String)
+    automatic_instance_redirect ||= "off"
+    automatic_instance_redirect = automatic_instance_redirect == "on"
+
     locale = env.params.body["locale"]?.try &.as(String)
     locale ||= CONFIG.default_user_preferences.locale
 
@@ -141,6 +145,7 @@ class Invidious::Routes::PreferencesRoute < Invidious::Routes::BaseRoute
       quality_dash:           quality_dash,
       default_home:           default_home,
       feed_menu:              feed_menu,
+      automatic_instance_redirect: automatic_instance_redirect,
       related_videos:         related_videos,
       sort:                   sort,
       speed:                  speed,

src/invidious/users.cr

@@ -36,6 +36,7 @@ struct Preferences
   property annotations : Bool = CONFIG.default_user_preferences.annotations
   property annotations_subscribed : Bool = CONFIG.default_user_preferences.annotations_subscribed
   property autoplay : Bool = CONFIG.default_user_preferences.autoplay
+  property automatic_instance_redirect : Bool = CONFIG.default_user_preferences.automatic_instance_redirect
 
   @[JSON::Field(converter: Preferences::StringToArray)]
   @[YAML::Field(converter: Preferences::StringToArray)]

src/invidious/views/preferences.ecr

@@ -176,6 +176,13 @@
                 <% end %>
             </div>
 
+            <legend><%= translate(locale, "Miscellaneous preferences") %></legend>
+
+            <div class="pure-control-group">
+                <label for="automatic_instance_redirect"><%= translate(locale, "Automatically redirect to another Instance: ") %></label>
+                <input name="automatic_instance_redirect" id="automatic_instance_redirect" type="checkbox" <% if preferences.automatic_instance_redirect %>checked<% end %>>
+            </div>
+
             <% if env.get? "user" %>
                 <legend><%= translate(locale, "Subscription preferences") %></legend>