import { PathLikeOrReadStream, PdfFormat, Metadata } from '../common';
import { DownloadFrom, Split } from '../common/types';
/**
 * Class uses PDF engines for various operations such as merging and conversion.
 */
export declare class PDFEngines {
    /**
     * Merges multiple PDF files into a single PDF document.
     *
     * @param {Object} options - Options for the merge operation.
     * @param {PathLikeOrReadStream[]} options.files - An array of PathLikes or ReadStreams to the PDF files to be merged.
     * @param {PdfFormat} [options.pdfa] - PDF format options.
     * @param {boolean} [options.pdfUA] - Indicates whether to generate PDF/UA compliant output.
     * @param {Metadata} [options.metadata] - Metadata to be written.
     * @param {DownloadFrom} [options.downloadFrom] - Download a file from a URL. It must return a Content-Disposition header with a filename parameter.
     * @param {boolean} [options.flatten] - Flatten the PDF document.
     *
     * @returns {Promise<Buffer>} A Promise resolving to the merged PDF content as a buffer
     */
    static merge({ files, pdfa, pdfUA, metadata, downloadFrom, flatten }: {
        files: PathLikeOrReadStream[];
        pdfa?: PdfFormat;
        pdfUA?: boolean;
        metadata?: Metadata;
        downloadFrom?: DownloadFrom;
        flatten?: boolean;
    }): Promise<Buffer>;
    /**
     * Converts various document formats to PDF.
     *
     * @param {Object} options - Options for the conversion operation.
     * @param {PathLikeOrReadStream[]} options.files - An array of PathLikes or ReadStreams to the files to be converted to PDF.
     * @param {PdfFormat} [options.pdfa] - PDF format options.
     * @param {boolean} [options.pdfUA] - Indicates whether to generate PDF/UA compliant output.
     * @param {DownloadFrom} [options.downloadFrom] - Download a file from a URL. It must return a Content-Disposition header with a filename parameter.
     * @returns {Promise<Buffer>} A Promise resolving to the converted PDF content as a buffer
     */
    static convert({ files, pdfa, pdfUA, downloadFrom }: {
        files: PathLikeOrReadStream[];
        pdfa?: PdfFormat;
        pdfUA?: boolean;
        downloadFrom?: DownloadFrom;
    }): Promise<Buffer>;
    /**
     * Splits a PDF file into multiple PDF files.
     *
     * @param {Object} options - Options for the split operation.
     * @param {PathLikeOrReadStream[]} options.files - An array of PathLikes or ReadStreams to the PDF files to be split.
     * @param {Split} options.options - Split configuration specifying mode ('pages' or 'intervals'), span, and unify options.
     * @returns {Promise<Buffer>} A Promise resolving to the split PDF content as a buffer
     */
    static split({ files, options }: {
        files: PathLikeOrReadStream[];
        options: Split;
    }): Promise<Buffer>;
    /**
     * Flattens a PDF file.
     *
     * @param {PathLikeOrReadStream[]} files - An array of PathLikes or ReadStreams to the PDF files to be flattened.
     * @returns {Promise<Buffer>} A Promise resolving to the flattened PDF content as a buffer
     */
    static flatten(files: PathLikeOrReadStream[]): Promise<Buffer>;
    /**
     * Reads metadata from the provided files.
     *
     * @param {PathLikeOrReadStream[]} files An array of PathLikes or ReadStreams to the PDF files.
     * @returns {Promise<Buffer>} A Promise resolving to the metadata buffer.
     */
    static readMetadata(files: PathLikeOrReadStream[]): Promise<Buffer>;
    /**
     * Writes metadata to the provided PDF files.
     *
     * @param {PathLikeOrReadStream[]} files - An array of PathLikes or ReadStreams to the PDF files.
     * @param {Metadata} metadata - Metadata to be written.
     * @returns {Promise<Buffer>} A Promise that resolves to the PDF file containing metadata as a buffer.
     */
    static writeMetadata({ files, metadata }: {
        files: PathLikeOrReadStream[];
        metadata: Metadata;
    }): Promise<Buffer>;
    /**
     * Generates a PDF file from a buffer and saves it to the "__generated__" directory.
     *
     * @param {string} filename - The filename for the generated PDF.
     * @param {Buffer} buffer - The PDF content as a buffer
     * @returns {Promise<void>} A Promise that resolves once the file is generated and saved.
     */
    static generate(filename: string, buffer: Buffer): Promise<void>;
}