import { PdfDocument } from './../pdf-document';
import { _PdfDictionary } from './../pdf-primitives';
import { _ExportHelper } from './xfdf-document';
import { PdfAnnotation } from './../annotations/annotation';
/**
 * Provides utilities to export and import FDF data for annotations and form fields and manages object mapping and serialization.
 *
 * @private
 */
export declare class _FdfDocument extends _ExportHelper {
    /**
     * Stores annotation objects collected during FDF export.
     *
     * Key and value types vary depending on annotation structure.
     *
     * @private
     */
    _annotationObjects: Map<any, any>;
    /**
     * Special character set used to normalize or escape content during FDF processing.
     *
     * @private
     */
    _specialCharacters: string;
    /**
     * Initializes the FDF export and import helper with an optional file name.
     *
     * @private
     * @param {string} fileName represent filename.
     */
    constructor(fileName?: string);
    /**
     * Prepares and exports annotations from the document as an FDF byte array.
     *
     * @private
     * @param {PdfDocument} document Source PDF document to read annotations.
     * @returns {Uint8Array} Generated FDF payload containing exported annotations.
     */
    _exportAnnotations(document: PdfDocument): Uint8Array;
    /**
     * Prepares and exports form fields from the document as an FDF byte array.
     *
     * @private
     * @param {PdfDocument} document Source PDF document to read form fields.
     * @returns {Uint8Array} Generated FDF payload containing exported form fields.
     */
    _exportFormFields(document: PdfDocument): Uint8Array;
    /**
     * Finalizes FDF serialization and returns the composed byte array.
     *
     * @private
     * @returns {Uint8Array} Serialized FDF data representing the current export.
     */
    _save(): Uint8Array;
    /**
     * Imports annotations from FDF bytes into the target PDF document.
     *
     * @private
     * @param {PdfDocument} document Target PDF document to receive annotations.
     * @param {Uint8Array} data Input FDF data containing annotations.
     * @returns {void}
     */
    _importAnnotations(document: PdfDocument, data: Uint8Array): void;
    /**
     * Imports form field values from FDF bytes into the target PDF document.
     *
     * @private
     * @param {PdfDocument} document Target PDF document to receive form values.
     * @param {Uint8Array} data Input FDF data containing form field entries.
     * @returns {void}
     */
    _importFormData(document: PdfDocument, data: Uint8Array): void;
    /**
     * Parses FDF content and fills internal tables for annotations or form values depending on mode.
     *
     * @private
     * @param {any} parser Parser used to iterate tokens and objects from FDF data.
     * @returns {void}
     */
    _readFdfData(parser: any): void;
    /**
     * Recursively parses a dictionary and resolves nested structures and references.
     *
     * @private
     * @param {_PdfDictionary} dictionary Dictionary to parse and normalize.
     * @returns {void}
     */
    _parseDictionary(dictionary: _PdfDictionary): void;
    /**
     * Resolves a specific dictionary entry and replaces references with concrete objects when available.
     *
     * @private
     * @param {_PdfDictionary} dictionary Dictionary holding the key to process.
     * @param {string} key Entry key to examine and resolve.
     * @returns {void}
     */
    _parseDictionaryData(dictionary: _PdfDictionary, key: string): void;
    /**
     * Parses an array and resolves any contained references into usable objects.
     *
     * @private
     * @param {Array<any>} array Array to inspect and rewrite when necessary.
     * @returns {void}
     */
    _parseArray(array: Array<any>): void;
    /**
     * Extracts annotation objects from parsed structures and removes trailer and root bookkeeping.
     *
     * @private
     * @returns {Map<any, any>} Map of annotation keys to their resolved dictionaries.
     */
    _parseAnnotationData(): Map<any, any>;
    /**
     * Applies imported form values from the table to matching fields in the document form.
     *
     * @private
     * @returns {void}
     */
    _importField(): void;
    /**
     * Iterates document pages and collects exportable annotations then writes FDF catalog and annots.
     *
     * @private
     * @param {PdfDocument} document Source document providing pages and annotations.
     * @param {number} pageCount Number of pages to process from the document.
     * @returns {void}
     */
    _exportAnnotationData(document: PdfDocument, pageCount: number): void;
    /**
     * Serializes a single annotation and related objects into FDF objects updating indices and references.
     *
     * @private
     * @param {PdfAnnotation} annotation Annotation to export.
     * @param {string} fdfString Current FDF buffer for concatenation.
     * @param {number} index Current object index used for indirect references.
     * @param {string[]} annot Accumulator of annotation object ids.
     * @param {number} pageIndex Page index where the annotation resides.
     * @param {boolean} appearance Indicates whether appearance streams should be included.
     * @returns {_FdfHelper} Helper with updated index annotation ids and queued objects.
     */
    _exportAnnotation(annotation: PdfAnnotation, fdfString: string, index: number, annot: string[], pageIndex: number, appearance: boolean): _FdfHelper;
    /**
     * Appends a stream section to the FDF output using content or compressed data as required.
     *
     * @private
     * @param {any} value Stream or stream holder to serialize.
     * @param {string} fdfString Current FDF buffer for concatenation.
     * @returns {void}
     */
    _appendStream(value: any, fdfString: string): void;
    /**
     * Appends dictionary entries to FDF output and queues nested objects for subsequent emission while tracking streams.
     *
     * @private
     * @param {Map<any, any>} list Queue of pending objects keyed by assigned object id.
     * @param {number[]} streamReference List of object ids that must include a stream body.
     * @param {number} index Current object index used to allocate new ids.
     * @param {_PdfDictionary} dictionary Dictionary to serialize.
     * @param {string} fdfString Current FDF buffer for concatenation.
     * @param {boolean} hasAppearance Indicates whether appearance related entries are allowed.
     * @returns {_FdfHelper} Helper with updated list stream references and index.
     */
    _getEntries(list: Map<any, any>, // eslint-disable-line
    streamReference: number[], index: number, dictionary: _PdfDictionary, fdfString: string, hasAppearance: boolean): _FdfHelper;
    /**
     * Appends an array to FDF output and captures indirect references for later emission.
     *
     * @private
     * @param {any[]} array Array to serialize.
     * @param {string} fdfString Current FDF buffer for concatenation.
     * @param {number} index Current object index used to allocate new ids.
     * @param {boolean} flag Marks whether contained references should be added to stream tracking.
     * @param {Map<any, any>} list Queue of pending objects keyed by assigned object id.
     * @param {number[]} streamReference List of object ids that must include a stream body.
     * @returns {_FdfHelper} Helper with updated list stream references and index.
     */
    _appendArray(array: any[], // eslint-disable-line
    fdfString: string, index: number, flag: boolean, list: Map<any, any>, // eslint-disable-line
    streamReference: number[]): _FdfHelper;
    /**
     * Appends a single element to FDF output handling names numbers strings arrays dictionaries references and booleans.
     *
     * @private
     * @param {any} element Element to serialize.
     * @param {string} fdfString Current FDF buffer for concatenation.
     * @param {number} index Current object index used to allocate new ids.
     * @param {boolean} flag Marks whether references should be added to stream tracking.
     * @param {Map<any, any>} list Queue of pending objects keyed by assigned object id.
     * @param {number[]} streamReference List of object ids that must include a stream body.
     * @returns {_FdfHelper} Helper with updated list stream references and index.
     */
    _appendElement(element: any, // eslint-disable-line
    fdfString: string, index: number, flag: boolean, list: Map<any, any>, // eslint-disable-line
    streamReference: number[]): _FdfHelper;
    /**
     * Escapes special characters in text for safe inclusion in FDF string literals.
     *
     * @private
     * @param {string} value Input text to sanitize for FDF output.
     * @returns {string} Text with escaped characters for FDF compatibility.
     */
    _getFormattedString(value: string): string;
    /**
     * Validates FDF header and toggles specification mode based on special character markers.
     *
     * @private
     * @param {string} element Complete FDF text used to detect header and encoding markers.
     * @returns {void}
     */
    _checkFdf(element: string): void;
    /**
     * Converts a text value to a hexadecimal string using PDF byte conversion rules.
     *
     * @private
     * @param {string} text Input text to convert into hex representation.
     * @returns {string} Hexadecimal string representing the input text.
     */
    _stringToHexString(text: string): string;
}
/**
 * Holds intermediate data during FDF serialization including queued objects reference indices and annotation id list.
 *
 * @private
 */
export declare class _FdfHelper {
    list: Map<any, any>;
    streamReference: number[];
    index: number;
    annot: string[];
}