/**
 * Einfaches Distributed Tracing
 * Erstellt Trace-IDs für Request-Tracking
 */

interface TraceContext {
  traceId: string;
  spanId: string;
  parentSpanId?: string;
  startTime: number;
}

const traces = new Map<string, TraceContext>();

/**
 * Erstellt einen neuen Trace
 */
export function createTrace(traceId?: string): TraceContext {
  const id = traceId || generateTraceId();
  const trace: TraceContext = {
    traceId: id,
    spanId: generateSpanId(),
    startTime: Date.now(),
  };
  traces.set(id, trace);
  return trace;
}

/**
 * Erstellt einen Child-Span
 */
export function createSpan(traceId: string, parentSpanId?: string): string {
  const trace = traces.get(traceId);
  if (!trace) {
    throw new Error(`Trace ${traceId} not found`);
  }

  const spanId = generateSpanId();
  trace.parentSpanId = parentSpanId || trace.spanId;

  return spanId;
}

/**
 * Beendet einen Trace und gibt die Dauer zurück
 */
export function endTrace(traceId: string): number {
  const trace = traces.get(traceId);
  if (!trace) {
    return 0;
  }

  const duration = Date.now() - trace.startTime;
  traces.delete(traceId);
  return duration;
}

/**
 * Generiert eine Trace-ID
 */
function generateTraceId(): string {
  return `trace-${Date.now()}-${Math.random().toString(36).substr(2, 9)}`;
}

/**
 * Generiert eine Span-ID
 */
function generateSpanId(): string {
  return `span-${Date.now()}-${Math.random().toString(36).substr(2, 9)}`;
}

/**
 * Holt Trace-Informationen
 */
export function getTrace(traceId: string): TraceContext | undefined {
  return traces.get(traceId);
}