export type ButtonGroupItem = {
    value: string | number;
    label?: string;
    disabled?: boolean;
};
/** `single` = radio semantics; `multiple` = toggle set; `none` = action buttons. */
export type ButtonGroupMode = 'single' | 'multiple' | 'none';
export type ButtonGroupValue = string | number | Array<string | number> | null;
/** Reactive inputs are passed as getters so the core tracks live prop changes. */
export type ButtonGroupConfig = {
    items: () => ReadonlyArray<ButtonGroupItem>;
    value: () => ButtonGroupValue;
    onChange?: (value: string | number | Array<string | number>) => void;
    mode?: () => ButtonGroupMode;
    disabled?: () => boolean;
    orientation?: () => 'horizontal' | 'vertical';
    /** Under `'rtl'` the horizontal Left/Right arrow direction flips. */
    dir?: () => 'ltr' | 'rtl' | 'auto' | undefined;
    id?: () => string | undefined;
    invalid?: () => boolean;
    required?: () => boolean;
    error?: () => string | undefined;
    hint?: () => string | undefined;
    ariaLabel?: () => string | undefined;
};
/** Normalize the value to an array (pure). */
export declare function toGroupArray(value: ButtonGroupValue): Array<string | number>;
export declare function createButtonGroup(config: ButtonGroupConfig): {
    /** Roving-focus target index (follows the selection in single mode). */
    readonly activeIndex: number;
    /** Selected values as an array (single mode -> 0 or 1 entry). */
    readonly selectedValues: (string | number)[];
    isSelected: (v: string | number) => boolean;
    isActive: (i: number) => boolean;
    pick: (i: number) => void;
    move: (delta: number) => void;
    onKeydown: (e: KeyboardEvent) => void;
    /** Spread onto the group container element. */
    rootProps: () => {
        onkeydown: (e: KeyboardEvent) => void;
        'aria-invalid': "true" | undefined;
        'aria-required': "true" | undefined;
        'aria-describedby': string | undefined;
        'aria-label': string | undefined;
        role: string;
        id: string | undefined;
        'aria-orientation': "horizontal" | "vertical";
    };
    /** Spread onto the button element at `index`. */
    buttonProps: (index: number) => {
        type: "button";
        role: "radio" | undefined;
        'data-idx': number;
        'aria-checked': boolean | undefined;
        'aria-pressed': boolean | undefined;
        'data-selected': string | undefined;
        disabled: true | undefined;
        tabindex: number;
        onclick: () => void;
    };
};
export type ButtonGroup = ReturnType<typeof createButtonGroup>;