油猴脚本-文件下载器(支持跨域, 多文件Zip打包, 并发限制)

monkey-file-downloader.ts

import FileSaver from 'file-saver';
import JSZip from 'jszip';
import mime from 'mime';
import pLimit, { LimitFunction } from 'p-limit';
import parseHeaders from 'parse-headers';

// vite-plugin-monkey
import { GM_xmlhttpRequest } from '$';

export interface DFile {
  url: string;
  name: string;
}

export async function downloadAndZip(files: DFile | DFile[], zipFileName: string, concurrency: number = 10): Promise<void> {
  const zip = new JSZip();
  const limit: LimitFunction = pLimit(concurrency);
  const fileArr = Array.isArray(files) ? files : [files];

  function fetchFile(file: DFile): Promise<void> {
    return new Promise<void>((resolve, reject) => {
      GM_xmlhttpRequest({
        method: 'GET',
        url: file.url,
        responseType: 'blob',
        onload: (response) => {
          if (response.status === 200) {
            const headers = parseHeaders(response.responseHeaders);
            const contentType = headers['content-type'] as string | undefined;
            const extension = mime.getExtension(contentType || '');
            const fileName = extension ? `${file.name}.${extension}` : file.name;
            zip.file(fileName, response.response);
            resolve();
          } else {
            reject(new Error(`Failed to fetch ${file.url} with status ${response.status}: ${response.statusText}`));
          }
        },
        onerror: (error) => reject(error)
      });
    });
  }

  const promises = fileArr.map(file => limit(() => fetchFile(file)));
  await Promise.all(promises);

  const content = await zip.generateAsync({ type: 'blob' });
  FileSaver.saveAs(content, zipFileName);
}

// 注意:
// JSZip 打包后会出现下载卡死问题
// 解决方法参考 https://github.com/lisonge/vite-plugin-monkey/issues/216#issuecomment-2745140560

// 示例:
const files = [
  { url: 'https://example.com/file1.txt', name: 'file1.txt' },
  { url: 'https://example.com/file2.txt', name: 'file2.txt' },
  { url: 'https://example.com/file3.txt', name: 'file3.txt' }
];
downloadAndZip(files, 'my-files.zip', 10)
  .then(() => console.log('Done!'))
  .catch(console.error);