99 lines
3.1 KiB
PHP
99 lines
3.1 KiB
PHP
<?php
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/**
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* Telegram RSS Proxy with cache
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*
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* GET /rss.php?channel=CHANNEL&limit=N
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* or via .htaccess rewrite: /rss/CHANNEL?limit=N
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*
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* Returns RSS XML from local cache (if fresh) or proxies from tg.i-c-a.su.
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* Enclosure URLs are rewritten to go through media.php for local caching.
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* Cache files are pre-rewritten so cache hits avoid DOMDocument entirely.
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*/
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define('CACHE_DIR', __DIR__ . '/cache');
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define('TG_BASE', 'https://tg.i-c-a.su');
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define('PROXY_BASE', 'https://proxy.budaev.org');
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define('UA', 'Mozilla/5.0 (compatible; ProxyBot/1.0)');
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define('CACHE_TTL', 600);
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$channel = preg_replace('/[^a-zA-Z0-9_]/', '', $_GET['channel'] ?? '');
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if (!$channel) {
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header('HTTP/1.1 400 Bad Request');
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echo 'Missing channel parameter';
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exit;
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}
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$limit = min(max((int)($_GET['limit'] ?? 10), 1), 100);
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// Staggered TTL: vary per channel to avoid mass expiration
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$stagger = crc32($channel) % 300;
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$ttl = CACHE_TTL + $stagger;
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// Non-standard limits: fetch directly, no caching
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if ($limit !== 10) {
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$xml = fetchFeed($channel, $limit, true);
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if ($xml === null) {
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header('HTTP/1.1 502 Bad Gateway');
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echo 'Failed to fetch feed';
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exit;
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}
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header('Content-Type: application/rss+xml; charset=utf-8');
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echo $xml;
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exit;
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}
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$cacheFile = CACHE_DIR . '/' . $channel . '.xml';
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// Cache hit — pre-rewritten, no DOMDocument needed
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if (file_exists($cacheFile) && filemtime($cacheFile) > time() - $ttl) {
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header('Content-Type: application/rss+xml; charset=utf-8');
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readfile($cacheFile);
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exit;
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}
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// Cache miss or stale — fetch and rewrite in one DOMDocument pass
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$xml = fetchFeed($channel, $limit, false);
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if ($xml === null) {
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// Serve stale cache if available
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if (file_exists($cacheFile)) {
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header('Content-Type: application/rss+xml; charset=utf-8');
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readfile($cacheFile);
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exit;
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}
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// No cache at all — return empty feed so bot doesn't fall back to tg.i-c-a.su
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header('Content-Type: application/rss+xml; charset=utf-8');
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echo '<?xml version="1.0" encoding="UTF-8"?><rss version="2.0"><channel><title>' . htmlspecialchars($channel) . '</title></channel></rss>';
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exit;
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}
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// Save pre-rewritten XML to cache
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file_put_contents($cacheFile, $xml);
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header('Content-Type: application/rss+xml; charset=utf-8');
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echo $xml;
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function fetchFeed(string $channel, int $limit, bool $skipRewrite): ?string {
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$url = TG_BASE . '/rss/' . $channel . '?limit=' . $limit;
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$ctx = stream_context_create(['http' => ['timeout' => 30, 'user_agent' => UA, 'follow_location' => true]]);
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$raw = @file_get_contents($url, false, $ctx);
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if (!$raw) return null;
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if ($skipRewrite) {
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return $raw;
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}
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// Parse DOM once, rewrite enclosures, return pre-rewritten XML
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$doc = new DOMDocument();
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@$doc->loadXML($raw);
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if (!$doc->documentElement) return null;
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foreach ($doc->getElementsByTagName('enclosure') as $enc) {
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$encUrl = $enc->getAttribute('url');
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if (strpos($encUrl, TG_BASE) !== false) {
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$enc->setAttribute('url', PROXY_BASE . '/media.php?url=' . urlencode($encUrl));
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}
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}
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return $doc->saveXML();
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}
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