cherfia/chromiumly

import { constants, createReadStream, promises } from 'fs';
import path from 'path';

import FormData from 'form-data';

import { GotenbergUtils } from '../../common';
import { LIBRE_OFFICE_EXTENSIONS } from './constants';
import {
    ConversionOptions,
    PageProperties,
    PathLikeOrReadStream
} from '../interfaces/libre-office.types';

/**
 * Utility class for handling common tasks related to LibreOffice conversions.
 */
export class LibreOfficeUtils {
    private static async getFileInfo(file: PathLikeOrReadStream) {
        if (typeof file === 'string') {
            await promises.access(file, constants.R_OK);
            const filename = path.basename(path.parse(file).base);
            return {
                data: createReadStream(file),
                ext: path.extname(filename).slice(1)
            };
        } else {
            return { data: file.data, ext: file.ext };
        }
    }

    /**
     * Adds files to the FormData object for LibreOffice conversion.
     *
     * @param {PathLikeOrReadStream[]} files - An array of files to be added to the FormData.
     * @param {FormData} data - The FormData object to which files will be added.
     * @throws {Error} Throws an error if the file extension is not supported.
     */
    public static async addFiles(
        files: PathLikeOrReadStream[],
        data: FormData
    ) {
        await Promise.all(
            files.map(async (file, key) => {
                const fileInfo = await this.getFileInfo(file);
                if (!LIBRE_OFFICE_EXTENSIONS.includes(fileInfo.ext)) {
                    throw new Error(`${fileInfo.ext} is not supported`);
                }
                data.append('files', fileInfo.data, `${key}.${fileInfo.ext}`);
            })
        );
    }

    /**
     * Adds page properties to the FormData object based on the provided PageProperties.
     *
     * @param {FormData} data - The FormData object to which page properties will be added.
     * @param {PageProperties} pageProperties - The page properties to be added to the FormData.
     */
    public static addPageProperties(
        data: FormData,
        pageProperties: PageProperties
    ): void {
        if (pageProperties.landscape) {
            data.append('landscape', String(pageProperties.landscape));
        }

        if (pageProperties.nativePageRanges) {
            GotenbergUtils.assert(
                pageProperties.nativePageRanges.from > 0 &&
                    pageProperties.nativePageRanges.to > 0 &&
                    pageProperties.nativePageRanges.to >=
                        pageProperties.nativePageRanges.from,
                'page ranges syntax error'
            );

            data.append(
                'nativePageRanges',
                `${pageProperties.nativePageRanges.from}-${pageProperties.nativePageRanges.to}`
            );
        }

        if (pageProperties.exportFormFields === false) {
            data.append(
                'exportFormFields',
                String(pageProperties.exportFormFields)
            );
        }

        if (pageProperties.singlePageSheets) {
            data.append(
                'singlePageSheets',
                String(pageProperties.singlePageSheets)
            );
        }
    }

    /**
     * Customizes the FormData object based on the provided conversion options.
     *
     * @param {FormData} data - The FormData object to be customized.
     * @param {ConversionOptions} options - The conversion options to apply to the FormData.
     * @returns {Promise<void>} A Promise that resolves once the customization is complete.
     */
    public static async customize(
        data: FormData,
        options: ConversionOptions
    ): Promise<void> {
        if (options.pdfa) {
            data.append('pdfa', options.pdfa);
        }

        if (options.pdfUA) {
            data.append('pdfUA', String(options.pdfUA));
        }

        if (options.merge) {
            data.append('merge', String(options.merge));
        }

        if (options.metadata) {
            data.append('metadata', JSON.stringify(options.metadata));
        }

        if (options.properties) {
            LibreOfficeUtils.addPageProperties(data, options.properties);
        }
    }
}