import { type FactoryWithRequiredInput, type IndexNumber, type Maybe, type Milliseconds } from '@dereekb/util';
import { type Observable, type SchedulerLike } from 'rxjs';
import { type LogicalDateStringCode } from './date.logical';
/**
 * Configuration for creating a periodic date-emitting Observable.
 */
export interface DateIntervalConfig {
    /**
     * How often to emit the date.
     *
     * Defaults to every second.
     */
    readonly period?: Maybe<Milliseconds>;
    /**
     * Emits the given logical date each interval (e.g. 'now', 'today_start').
     */
    readonly logicalDate?: Maybe<LogicalDateStringCode>;
    /**
     * Custom factory to use for producing each date value.
     */
    readonly factory?: FactoryWithRequiredInput<Date, IndexNumber>;
    /**
     * Whether to emit every interval tick regardless of whether the date changed. False by default.
     */
    readonly emitAll?: boolean;
    /**
     * Scheduler for the rxjs interval.
     */
    readonly scheduler?: SchedulerLike | undefined;
}
/**
 * Creates an Observable that emits a Date at regular intervals based on the given configuration.
 *
 * By default emits the current time every second and deduplicates consecutive equal dates.
 *
 * @param config - Interval and date generation configuration.
 * @returns An Observable that emits Date values.
 *
 * @example
 * ```ts
 * // Emit start-of-today every 5 seconds
 * const today$ = dateInterval({ logicalDate: 'today_start', period: 5000 });
 * ```
 */
export declare function dateInterval(config: DateIntervalConfig): Observable<Date>;
/**
 * Convenience function for {@link dateInterval} that emits the current time at each interval tick.
 *
 * Unlike the default dateInterval, this always emits (no deduplication) since each "now" is unique.
 *
 * @param period - Optional emission interval in milliseconds (defaults to 1 second)
 * @returns An Observable that emits the current Date.
 *
 * @example
 * ```ts
 * const now$ = nowInterval(1000);
 * now$.subscribe((date) => console.log('Current time:', date));
 * ```
 */
export declare function nowInterval(period?: Maybe<Milliseconds>): Observable<Date>;