video-surveillance-app/src/main/java/me/belkacemi/iotalarm/infrastructure/persistence/AlarmReadModelAdapter.java

package me.belkacemi.iotalarm.infrastructure.persistence;

import me.belkacemi.iotalarm.application.query.port.AlarmReadModelPort;
import me.belkacemi.iotalarm.application.query.view.AlarmStatusView;
import me.belkacemi.iotalarm.application.query.view.AlertView;
import me.belkacemi.iotalarm.domain.model.AlarmPolicy;
import me.belkacemi.iotalarm.domain.model.AlarmState;
import me.belkacemi.iotalarm.infrastructure.persistence.jpa.AlarmStateJpaRepository;
import me.belkacemi.iotalarm.infrastructure.persistence.jpa.AlertJpaRepository;
import me.belkacemi.iotalarm.infrastructure.persistence.mapper.AlertMapper;
import org.springframework.data.domain.PageRequest;
import org.springframework.stereotype.Component;

import java.time.Clock;
import java.util.List;
import java.util.Optional;
import java.util.UUID;

/**
 * ADAPTER SORTANT du cote LECTURE : implementation du {@link AlarmReadModelPort}.
 *
 * <p>Il ne charge jamais l'agregat. Il assemble une vue a partir de requetes
 * ciblees - c'est la raison d'etre du CQRS : afficher un compteur d'alertes non
 * acquittees via un {@code COUNT(*)} plutot qu'en rehydratant un objet metier
 * complet dont on n'utiliserait aucune methode.</p>
 */
@Component
public class AlarmReadModelAdapter implements AlarmReadModelPort {

    private final AlertJpaRepository alertRepository;
    private final AlarmStateJpaRepository alarmStateRepository;
    private final AlarmPolicy policy;
    private final Clock clock;

    public AlarmReadModelAdapter(AlertJpaRepository alertRepository,
                                 AlarmStateJpaRepository alarmStateRepository,
                                 AlarmPolicy policy,
                                 Clock clock) {
        this.alertRepository = alertRepository;
        this.alarmStateRepository = alarmStateRepository;
        this.policy = policy;
        this.clock = clock;
    }

    @Override
    public Optional<AlarmStatusView> alarmStatus(String zoneId) {
        long unacknowledged = alertRepository.countByZoneIdAndAcknowledgedFalse(zoneId);
        AlertView lastAlert = alertRepository.findFirstByZoneIdOrderByDetectedAtDesc(zoneId)
                .map(AlertMapper::toView)
                .orElse(null);

        return Optional.of(alarmStateRepository.findById(zoneId)
                .map(entity -> new AlarmStatusView(
                        entity.getZoneId(),
                        entity.getState().name(),
                        entity.getStateChangedAt(),
                        policy.exitDelay().toSeconds(),
                        entity.getLastAlertAt(),
                        unacknowledged,
                        lastAlert))
                // Base neuve : l'alarme n'a simplement jamais ete armee. La
                // console doit afficher DESARMEE, pas une erreur 404.
                .orElseGet(() -> new AlarmStatusView(
                        zoneId,
                        AlarmState.DISARMED.name(),
                        clock.instant(),
                        policy.exitDelay().toSeconds(),
                        null,
                        unacknowledged,
                        lastAlert)));
    }

    @Override
    public List<AlertView> recentAlerts(String zoneId, int limit) {
        return alertRepository
                .findByZoneIdOrderByDetectedAtDesc(zoneId, PageRequest.of(0, limit))
                .stream()
                .map(AlertMapper::toView)
                .toList();
    }

    @Override
    public Optional<AlertView> findAlert(UUID alertId) {
        return alertRepository.findById(alertId).map(AlertMapper::toView);
    }
}