import type { OrchestrationEvent, OrchestrationThreadStreamItem } from "@t3tools/contracts";import * as Deferred from "effect/Deferred";import * as Duration from "effect/Duration";import * as Effect from "effect/Effect";import * as Fiber from "effect/Fiber";import * as Predicate from "effect/Predicate";import * as Queue from "effect/Queue";import * as Semaphore from "effect/Semaphore";import * as Stream from "effect/Stream"; import { projectActivityEvent } from "./ActivityPayloadProjection.ts"; const COALESCE_WINDOW = Duration.millis(50);const MAX_PENDING_UPDATES = 512; export type ThreadLiveInput =  | { readonly kind: "event"; readonly event: OrchestrationEvent }  | { readonly kind: "synchronized" }; function isToolUpdated(event: OrchestrationEvent): boolean {  return (    event.type === "thread.activity-appended" && event.payload.activity.kind === "tool.updated"  );} function asTrimmedString(value: unknown): string | null {  if (!Predicate.isString(value)) {    return null;  }  const trimmed = value.trim();  return trimmed.length > 0 ? trimmed : null;} function stableToolCallIdentity(event: OrchestrationEvent): string | null {  if (event.type !== "thread.activity-appended") {    return null;  }  const payload = event.payload.activity.payload;  if (!Predicate.isObject(payload)) {    return null;  }  const data = Predicate.isObject(payload.data) ? payload.data : null;  return asTrimmedString(payload.toolCallId) ?? asTrimmedString(data?.toolCallId);} /** * Retain only the latest in-flight update for each stable tool-call id in a * live run. Anonymous calls pass through because labels are not unique when * tools execute in parallel. Survivors remain in sequence order. */export function coalesceLiveToolUpdatedEvents(  events: ReadonlyArray<OrchestrationEvent>,): ReadonlyArray<OrchestrationEvent> {  const survivors: Array<OrchestrationEvent> = [];  let pendingUpdates: Array<OrchestrationEvent> = [];   const flushUpdates = () => {    const seen = new Set<string>();    const latestUpdates: Array<OrchestrationEvent> = [];    for (let index = pendingUpdates.length - 1; index >= 0; index -= 1) {      const event = pendingUpdates[index]!;      const identity = stableToolCallIdentity(event);      const activity =        event.type === "thread.activity-appended" ? event.payload.activity : undefined;      const key = identity ? `${activity?.turnId ?? ""}\u0000${identity}` : null;      if (key && seen.has(key)) {        continue;      }      if (key) {        seen.add(key);      }      latestUpdates.push(event);    }    latestUpdates.reverse();    survivors.push(...latestUpdates);    pendingUpdates = [];  };   for (const event of events) {    if (isToolUpdated(event)) {      pendingUpdates.push(event);      continue;    }    flushUpdates();    survivors.push(event);  }  flushUpdates();  return survivors;} export const makeThreadLiveEventCoalescer = Effect.fn("makeThreadLiveEventCoalescer")(  function* (options?: { readonly coalesceWindow?: Duration.Input }) {    const output = yield* Queue.unbounded<OrchestrationThreadStreamItem>();    const input = yield* Queue.unbounded<{      readonly value: ThreadLiveInput;      readonly processed?: Deferred.Deferred<void>;    }>();    const mutex = yield* Semaphore.make(1);    const coalesceWindow = options?.coalesceWindow ?? COALESCE_WINDOW;    let pendingUpdates: Array<OrchestrationEvent> = [];    let windowGeneration = 0;    let windowFiber: Fiber.Fiber<void, never> | null = null;     const cancelWindow = Effect.fn("ThreadLiveEventCoalescer.cancelWindow")(function* () {      const fiber = windowFiber;      if (!fiber) {        return;      }      windowFiber = null;      yield* Fiber.interrupt(fiber);    });     const flushPending = Effect.fn("ThreadLiveEventCoalescer.flushPending")(function* (      boundary?: OrchestrationEvent,    ) {      const events = boundary ? [...pendingUpdates, boundary] : pendingUpdates;      pendingUpdates = [];      if (events.length === 0) {        return;      }      yield* Queue.offerAll(        output,        coalesceLiveToolUpdatedEvents(events).map((event) => ({          kind: "event" as const,          event: projectActivityEvent(event),        })),      );    });     const flushWindow = (generation: number) =>      Effect.sleep(coalesceWindow).pipe(        Effect.andThen(          mutex.withPermits(1)(            Effect.suspend(() => (generation === windowGeneration ? flushPending() : Effect.void)),          ),        ),        Effect.ensuring(          Effect.sync(() => {            if (generation === windowGeneration) {              windowFiber = null;            }          }),        ),      );     const process = Effect.fn("ThreadLiveEventCoalescer.process")(function* (      input: ThreadLiveInput,    ) {      yield* mutex.withPermits(1)(        Effect.gen(function* () {          if (input.kind === "event" && isToolUpdated(input.event)) {            pendingUpdates.push(input.event);            if (pendingUpdates.length === 1) {              const generation = ++windowGeneration;              windowFiber = yield* Effect.forkScoped(flushWindow(generation));            }            if (pendingUpdates.length >= MAX_PENDING_UPDATES) {              yield* cancelWindow();              windowGeneration += 1;              yield* flushPending();            }            return;          }           yield* cancelWindow();          windowGeneration += 1;          // A non-update event closes the run immediately. The coalescer keeps          // that boundary after the final update from the run.          if (input.kind === "event") {            yield* flushPending(input.event);          } else {            yield* flushPending();            yield* Queue.offer(output, { kind: "synchronized" });          }        }),      );    });     yield* Stream.fromQueue(input).pipe(      Stream.runForEach(({ value, processed }) =>        process(value).pipe(          Effect.andThen(processed ? Deferred.succeed(processed, undefined) : Effect.void),        ),      ),      Effect.forkScoped,    );     const offer = (value: ThreadLiveInput) => Queue.offer(input, { value }).pipe(Effect.asVoid);     // Synchronization callers wait for their marker to pass through the same    // ordered input queue before draining output produced ahead of it.    const offerAndWait = Effect.fn("ThreadLiveEventCoalescer.offerAndWait")(function* (      value: ThreadLiveInput,    ) {      const processed = yield* Deferred.make<void>();      yield* Queue.offer(input, { value, processed });      yield* Deferred.await(processed);    });     return {      offer,      offerAndWait,      stream: Stream.fromQueue(output),      takeAll: Queue.takeAll(output),    } as const;  },);