const express = require('express');
const router = express.Router();
const contentService = require('../services/content');

router.get('/sitemap.xml', (req, res) => {
  const siteUrl = res.locals.site.url;
  const posts = contentService.getAllPosts();
  const pages = Array.from(contentService.pagesBySlug.values());

  let xml = '<?xml version="1.0" encoding="UTF-8"?>\n';
  xml += '<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">\n';

  // Static / Top-level pages
  const staticRoutes = ['/', '/blogs', '/search'];
  for (const route of staticRoutes) {
    xml += '  <url>\n';
    xml += `    <loc>${siteUrl}${route}</loc>\n`;
    xml += `    <changefreq>daily</changefreq>\n`;
    xml += `    <priority>${route === '/' ? '1.0' : '0.8'}</priority>\n`;
    xml += '  </url>\n';
  }

  // Standalone pages
  for (const page of pages) {
    if (!page.slug || page.slug === '/') continue;
    const cleanSlug = page.slug.startsWith('/') ? page.slug : `/${page.slug}`;
    if (cleanSlug === '/guanli' || cleanSlug.startsWith('/guanli/') || cleanSlug === '/admin' || cleanSlug.startsWith('/admin/')) {
      continue;
    }
    xml += '  <url>\n';
    xml += `    <loc>${siteUrl}${cleanSlug}</loc>\n`;
    xml += `    <changefreq>weekly</changefreq>\n`;
    xml += `    <priority>0.7</priority>\n`;
    xml += '  </url>\n';
  }

  // Blog posts (including translations)
  for (const post of posts) {
    if (!post.slug || post.slug.startsWith('guanli') || post.slug.startsWith('admin')) continue;
    xml += '  <url>\n';
    xml += `    <loc>${siteUrl}/${post.slug}</loc>\n`;
    xml += `    <lastmod>${post.date.toISOString().split('T')[0]}</lastmod>\n`;
    xml += `    <changefreq>monthly</changefreq>\n`;
    xml += `    <priority>0.9</priority>\n`;
    xml += '  </url>\n';

    // Bilingual URLs
    if (post.availableLanguages) {
      for (const lang of post.availableLanguages) {
        if (lang !== post.lang && lang !== 'default') {
          xml += '  <url>\n';
          xml += `    <loc>${siteUrl}/${post.slug}/${lang}</loc>\n`;
          xml += `    <lastmod>${post.date.toISOString().split('T')[0]}</lastmod>\n`;
          xml += `    <changefreq>monthly</changefreq>\n`;
          xml += `    <priority>0.8</priority>\n`;
          xml += '  </url>\n';
        }
      }
    }
  }

  xml += '</urlset>';

  res.header('Content-Type', 'application/xml; charset=utf-8');
  res.send(xml);
});

router.get('/robots.txt', (req, res) => {
  const siteUrl = res.locals.site.url;
  const content = `User-agent: *\nDisallow: /admin/\nAllow: /\n\nSitemap: ${siteUrl}/sitemap.xml\n`;
  res.header('Content-Type', 'text/plain; charset=utf-8');
  res.send(content);
});

module.exports = router;