/**
 * LocalStorage Storage Adapter
 *
 * Browser-compatible storage using the Web Storage API (localStorage).
 * Persistent across page reloads but limited to ~5MB per origin.
 *
 * Supports optional AES-256-GCM at-rest encryption when an encryption key
 * is provided, preventing clear-text storage of sensitive values.
 */
import { BaseStorageAdapter } from './base';
import type { SetOptions, MessageHandler, Unsubscribe } from '../types';
/**
 * Options for the LocalStorage adapter.
 */
export interface LocalStorageAdapterOptions {
    /**
     * Key prefix for namespacing.
     * @default 'frontmcp:'
     */
    prefix?: string;
    /**
     * Optional 32-byte AES-256-GCM encryption key.
     * When provided, all values are encrypted at rest in localStorage.
     */
    encryptionKey?: Uint8Array;
    /**
     * Whether to allow plaintext storage when no encryption key is provided.
     * @default true
     */
    allowPlaintext?: boolean;
}
/**
 * Browser localStorage-based storage adapter.
 *
 * Features:
 * - Persistent across page reloads
 * - Synchronous underlying API (async interface for consistency)
 * - TTL support via stored expiration timestamps
 * - Size-limited (~5MB per origin)
 *
 * Limitations:
 * - No pub/sub support
 * - incr/decr/incrBy are non-atomic (read-then-write); do not assume atomicity under concurrent access
 * - String-only values (matches StorageAdapter contract)
 * - Pattern matching uses simple iteration
 */
export declare class LocalStorageAdapter extends BaseStorageAdapter {
    protected readonly backendName = "localstorage";
    private readonly prefix;
    private readonly encryptionKey;
    private readonly allowPlaintext;
    private readonly encoder;
    private readonly decoder;
    constructor(options?: LocalStorageAdapterOptions);
    private assertAvailable;
    private key;
    private stripPrefix;
    connect(): Promise<void>;
    disconnect(): Promise<void>;
    ping(): Promise<boolean>;
    get(key: string): Promise<string | null>;
    set(key: string, value: string, options?: SetOptions): Promise<void>;
    protected doSet(key: string, value: string, options?: SetOptions): Promise<void>;
    delete(key: string): Promise<boolean>;
    exists(key: string): Promise<boolean>;
    mget(keys: string[]): Promise<(string | null)[]>;
    mset(entries: {
        key: string;
        value: string;
        options?: SetOptions;
    }[]): Promise<void>;
    mdelete(keys: string[]): Promise<number>;
    expire(key: string, ttlSeconds: number): Promise<boolean>;
    ttl(key: string): Promise<number | null>;
    keys(pattern?: string): Promise<string[]>;
    count(pattern?: string): Promise<number>;
    incr(key: string): Promise<number>;
    decr(key: string): Promise<number>;
    incrBy(key: string, amount: number): Promise<number>;
    publish(): Promise<number>;
    subscribe(_channel: string, _handler: MessageHandler): Promise<Unsubscribe>;
    supportsPubSub(): boolean;
    private matchPattern;
}