Add cold-start follow recommendations (#15945)

config/locales/en.yml

@@ -440,6 +440,14 @@ en:
         create: Add domain
         title: Block new e-mail domain
       title: Blocked e-mail domains
+    follow_recommendations:
+      description_html: "<strong>Follow recommendations help new users quickly find interesting content</strong>. When a user has not interacted with others enough to form personalized follow recommendations, these accounts are recommended instead. They are re-calculated on a daily basis from a mix of accounts with the highest recent engagements and highest local follower counts for a given language."
+      language: For language
+      status: Status
+      suppress: Suppress follow recommendation
+      suppressed: Suppressed
+      title: Follow recommendations
+      unsuppress: Restore follow recommendation
     instances:
       by_domain: Domain
       delivery_available: Delivery is available

config/navigation.rb

@@ -39,6 +39,7 @@ SimpleNavigation::Configuration.run do |navigation|
       s.item :accounts, safe_join([fa_icon('users fw'), t('admin.accounts.title')]), admin_accounts_url, highlights_on: %r{/admin/accounts|/admin/pending_accounts}
       s.item :invites, safe_join([fa_icon('user-plus fw'), t('admin.invites.title')]), admin_invites_path
       s.item :tags, safe_join([fa_icon('hashtag fw'), t('admin.tags.title')]), admin_tags_path, highlights_on: %r{/admin/tags}
+      s.item :follow_recommendations, safe_join([fa_icon('user-plus fw'), t('admin.follow_recommendations.title')]), admin_follow_recommendations_path, highlights_on: %r{/admin/follow_recommendations}
       s.item :instances, safe_join([fa_icon('cloud fw'), t('admin.instances.title')]), admin_instances_url(limited: whitelist_mode? ? nil : '1'), highlights_on: %r{/admin/instances|/admin/domain_blocks|/admin/domain_allows}, if: -> { current_user.admin? }
       s.item :email_domain_blocks, safe_join([fa_icon('envelope fw'), t('admin.email_domain_blocks.title')]), admin_email_domain_blocks_url, highlights_on: %r{/admin/email_domain_blocks}, if: -> { current_user.admin? }
       s.item :ip_blocks, safe_join([fa_icon('ban fw'), t('admin.ip_blocks.title')]), admin_ip_blocks_url, highlights_on: %r{/admin/ip_blocks}, if: -> { current_user.admin? }

config/routes.rb

@@ -292,6 +292,7 @@ Rails.application.routes.draw do
     end
 
     resources :account_moderation_notes, only: [:create, :destroy]
+    resource :follow_recommendations, only: [:show, :update]
 
     resources :tags, only: [:index, :show, :update] do
       collection do
@@ -507,6 +508,7 @@ Rails.application.routes.draw do
     namespace :v2 do
       resources :media, only: [:create]
       get '/search', to: 'search#index', as: :search
+      resources :suggestions, only: [:index]
     end
 
     namespace :web do

config/sidekiq.yml

@@ -25,6 +25,10 @@
     cron: '<%= Random.rand(0..59) %> <%= Random.rand(0..2) %> * * *'
     class: Scheduler::FeedCleanupScheduler
     queue: scheduler
+  follow_recommendations_scheduler:
+    cron: '<%= Random.rand(0..59) %> <%= Random.rand(6..9) %> * * *'
+    class: Scheduler::FollowRecommendationsScheduler
+    queue: scheduler
   doorkeeper_cleanup_scheduler:
     cron: '<%= Random.rand(0..59) %> <%= Random.rand(0..2) %> * * 0'
     class: Scheduler::DoorkeeperCleanupScheduler