<?php
/**
 * ==============================================================================
 * RojgarXpress - Production Post Permalink & Social Sharing Engine
 * Injects dynamic Open Graph (og:image, og:title, og:description) and Twitter
 * Cards server-side so Facebook, WhatsApp, Twitter, Viber, Telegram, etc.
 * ALWAYS display the actual featured photo and article title in link previews.
 * ==============================================================================
 */

// Disable error display in production
error_reporting(0);
ini_set('display_errors', 0);

// Determine base URL dynamically (with HTTPS priority for social media crawlers)
$isHttps = (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off')
    || (isset($_SERVER['SERVER_PORT']) && $_SERVER['SERVER_PORT'] == 443)
    || (!empty($_SERVER['HTTP_X_FORWARDED_PROTO']) && $_SERVER['HTTP_X_FORWARDED_PROTO'] === 'https')
    || (!empty($_SERVER['HTTP_CF_VISITOR']) && strpos($_SERVER['HTTP_CF_VISITOR'], 'https') !== false);

$protocol = $isHttps ? 'https' : 'http';
$host = $_SERVER['HTTP_HOST'] ?? 'rojgarxpress.com';

// In production (non-localhost), ALWAYS force https for all social crawlers and canonical URLs
$isLocal = ($host === 'localhost' || strpos($host, '127.0.0.1') !== false || strpos($host, '192.168.') !== false);
if (!$isLocal) {
    $protocol = 'https';
}

$baseUrl = $protocol . '://' . $host;

// Resolve target slug / id from query string or request URI
$targetSlug = isset($_GET['slug']) ? trim($_GET['slug']) : (isset($_GET['post']) ? trim($_GET['post']) : '');
$targetId = isset($_GET['id']) ? trim($_GET['id']) : '';

// Also check URI like /post/:slug or /news/:slug
if (!$targetSlug && !$targetId) {
    $uriPath = parse_url($_SERVER['REQUEST_URI'] ?? '', PHP_URL_PATH);
    if (preg_match('#/(post|news)/([a-zA-Z0-9_-]+)#i', $uriPath, $matches)) {
        $targetSlug = trim($matches[2]);
    }
}

// Helper to slugify
function rx_slugify($text) {
    if (!$text) return '';
    $clean = strtolower($text);
    $clean = preg_replace('/[^a-z0-9\s-]/', ' ', $clean);
    $clean = preg_replace('/\s+/', '-', $clean);
    return trim(preg_replace('/-+/', '-', $clean), '-');
}

$article = null;
$dbPath = __DIR__ . '/data/database.json';

if (file_exists($dbPath) && ($targetSlug || $targetId)) {
    $raw = @file_get_contents($dbPath);
    $db = @json_decode($raw, true);
    if (is_array($db)) {
        $all = array_merge(
            isset($db['news']) && is_array($db['news']) ? $db['news'] : [],
            isset($db['deshDuniyaNews']) && is_array($db['deshDuniyaNews']) ? $db['deshDuniyaNews'] : [],
            isset($db['diasporaNews']) && is_array($db['diasporaNews']) ? $db['diasporaNews'] : []
        );

        $slugLower = strtolower($targetSlug);

        // 1. Match slug
        if ($targetSlug) {
            foreach ($all as $item) {
                if (isset($item['slug']) && strtolower(strval($item['slug'])) === $slugLower) {
                    $article = $item;
                    break;
                }
            }
        }

        // 2. Match id
        if (!$article && $targetId) {
            foreach ($all as $item) {
                if (isset($item['id']) && strval($item['id']) === strval($targetId)) {
                    $article = $item;
                    break;
                }
            }
        }

        // 3. Fallback: Match slug against id
        if (!$article && $targetSlug) {
            foreach ($all as $item) {
                if (isset($item['id']) && strval($item['id']) === strval($targetSlug)) {
                    $article = $item;
                    break;
                }
            }
        }

        // 4. Fallback: Match slug against slugified title
        if (!$article && $targetSlug) {
            foreach ($all as $item) {
                if (!empty($item['title']) && rx_slugify($item['title']) === $slugLower) {
                    $article = $item;
                    break;
                }
            }
        }
    }
}

// Fallback to first article if not found
if (!$article && !empty($all)) {
    $article = $all[0];
}

// Extract article data
$title = $article ? ($article['titleNe'] ?? ($article['title'] ?? 'वैदेशिक रोजगार समाचार')) : 'RojgarXpress - नेपालको आधिकारिक वैदेशिक रोजगार पोर्टल';
$fullTitle = $title . ' | RojgarXpress';
$summary = $article ? ($article['summary'] ?? 'वैदेशिक रोजगार, भिसा, डिमान्ड र ताजा समाचार।') : 'नेपालको आधिकारिक वैदेशिक रोजगार सूचना पोर्टल - प्रमाणित डिमान्ड, दैनिक विनिमय दर र समाचार।';
$cleanSummary = mb_substr(strip_tags($summary), 0, 200, 'UTF-8');

// Ensure image is absolute and HTTPS
$rawImage = $article && !empty($article['image']) ? $article['image'] : "$baseUrl/images/og-banner.png";
if (!preg_match('/^https?:\/\//i', $rawImage)) {
    $cleanPath = '/' . ltrim($rawImage, '/');
    $image = $baseUrl . $cleanPath;
} else {
    $image = $rawImage;
}
if (!$isLocal && strpos($image, 'http://') === 0) {
    $image = 'https://' . substr($image, 7);
}

// Permalink URL
$articleSlug = $article['slug'] ?? ($article['id'] ?? ($targetSlug ?: $targetId));
$canonicalUrl = "$baseUrl/news.html?slug=" . urlencode($articleSlug);
$shareUrl = "$baseUrl/post.php?slug=" . urlencode($articleSlug);

// Load the complete news.html template and inject dynamic tags
$htmlFile = __DIR__ . '/news.html';
if (file_exists($htmlFile)) {
    $html = file_get_contents($htmlFile);

    // Ensure <base href="/"> is present for clean multi-segment URLs like /post/:slug
    if (strpos($html, '<base') === false) {
        $html = preg_replace('/<head[^>]*>/i', "$0\n  <base href=\"/\">", $html, 1);
    }

    // Replace Title & Description
    $html = preg_replace('/<title[^>]*>.*?<\/title>/si', '<title>' . htmlspecialchars($fullTitle) . '</title>', $html);
    $html = preg_replace('/<meta\s+name=["\']title["\'][^>]*>/si', '<meta name="title" content="' . htmlspecialchars($fullTitle) . '">', $html);
    $html = preg_replace('/<meta\s+name=["\']description["\'][^>]*>/si', '<meta name="description" content="' . htmlspecialchars($cleanSummary) . '">', $html);

    // Replace Canonical
    $html = preg_replace('/<link\s+rel=["\']canonical["\'][^>]*>/si', '<link rel="canonical" href="' . htmlspecialchars($canonicalUrl) . '">', $html);

    // Replace OpenGraph tags
    $html = preg_replace('/<meta\s+property=["\']og:title["\'][^>]*>/si', '<meta property="og:title" content="' . htmlspecialchars($fullTitle) . '">', $html);
    $html = preg_replace('/<meta\s+property=["\']og:description["\'][^>]*>/si', '<meta property="og:description" content="' . htmlspecialchars($cleanSummary) . '">', $html);
    
    // Replace OpenGraph image tags cleanly
    $ogImgTags = '<meta property="og:image" content="' . htmlspecialchars($image) . '">' . "\n" .
                 '  <meta property="og:image:secure_url" content="' . htmlspecialchars($image) . '">' . "\n" .
                 '  <meta property="og:image:width" content="1200">' . "\n" .
                 '  <meta property="og:image:height" content="630">';
    $html = preg_replace('/<meta\s+property=["\']og:image:secure_url["\'][^>]*>/si', '', $html);
    $html = preg_replace('/<meta\s+property=["\']og:image["\'][^>]*>/si', $ogImgTags, $html);

    $html = preg_replace('/<meta\s+property=["\']og:url["\'][^>]*>/si', '<meta property="og:url" content="' . htmlspecialchars($canonicalUrl) . '">', $html);
    $html = preg_replace('/<meta\s+property=["\']og:type["\'][^>]*>/si', '<meta property="og:type" content="article">', $html);

    // Replace Twitter Card tags
    $html = preg_replace('/<meta\s+name=["\']twitter:title["\'][^>]*>/si', '<meta name="twitter:title" content="' . htmlspecialchars($fullTitle) . '">', $html);
    $html = preg_replace('/<meta\s+name=["\']twitter:description["\'][^>]*>/si', '<meta name="twitter:description" content="' . htmlspecialchars($cleanSummary) . '">', $html);
    $html = preg_replace('/<meta\s+name=["\']twitter:image["\'][^>]*>/si', '<meta name="twitter:image" content="' . htmlspecialchars($image) . '">', $html);

    // Replace Schema.org NewsArticle JSON-LD
    $schemaJson = json_encode([
        '@context' => 'https://schema.org',
        '@type' => 'NewsArticle',
        'mainEntityOfPage' => [
            '@type' => 'WebPage',
            '@id' => $canonicalUrl
        ],
        'headline' => $title,
        'image' => [$image],
        'datePublished' => $article['createdAt'] ?? '2026-09-08T00:00:00+05:45',
        'dateModified' => $article['updatedAt'] ?? ($article['createdAt'] ?? '2026-09-08T00:00:00+05:45'),
        'author' => [
            '@type' => 'Person',
            'name' => $article['source'] ?? ($article['author'] ?? 'Rojgar Desk')
        ],
        'publisher' => [
            '@type' => 'NewsMediaOrganization',
            'name' => 'RojgarXpress',
            'logo' => [
                '@type' => 'ImageObject',
                'url' => "$baseUrl/images/logo.svg"
            ]
        ],
        'description' => $cleanSummary
    ], JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_PRETTY_PRINT);

    $html = preg_replace('/<script\s+type=["\']application\/ld\+json["\']\s+id=["\']newsSchemaJsonLd["\'][^>]*>.*?<\/script>/si', '<script type="application/ld+json" id="newsSchemaJsonLd">' . "\n" . $schemaJson . "\n" . '</script>', $html);

    header('Content-Type: text/html; charset=utf-8');
    echo $html;
    exit;
}

// Fallback if news.html not found: render standalone rich meta page
?>
<!DOCTYPE html>
<html lang="ne" prefix="og: https://ogp.me/ns#">
<head>
  <meta charset="UTF-8">
  <base href="/">
  <title><?= htmlspecialchars($fullTitle) ?></title>
  <meta name="description" content="<?= htmlspecialchars($cleanSummary) ?>">
  <link rel="canonical" href="<?= htmlspecialchars($canonicalUrl) ?>">
  <meta property="og:type" content="article">
  <meta property="og:site_name" content="RojgarXpress">
  <meta property="og:title" content="<?= htmlspecialchars($fullTitle) ?>">
  <meta property="og:description" content="<?= htmlspecialchars($cleanSummary) ?>">
  <meta property="og:image" content="<?= htmlspecialchars($image) ?>">
  <meta property="og:image:secure_url" content="<?= htmlspecialchars($image) ?>">
  <meta property="og:image:width" content="1200">
  <meta property="og:image:height" content="630">
  <meta property="og:url" content="<?= htmlspecialchars($canonicalUrl) ?>">
  <meta property="og:locale" content="ne_NP">
  <meta name="twitter:card" content="summary_large_image">
  <meta name="twitter:title" content="<?= htmlspecialchars($fullTitle) ?>">
  <meta name="twitter:description" content="<?= htmlspecialchars($cleanSummary) ?>">
  <meta name="twitter:image" content="<?= htmlspecialchars($image) ?>">
  <meta http-equiv="refresh" content="0;url=<?= htmlspecialchars($canonicalUrl) ?>">
  <script>window.location.replace("<?= addslashes($canonicalUrl) ?>");</script>
</head>
<body style="font-family:sans-serif; background:#0f1e36; color:#fff; text-align:center; padding-top:20vh;">
  <h2>लोड हुँदैछ (Loading article)...</h2>
  <p><a href="<?= htmlspecialchars($canonicalUrl) ?>" style="color:#38bdf8;">यदि केही क्षणमा नखुले यहाँ थिच्नुहोस् &rarr;</a></p>
</body>
</html>