add hook_pre_subscribe

1 files changed, 18 insertions, 1 deletions

diff --git a/init.php b/init.php
index 3191bcb..cd19e8c 100644
--- a/init.php
+++ b/init.php
@@ -27,14 +27,31 @@ class Af_Lemmy extends Plugin {
 		$host->add_hook($host::HOOK_PRE_SUBSCRIBE, $this);
 	}
 
-	// TODO: maybe support other federated instances like beehaw? whitelist?
 	function hook_pre_subscribe(&$url, $auth_login, $auth_pass) {
 
 		$origin_domain = parse_url($url, PHP_URL_HOST);
 
 		if (in_array($origin_domain, $this->lemmy_domains)) {
+			$content = UrlHelper::fetch(["url" => $url,
+					"login" => $auth_login,
+					"pass" => $auth_pass,
+					"http_accept" => "text/*"]);
 
+			if ($content) {
+				$doc = new DOMDocument();
 
+				if (@$doc->loadHTML($content)) {
+					$xpath = new DOMXPath($doc);
+
+					/** @var ?DOMElement $rss_url */
+					$rss_url = $xpath->query("//a[contains(@href, '/feeds/')]")->item(0);
+
+					if ($rss_url) {
+						$url = UrlHelper::rewrite_relative($url, $rss_url->getAttribute('href'));
+						return true;
+					}
+				}
+			}
 		}
 
 		return false;