bldl/src/utils.js

A CLI tool for downloading Bilibili streams

import fs from 'node:fs/promises';
import { createWriteStream } from 'node:fs';
import os from 'node:os';
import path from 'node:path';
import stream from 'node:stream';
import { promisify } from 'node:util';
import got from 'got';

const pipeline = promisify(stream.pipeline);

function makeDirectoryIfNeeded(directoryPath) {
  const resolvedPath = path.resolve(directoryPath);

  return fs
    .mkdir(resolvedPath, { recursive: true })
    .then(() => resolvedPath)
    .catch(() => {
      throw new Error(`Fail to create directory: ${directoryPath}`);
    });
}

export function makeGotOptions(credential, url) {
  const defaultOrigin = 'https://www.bilibili.com';
  const userAgent =
    os.platform() === 'darwin'
      ? 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/110.0.0.0 Safari/537.36'
      : 'Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/110.0.0.0 Safari/537.36';

  return {
    headers: {
      cookie: `SESSDATA=${credential}`,
      origin: url ? new URL(url).origin : defaultOrigin,
      referer: url || defaultOrigin,
      'user-agent': userAgent,
    },
  };
}

export async function downloadTrack({
  track,
  credential,
  saveToDirectory,
  onProgress,
}) {
  await makeDirectoryIfNeeded(saveToDirectory);

  const urlPath = track.url.split('?')[0];

  const saveToFile = path.resolve(
    saveToDirectory,
    `${track.type}${path.extname(urlPath)}`
  );

  return pipeline(
    got
      .stream(track.url, makeGotOptions(credential))
      // {percent, transferred, total}
      .on('downloadProgress', onProgress),
    createWriteStream(saveToFile)
  )
    .then(() => saveToFile)
    .catch(() => {
      throw new Error(`Fail to download stream: ${track.url}`);
    });
}