<?php
header('Content-Type: application/xml; charset=utf-8');
$scheme = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off') ? 'https' : 'http';
$host = $_SERVER['HTTP_HOST'] ?? ($_SERVER['SERVER_NAME'] ?? '');
$urls = [
    ['loc' => '/', 'priority' => '1.0', 'changefreq' => 'daily'],
    ['loc' => '/news/video-guide/', 'priority' => '0.9', 'changefreq' => 'daily'],
    ['loc' => '/news/mobile-observe/', 'priority' => '0.8', 'changefreq' => 'weekly'],
    ['loc' => '/news/tutorial-video/', 'priority' => '0.8', 'changefreq' => 'weekly'],
    ['loc' => '/topics/', 'priority' => '0.8', 'changefreq' => 'weekly'],
    ['loc' => '/authors/', 'priority' => '0.7', 'changefreq' => 'weekly'],
    ['loc' => '/faq/', 'priority' => '0.7', 'changefreq' => 'monthly'],
    ['loc' => '/about/', 'priority' => '0.6', 'changefreq' => 'monthly'],
    ['loc' => '/contact/', 'priority' => '0.6', 'changefreq' => 'monthly'],
    ['loc' => '/search/', 'priority' => '0.4', 'changefreq' => 'monthly']
];
echo '<?xml version="1.0" encoding="UTF-8"?>' . PHP_EOL;
?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
<?php foreach ($urls as $url): ?>
  <url>
    <loc><?php echo htmlspecialchars($scheme . '://' . $host . $url['loc'], ENT_XML1, 'UTF-8'); ?></loc>
    <lastmod><?php echo date('Y-m-d'); ?></lastmod>
    <changefreq><?php echo $url['changefreq']; ?></changefreq>
    <priority><?php echo $url['priority']; ?></priority>
  </url>
<?php endforeach; ?>
</urlset>
