// @ts-check
import fsp from 'fs/promises'
import path from 'path';

import { processHosts, processFilterRules } from './lib/parse-filter';
import createTrie from './lib/trie';

import { HOSTS, ADGUARD_FILTERS, PREDEFINED_WHITELIST, PREDEFINED_ENFORCED_BACKLIST } from './lib/reject-data-source';
import { createRuleset, compareAndWriteFile } from './lib/create-file';
import { processLine } from './lib/process-line';
import { domainDeduper } from './lib/domain-deduper';
import createKeywordFilter from './lib/aho-corasick';
import { readFileByLine } from './lib/fetch-remote-text-by-line';
import { createDomainSorter } from './lib/stable-sort-domain';
import { traceSync, task } from './lib/trace-runner';
import { getGorhillPublicSuffixPromise } from './lib/get-gorhill-publicsuffix';
import * as tldts from 'tldts';

/** Whitelists */
const filterRuleWhitelistDomainSets = new Set(PREDEFINED_WHITELIST);
/** @type {Set<string>} Dedupe domains inclued by DOMAIN-KEYWORD */
const domainKeywordsSet: Set<string> = new Set();
/** @type {Set<string>} Dedupe domains included by DOMAIN-SUFFIX */
const domainSuffixSet: Set<string> = new Set();

export const buildRejectDomainSet = task(__filename, async () => {
  /** @type Set<string> */
  const domainSets: Set<string> = new Set();

  // Parse from AdGuard Filters
  console.time('* Download and process Hosts / AdBlock Filter Rules');

  let shouldStop = false;

  const [gorhill] = await Promise.all([
    getGorhillPublicSuffixPromise(),
    // Parse from remote hosts & domain lists
    ...HOSTS.map(entry => processHosts(entry[0], entry[1]).then(hosts => {
      hosts.forEach(host => {
        if (host) {
          domainSets.add(host);
        }
      });
    })),
    ...ADGUARD_FILTERS.map(input => {
      const promise = typeof input === 'string'
        ? processFilterRules(input)
        : processFilterRules(input[0], input[1] || undefined);

      return promise.then((i) => {
        if (i) {
          const { white, black, foundDebugDomain } = i;
          if (foundDebugDomain) {
            shouldStop = true;
            // we should not break here, as we want to see full matches from all data source
          }
          white.forEach(i => filterRuleWhitelistDomainSets.add(i));
          black.forEach(i => domainSets.add(i));
        } else {
          process.exitCode = 1;
          throw new Error('Failed to process AdGuard Filter Rules!');
        }
      });
    }),
    ...([
      'https://raw.githubusercontent.com/AdguardTeam/AdGuardSDNSFilter/master/Filters/exceptions.txt',
      'https://raw.githubusercontent.com/AdguardTeam/AdGuardSDNSFilter/master/Filters/exclusions.txt'
    ].map(input => processFilterRules(input).then((i) => {
      if (i) {
        const { white, black } = i;
        white.forEach(i => {
          filterRuleWhitelistDomainSets.add(i);
        });
        black.forEach(i => {
          filterRuleWhitelistDomainSets.add(i);
        });
      } else {
        process.exitCode = 1;
        throw new Error('Failed to process AdGuard Filter Rules!');
      }
    })))
  ]);

  // remove pre-defined enforced blacklist from whitelist
  const trie0 = createTrie(filterRuleWhitelistDomainSets);
  PREDEFINED_ENFORCED_BACKLIST.forEach(enforcedBlack => {
    trie0.find(enforcedBlack).forEach(found => filterRuleWhitelistDomainSets.delete(found));
  });

  console.timeEnd('* Download and process Hosts / AdBlock Filter Rules');

  if (shouldStop) {
    // eslint-disable-next-line n/no-process-exit -- force stop
    process.exit(1);
  }

  let previousSize = domainSets.size;
  console.log(`Import ${previousSize} rules from Hosts / AdBlock Filter Rules!`);

  for await (const line of readFileByLine(path.resolve(__dirname, '../Source/domainset/reject_sukka.conf'))) {
    const l = processLine(line);
    if (l) {
      domainSets.add(l);
    }
  }

  previousSize = domainSets.size - previousSize;
  console.log(`Import ${previousSize} rules from reject_sukka.conf!`);

  for await (const line of readFileByLine(path.resolve(__dirname, '../Source/non_ip/reject.conf'))) {
    if (line.startsWith('DOMAIN-KEYWORD')) {
      const [, ...keywords] = line.split(',');
      domainKeywordsSet.add(keywords.join(',').trim());
    } else if (line.startsWith('DOMAIN-SUFFIX')) {
      const [, ...keywords] = line.split(',');
      domainSuffixSet.add(keywords.join(',').trim());
    }
  }

  for await (const line of readFileByLine(path.resolve(__dirname, '../List/domainset/reject_phishing.conf'))) {
    const l = processLine(line);
    if (l && l[0] === '.') {
      domainSuffixSet.add(l.slice(1));
    }
  }

  console.log(`Import ${domainKeywordsSet.size} black keywords and ${domainSuffixSet.size} black suffixes!`);

  previousSize = domainSets.size;
  // Dedupe domainSets
  console.log(`Start deduping from black keywords/suffixes! (${previousSize})`);
  console.time('* Dedupe from black keywords/suffixes');

  const trie1 = createTrie(domainSets);
  domainSuffixSet.forEach(suffix => {
    trie1.find(suffix, true).forEach(f => domainSets.delete(f));
  });
  filterRuleWhitelistDomainSets.forEach(suffix => {
    trie1.find(suffix, true).forEach(f => domainSets.delete(f));
  });

  // remove pre-defined enforced blacklist from whitelist
  const kwfilter = createKeywordFilter(domainKeywordsSet);

  // Build whitelist trie, to handle case like removing `g.msn.com` due to white `.g.msn.com` (`@@||g.msn.com`)
  const trieWhite = createTrie(filterRuleWhitelistDomainSets);
  for (const domain of domainSets) {
    if (domain[0] === '.') {
      if (trieWhite.contains(domain)) {
        domainSets.delete(domain);
        continue;
      }
    } else if (trieWhite.has(`.${domain}`)) {
      domainSets.delete(domain);
      continue;
    }

    // Remove keyword
    if (kwfilter.search(domain)) {
      domainSets.delete(domain);
    }
  }

  console.timeEnd('* Dedupe from black keywords/suffixes');
  console.log(`Deduped ${previousSize} - ${domainSets.size} = ${previousSize - domainSets.size} from black keywords and suffixes!`);

  previousSize = domainSets.size;
  // Dedupe domainSets
  console.log(`Start deduping! (${previousSize})`);

  const dudupedDominArray = traceSync('* Dedupe from covered subdomain', () => domainDeduper(Array.from(domainSets)));
  console.log(`Deduped ${previousSize - dudupedDominArray.length} rules!`);

  // Create reject stats
  const rejectDomainsStats: [string, number][] = traceSync(
    '* Collect reject domain stats',
    () => Object.entries(
      dudupedDominArray.reduce<Record<string, number>>((acc, cur) => {
        const suffix = tldts.getDomain(cur, { allowPrivateDomains: false, detectIp: false });
        if (suffix) {
          acc[suffix] = (acc[suffix] ?? 0) + 1;
        }
        return acc;
      }, {})
    ).filter(a => a[1] > 10).sort((a, b) => {
      const t = b[1] - a[1];
      if (t !== 0) {
        return t;
      }

      return a[0].localeCompare(b[0]);
    })
  );

  const domainSorter = createDomainSorter(gorhill);
  const domainset = traceSync('* Sort reject domainset', () => dudupedDominArray.sort(domainSorter));

  const description = [
    'License: AGPL 3.0',
    'Homepage: https://ruleset.skk.moe',
    'GitHub: https://github.com/SukkaW/Surge',
    '',
    'The domainset supports AD blocking, tracking protection, privacy protection, anti-phishing, anti-mining',
    '',
    'Build from:',
    ...HOSTS.map(host => ` - ${host[0]}`),
    ...ADGUARD_FILTERS.map(filter => ` - ${Array.isArray(filter) ? filter[0] : filter}`)
  ];

  return Promise.all([
    ...createRuleset(
      'Sukka\'s Ruleset - Reject Base',
      description,
      new Date(),
      domainset,
      'domainset',
      path.resolve(__dirname, '../List/domainset/reject.conf'),
      path.resolve(__dirname, '../Clash/domainset/reject.txt')
    ),
    compareAndWriteFile(
      rejectDomainsStats.map(([domain, count]) => `${domain}${' '.repeat(100 - domain.length)}${count}`),
      path.resolve(__dirname, '../List/internal/reject-stats.txt')
    ),
    // Copy reject_sukka.conf for backward compatibility
    fsp.cp(
      path.resolve(__dirname, '../Source/domainset/reject_sukka.conf'),
      path.resolve(__dirname, '../List/domainset/reject_sukka.conf'),
      { force: true, recursive: true }
    )
  ]);
});

if (import.meta.main) {
  buildRejectDomainSet();
}