module ActiveRecord #:nodoc:
  class Base
    class << self # Class methods
      
      private

        def construct_conditions_from_arguments(attribute_names, arguments)
          conditions = []
          attribute_names.each_with_index do |name, idx|
            if fk = foreign_key_for(name)
              name = fk
              arguments[idx] = arguments[idx].id if arguments[idx].is_a?(ActiveRecord::Base)
            end
            conditions << "#{table_name}.#{connection.quote_column_name(name)} #{attribute_condition(arguments[idx])} "
          end
          [ conditions.join(" AND "), *arguments[0...attribute_names.length] ]
        end
        
        def construct_attributes_from_arguments(attribute_names, arguments)
          attributes = {}
          attribute_names.each_with_index do |name, idx|
            if fk = foreign_key_for(name)
              arguments[idx] = arguments[idx].id if arguments[idx].is_a?(ActiveRecord::Base)
              attributes[fk] = arguments[idx]
            else
              attributes[name] = arguments[idx]
            end
          end
          attributes
        end

        def all_attributes_exists?(attribute_names)
          attribute_names.all? do |name|
            column_methods_hash.include?(name.to_sym) || !foreign_key_for(name).nil?
          end
        end
        
        def foreign_key_for(name)
          if (ref = reflect_on_association(name.to_sym)) && ref.macro == :belongs_to
            ref.primary_key_name
          else
            nil
          end
        end

    end
  end
end