module Authlogic
  module Session
    # Handles authenticating via a traditional username and password.
    module Klass
      def self.included(klass)
        klass.class_eval do
          extend Config
          include InstanceMethods

          class << self
            attr_accessor :configured_klass_methods
          end
        end
      end

      module Config
        # Lets you change which model to use for authentication.
        #
        # * <tt>Default:</tt> inferred from the class name. UserSession would
        #   automatically try User
        # * <tt>Accepts:</tt> an ActiveRecord class
        def authenticate_with(klass)
          @klass_name = klass.name
          @klass = klass
        end
        alias_method :authenticate_with=, :authenticate_with

        # The name of the class that this session is authenticating with. For
        # example, the UserSession class will authenticate with the User class
        # unless you specify otherwise in your configuration. See
        # authenticate_with for information on how to change this value.
        def klass
          @klass ||= klass_name ? klass_name.constantize : nil
        end

        # The string of the model name class guessed from the actual session class name.
        def klass_name
          return @klass_name if defined?(@klass_name)
          @klass_name = name.scan(/(.*)Session/)[0]
          @klass_name = klass_name ? klass_name[0] : nil
        end
      end

      module InstanceMethods
        # Creating an alias method for the "record" method based on the klass
        # name, so that we can do:
        #
        #   session.user
        #
        # instead of:
        #
        #   session.record
        def initialize(*args)
          unless self.class.configured_klass_methods
            self.class.send(:alias_method, klass_name.demodulize.underscore.to_sym, :record)
            self.class.configured_klass_methods = true
          end
          super
        end

        private

        def klass
          self.class.klass
        end

        def klass_name
          self.class.klass_name
        end
      end
    end
  end
end