module Sandthorn
  module AggregateRootSnapshot
    attr_reader :aggregate_snapshot

    def snapshot
      aggregate_snapshot!
      save_snapshot
      self
    end

    def aggregate_snapshot!
      raise Errors::SnapshotError.new "Can't take snapshot on object with unsaved events" if @aggregate_events.count > 0
      @aggregate_snapshot = {
        :event_name => "aggregate_set_from_snapshot",
        :event_args => [self],
        :aggregate_version => @aggregate_current_event_version
      }
    end

    def save_snapshot
      raise Errors::SnapshotError.new "No snapshot has been created!" unless aggregate_snapshot
      @aggregate_snapshot[:event_data] = Sandthorn.serialize aggregate_snapshot[:event_args]
      @aggregate_snapshot[:event_args] = nil
      Sandthorn.save_snapshot aggregate_snapshot, aggregate_id, self.class.name
      @aggregate_snapshot = nil
    end
  end
end