import { Interval } from 'date-fns';
export declare const M_MS: number;
export declare const D_M: number;
export declare const D_MS: number;
export declare function isTime(time: any): time is Date;
export declare function isValidTime(time: any): time is Date;
export declare function isValidOptionalTime(time: any): time is Date | undefined;
export declare function isSameTime(t1: Date | undefined, t2: Date | undefined): boolean;
export declare function isSameDay(t1: Date | undefined, t2: Date | undefined): boolean;
export declare function isLateTime(t1: Date | undefined, t2: Date | undefined): boolean;
/** 对比两个时间的大小，undefined 和无效时间等同于负无穷 */
export declare function compareTime(t1: Date | undefined, t2: Date | undefined): -1 | 0 | 1;
export declare function mergeDateAndTime(date: Date | undefined, time: Date | undefined): Date | undefined;
/**
 * 确保一个时间值被限制在所指定的起止区间或邻域区间内
 * NOTE: 这里的邻域是闭区间
 */
export declare function clampTime(time: Date, start: Date | undefined, end: Date | undefined): Date;
export declare function clampTime(time: Date, center: Date, radius: number): Date;
export declare type SliderStep = 'second' | 'minute' | 'hour';
export interface StepInfo {
    key: SliderStep;
    s: number;
    ms: number;
    tf: string;
    floor: <V extends Date | undefined>(time: V) => V extends Date ? Date : undefined;
    ceil: <V extends Date | undefined>(time: V) => V extends Date ? Date : undefined;
    prev: <V extends Date | undefined>(time: V) => V extends Date ? Date : undefined;
    next: <V extends Date | undefined>(time: V) => V extends Date ? Date : undefined;
}
export declare const STEP_INFOS: {
    [key in SliderStep]: StepInfo;
};
/**
 * 表示一个时间区间，其中包含两个可能未定义的 Date 类型的时间点。
 *
 * **NOTE:**
 *
 * 在 Range 类型中，时间点并不一定是按序的（即有可能第 1 个时间点是结束时间，而第 2 个时间点是起始时间），
 * 因此，我们定义了两套时间点的名称：
 *
 * - leftPoint: 区间中第一个时间点
 * - rightPoint: 区间中第二个时间点
 * - startPoint: 区间中的超始时间点
 * - endPoint: 区间中的结束时间点
 *
 * 另外若区间中只有一个有效时间点，则该时间点为 startPoint，而 endPoint 则会是 undefined。
 */
export declare type Range = (Date | undefined)[];
export declare type PointFixedSide = 'left' | 'right';
export declare type PointRelativeSide = 'start' | 'end';
export declare const EMPTY_RANGE: Range;
export declare function isValidRange(range: any): range is Range;
export declare function isFullRange(range: any): range is Date[];
export declare function isEmptyRange(range: Range): boolean;
export declare function isSameRange(r1: Range, r2: Range): boolean;
export declare function diffRange(r1: Range, r2: Range): {
    start: boolean;
    end: boolean;
};
export declare function checkMovedPoint(r1: Range, r2: Range): PointRelativeSide | undefined;
/**
 * 确保所返回的时间区间中：
 * 1. 如果有两个时间点，则左时间点一定小于或等于右时间点；
 * 2. 如果只有一个时间点，则一定是左时间点，而右时间点为 undefined；
 * 3. 所有时间点一定是有效时间。
 */
export declare function normalizeRange(range: Range): Range;
/**
 * 确保 r1 的方向与 r2 保持一致。
 * 即确保若 r2 的左时间为起始时间点，则 r1 的左时间也为起始时间点，若 r2 的左时间为结束时间点，则 r1 也一样。
 * 若 r1 的方向与 r2 一样，若 r2 为 undefined，则直接返回 r1 的原值。
 */
export declare function ensureSameDirection(r1: Range, r2: Range): Range;
export declare function getStartPoint(range: Range): {
    time: Date | undefined;
    side: PointFixedSide;
};
export declare function getEndPoint(range: Range): {
    time: Date | undefined;
    side: PointFixedSide;
};
export declare function getLeftPoint(range: Range | undefined): Date | undefined;
export declare function getRightPoint(range: Range | undefined): Date | undefined;
export declare function getRangeDuration(range: Range, step: StepInfo): number;
export declare function getMiddleTime(range: Date[]): Date;
export declare function intersection(r1: Interval, r2: Interval): Interval | undefined;
export declare function clamp(val: number, min: number, max: number): number;
export declare function clampIndex(val: number, len: number): number;
export declare function assert(condition: unknown, message?: string): asserts condition;
/** 检查鼠标左键是否被按下 */
export declare function detectLeftButton(event: PointerEvent): boolean;
/** 计算两点之间的距离 */
export declare function calcDistance(x1: number, y1: number, x2: number, y2: number): number;
export declare function notNil<TValue>(value: TValue | null | undefined): value is TValue;