/**
 * Browser-compatible timer scheduler for Service Worker environments.
 *
 * Replaces the server-side Scheduler with one that uses
 * Periodic Background Sync (where available) or falls back to
 * `setTimeout`-based polling.
 *
 * @module service-worker/scheduler
 */
import type { TimerEntry } from '../core/types';
import type { Storage } from '../storage/interface';
/**
 * Constructor options for {@link ServiceWorkerScheduler}.
 *
 * @example
 * ```ts
 * import { ServiceWorkerScheduler, type ServiceWorkerSchedulerOptions } from '@lostgradient/weft/service-worker';
 * import { MemoryStorage } from '@lostgradient/weft';
 *
 * const storage = new MemoryStorage();
 *
 * const options: ServiceWorkerSchedulerOptions = {
 *   storage,
 *   onTimerFired: (entry) => {
 *     console.log(`Timer ${entry.id} fired.`);
 *   },
 * };
 * const scheduler = new ServiceWorkerScheduler(options);
 * void scheduler;
 * ```
 */
export interface ServiceWorkerSchedulerOptions {
    storage: Storage;
    onTimerFired: (entry: TimerEntry) => void | Promise<void>;
    registration?: ServiceWorkerRegistration;
    periodicSyncTag?: string;
    fallbackIntervalMilliseconds?: number;
    getNow?: () => number;
}
/**
 * Scheduler for browser Service Worker environments, backed by durable storage.
 *
 * @example
 * ```ts
 * import { ServiceWorkerScheduler, createPeriodicSyncHandler } from '@lostgradient/weft/service-worker';
 * import { MemoryStorage } from '@lostgradient/weft';
 *
 * const storage = new MemoryStorage();
 *
 * const scheduler = new ServiceWorkerScheduler({
 *   storage,
 *   onTimerFired: (entry) => {
 *     console.log(`Timer ${entry.id} fired.`);
 *   },
 * });
 *
 * const handlePeriodicSync = createPeriodicSyncHandler(scheduler);
 * void handlePeriodicSync;
 * ```
 */
export declare class ServiceWorkerScheduler implements Disposable {
    #private;
    constructor(options: ServiceWorkerSchedulerOptions);
    /** Schedule a durable timer (writes to storage). */
    schedule(entry: TimerEntry): Promise<void>;
    /** Cancel a timer (removes from storage). */
    cancel(id: string): Promise<void>;
    /** Scan for expired timers, fire callbacks, and clean up. */
    tick(now?: number): Promise<void>;
    /** Process all expired timers then stop. */
    flush(now?: number): Promise<void>;
    /** Start the scheduler. Uses Periodic Background Sync if available, otherwise falls back to setTimeout polling. */
    start(): void;
    /** Stop the scheduler and clear all timeout handles. */
    stop(): void;
    [Symbol.dispose](): void;
}