Add ability to disable login and mark accounts as memorial (#5615)

Fix #5597

app/models/user.rb

@@ -5,7 +5,6 @@
 #
 #  id                        :integer          not null, primary key
 #  email                     :string           default(""), not null
-#  account_id                :integer          not null
 #  created_at                :datetime         not null
 #  updated_at                :datetime         not null
 #  encrypted_password        :string           default(""), not null
@@ -31,10 +30,13 @@
 #  last_emailed_at           :datetime
 #  otp_backup_codes          :string           is an Array
 #  filtered_languages        :string           default([]), not null, is an Array
+#  account_id                :integer          not null
+#  disabled                  :boolean          default(FALSE), not null
 #
 
 class User < ApplicationRecord
   include Settings::Extend
+
   ACTIVE_DURATION = 14.days
 
   devise :registerable, :recoverable,
@@ -72,12 +74,26 @@ class User < ApplicationRecord
     confirmed_at.present?
   end
 
+  def disable!
+    update!(disabled: true,
+            last_sign_in_at: current_sign_in_at,
+            current_sign_in_at: nil)
+  end
+
+  def enable!
+    update!(disabled: false)
+  end
+
   def disable_two_factor!
     self.otp_required_for_login = false
     otp_backup_codes&.clear
     save!
   end
 
+  def active_for_authentication?
+    super && !disabled?
+  end
+
   def setting_default_privacy
     settings.default_privacy || (account.locked? ? 'private' : 'public')
   end