<?php
function fetchOpenGraphData($url) {
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
    curl_setopt($ch, CURLOPT_TIMEOUT, 5);
    curl_setopt($ch, CURLOPT_USERAGENT, 'Mozilla/5.0 (compatible; Bot/1.0)');
    $html = curl_exec($ch);
    $info = curl_getinfo($ch);
    curl_close($ch);

    if (!$html || $info['http_code'] !== 200) return null;

    $doc = new DOMDocument();
    @$doc->loadHTML($html);
    $metas = $doc->getElementsByTagName('meta');

    $data = [
        'title' => '',
        'description' => '',
        'image' => '',
        'url' => $url,
        'site_name' => ''
    ];

    // Try title tag if og:title is missing
    $titles = $doc->getElementsByTagName('title');
    if ($titles->length > 0) {
        $data['title'] = $titles->item(0)->nodeValue;
    }

    foreach ($metas as $meta) {
        $property = $meta->getAttribute('property');
        $name = $meta->getAttribute('name');
        $content = $meta->getAttribute('content');

        if ($property === 'og:title' || $name === 'twitter:title') $data['title'] = $content;
        if ($property === 'og:description' || $name === 'description' || $name === 'twitter:description') $data['description'] = $content;
        if ($property === 'og:image' || $name === 'twitter:image') $data['image'] = $content;
        if ($property === 'og:site_name') $data['site_name'] = $content;
    }

    // Filter out empty results
    if (empty($data['title']) && empty($data['description'])) return null;

    return $data;
}

function extractUrls($text) {
    $pattern = '/https?:\/\/[^\s<]+/';
    preg_match_all($pattern, $text, $matches);
    return $matches[0];
}