module Mutant
  module Parallel
    # Parallel execution worker
    class Worker
      include Adamantium::Flat, Anima.new(:mailbox, :processor, :parent)

      # Run worker
      #
      # @param [Hash<Symbol, Object] attributes
      #
      # @return [self]
      #
      # @api private
      def self.run(attributes)
        new(attributes).run
        self
      end

      private_class_method :new

      # Worker loop
      #
      # @return [self]
      #
      # rubocop:disable Lint/Loop
      #
      # @api private
      def run
        begin
          parent.call(Actor::Message.new(:ready, mailbox.sender))
        end until handle(mailbox.receiver.call)
      end

    private

      # Handle job
      #
      # @param [Message] message
      #
      # @return [Boolean]
      #
      # @api private
      def handle(message)
        type, payload = message.type, message.payload
        case message.type
        when :job
          handle_job(payload)
          nil
        when :stop
          true
        else
          fail Actor::ProtocolError, "Unknown command: #{type.inspect}"
        end
      end

      # Handle mutation
      #
      # @param [Job] job
      #
      # @return [undefined]
      #
      # @api private
      def handle_job(job)
        result = processor.call(job.payload)
        parent.call(Actor::Message.new(:result, JobResult.new(job: job, payload: result)))
      end

    end # Worker
  end # Parallel
end # Mutant