Add ability to manage which websites can credit you in link previews (#31819)

app/models/account.rb

@@ -51,6 +51,7 @@
 #  reviewed_at                   :datetime
 #  requested_review_at           :datetime
 #  indexable                     :boolean          default(FALSE), not null
+#  attribution_domains           :string           default([]), is an Array
 #
 
 class Account < ApplicationRecord
@@ -88,6 +89,7 @@ class Account < ApplicationRecord
   include Account::Merging
   include Account::Search
   include Account::StatusesSearch
+  include Account::AttributionDomains
   include DomainMaterializable
   include DomainNormalizable
   include Paginable

app/models/concerns/account/attribution_domains.rb

@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+module Account::AttributionDomains
+  extend ActiveSupport::Concern
+
+  included do
+    validates :attribution_domains_as_text, domain: { multiline: true }, lines: { maximum: 100 }, if: -> { local? && will_save_change_to_attribution_domains? }
+  end
+
+  def attribution_domains_as_text
+    self[:attribution_domains].join("\n")
+  end
+
+  def attribution_domains_as_text=(str)
+    self[:attribution_domains] = str.split.filter_map do |line|
+      line.strip.delete_prefix('*.')
+    end
+  end
+
+  def can_be_attributed_from?(domain)
+    segments = domain.split('.')
+    variants = segments.map.with_index { |_, i| segments[i..].join('.') }.to_set
+    self[:attribution_domains].to_set.intersect?(variants)
+  end
+end