// loaders.gl
// SPDX-License-Identifier: MIT
// Copyright (c) vis.gl contributors
// This file is derived from the tar-js code base under MIT license
// See https://github.com/beatgammit/tar-js/blob/master/LICENSE
/*
 * tar-js
 * MIT (c) 2011 T. Jameson Little
 */
/* eslint-disable */
import * as utils from "./utils.js";
/*
struct posix_header {             // byte offset
    char name[100];               //   0
    char mode[8];                 // 100
    char uid[8];                  // 108
    char gid[8];                  // 116
    char size[12];                // 124
    char mtime[12];               // 136
    char chksum[8];               // 148
    char typeflag;                // 156
    char linkname[100];           // 157
    char magic[6];                // 257
    char version[2];              // 263
    char uname[32];               // 265
    char gname[32];               // 297
    char devmajor[8];             // 329
    char devminor[8];             // 337
    char prefix[155];             // 345
                                  // 500
};
*/
const structure = {
    fileName: 100,
    fileMode: 8,
    uid: 8,
    gid: 8,
    fileSize: 12,
    mtime: 12,
    checksum: 8,
    type: 1,
    linkName: 100,
    ustar: 8,
    owner: 32,
    group: 32,
    majorNumber: 8,
    minorNumber: 8,
    filenamePrefix: 155,
    padding: 12
};
/**
 * Getting the header
 * @param data
 * @param [cb]
 * @returns {Uint8Array} | Array
 */
export function format(data, cb) {
    const buffer = utils.clean(512);
    let offset = 0;
    Object.entries(structure).forEach(([field, length]) => {
        const str = data[field] || '';
        let i;
        let fieldLength;
        for (i = 0, fieldLength = str.length; i < fieldLength; i += 1) {
            buffer[offset] = str.charCodeAt(i);
            offset += 1;
        }
        // space it out with nulls
        offset += length - i;
    });
    if (typeof cb === 'function') {
        return cb(buffer, offset);
    }
    return buffer;
}