#
# Author: Nick Karanatsios <nickkaranatsios@gmail.com>
#
# Copyright (C) 2008-2012 NEC Corporation
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License, version 2, as
# published by the Free Software Foundation.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License along
# with this program; if not, write to the Free Software Foundation, Inc.,
# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
#


class Queue
  class << self
    # @param [PacketQueue] queue
    #  the {PacketQueue} to append to the list.
    attr_accessor :queues
  end

  
  # Add queue to list.
  # @param [PacketQueue] queue a {PacketQueue} instance.
  def self.append queue
    @queues ||= []
    @queues << queue unless @queues.include?(queue)
  end
  
  
  # @return [Array]
  #   an array of {PacketQueue} objects.
  def self.queues
    @queues
  end
  

  # Iterate over each {PacketQueue} item.
  # @return [Array] a list of {PacketQueue} items.
  def self.each &block
    @queues.each do | each |
      block.call each
    end
  end
end


class PacketQueue
  # No property for queue.
  OFPQT_NONE = 0
  # Minimum datarate guaranteed.
  OFPQT_MIN_RATE = 1
  
  
  # Id for the specific queue.
  # @return [Number] queue_id
  #   the value of attribute queue_id.  
  attr_accessor :queue_id
  # Queue description's length in bytes.
  # @return [Number] len
  #   the value of attribute len.
  attr_accessor :len
  # List of queue properties.
  # @return [Array] properties
  #   the value of attribute properties.
  attr_accessor :properties


  # @overload initialize(options={})
  # @param [Hash] options ths options hash.
  # @option options [Symbol] :queue_id
  #   id for the specific queue.
  # @option options [Symbol] :len
  #   queue description's length in bytes.
  # 
  def initialize options
    @queue_id = options[ :queue_id ]
    @len = options[ :len ]
    @properties = []
  end


  # @param [MinRateQueue] queue
  #   a property queue {MinRateQueue} object to append to the properties list.
  def append queue
    @properties << queue
  end


  # @return [String]
  #   text representation of {PacketQueue}'s attributes and all its properties
  #   queue object's attributes.
  def to_s
    str = "queue_id: #{@queue_id} len: #{@len} "
    @properties.each do | each |
      str += each.to_s
    end
     str
  end
end


class QueueProperty
  # Property queue id.
  # For minimum-rate type queue the property value is set to 1, otherwise defaults
  # to zero.
  # @return [Number]
  #   the value of attribute property.
  attr_accessor :property
  # length of property. If >= 8 minimum-rate type queue is defined.
  # @return [Number]
  #   the value of attribute len.
  attr_accessor :len


  # Each queue is described by a set of properties, each of a specific type and
  # configuration.
  # @param [Number] property
  #   property queue id.
  # @param [Number] len
  #   length in bytes of the property queue.
  def initialize property, len
    @property = property
    @len = len
  end


  # @return [String]
  #  text representation of its attributes (property,len).
  def to_s
    "property: #{@property} len: #{@len} "
  end
end


class MinRateQueue < QueueProperty
  # the rate value of the minimum rate queue.
  # @return [Number]
  #   the value of attribute rate.
  attr_accessor :rate

  
  # An object that encapsulates the minimum rate queue property description.
  # @param [Number] property
  #   property queue id.
  # @param [Number] len
  #   length in bytes of the property queue.
  # @param [Number] rate
  #   the rate value of the mimimum rate queue.
  # @param [PacketQueue] packet_queue
  #   A {PacketQueue} instance to use to save the minimum rate queue.
  def initialize property, len, rate, packet_queue
    super property, len
    @rate = rate
    packet_queue.append self
    Queue.append packet_queue
  end


  # @return [String]
  #  text representation of rate prefixed by property and length attributes.
  def to_s
    super.to_s + " rate: #{rate} "
  end
end


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### mode: Ruby
### coding: utf-8-unix
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