import { task } from './trace';
import path from 'node:path';
import fs from 'node:fs';
import { pipeline } from 'node:stream/promises';
import { OUTPUT_MOCK_DIR } from './constants/dir';
import { mkdirp } from './lib/misc';
import { $$fetch } from './lib/fetch-retry';

const ASSETS_LIST = {
  'www-google-analytics-com_ga.js': 'https://cdn.jsdelivr.net/npm/@adguard/scriptlets@latest/dist/redirect-files/google-analytics-ga.js',
  'www-googletagservices-com_gpt.js': 'https://cdn.jsdelivr.net/npm/@adguard/scriptlets@latest/dist/redirect-files/googletagservices-gpt.js',
  'www-google-analytics-com_analytics.js': 'https://cdn.jsdelivr.net/npm/@adguard/scriptlets@latest/dist/redirect-files/google-analytics.js',
  'www-googlesyndication-com_adsbygoogle.js': 'https://cdn.jsdelivr.net/npm/@adguard/scriptlets@latest/dist/redirect-files/googlesyndication-adsbygoogle.js',
  'amazon-adsystem-com_amazon-apstag.js': 'https://cdn.jsdelivr.net/npm/@adguard/scriptlets@latest/dist/redirect-files/amazon-apstag.js'
} as const;

export const downloadMockAssets = task(require.main === module, __filename)(async (span) => {
  const p = mkdirp(OUTPUT_MOCK_DIR);
  if (p) {
    await p;
  }

  return Promise.all(Object.entries(ASSETS_LIST).map(
    ([filename, url]) => span
      .traceChildAsync(url, async () => {
        const res = await $$fetch(url);
        if (!res.ok) {
          console.error(`Failed to download ${url}`);

          // we can safely skip this since we can always use previous version
          return;
        }

        if (!res.body) {
          console.error(`Empty body from ${url}`);

          // we can safely skip this since we can always use previous version
          return;
        }

        const src = path.join(OUTPUT_MOCK_DIR, filename);

        return pipeline(
          res.body,
          fs.createWriteStream(src, 'utf-8')
        );
      })
  ));
});