import { UserInfo } from '../types';
import { LiteLLMClient } from '../client';
/**
 * Clock abstraction for testing. Allows tests to fake time without real delays.
 */
export interface Clock {
    now(): number;
}
/**
 * Simple LRU cache with per-entry TTL.
 * - Max ~500 entries; LRU eviction when full.
 * - Each entry has its own expiry time.
 * - Tracks pending promises for single-flight deduplication.
 */
export declare class UserInfoCache {
    private static readonly MAX_ENTRIES;
    private cache;
    private pending;
    private clock;
    private ttlMs;
    constructor(ttlMs?: number, clock?: Clock);
    /**
     * Get a cached value, or null if not found or expired.
     */
    get(userId: string): UserInfo | null;
    /**
     * Set a cache entry (does not expire).
     */
    set(userId: string, value: UserInfo): void;
    /**
     * Invalidate a single user's cache entry.
     */
    invalidate(userId: string): void;
    /**
     * Clear all cache entries and pending promises.
     */
    clear(): void;
    /**
     * Internal: track a pending promise for single-flight deduplication.
     * Returns the promise, which is stored and shared across concurrent requests.
     */
    private getPending;
    /**
     * Load a value through the cache with single-flight deduplication.
     * If the value is already cached and not expired, return it.
     * If another request is loading the same userId, wait for that promise.
     * Otherwise, call the loader and cache the result (unless null or error).
     *
     * Errors and null results are NOT cached.
     */
    load(userId: string, loader: () => Promise<UserInfo | null>): Promise<UserInfo | null>;
}
/**
 * Wraps a LiteLLMClient to inject getUserInfo caching and automatic cache
 * invalidation on mutations.
 *
 * Returns a Proxy that:
 * - Routes getUserInfo(userId) through the cache
 * - Invalidates the cache (clear all) after any method matching the mutation pattern
 * - Delegates all other methods to the wrapped client unchanged
 */
export declare function withUserInfoCache(client: LiteLLMClient, options?: {
    ttlMs?: number;
    clock?: Clock;
}): LiteLLMClient;