import { PdfFile } from './document.js';
/** A marked-content reference: a page index plus an MCID on that page. */
export interface StructMcid {
    /** Zero-based page index the MCID lives on. */
    readonly page: number;
    readonly mcid: number;
}
/**
 * One node of the recovered logical structure tree (ISO 32000-1 §14.7): a
 * `/StructElem`'s role, its own marked-content references (the text it owns) and
 * its child elements.
 */
export interface StructNode {
    /** The `/S` role name (`Document`, `P`, `H1`, `Table`, `TR`, `TD`, `L`, `LI`, …). */
    readonly type: string;
    /** The element's own marked content, linking it to interpreter-extracted text (EP2). */
    readonly mcids: ReadonlyArray<StructMcid>;
    readonly children: ReadonlyArray<StructNode>;
    /** `/Alt` — alternate text (figures). */
    readonly alt?: string;
    /** `/A /Table /ColSpan` on a table cell. */
    readonly colSpan?: number;
    /** `/A /Table /RowSpan` on a table cell. */
    readonly rowSpan?: number;
}
/**
 * Read the `/StructTreeRoot` (ISO 32000-1 §14.7) into a {@link StructNode} tree,
 * recovering reading order and roles. Walks each `/StructElem`'s `/K` children —
 * resolving nested elements, bare-integer and `/MCR` marked-content references
 * (carrying the owning page), and skipping `/OBJR` object references (no text) —
 * guards against cycles and pathological size, and lifts `/Alt` plus table cell
 * `/ColSpan`/`/RowSpan`. Multiple top-level roots are wrapped in a synthetic
 * `Document` node.
 *
 * @returns The structure-tree root, or `undefined` when the catalog has no
 *          `/StructTreeRoot` (an untagged PDF).
 */
export declare function readStructTree(file: PdfFile): StructNode | undefined;