<?php
header("Content-Type: application/xml; charset=utf-8");
$configFile = 'site_config.json';
$articlesFile = 'articles.json';

$config = file_exists($configFile) ? json_decode(file_get_contents($configFile), true) : [];
$siteUrl = rtrim($config['siteUrl'] ?? 'https://shexiangtoubaike.com', '/');
$articles = file_exists($articlesFile) ? json_decode(file_get_contents($articlesFile), true) : [];

echo '<?xml version="1.0" encoding="UTF-8"?>' . PHP_EOL;
echo '<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">' . PHP_EOL;
echo "  <url>\n    <loc>{$siteUrl}/</loc>\n    <changefreq>daily</changefreq>\n    <priority>1.0</priority>\n  </url>" . PHP_EOL;

if (is_array($articles)) {
    foreach ($articles as $art) {
        $rawSlug = !empty($art['slug']) ? $art['slug'] : $art['id'];
        $cleanSlug = preg_replace('/\.html$/i', '', $rawSlug);
        $date = !empty($art['date']) ? $art['date'] : date('Y-m-d');
        echo "  <url>\n    <loc>{$siteUrl}/articles/{$cleanSlug}.html</loc>\n    <lastmod>{$date}</lastmod>\n    <changefreq>weekly</changefreq>\n    <priority>0.8</priority>\n  </url>" . PHP_EOL;
    }
}
echo '</urlset>';
?>