default scope for uniqueness validator

module SharedDatabase
  module UniquenessValidator
    def self.included(validator)
      validator.class_eval do
        def setup_with_subdomain_account(klass)
          return unless klass.table_exists?

          if klass.column_names.include? 'subdomain_account_id'
            scope = [:subdomain_account_id]

            if defined? @options[:scope] and @options[:scope]
              if @options[:scope].kind_of? Array
                scope.push *@options[:scope]
              else
                scope.push @options[:scope]
              end
            end

            @options = @options.dup
            @options[:scope] = scope
            @options.freeze
          end

          setup_without_subdomain_account(klass)
        end

        alias_method_chain :setup, :subdomain_account
      end
    end
  end
end

ActiveRecord::Validations::UniquenessValidator.class_eval do
  include SharedDatabase::UniquenessValidator
end