Change auto-following admin-selected accounts, show in recommendations (#16078)

app/models/account_suggestions/global_source.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+class AccountSuggestions::GlobalSource < AccountSuggestions::Source
+  def key
+    :global
+  end
+
+  def get(account, skip_account_ids: [], limit: 40)
+    account_ids = account_ids_for_locale(account.user_locale) - [account.id] - skip_account_ids
+
+    as_ordered_suggestions(
+      scope(account).where(id: account_ids),
+      account_ids
+    ).take(limit)
+  end
+
+  def remove(_account, _target_account_id)
+    nil
+  end
+
+  private
+
+  def scope(account)
+    Account.searchable
+           .followable_by(account)
+           .not_excluded_by_account(account)
+           .not_domain_blocked_by_account(account)
+  end
+
+  def account_ids_for_locale(locale)
+    Redis.current.zrevrange("follow_recommendations:#{locale}", 0, -1).map(&:to_i)
+  end
+
+  def to_ordered_list_key(account)
+    account.id
+  end
+end