const fs = require('fs');
const path = require('path');

function getKstDate(d = new Date()) {
  return d.toLocaleDateString('sv-SE', { timeZone: 'Asia/Seoul' });
}

const siteDomains = {
  seoul: 'https://aeseo.cloud',
  gyeonggi: 'https://aeseo.shop',
  incheon: 'https://aeseo.site',
  gwangju: 'https://aeseo.store',
  busan: 'https://soohyun.cloud',
  daegu: 'https://soohyun.store',
  ulsan: 'https://soohyun.xyz',
  site1: 'https://aeseo.cloud'
};

const subjects = ['수학', '영어', '국어', '과학', '사회'];
const grades = ['초등학생', '중학생', '고등학생'];
const todayKst = getKstDate();

for (const [dir, baseUrl] of Object.entries(siteDomains)) {
  const regionsPath = path.join(__dirname, dir, 'data', 'regions.json');
  if (!fs.existsSync(regionsPath)) continue;
  const regionsData = JSON.parse(fs.readFileSync(regionsPath, 'utf8'));
  const list = regionsData.list || [];

  let xml = '<?xml version="1.0" encoding="UTF-8"?>\n';
  xml += '<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">\n';
  xml += `  <url>\n    <loc>${baseUrl}/</loc>\n    <lastmod>${todayKst}</lastmod>\n    <changefreq>daily</changefreq>\n    <priority>1.0</priority>\n  </url>\n`;

  const seenDongs = new Set();
  for (const r of list) {
    if (!r.dong || seenDongs.has(r.dong)) continue;
    seenDongs.add(r.dong);
    const encDong = encodeURIComponent(r.dong);
    xml += `  <url>\n    <loc>${baseUrl}/${encDong}</loc>\n    <lastmod>${todayKst}</lastmod>\n    <changefreq>weekly</changefreq>\n    <priority>0.8</priority>\n  </url>\n`;
    for (const g of grades) {
      const encGrade = encodeURIComponent(g);
      for (const sub of subjects) {
        const encSub = encodeURIComponent(sub);
        xml += `  <url>\n    <loc>${baseUrl}/${encDong}/${encGrade}/${encSub}</loc>\n    <lastmod>${todayKst}</lastmod>\n    <changefreq>weekly</changefreq>\n    <priority>0.7</priority>\n  </url>\n`;
      }
    }
  }
  xml += '</urlset>\n';

  const sitemapPath = path.join(__dirname, dir, 'public', 'sitemap.xml');
  fs.writeFileSync(sitemapPath, xml, 'utf8');
  console.log(`Updated sitemap.xml for ${dir}: ${seenDongs.size} dongs, ${1 + seenDongs.size * (1 + grades.length * subjects.length)} total URLs`);
}