import type { IDisposable } from '../functions/disposer.js';
import { type EventHandler, type IEvent } from './event.js';
export type TimerState = {
    timer: Timer;
    elapsed: number;
    left: number;
    now: number;
};
/**
 * A timer wraps `setInterval` and provides a more convenient API.
 * It will fire an event every `interval` milliseconds.
 * It also may have duration which means it will stop when elapsed time is greater than or equal to the duration.
 */
export declare class Timer implements IDisposable, IEvent<TimerState> {
    readonly interval: number;
    private readonly _event;
    private readonly _onFinished;
    private _now;
    private _elapsed;
    private _left;
    private _duration;
    private _handle;
    /**
     * @param interval timer firing interval in milliseconds
     * @param start whether to start the timer immediately. default is `true`
     */
    constructor(interval?: number, start?: boolean);
    /** the timestamp when the timer last fired  */
    get now(): number;
    /** the duration of the timer in milliseconds. If was not set, `Number.MAX_SAFE_INTEGER` */
    get duration(): number;
    /** the elapsed milliseconds since the timer started */
    get elapsed(): number;
    /** left milliseconds for this timer. If duration was not set, `Number.MAX_SAFE_INTEGER` */
    get left(): number;
    /** Fired when the timer has finished by duration, if set */
    get onFinished(): IEvent<TimerState>;
    /** Adds duration in milliseconds for the timer so it will auto-stop when elapsed is >= duration */
    withDuration(duration: number): this;
    on(handler: EventHandler<TimerState>): () => void;
    off(handler: EventHandler<TimerState>): void;
    /** (Re-)Starts the timer */
    restart(): void;
    /** Stops the timer but does not clean all counters. */
    dispose(): void;
}