export function healthEventFingerprint(event = {}) {
  return [
    event.eventType,
    event.ruleId ?? '',
    event.metricType ?? '',
    event.symptomCode ?? '',
  ].join('|');
}

export function mapPgHealthEventRow(row, userId) {
  const parseJson = (value, fallback = []) => {
    if (value == null) return fallback;
    if (typeof value === 'object') return value;
    try {
      return JSON.parse(String(value));
    } catch {
      return fallback;
    }
  };
  return {
    id: Number(row.id),
    userId: String(userId),
    eventType: row.event_type,
    severity: row.severity,
    detectedAt: row.detected_at ? new Date(row.detected_at).getTime() : Date.now(),
    ruleId: row.rule_id ?? null,
    metricsInvolved: parseJson(row.metrics_involved),
    evidenceObservationIds: parseJson(row.evidence_observation_ids),
    agentSummary: row.agent_summary ?? null,
    status: row.status ?? 'open',
    message: row.agent_summary ?? null,
    metricType: parseJson(row.metrics_involved)[0]?.metricType ?? null,
    symptomCode: parseJson(row.metrics_involved)[0]?.symptomCode ?? null,
    createdAt: row.created_at ? new Date(row.created_at).getTime() : Date.now(),
  };
}

export function mapHealthEventToPgPayload(event, now = Date.now()) {
  const metricsInvolved = [];
  if (event.metricType) {
    metricsInvolved.push({
      metricType: event.metricType,
      symptomCode: event.symptomCode ?? null,
      value: event.value ?? null,
      baselineMean: event.baselineMean ?? null,
    });
  }
  return {
    event_type: event.eventType,
    severity: event.severity,
    detected_at: new Date(event.createdAt ?? event.detectedAt ?? now).toISOString(),
    rule_id: event.ruleId ?? null,
    metrics_involved: JSON.stringify(metricsInvolved),
    evidence_observation_ids: JSON.stringify(event.evidenceObservationIds ?? []),
    agent_summary: event.message ?? event.agentSummary ?? null,
    status: 'open',
  };
}