// ============================================================
// EVENT LOGGER
// Deduplicates and logs anomaly events to database
// ============================================================

const anomalies = msg.payload || [];

if (!Array.isArray(anomalies) || anomalies.length === 0) {
    return null;
}

// Get or initialize active anomalies list
let activeAnomalies = global.get("activeAnomalies") || [];
const now = Date.now();
const DEDUP_WINDOW = 5 * 60 * 1000; // 5 minutes

const dbInserts = [];
const uiUpdates = [];

anomalies.forEach(anomaly => {
    // ============================================================
    // DEDUPLICATION LOGIC
    // Don't create new event if same type exists in last 5 minutes
    // ============================================================
    const existingIndex = activeAnomalies.findIndex(existing =>
        existing.anomaly_type === anomaly.anomaly_type &&
        existing.work_order_id === anomaly.work_order_id &&
        existing.status === 'active' &&
        (now - existing.timestamp) < DEDUP_WINDOW
    );

    if (existingIndex !== -1) {
        // Update existing event
        const existing = activeAnomalies[existingIndex];
        existing.occurrence_count = (existing.occurrence_count || 1) + 1;
        existing.last_occurrence = now;

        // Update in database
        const updateQuery = `UPDATE anomaly_events
            SET occurrence_count = ?, last_occurrence = ?
            WHERE event_id = ?`;

        dbInserts.push({
            topic: updateQuery,
            payload: [existing.occurrence_count, existing.last_occurrence, existing.event_id]
        });

        node.warn(`[EVENT LOGGER] Updated existing ${anomaly.anomaly_type} event (occurrence #${existing.occurrence_count})`);

    } else if (anomaly.status === 'resolved') {
        // ============================================================
        // RESOLVE EVENT
        // ============================================================
        const resolveIndex = activeAnomalies.findIndex(existing =>
            existing.anomaly_type === anomaly.anomaly_type &&
            existing.work_order_id === anomaly.work_order_id &&
            existing.status === 'active'
        );

        if (resolveIndex !== -1) {
            const existing = activeAnomalies[resolveIndex];
            existing.status = 'resolved';
            existing.resolved_at = anomaly.resolved_at || now;
            existing.auto_resolved = anomaly.auto_resolved || false;

            // Update in database
            const resolveQuery = `UPDATE anomaly_events
                SET status = 'resolved', resolved_at = ?, auto_resolved = ?
                WHERE event_id = ?`;

            dbInserts.push({
                topic: resolveQuery,
                payload: [existing.resolved_at, existing.auto_resolved, existing.event_id]
            });

            // Remove from active list
            activeAnomalies.splice(resolveIndex, 1);

            node.warn(`[EVENT LOGGER] Resolved ${anomaly.anomaly_type} event (auto: ${existing.auto_resolved})`);

            uiUpdates.push({
                event_id: existing.event_id,
                status: 'resolved'
            });
        }

    } else {
        // ============================================================
        // NEW EVENT
        // ============================================================
        const insertQuery = `INSERT INTO anomaly_events
            (timestamp, work_order_id, anomaly_type, severity, title, description,
             data_json, kpi_snapshot_json, status, cycle_count, occurrence_count, last_occurrence)
            VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`;

        const dataJson = JSON.stringify(anomaly.data || {});
        const kpiJson = JSON.stringify(anomaly.kpi_snapshot || {});

        dbInserts.push({
            topic: insertQuery,
            payload: [
                anomaly.timestamp,
                anomaly.work_order_id,
                anomaly.anomaly_type,
                anomaly.severity,
                anomaly.title,
                anomaly.description,
                dataJson,
                kpiJson,
                'active',
                anomaly.cycle_count,
                1,  // occurrence_count
                anomaly.timestamp  // last_occurrence
            ],
            _storeEventId: true,  // Flag to get generated event_id
            _anomaly: anomaly  // Keep reference for later
        });

        node.warn(`[EVENT LOGGER] New ${anomaly.anomaly_type} event: ${anomaly.title}`);
    }
});

// Save active anomalies to global context
global.set("activeAnomalies", activeAnomalies);

// ============================================================
// OUTPUT
// ============================================================
// Output 1: Database inserts (to mysql node)
// Output 2: UI updates (to Home/Alerts tabs)

if (dbInserts.length > 0) {
    // Send each insert as a separate message
    return [dbInserts, {
        topic: "anomaly-ui-update",
        payload: {
            activeCount: activeAnomalies.length,
            activeAnomalies: activeAnomalies,
            updates: uiUpdates
        }
    }];
} else {
    return [null, {
        topic: "anomaly-ui-update",
        payload: {
            activeCount: activeAnomalies.length,
            activeAnomalies: activeAnomalies,
            updates: uiUpdates
        }
    }];
}