module HipstersInc
  module Acts
    module Restorable
      
      def self.included(mod)
        mod.extend(ClassMethods)
      end
      
      module ClassMethods
        def acts_as_restorable(opts = {})
          write_inheritable_attribute(:backup_table, opts[:backup_table] || DeletedRecord)
          write_inheritable_attribute(:acts_as_undeletable, true)
          class_eval do
            extend HipstersInc::Acts::Restorable::SingletonMethods
          end
          include HipstersInc::Acts::Restorable::InstanceMethods

          alias_method :before_destory_without_backup, :before_destroy unless method_defined?(:before_destory_without_backup)
          alias_method :before_destroy, :before_destory_with_backup
        end
        
        def restore_from_xml(xml, params = {})
          doc = REXML::Document.new(xml)
          root = doc.elements[1]
          
          root.elements.each do |el|
            params[el.name.to_sym] = el.text
          end
          new(params)
        end
      end
      
      module SingletonMethods
      end
      
      module InstanceMethods
        def as_xml(opts = {})
          to_xml(opts)
        end
        
        def before_destory_with_backup
          dependents = []
          self.class.reflect_on_all_associations.each do |association|
            dependents << association.name if association.options[:dependent] == :destroy
          end

          self.class.read_inheritable_attribute(:backup_table).create(
            :model => self.class.to_s,
            :model_primary_key => self.id,
            :record_data => self.to_xml(:include => dependents)
          )
          before_destory_without_backup
        end
      end
      
    end
  end
end


ActiveRecord::Base.class_eval do
  include HipstersInc::Acts::Restorable
end