/**
 * Copyright (c) 2026 ByteDance Ltd. and/or its affiliates
 * SPDX-License-Identifier: MIT
 *
 * Per-chat name → openId registry.
 *
 * Backs `normalizeOutboundMentions` / `ensureMention` on the outbound side:
 * when the LLM writes "@Alice" in a reply, the outbound layer needs to look
 * up which `ou_xxx` "Alice" maps to in this specific chat to produce a real
 * Feishu `<at user_id="ou_xxx">` element that actually triggers delivery.
 *
 * Two ingestion paths feed the registry:
 *   1. `recordSender(chatId, openId, name)` — every inbound message's sender
 *   2. `recordMention(chatId, openId, name)` — every @-target in inbound text
 *
 * Entries decay with TTL so stale display names (renames, departed members)
 * don't pollute future lookups indefinitely. The registry is process-local;
 * it's a best-effort cache, not a source of truth, and a cache miss simply
 * means the outbound mention falls back to plain "@Name" text (which Feishu
 * won't deliver as a notification — that's a graceful degradation, not a
 * functional failure).
 */
/**
 * Record an @-mention target observed in inbound text.
 *
 * The name passed here should be the human-readable display name as parsed
 * out of the Feishu mention element, not the raw `@user_xxx` placeholder.
 */
export declare function recordMention(chatId: string, openId: string, name: string): void;
/**
 * Record the sender of an inbound message.
 *
 * Even when the sender is never @-mentioned, recording lets the outbound
 * layer @ them back by name. In bot↔bot flows this is the only way the
 * receiving bot learns the peer bot's name → openId mapping.
 */
export declare function recordSender(chatId: string, openId: string, name: string): void;
/**
 * Look up the openId for a name in a given chat. Returns `undefined` when
 * the name has never been seen, or when the entry has aged out past TTL.
 *
 * Caller may pass either the raw mention spelling ("alice", "Alice", "
 *  Alice ") — name comparison is case-insensitive and ignores surrounding
 * whitespace.
 */
export declare function lookupByName(chatId: string, name: string, opts?: {
    ttlMs?: number;
}): string | undefined;
/**
 * Reset the registry. Intended for tests; production code should rely on
 * TTL expiry instead.
 */
export declare function resetMentionRegistry(): void;
/**
 * Drop all entries older than `ttlMs` across every chat. Optional helper
 * for callers that want a deterministic cleanup tick — `lookupByName`
 * already does lazy eviction on read.
 */
export declare function purgeStaleEntries(ttlMs?: number): void;