CommunicationService.java

package devices.configuration.communication;

import java.time.Clock;
import java.time.Duration;
import java.time.Instant;
import java.util.function.Function;
import lombok.AllArgsConstructor;
import org.springframework.context.ApplicationEventPublisher;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;

@Service
@Transactional
@AllArgsConstructor
public class CommunicationService {
  private final Clock clock;
  private final HeartbeatInterval intervals;
  private final KnownDevices devices;
  private final ApplicationEventPublisher publisher;

  public BootResponse handleBoot(BootNotification boot) {
    BootResponse response =
        new BootResponse(
            Instant.now(clock),
            intervals.heartbeatIntervalFor(boot),
            devices.queryDevice(boot.deviceId()));
    publisher.publishEvent(boot);
    return response;
  }

  public void handleStatus(DeviceStatuses status) {
    publisher.publishEvent(status);
  }

  public record BootResponse(Instant serverTime, Duration interval, KnownDevices.State state) {

    public <T> T map(Function<BootResponse, T> func) {
      return func.apply(this);
    }

    public int intervalInSeconds() {
      return (int) interval.getSeconds();
    }

    public <T> T state(Function<KnownDevices.State, T> func) {
      return func.apply(state);
    }
  }
}