# Copyright 2011-2012 Amazon.com, Inc. or its affiliates. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"). You
# may not use this file except in compliance with the License. A copy of
# the License is located at
#
#     http://aws.amazon.com/apache2.0/
#
# or in the "license" file accompanying this file. This file is
# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
# ANY KIND, either express or implied. See the License for the specific
# language governing permissions and limitations under the License.

module AWS
  module Core

    # @private
    class Response
  
      include AsyncHandle
  
      # @return [AWS::Error] Returns nil unless the request failed.
      #   Normally this will be nil unless you are using the Asynchronous 
      #   interface.
      attr_accessor :error
      
      # @return [Hash] The hash of options passed to the low level request 
      #   method that generated this response.
      attr_accessor :request_options
  
      # @return [Symbol] The low-level request method that generated
      #   this response
      attr_accessor :request_type
      
      # @return [Http::Request] the HTTP request object 
      attr_accessor :http_request
  
      # @return [Http::Response] the HTTP response object 
      attr_accessor :http_response
  
      # @return [Boolean] true if the response is cached
      attr_accessor :cached
  
      # @param [Http::Request] http_request
      # @param [Http::Response] http_request
      def initialize http_request = nil, http_response = nil, &block
        @http_request = http_request
        @http_response = http_response
        @request_builder = block
        rebuild_request if @request_builder && !http_request
      end
  
      # Rebuilds the HTTP request using the block passed to the initializer
      def rebuild_request
        @http_request = @request_builder.call
      end
  
      # @return [Boolean] Returns true unless there is a response error.
      def successful?
        error.nil?
      end
  
      # @return [Boolean] Returns true if the http request was throttled
      #   by AWS.
      def throttled?
        !successful? and
          http_response.body and
          parsed_body = XmlGrammar.parse(http_response.body) and
          parsed_body.respond_to?(:code) and
          parsed_body.code == "Throttling"
      end
  
      # @return [Boolean] Returns true if the http request timed out.
      def timeout?
        http_response.timeout?
      end
  
      # @private
      def inspect
        if request_type
          "<#{self.class}:#{request_type}>"
        else
          "<#{self.class}>"
        end
      end
  
      def cache_key
        [http_request.access_key_id,
         http_request.host,
         request_type,
         serialized_options].join(":")
      end
  
      def serialized_options
        serialize_options_hash(request_options)
      end
  
      private
      def serialize_options_hash(hash)
        "(" + hash.keys.sort_by(&:to_s).map do |key|
          "#{key}=#{serialize_options_value(hash[key])}"
        end.join(" ") + ")"
      end
  
      private
      def serialize_options_value(value)
        case value
        when Hash
          serialize_options_hash(value)
        when Array
          serialize_options_array(value)
        else
          value.inspect
        end
      end
  
      private
      def serialize_options_array(ary)
        "[" + ary.map { |v| serialize_options_value(v) }.join(" ") +
          "]"
      end
  
    end
  end
end