class ActionController::Routing::RouteSet
  #
  # Example usage:
  #
  #   ActionController::Routing::Routes.draw do |map| 
  #
  #     map.rewrite /\.(\w+)$/, '?flav=\1'
  #
  #     map.rewrite { |request|
  #       request.query_parameters.update("action"=>request.method.to_s)
  #     }
  #
  #     map.connect ':controller/:id'
  #
  #   end
  #
  def rewrite(*args, &filter)
    if args.length == 2
      pattern,replacement = *args
      filter = proc { |request|
        request.path,query = request.path.sub(pattern,replacement).split("?",2)
        if query
          request.query_parameters.update CGIMethods.parse_query_parameters(query)
        end
      }
    elsif !filter
      raise ArgumentError, "wrong number of arguments (#{a.length} for 2)"
    end
 
    @filters, @init_filters = [], true unless @init_filters 
    @filters.push filter
  end

  #
  # Hook rewrite filters into the request recognition process
  #
  def recognize! request

    # replace path and query_parameters implementation for this request only
    path,query = request.path, request.query_parameters
    request.instance_eval {
      def path() @path end
      def path=(value) @path=value end
      def query_parameters() @query_parameters end
      def query_parameters=(value) @query_parameters=value end
    }
    request.path, request.query_parameters = path, query

    # invoke filters
    @filters.each {|filter| filter.call(request)} if @filters

    # at this point, reset all filters if any new ones are defined
    @init_filters = false

    # proceed with recognition
    recognize request
  end
end