/**
 * Handler invoked on every service worker `statechange` event, receiving the
 * worker's current lifecycle state.
 */
export type ServiceWorkerStateChangeHandler = (state: ServiceWorkerState) => void;
/**
 * Options for {@link ServiceWorker.register}.
 */
export interface ServiceWorkerOptions {
    /**
     * Optional handler invoked on every service worker `statechange` event.
     *
     * When provided, this handler replaces the built-in Pinpoint auto-recording:
     * the built-in analytics event is only recorded when no handler is supplied,
     * which prevents duplicate telemetry for the same state change.
     */
    onStateChange?: ServiceWorkerStateChangeHandler;
}
/**
 * Provides a means to registering a service worker in the browser
 * and communicating with it via postMessage events.
 * https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API/
 *
 * postMessage events are currently not supported in all browsers. See:
 * https://developer.mozilla.org/en-US/docs/Web/API/Service_Worker_API
 *
 * At the minmum this class will register the service worker and listen
 * and attempt to dispatch messages on state change and record analytics
 * events based on the service worker lifecycle.
 */
export declare class ServiceWorkerClass {
    private _serviceWorker?;
    private _registration?;
    private _publicKey?;
    private _subscription?;
    private _onStateChange?;
    private _logger;
    /**
     * Get the currently active service worker
     */
    get serviceWorker(): ServiceWorker;
    /**
     * Register the service-worker.js file in the browser
     * Make sure the service-worker.js is part of the build
     * for example with Angular, modify the angular-cli.json file
     * and add to "assets" array "service-worker.js"
     *
     * Note: when `options.onStateChange` is omitted, this method implicitly
     * records service worker lifecycle (`statechange`) events to Amazon
     * Pinpoint. That built-in auto-recording is deprecated and will be removed
     * in a future major version — only the implicit Pinpoint recording is
     * deprecated, not `register()` itself. Provide `options.onStateChange` to
     * observe lifecycle state changes and emit vendor-neutral telemetry instead.
     * @param {string} filePath Service worker file. Defaults to "/service-worker.js"
     * @param {string} scope The service worker scope. Defaults to "/"
     *  - API Doc: https://developer.mozilla.org/en-US/docs/Web/API/ServiceWorkerContainer/register
     * @param {ServiceWorkerOptions} [options] Optional registration options. When
     * `onStateChange` is provided it is invoked on every service worker state
     * change and replaces the built-in Pinpoint auto-recording. It is also
     * invoked once with the worker's current state at registration time, so an
     * already-active worker (which dispatches no `statechange` event) is still
     * observed. This initial emit applies only to `onStateChange`; the built-in
     * Pinpoint path is unaffected.
     * @returns {Promise}
     *	- resolve(ServiceWorkerRegistration)
     *	- reject(Error)
     **/
    register(filePath?: string, scope?: string, options?: ServiceWorkerOptions): Promise<unknown>;
    /**
     * Enable web push notifications. If not subscribed, a new subscription will
     * be created and registered.
     * 	Test Push Server: https://web-push-codelab.glitch.me/
     * 	Push Server Libraries: https://github.com/web-push-libs/
     * 	API Doc: https://developers.google.com/web/fundamentals/codelabs/push-notifications/
     * @param publicKey
     * @returns {Promise}
     * 	- resolve(PushSubscription)
     *  - reject(Error)
     */
    enablePush(publicKey: string): Promise<unknown>;
    /**
     * Convert a base64 encoded string to a Uint8 array for the push server key
     * @param base64String
     */
    private _urlB64ToUint8Array;
    /**
     * Send a message to the service worker. The service worker needs
     * to implement `self.addEventListener('message') to handle the
     * message. This ***currently*** does not work in Safari or IE.
     * @param {object | string} message An arbitrary JSON object or string message to send to the service worker
     *	- see: https://developer.mozilla.org/en-US/docs/Web/API/Transferable
     * @returns {Promise}
     **/
    send(message: object | string): void;
    /**
     * Listen for service worker state change and message events
     * https://developer.mozilla.org/en-US/docs/Web/API/ServiceWorker/state
     *
     * Each call to `register()` attaches its own `statechange` listener. The
     * `onStateChange` handler is captured in a local at listener-creation time,
     * so re-registering with a different handler only affects its own listener
     * and never re-targets a previously attached one.
     **/
    _setupListeners(): void;
    /**
     * Invoke the consumer `onStateChange` handler with the given state, isolating
     * any error it throws (or rejects with, for an async handler) so it cannot
     * surface as an unhandled rejection. Awaiting the handler means a rejected
     * promise from an async handler is caught here too; `await undefined`
     * resolves immediately for sync or absent handlers.
     */
    private _notifyStateChange;
}