# Copyright (2008) Sandia Corporation.
# Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
# the U.S. Government retains certain rights in this software.
#
# Original Author: Bryan T. Richardson, Sandia National Laboratories <btricha@sandia.gov>
# Derived From: code written by Michael Berg <mjberg@sandia.gov>
#
# This library is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or (at
# your option) any later version.
#
# This library 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 Lesser General Public License for more
# details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this library; if not, write to the Free Software Foundation, Inc.,
# 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 

# Node class that wraps the nodes table in the ANTFARM database.
#
# * has many layer 2 interfaces
# * has many layer 3 interfaces through layer 2 interfaces
class Node < ActiveRecord::Base
  has_many :layer2_interfaces
  has_many :layer3_interfaces, :through => :layer2_interfaces

  before_save :clamp_certainty_factor

  validates_presence_of :certainty_factor

  # Find and return the first node found with the given name.
  def self.node_named(name)
    unless name
      raise(ArgumentError, "nil argument supplied", caller)
    end

    node = self.find_all_by_name(name)

    case node.length
    when 0
      logger.warn("Node: did not find an existing node with given name.")
      return nil
    else
      logger.info("Node: found existing nodes with given name.")
      return node[0]
    end
  end

  # Find and return all the nodes found that are the given type.
  def self.nodes_of_device_type(device_type)
    unless device_type
      raise(ArgumentError, "nil argument supplied", caller)
    end

    nodes = self.find_all_by_device_type(device_type)

    case nodes.length
    when 0
      logger.warn("Node: did not find any existing nodes of given device type.")
      return nil
    else
      logger.info("Node: found existing nodes of given device type.")
      return nodes
    end
  end

  #######
  private
  #######

  def clamp_certainty_factor
    self.certainty_factor = Antfarm.clamp(self.certainty_factor)
  end
end