import './utils/disposable';
import type { Unsubscribe, Logger } from './types';
interface TabSyncOptions {
    /** Enable debug logging (default: false). */
    debug?: boolean;
    /** Custom logger (default: console). */
    logger?: Logger;
}
/**
 * Cross-tab state synchronization via BroadcastChannel.
 * No WebSocket needed — works standalone for sharing state between browser tabs.
 *
 * @example
 * const sync = new TabSync('my-app');
 * sync.set('theme', 'dark');
 * sync.on('theme', (theme) => applyTheme(theme));
 *
 * @example
 * // With debug logging
 * const sync = new TabSync('my-app', { debug: true });
 */
export declare class TabSync implements Disposable {
    private store;
    private listeners;
    private bc;
    private disposed;
    private readonly log;
    constructor(channel?: string, options?: TabSyncOptions);
    /** Set a value and broadcast to all tabs. Local listeners also fire. */
    set<T>(key: string, value: T): void;
    /** Get current value from local store. */
    get<T>(key: string): T | undefined;
    /** Delete a key and broadcast deletion to all tabs. */
    delete(key: string): void;
    /** Check if a key exists in the local store. */
    has(key: string): boolean;
    /** Get all keys in the local store. */
    keys(): string[];
    /** Get number of entries. */
    get size(): number;
    /**
     * Listen for changes to a key. Fires when any tab (including this one) calls set().
     *
     * @example
     * sync.on('cart', (cart) => updateBadge(cart.items.length));
     */
    on<T>(key: string, fn: (value: T) => void): Unsubscribe;
    /** Listen for a key change once, then auto-unsubscribe. */
    once<T>(key: string, fn: (value: T) => void): Unsubscribe;
    /** Clear all keys and notify listeners. */
    clear(): void;
    /** Dispose — close BroadcastChannel and clear all state. */
    dispose(): void;
    private emit;
    [Symbol.dispose](): void;
}
export {};