From 93ae2cdaa9d1f06eec470acb7853557653026514 Mon Sep 17 00:00:00 2001
From: Troy Grunt <github@troy-grunt.de>
Date: Sat, 14 Feb 2026 15:55:41 +0100
Subject: [PATCH] links

---
 link-meta.php | 183 ++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 183 insertions(+)
 create mode 100644 link-meta.php

diff --git a/link-meta.php b/link-meta.php
new file mode 100644
index 0000000..a92db62
--- /dev/null
+++ b/link-meta.php
@@ -0,0 +1,183 @@
+<?php
+
+function httpContext(int $timeout = 8) {
+    return stream_context_create([
+        'http' => [
+            'timeout' => $timeout,
+            'follow_location' => 1,
+            'max_redirects' => 4,
+            'user_agent' => 'star-citizen.de-linkbot/1.0',
+            'ignore_errors' => true
+        ],
+        'ssl' => [
+            'verify_peer' => true,
+            'verify_peer_name' => true
+        ]
+    ]);
+}
+
+function normalizeUrl(string $url): ?string {
+    $url = trim($url);
+    if (!filter_var($url, FILTER_VALIDATE_URL)) {
+        return null;
+    }
+
+    $parts = parse_url($url);
+    if (!$parts || !isset($parts['scheme'])) {
+        return null;
+    }
+
+    $scheme = strtolower($parts['scheme']);
+    if ($scheme !== 'http' && $scheme !== 'https') {
+        return null;
+    }
+
+    return $url;
+}
+
+function resolveUrl(string $url, string $baseUrl): ?string {
+    $url = trim($url);
+    if (filter_var($url, FILTER_VALIDATE_URL)) {
+        return $url;
+    }
+
+    $baseParts = parse_url($baseUrl);
+    if (!$baseParts || !isset($baseParts['scheme']) || !isset($baseParts['host'])) {
+        return null;
+    }
+
+    if (strpos($url, '//') === 0) {
+        return $baseParts['scheme'] . ':' . $url;
+    }
+
+    $path = '/';
+    if (!empty($baseParts['path'])) {
+        $path = preg_replace('#/[^/]*$#', '/', $baseParts['path']);
+        if ($path === null || $path === '') {
+            $path = '/';
+        }
+    }
+
+    if (strlen($url) && $url[0] === '/') {
+        return $baseParts['scheme'] . '://' . $baseParts['host'] . $url;
+    }
+
+    return $baseParts['scheme'] . '://' . $baseParts['host'] . $path . $url;
+}
+
+function safeFetch(string $url, int $timeout = 8): ?string {
+    $ctx = httpContext($timeout);
+    $content = @file_get_contents($url, false, $ctx);
+    return $content === false ? null : $content;
+}
+
+function downloadImageFromUrl(string $url, string $baseUrl, string $destinationFolder = 'upl/'): ?string {
+    $resolved = resolveUrl($url, $baseUrl);
+    if ($resolved === null) {
+        return null;
+    }
+
+    if (!preg_match('/\.(jpg|jpeg|png|gif|bmp|webp)(?:\?|#|$)/i', $resolved)) {
+        return null;
+    }
+
+    $imageContent = safeFetch($resolved, 10);
+    if ($imageContent === null || strlen($imageContent) === 0 || strlen($imageContent) > (5 * 1024 * 1024)) {
+        return null;
+    }
+
+    $path = parse_url($resolved, PHP_URL_PATH) ?? '';
+    $ext = strtolower(pathinfo($path, PATHINFO_EXTENSION));
+    if ($ext === '' || !preg_match('/^(jpg|jpeg|png|gif|bmp|webp)$/', $ext)) {
+        $ext = 'png';
+    }
+
+    if (!is_dir($destinationFolder)) {
+        @mkdir($destinationFolder, 0775, true);
+    }
+
+    $md5Hash = md5($imageContent);
+    $filePath = rtrim($destinationFolder, '/\\') . '/' . $md5Hash . '.' . $ext;
+    $written = @file_put_contents($filePath, $imageContent);
+    if ($written === false) {
+        return null;
+    }
+
+    return $filePath;
+}
+
+function parseMetaContent(string $html, string $attr, string $name): ?string {
+    $pattern = '/<meta[^>]*' . $attr . '=["\']' . preg_quote($name, '/') . '["\'][^>]*content=["\']([^"\']+)["\'][^>]*>/i';
+    if (preg_match($pattern, $html, $matches) && isset($matches[1])) {
+        return trim(html_entity_decode($matches[1], ENT_QUOTES | ENT_HTML5, 'UTF-8'));
+    }
+    return null;
+}
+
+function getPageInfo(string $url): array {
+    $ret = [
+        'ok' => false,
+        'title' => '',
+        'description' => '',
+        'logo' => null,
+        'error' => null
+    ];
+
+    $normalized = normalizeUrl($url);
+    if ($normalized === null) {
+        $ret['error'] = 'ungueltige_url';
+        return $ret;
+    }
+
+    $html = safeFetch($normalized, 10);
+    if ($html === null) {
+        $ret['error'] = 'seite_nicht_erreichbar';
+        return $ret;
+    }
+
+    $title = parseMetaContent($html, 'property', 'og:title') ?? parseMetaContent($html, 'name', 'title');
+    $description = parseMetaContent($html, 'property', 'og:description') ?? parseMetaContent($html, 'name', 'description');
+    $image = parseMetaContent($html, 'property', 'og:image') ?? parseMetaContent($html, 'name', 'image');
+
+    if ($title === null && preg_match('/<title>\s*(.*?)\s*<\/title>/is', $html, $matchTitle)) {
+        $title = trim(html_entity_decode($matchTitle[1], ENT_QUOTES | ENT_HTML5, 'UTF-8'));
+    }
+
+    $logo = null;
+    if ($image !== null && $image !== '') {
+        $img = downloadImageFromUrl($image, $normalized);
+        if ($img !== null) {
+            $logo = '/' . ltrim($img, '/');
+        }
+    }
+
+    $ret['ok'] = true;
+    $ret['title'] = $title ?? '';
+    $ret['description'] = $description ?? '';
+    $ret['logo'] = $logo;
+    return $ret;
+}
+
+function sanitizeTags($input): array {
+    if (!is_array($input)) {
+        return [];
+    }
+
+    $ret = [];
+    foreach ($input as $tag) {
+        if (!is_string($tag)) {
+            continue;
+        }
+        $clean = onlyAlpha(trim($tag), '_\-');
+        if ($clean === '') {
+            continue;
+        }
+        $clean = ucfirst(substr($clean, 0, 35));
+        $ret[$clean] = true;
+        if (count($ret) >= 20) {
+            break;
+        }
+    }
+    return array_keys($ret);
+}
+