Add more instance stats APIs (#6125)

* Add GET /api/v1/instance/peers API to reveal known domains

* Add GET /api/v1/instance/activity API

* Make new APIs disableable, exclude private statuses from activity stats

* Fix code style issue

* Fix week timestamps

6 files changed, 67 insertions, 6 deletions

diff --git a/app/controllers/admin/settings_controller.rb b/app/controllers/admin/settings_controller.rb
index eed5fb6b5..487282dc3 100644
--- a/app/controllers/admin/settings_controller.rb
+++ b/app/controllers/admin/settings_controller.rb
@@ -17,6 +17,8 @@ module Admin
       bootstrap_timeline_accounts
       thumbnail
       min_invite_role
+      activity_api_enabled
+      peers_api_enabled
     ).freeze
 
     BOOLEAN_SETTINGS = %w(
@@ -24,6 +26,8 @@ module Admin
       open_deletion
       timeline_preview
       show_staff_badge
+      activity_api_enabled
+      peers_api_enabled
     ).freeze
 
     UPLOAD_SETTINGS = %w(
diff --git a/app/controllers/api/v1/instances/activity_controller.rb b/app/controllers/api/v1/instances/activity_controller.rb
new file mode 100644
index 000000000..36f52c38d
--- /dev/null
+++ b/app/controllers/api/v1/instances/activity_controller.rb
@@ -0,0 +1,36 @@
+# frozen_string_literal: true
+
+class Api::V1::Instances::ActivityController < Api::BaseController
+  before_action :require_enabled_api!
+
+  respond_to :json
+
+  def show
+    render_cached_json('api:v1:instances:activity:show', expires_in: 1.day) { activity }
+  end
+
+  private
+
+  def activity
+    weeks = []
+
+    12.times do |i|
+      day     = i.weeks.ago.to_date
+      week_id = day.cweek
+      week    = Date.commercial(day.cwyear, week_id)
+
+      weeks << {
+        week: week.to_time.to_i.to_s,
+        statuses: Redis.current.get("activity:statuses:local:#{week_id}") || 0,
+        logins: Redis.current.pfcount("activity:logins:#{week_id}"),
+        registrations: Redis.current.get("activity:accounts:local:#{week_id}") || 0,
+      }
+    end
+
+    weeks
+  end
+
+  def require_enabled_api!
+    head 404 unless Setting.activity_api_enabled
+  end
+end
diff --git a/app/controllers/api/v1/instances/peers_controller.rb b/app/controllers/api/v1/instances/peers_controller.rb
new file mode 100644
index 000000000..2070c487d
--- /dev/null
+++ b/app/controllers/api/v1/instances/peers_controller.rb
@@ -0,0 +1,17 @@
+# frozen_string_literal: true
+
+class Api::V1::Instances::PeersController < Api::BaseController
+  before_action :require_enabled_api!
+
+  respond_to :json
+
+  def index
+    render_cached_json('api:v1:instances:peers:index', expires_in: 1.day) { Account.remote.domains }
+  end
+
+  private
+
+  def require_enabled_api!
+    head 404 unless Setting.peers_api_enabled
+  end
+end
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index a213302cb..51a978f44 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -121,4 +121,13 @@ class ApplicationController < ActionController::Base
       end
     end
   end
+
+  def render_cached_json(cache_key, **options)
+    data = Rails.cache.fetch(cache_key, { raw: true }.merge(options)) do
+      yield.to_json
+    end
+
+    expires_in options[:expires_in], public: true
+    render json: data
+  end
 end
diff --git a/app/controllers/auth/confirmations_controller.rb b/app/controllers/auth/confirmations_controller.rb
index d5e8e58ed..2fdb281f4 100644
--- a/app/controllers/auth/confirmations_controller.rb
+++ b/app/controllers/auth/confirmations_controller.rb
@@ -2,10 +2,4 @@
 
 class Auth::ConfirmationsController < Devise::ConfirmationsController
   layout 'auth'
-
-  def show
-    super do |user|
-      BootstrapTimelineWorker.perform_async(user.account_id) if user.errors.empty?
-    end
-  end
 end
diff --git a/app/controllers/concerns/user_tracking_concern.rb b/app/controllers/concerns/user_tracking_concern.rb
index 8663c3086..1e3132941 100644
--- a/app/controllers/concerns/user_tracking_concern.rb
+++ b/app/controllers/concerns/user_tracking_concern.rb
@@ -17,6 +17,7 @@ module UserTrackingConcern
 
     # Mark as signed-in today
     current_user.update_tracked_fields!(request)
+    ActivityTracker.record('activity:logins', current_user.id)
 
     # Regenerate feed if needed
     regenerate_feed! if user_needs_feed_update?