package dev.lions.unionflow.server.messaging;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import io.smallrye.reactive.messaging.kafka.Record;
import jakarta.enterprise.context.ApplicationScoped;
import jakarta.inject.Inject;
import org.eclipse.microprofile.reactive.messaging.Channel;
import org.eclipse.microprofile.reactive.messaging.Emitter;
import org.jboss.logging.Logger;

import java.time.Instant;
import java.util.HashMap;
import java.util.Map;
import java.util.UUID;

/**
 * Producer Kafka pour publier des events UnionFlow.
 * <p>
 * Publie sur différents topics Kafka qui sont ensuite consommés
 * par le WebSocket server pour broadcast aux clients mobiles/web.
 */
@ApplicationScoped
public class KafkaEventProducer {

    private static final Logger LOG = Logger.getLogger(KafkaEventProducer.class);

    @Inject
    ObjectMapper objectMapper;

    @Channel("finance-approvals-out")
    Emitter<Record<String, String>> financeApprovalsEmitter;

    @Channel("dashboard-stats-out")
    Emitter<Record<String, String>> dashboardStatsEmitter;

    @Channel("notifications-out")
    Emitter<Record<String, String>> notificationsEmitter;

    @Channel("members-events-out")
    Emitter<Record<String, String>> membersEventsEmitter;

    @Channel("contributions-events-out")
    Emitter<Record<String, String>> contributionsEventsEmitter;

    @Channel("chat-messages-out")
    Emitter<Record<String, String>> chatMessagesEmitter;

    /**
     * Publie un event d'approbation en attente.
     */
    public void publishApprovalPending(UUID approvalId, String organizationId, Map<String, Object> approvalData) {
        var event = buildEvent("APPROVAL_PENDING", organizationId, approvalData);
        publishToChannel(financeApprovalsEmitter, approvalId.toString(), event, "finance-approvals");
    }

    /**
     * Publie un event d'approbation approuvée.
     */
    public void publishApprovalApproved(UUID approvalId, String organizationId, Map<String, Object> approvalData) {
        var event = buildEvent("APPROVAL_APPROVED", organizationId, approvalData);
        publishToChannel(financeApprovalsEmitter, approvalId.toString(), event, "finance-approvals");
    }

    /**
     * Publie un event d'approbation rejetée.
     */
    public void publishApprovalRejected(UUID approvalId, String organizationId, Map<String, Object> approvalData) {
        var event = buildEvent("APPROVAL_REJECTED", organizationId, approvalData);
        publishToChannel(financeApprovalsEmitter, approvalId.toString(), event, "finance-approvals");
    }

    /**
     * Publie une mise à jour des stats dashboard.
     */
    public void publishDashboardStatsUpdate(String organizationId, Map<String, Object> stats) {
        var event = buildEvent("DASHBOARD_STATS_UPDATED", organizationId, stats);
        publishToChannel(dashboardStatsEmitter, organizationId, event, "dashboard-stats");
    }

    /**
     * Publie un KPI temps réel.
     */
    public void publishKpiUpdate(String organizationId, Map<String, Object> kpiData) {
        var event = buildEvent("KPI_UPDATED", organizationId, kpiData);
        publishToChannel(dashboardStatsEmitter, organizationId, event, "dashboard-stats");
    }

    /**
     * Publie une notification utilisateur.
     */
    public void publishUserNotification(String userId, Map<String, Object> notificationData) {
        var event = buildEvent("USER_NOTIFICATION", null, notificationData);
        event.put("userId", userId);
        publishToChannel(notificationsEmitter, userId, event, "notifications");
    }

    /**
     * Publie une notification broadcast (toute une organisation).
     */
    public void publishBroadcastNotification(String organizationId, Map<String, Object> notificationData) {
        var event = buildEvent("BROADCAST_NOTIFICATION", organizationId, notificationData);
        publishToChannel(notificationsEmitter, organizationId, event, "notifications");
    }

    /**
     * Publie un event de création de membre.
     */
    public void publishMemberCreated(UUID memberId, String organizationId, Map<String, Object> memberData) {
        var event = buildEvent("MEMBER_CREATED", organizationId, memberData);
        publishToChannel(membersEventsEmitter, memberId.toString(), event, "members-events");
    }

    /**
     * Publie un event de modification de membre.
     */
    public void publishMemberUpdated(UUID memberId, String organizationId, Map<String, Object> memberData) {
        var event = buildEvent("MEMBER_UPDATED", organizationId, memberData);
        publishToChannel(membersEventsEmitter, memberId.toString(), event, "members-events");
    }

    /**
     * Publie un event de désactivation de membre (soft delete).
     * Les consommateurs peuvent réagir : bloquer comptes épargne, annuler inscriptions,
     * reassigner approvals pending, nettoyer notifications, etc.
     */
    public void publishMemberDeactivated(dev.lions.unionflow.server.entity.Membre membre) {
        if (membre == null || membre.getId() == null) return;
        Map<String, Object> data = new java.util.HashMap<>();
        data.put("membreId", membre.getId().toString());
        data.put("email", membre.getEmail());
        data.put("nomComplet", membre.getNomComplet());
        data.put("numeroMembre", membre.getNumeroMembre());
        // organisationId principal (si présent) pour routage par org
        String orgId = membre.getMembresOrganisations() != null
                && !membre.getMembresOrganisations().isEmpty()
                && membre.getMembresOrganisations().get(0).getOrganisation() != null
            ? membre.getMembresOrganisations().get(0).getOrganisation().getId().toString()
            : "";
        var event = buildEvent("MEMBER_DEACTIVATED", orgId, data);
        publishToChannel(membersEventsEmitter, membre.getId().toString(), event, "members-events");
    }

    /**
     * Publie un event de cotisation payée.
     */
    public void publishContributionPaid(UUID contributionId, String organizationId, Map<String, Object> contributionData) {
        var event = buildEvent("CONTRIBUTION_PAID", organizationId, contributionData);
        publishToChannel(contributionsEventsEmitter, contributionId.toString(), event, "contributions-events");
    }

    /**
     * Publie un event de nouveau message de chat.
     * Les clients WebSocket de l'organisation sont notifiés pour rafraîchir leurs messages.
     */
    public void publishNouveauMessage(UUID conversationId, String organizationId, Map<String, Object> messageData) {
        var event = buildEvent("NOUVEAU_MESSAGE", organizationId, messageData);
        publishToChannel(chatMessagesEmitter, conversationId.toString(), event, "chat-messages");
    }

    /**
     * Construit un event avec structure standardisée.
     */
    private Map<String, Object> buildEvent(String eventType, String organizationId, Map<String, Object> data) {
        var event = new HashMap<String, Object>();
        event.put("eventType", eventType);
        event.put("timestamp", Instant.now().toString());
        if (organizationId != null) {
            event.put("organizationId", organizationId);
        }
        event.put("data", data);
        return event;
    }

    /**
     * Publie un event sur un channel Kafka avec gestion d'erreur.
     */
    private void publishToChannel(Emitter<Record<String, String>> emitter, String key, Map<String, Object> event, String topicName) {
        try {
            String eventJson = objectMapper.writeValueAsString(event);
            emitter.send(Record.of(key, eventJson));
            LOG.debugf("Published event to %s: %s", topicName, eventJson);
        } catch (JsonProcessingException e) {
            LOG.errorf(e, "Failed to serialize event for topic %s", topicName);
        } catch (Exception e) {
            LOG.errorf(e, "Failed to publish event to topic %s", topicName);
        }
    }
}