Function prepareTimelineEvents

frontend/src/store/executionTimelineStore.ts:145–209

(
  rawEvents: ExecutionLog[],
  workflowStartTime?: number | null,
)

const MIN_TIMELINE_DURATION_MS = 1;

const prepareTimelineEvents = (
  rawEvents: ExecutionLog[],
  workflowStartTime?: number | null,
): {
  events: TimelineEvent[];
  totalDuration: number;
  timelineStartTime: number | null;
} => {
  if (!rawEvents || rawEvents.length === 0) {
    return {
      events: [],
      totalDuration: 0,
      timelineStartTime: workflowStartTime ?? null,
    };
  }

  const sortedEvents = [...rawEvents].sort(
    (a, b) => new Date(a.timestamp).getTime() - new Date(b.timestamp).getTime(),
  );

  if (sortedEvents.length === 0) {
    return {
      events: [],
      totalDuration: 0,
      timelineStartTime: workflowStartTime ?? 0,
    };
  }

  // Use workflow start time if provided, otherwise use first event timestamp
  // Always prefer workflowStartTime when available (it's the authoritative source)
  const firstEventTime = new Date(sortedEvents[0].timestamp).getTime();
  const startTime =
    workflowStartTime !== null && workflowStartTime !== undefined
      ? workflowStartTime
      : firstEventTime;
  const endTime = new Date(sortedEvents[sortedEvents.length - 1].timestamp).getTime();
  const totalDuration = Math.max(endTime - startTime, MIN_TIMELINE_DURATION_MS);

  const events: TimelineEvent[] = sortedEvents.map((event, index) => {
    const eventTime = new Date(event.timestamp).getTime();
    const offsetMs = eventTime - startTime;

    // Calculate duration based on next event or a default duration
    let duration = 0;
    if (index < sortedEvents.length - 1) {
      const nextEventTime = new Date(sortedEvents[index + 1].timestamp).getTime();
      duration = Math.max(nextEventTime - eventTime, 100); // Minimum 100ms duration
    } else {
      duration = Math.max(totalDuration - offsetMs, 100); // For last event, use remaining time
    }

    return {
      ...event,
      visualTime: totalDuration > 0 ? offsetMs / totalDuration : 0,
      duration,
      offsetMs,
    };
  });