export type Side = 'top' | 'right' | 'bottom' | 'left';
export type Alignment = 'start' | 'end';
export type Placement = Side | `${Side}-${Alignment}`;
export type Strategy = 'absolute' | 'fixed';
export interface Middleware {
    name: string;
    fn(state: MiddlewareState): MiddlewareReturn;
}
export interface MiddlewareState {
    x: number;
    y: number;
    placement: Placement;
    initialPlacement: Placement;
    rects: {
        reference: DOMRect;
        floating: {
            width: number;
            height: number;
        };
    };
    elements: {
        reference: HTMLElement;
        floating: HTMLElement;
    };
    middlewareData: Record<string, unknown>;
    strategy: Strategy;
}
export interface MiddlewareReturn {
    x?: number;
    y?: number;
    data?: Record<string, unknown>;
    reset?: boolean | {
        placement?: Placement;
    };
}
export interface ComputePositionReturn {
    x: number;
    y: number;
    placement: Placement;
    strategy: Strategy;
    middlewareData: Record<string, unknown>;
}
export declare function computePosition(reference: HTMLElement, floating: HTMLElement, options?: {
    placement?: Placement;
    strategy?: Strategy;
    middleware?: Middleware[];
}): Promise<ComputePositionReturn>;
export declare function offset(value: number | {
    mainAxis?: number;
    crossAxis?: number;
}): Middleware;
export declare function flip(options?: {
    padding?: number;
}): Middleware;
export declare function shift(options?: {
    padding?: number;
}): Middleware;
export declare function arrow(options: {
    element: HTMLElement;
    padding?: number;
}): Middleware;
export declare function size(options: {
    apply: (args: MiddlewareState & {
        availableWidth: number;
        availableHeight: number;
    }) => void;
}): Middleware;
export declare function autoUpdate(reference: HTMLElement, floating: HTMLElement, callback: () => void): () => void;