import { task } from './trace';
import { SHARED_DESCRIPTION } from './constants/description';
import { createMemoizedPromise } from './lib/memo-promise';
import { RulesetOutput } from './lib/rules/ruleset';
import Worktank from 'worktank';

const pool = new Worktank({
  name: 'build-internal-reverse-chn-cidr',
  size: 1,
  timeout: 10000, // The maximum number of milliseconds to wait for the result from the worker, if exceeded the worker is terminated and the execution promise rejects
  warmup: true,
  autoterminate: 30000, // The interval of milliseconds at which to check if the pool can be automatically terminated, to free up resources, workers will be spawned up again if needed
  env: {},
  methods: {
    // eslint-disable-next-line object-shorthand -- workertank
    getMicrosoftCdnRuleset: async function (importMetaUrl: string): Promise<[domains: string[], domainSuffixes: string[]]> {
      // TODO: createRequire is a temporary workaround for https://github.com/nodejs/node/issues/51956
      const { default: module } = await import('node:module');
      const __require = module.createRequire(importMetaUrl);

      const { HostnameSmolTrie } = __require('./lib/trie');
      const { PROBE_DOMAINS, DOMAINS, DOMAIN_SUFFIXES, BLACKLIST } = __require('./constants/microsoft-cdn') as typeof import('./constants/microsoft-cdn');
      const { fetchRemoteTextByLine } = __require('./lib/fetch-text-by-line') as typeof import('./lib/fetch-text-by-line');
      const { appendArrayInPlace } = __require('./lib/append-array-in-place') as typeof import('./lib/append-array-in-place');
      const { extractDomainsFromFelixDnsmasq } = __require('./lib/parse-dnsmasq') as typeof import('./lib/parse-dnsmasq');

      const trie = new HostnameSmolTrie();

      for await (const line of await fetchRemoteTextByLine('https://raw.githubusercontent.com/felixonmars/dnsmasq-china-list/master/accelerated-domains.china.conf')) {
        const domain = extractDomainsFromFelixDnsmasq(line);
        if (domain) {
          trie.add(domain);
        }
      }

      // remove blacklist domain from trie, to prevent them from being included in the later dump
      BLACKLIST.forEach(black => trie.whitelist(black));

      const domains: string[] = DOMAINS;
      const domainSuffixes = appendArrayInPlace(PROBE_DOMAINS.flatMap(domain => trie.find(domain)), DOMAIN_SUFFIXES);

      return [domains, domainSuffixes] as const;
    }
  }
});

export const getMicrosoftCdnRulesetPromise = createMemoizedPromise<[domains: string[], domainSuffixes: string[]]>(async () => {
  const res = await pool.exec(
    'getMicrosoftCdnRuleset',
    [import.meta.url]
  );
  pool.terminate();

  return res;
});

export const buildMicrosoftCdn = task(require.main === module, __filename)(async (span) => {
  const description = [
    ...SHARED_DESCRIPTION,
    '',
    'This file contains Microsoft\'s domains using their China mainland CDN servers.',
    '',
    'Data from:',
    ' - https://github.com/felixonmars/dnsmasq-china-list'
  ];

  const [domains, domainSuffixes] = await span.traceChildPromise('get microsoft cdn domains', getMicrosoftCdnRulesetPromise());

  return new RulesetOutput(span, 'microsoft_cdn', 'non_ip')
    .withTitle('Sukka\'s Ruleset - Microsoft CDN')
    .withDescription(description)
    .bulkAddDomain(domains)
    .bulkAddDomainSuffix(domainSuffixes)
    .write();
});