import type { ProviderEvent } from "@t3tools/contracts";import { useMemo } from "react";import { deriveTurnDiffSummaries, inferCheckpointTurnCountByTurnId } from "../session-logic";import type { Thread, TurnDiffSummary } from "../types"; const derivedTurnDiffSummaryCache = new WeakMap<readonly ProviderEvent[], TurnDiffSummary[]>(); function deriveTurnDiffSummariesCached(events: ProviderEvent[]): TurnDiffSummary[] {  const cached = derivedTurnDiffSummaryCache.get(events);  if (cached) {    return cached;  }  const derived = deriveTurnDiffSummaries(events);  derivedTurnDiffSummaryCache.set(events, derived);  return derived;} export function useTurnDiffSummaries(activeThread: Thread | undefined) {  const turnDiffSummaries = useMemo(() => {    if (!activeThread) {      return [];    }    if (activeThread.turnDiffSummaries.length > 0) {      return activeThread.turnDiffSummaries;    }    return deriveTurnDiffSummariesCached(activeThread.events);  }, [activeThread]);   const inferredCheckpointTurnCountByTurnId = useMemo(    () => inferCheckpointTurnCountByTurnId(turnDiffSummaries),    [turnDiffSummaries],  );   return { turnDiffSummaries, inferredCheckpointTurnCountByTurnId };}