export interface CssStyle {
    fontBold: boolean;
    fontItalic: boolean;
    fontUnderline: boolean;
    fontColor: string | null;
    backgroundColor: string | null;
}
export interface CellMeta {
    className?: string | string[];
    readOnly?: boolean;
    borders?: Record<string, {
        width: number;
        color: string;
    }>;
    type?: string;
    source?: unknown[];
    comment?: {
        value?: unknown;
    };
    numericFormat?: {
        pattern?: string;
        style?: string;
        currency?: string;
        minimumFractionDigits?: number;
        maximumFractionDigits?: number;
        useGrouping?: boolean;
    } | null;
    locale?: string;
    checkedTemplate?: unknown;
    [key: string]: unknown;
}
/**
 * Clears the per-export CSS style caches for the given document.
 *
 * Call this once at the start of each export so that CSS rule changes made
 * between exports are picked up instead of returning stale cached values.
 *
 * @param {Document} doc The owner document whose cache entries should be cleared.
 */
export declare function clearStyleCaches(doc: Document): void;
/**
 * Reads visual style properties from a rendered Handsontable cell element via
 * `getComputedStyle`.
 *
 * Font color is only read when the cell has at least one CSS class that is not a
 * Handsontable alignment class (`htLeft`, `htRight`, etc.), because alignment-only
 * cells carry only the inherited default text color.
 *
 * Background color is only emitted when a custom meta class actually changes the
 * computed background. Detection is done via a temporary off-screen probe element
 * (see `detectExplicitBackgroundColor`) — the actual table cell is never modified.
 *
 * When `element` is `null` (cell outside the render viewport) but `rootDocument`
 * and `rootWindow` are provided, style information is derived via a temporary probe
 * element (see `getCssStyleFromProbe`). Returns `null` only when no element and no
 * document fallback are available, or when the className has no custom classes.
 *
 * @param {HTMLElement|null} element The rendered `<td>` element, or `null`.
 * @param {string|string[]|undefined} className The cell's `className` meta value.
 * @param {Document|null} [rootDocument] Fallback document used when `element` is `null`.
 * @param {Window|null} [rootWindow] Fallback window used when `element` is `null`.
 * @returns {{ fontBold: boolean, fontItalic: boolean, fontUnderline: boolean,
 *             fontColor: string|null, backgroundColor: string|null }|null}
 */
export declare function getCssStyleFromElement(element: HTMLElement | null, className: string | string[] | undefined, rootDocument?: Document | null, rootWindow?: Window | null): CssStyle | null;
/**
 * Converts a CSS hex color string to an ARGB hex string expected by ExcelJS.
 *
 * @private
 * @param {string} color CSS color string.
 * @returns {string} Eight-character ARGB hex string (e.g. `'FF3366CC'`).
 */
export declare function cssColorToArgb(color: string): string;
/**
 * Derives an ExcelJS `alignment` object from a CSS className string.
 *
 * @private
 * @param {string|undefined} className CSS class string.
 * @returns {object|null}
 */
export declare function getAlignmentFromClassName(className: string | undefined): object | null;
/**
 * Derives an ExcelJS `alignment` object from the cell meta `className`.
 *
 * Recognised Handsontable alignment classes:
 * - Horizontal: `htLeft`, `htCenter`, `htRight`, `htJustify`
 * - Vertical: `htTop`, `htMiddle`, `htBottom`
 *
 * @private
 * @param {object|undefined} meta Cell meta object.
 * @returns {object|null}
 */
export declare function getAlignmentFromMeta(meta: CellMeta | undefined): object | null;
/**
 * Derives an ExcelJS `border` object from custom border data stored in cell meta.
 *
 * Border widths are mapped to the nearest Excel border style:
 * `1` → `'thin'`, `2` → `'medium'`, `3+` → `'thick'`.
 *
 * @private
 * @param {object|undefined} meta Cell meta object.
 * @returns {object|null}
 */
export declare function getBorderFromMeta(meta: CellMeta | undefined): object | null;
/**
 * Derives an ExcelJS `font` object from computed CSS style.
 *
 * All boolean properties (bold, italic, underline) and color are read exclusively
 * from the `cssStyle` object produced by `getCssStyleFromElement`. When `cssStyle`
 * is `null` (e.g. the cell is outside the rendered viewport), no font styling is
 * applied unless `meta.readOnly` is set.
 *
 * When `meta.readOnly` is `true` and no explicit color is found, a default dimmed text
 * color (`READ_ONLY_TEXT_ARGB`) is applied.
 *
 * @param {object|undefined} meta Cell meta object.
 * @param {{ fontBold: boolean, fontItalic: boolean, fontUnderline: boolean,
 *           fontColor: string|null }|null} [cssStyle] Computed CSS style from
 *   `getCssStyleFromElement`, or `null` for non-rendered cells.
 * @returns {object|null}
 */
export declare function getFontFromMeta(meta: CellMeta | undefined, cssStyle?: CssStyle | null): object | null;
/**
 * Derives an ExcelJS solid `fill` object from the computed CSS background color.
 *
 * Background color is read exclusively from `cssStyle.backgroundColor`.
 * When `meta.readOnly` is `true` and no explicit color is found, a default light gray fill
 * (`READ_ONLY_BG_ARGB`) is applied.
 *
 * @private
 * @param {object|undefined} meta Cell meta object.
 * @param {{ backgroundColor: string|null }|null} [cssStyle] Computed CSS style from
 *   `getCssStyleFromElement`, or `null` for non-rendered cells.
 * @returns {object|null}
 */
export declare function getFillFromMeta(meta: CellMeta | undefined, cssStyle?: {
    backgroundColor: string | null;
} | null): object | null;
/**
 * Returns an ExcelJS data validation object for dropdown and autocomplete cell types.
 *
 * @private
 * @param {object|undefined} meta Cell meta object.
 * @param {string|null} rangeRef Excel range reference to the validation list
 *   (e.g. `'_HotValidation'!$A$1:$A$3`). When `null` or `undefined`, returns `null`.
 * @returns {object|null}
 */
export declare function getDropdownValidation(meta: CellMeta | undefined, rangeRef: string | null): object | null;