module ActiveRecord #:nodoc:
  module Associations #:nodoc:
    module Scope #:nodoc:
      def self.included(base)
        base.extend(ClassMethods)
      end
  
      module ClassMethods
        def with_association_scope(options = {}, &block)
          write_inheritable_attribute(:association_scope, options)
          class_eval { extend ActiveRecord::Associations::Scope::SingletonMethods }
          yield
          SingletonMethods.define_methods(self, true)
        end
      end
      
      module SingletonMethods
        def self.extend_object(base)
          define_methods(base)
          super
        end
        
        def self.define_methods(base, remove = false)
          extra = (remove ? "" : "association_scope_options!(options);")
          association_methods.each do |assoc|
            base.class_eval "def self.#{assoc}(assoc, options = {}) #{extra} super end"
          end
        end
        
        def self.association_methods
          [:has_many, :has_one, :has_and_belongs_to_many, :belongs_to]
        end

        def association_scope_options!(options = {})
          return unless options.is_a? Hash
          options.reverse_merge! read_inheritable_attribute(:association_scope) 
        end
      end
      
    end
  end
end