class Customize::InheritNode < ActiveRecord::Base
	self.table_name = "customize_inherit_nodes"
	belongs_to :parent_node, :class_name=>self.name, :foreign_key=> 'parent_id'
	belongs_to :node, :polymorphic=>true
	has_many :children, :class_name=>self.name, :foreign_key=>'parent_id'
	has_many :ancestors, :class_name=>self.name, :finder_sql=> proc {
		%Q{
		select distinct nodes.*
		from customize_inherit_nodes nodes
		where nodes.right > #{right} and nodes.left < #{left} and nodes.node_type = "#{node_type}"
		}
	}

	validates_presence_of :node_type, :node_id

	scope :by_type, lambda { |type| where(:node_type=>type) }
		
	after_destroy { |object|
		object.class.where("right > :right and node_type = :type", 
											 :right=>object.right, :type=>object.node_type).update_all("right = right -2")
		object.class.where("left > :right and node_type = :type", 
											 :right=>object.right, :type=>object.node_type).update_all("left = left -2")
	}
	before_create { |object|
		if object.parent_id.nil?
			left = self.class.where(:node_type=>object.node_type).maximum(:right) || -1
			left = left + 1
			object.left = left
			object.right = left + 1
		else
			object.left = object.parent_node.right
			object.right = object.parent_node.right + 1
			object.class.where("right >= :right and node_type = :type", 
												 :right=>object.left, :type=>object.node_type).update_all("right = right + 2")
			object.class.where("left >= :right and node_type = :type", 
												 :right=>object.right, :type=>object.node_type).update_all("left = left + 2")
		end
	}


	def leaf?
		children.empty?
	end

end