/**
 * PDF form field (AcroForm) extractor.
 *
 * Extracts interactive form fields from a PDF's `/AcroForm` dictionary.
 * Supports all standard field types:
 * - **Text** (`/Tx`) — Text input fields
 * - **Button** (`/Btn`) — Checkboxes, radio buttons, push buttons
 * - **Choice** (`/Ch`) — Dropdowns (combo boxes) and list boxes
 * - **Signature** (`/Sig`) — Digital signature fields
 *
 * Handles field hierarchies (parent/child), inherited values, and default appearances.
 *
 * @see PDF Reference 1.7, §12.7 - Interactive Forms
 */
import type { PdfDocument } from "./pdf-document.js";
/** Type of form field. */
export type PdfFormFieldType = "text" | "checkbox" | "radio" | "dropdown" | "listbox" | "button" | "signature" | "unknown";
/** A single form field extracted from the PDF. */
export interface PdfFormField {
    /** Fully qualified field name (e.g. "form1.address.city") */
    name: string;
    /** Field type */
    type: PdfFormFieldType;
    /** Current value of the field */
    value: string;
    /** Default value (/DV entry) */
    defaultValue: string;
    /** Whether the field is read-only */
    readOnly: boolean;
    /** Whether the field is required */
    required: boolean;
    /** For choice fields: the list of available options */
    options: string[];
    /** For checkboxes/radio buttons: the export value when checked */
    exportValue: string;
    /** Field flags (/Ff entry) — raw bit field */
    flags: number;
}
/**
 * Extract form fields from a PDF document.
 *
 * Reads the `/AcroForm` dictionary from the catalog and recursively
 * traverses the field tree.
 *
 * @param doc - The PDF document
 * @returns Array of extracted form fields
 */
export declare function extractFormFields(doc: PdfDocument): PdfFormField[];