# Including this module causes indexing and index removal to occur in
# DelayedJobs. Requires all automatic index/removal code to be enabled (the
# default) to work properly. Include this module after calling searchable.
#
#  searchable do      # TODO: automatically enable after calling searchable?
#    text :name
#  end
#
#  include DelayedIndex
module DelayedIndex
  def self.included(receiver)
    receiver.extend         ClassMethods
    receiver.send :include, InstanceMethods

    # HACK: Work around some funkiness with remove_from_index, not sure why
    # it can't be overidden in InstanceMethods.
    receiver.send :alias_method, :remove_from_index, :solr_remove_from_index
  end

  module ClassMethods
    # Removes an object from the index by id, the object is already destroyed
    # and it's data is gone. Necessary because the remove command needs to be
    # sent from a serializable object to work with DelayedJob.
    def remove_from_index_by_id(id)
      Sunspot.remove_by_id!(self, id)
    end

  end

  module InstanceMethods
    # Override the default method and make it backgrounded and auto-committed.
    def solr_remove_from_index
      self.class.send_later :remove_from_index_by_id, id
    end

    # Override the default method and make it backgrounded and auto-committed.
    def solr_index
      send_later :solr_index!
    end

    # Improved maybe_mark_for_auto_indexing.
    def maybe_mark_for_auto_indexing
      @marked_for_auto_indexing = new_record? ||
        (changed.map(&:to_s) - self.class.sunspot_options[:ignore_attribute_changes_of].to_a.map(&:to_s)).present?

      true
    end

  end

end