module UniverseCompiler
  module Universe

    module Duplication

      def dup
        UniverseCompiler.logger.debug "Starting '#{name}' universe duplication"
        duplicated_universe = build_duplicated_universe_with_references
        duplicated_universe.resolve_entities_reference
        raise UniverseCompiler::Error, "Compilation error: Generated universe '#{duplicated_universe.name}' is invalid!" unless duplicated_universe.valid?
        UniverseCompiler.logger.debug "Completed '#{name}' universe duplication"
        duplicated_universe
      end


      protected

      def resolve_entities_reference
        entities.map!(&:resolve_fields_references!)
        self
      end

      private

      def duplicate_entities(target_universe = nil)
        entities.map do |entity|
          debug_msg = "Duplicating '#{entity.to_composite_key}' from universe '#{self.name}'"
          debug_msg += " to universe '#{target_universe.name}'" unless target_universe.nil?
          UniverseCompiler.logger.debug debug_msg
          fields = Marshal::load(Marshal.dump entity).fields
          fields[:name] = entity.name if entity.class.auto_named_entity_type?
          entity_copy = entity.class.new fields: fields, universe: target_universe
          deep_map entity_copy.fields do |leaf|
            case leaf
            when UniverseCompiler::Entity::Base
              # All entities are supposed to be now references instead after the Marshall dump/load process
              raise UniverseCompiler::Error, 'Should never happen!!'
            when UniverseCompiler::Entity::Reference
              leaf.universe = target_universe
            else
              raise UniverseCompiler::Error, 'Should never happen too!!' if leaf.respond_to? :universe
              leaf
            end
          end
          target_universe.add entity_copy unless target_universe.nil?
        end
      end

      def build_duplicated_universe_with_references
        target_name = '%s - COMPILED #%s' % [name, '%s']
        duplicated_universe = self.class.new target_name
        duplicated_universe.compiled = true
        duplicated_universe.name = duplicated_universe.name % [duplicated_universe.object_id]
        UniverseCompiler.logger.debug "Generating new universe '#{duplicated_universe.name}'."
        duplicate_entities duplicated_universe
        duplicated_universe
      end

    end

  end
end