ProviderWebSocketEvents.java

import io.arleigh.gantry.activeclient.ActiveClientService;
import io.arleigh.gantry.clientsession.ClientSessionService;
import io.arleigh.gantry.util.SecurityUtils;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import lombok.val;
import org.springframework.context.event.EventListener;
import org.springframework.messaging.simp.SimpMessagingTemplate;
import org.springframework.messaging.simp.user.SimpUser;
import org.springframework.messaging.simp.user.SimpUserRegistry;
import org.springframework.stereotype.Component;
import org.springframework.web.socket.messaging.SessionConnectedEvent;
import org.springframework.web.socket.messaging.SessionDisconnectEvent;

import java.util.Objects;
import java.util.Optional;

@Component
@Slf4j
@RequiredArgsConstructor
class ProviderWebSocketEvents {

    private final SimpUserRegistry simpUserRegistry;
    private final SimpMessagingTemplate simpMessagingTemplate;
    private final ActiveClientService activeClientService;
    private final ClientSessionService clientSessionService;

    @EventListener(condition = "@securityUtils.isAuthenticated(#event.user)")
    public void stompDidConnect(SessionConnectedEvent event) {
        val eventUser = Objects.requireNonNull(event.getUser());
        val provider = SecurityUtils.getPrincipalName(eventUser);
        val hasSessions = Optional.ofNullable(simpUserRegistry.getUser(provider))
            .map(SimpUser::hasSessions)
            .orElse(false);
        if (!hasSessions) {
            return;
        }

        simpMessagingTemplate.convertAndSend(
            "/topic/" + ProviderController.AVAILABILITY_PATH.replace(".", "." + provider + "."),
            ProviderAvailability.BUSY
        );

        getActiveClientUsername(provider).ifPresent(username -> {
            simpMessagingTemplate.convertAndSendToUser(
                username,
                "/queue/" + ProviderController.AVAILABILITY_PATH,
                ProviderAvailability.AVAILABLE
            );
        });
    }

    @EventListener(condition = "@securityUtils.isAuthenticated(#event.user)")
    public void stompIsDisconnecting(SessionDisconnectEvent event) {
        val eventUser = Objects.requireNonNull(event.getUser());
        val provider = SecurityUtils.getPrincipalName(eventUser);
        val hasSessions = Optional.ofNullable(simpUserRegistry.getUser(provider))
            .map(SimpUser::hasSessions)
            .orElse(false);
        if (hasSessions) {
            return;
        }

        getActiveClientUsername(provider).ifPresent(username -> {
            simpMessagingTemplate.convertAndSendToUser(
                username,
                "/queue/" + ProviderController.AVAILABILITY_PATH,
                ProviderAvailability.OFFLINE
            );
        });

        simpMessagingTemplate.convertAndSend(
            "/topic/" + ProviderController.AVAILABILITY_PATH.replace(".", "." + provider + "."),
            ProviderAvailability.OFFLINE
        );
    }

    private Optional<String> getActiveClientUsername(String providerLogin) {
        return Optional.ofNullable(activeClientService.getActiveClient(providerLogin)).flatMap(clientSessionService::getUsername);
    }
}