Make the watch route generate a full YouTube URL (fixes #402)

classes/App.php

@@ -94,7 +94,7 @@ class App extends \Slim\App
 
         $this->any(
             '/watch',
-            [$frontController, 'info']
+            [$frontController, 'watch']
         );
 
         $this->any(

classes/Controller/BaseController.php

@@ -169,10 +169,8 @@ abstract class BaseController
      */
     protected function getVideoPageUrl(Request $request): string
     {
-        $url = $request->getQueryParam('url') ?: $request->getQueryParam('v');
-
         // Prevent SSRF attacks.
-        $parts = Url::validateUrl($url, new Options());
+        $parts = Url::validateUrl($request->getQueryParam('url'), new Options());
 
         return $parts['url'];
     }

classes/Controller/FrontController.php

@@ -14,6 +14,7 @@ use Alltube\Middleware\CspMiddleware;
 use Exception;
 use Graby\HttpClient\Plugin\ServerSideRequestForgeryProtection\Exception\InvalidURLException;
 use Slim\Http\StatusCode;
+use Slim\Http\Uri;
 use stdClass;
 use Symfony\Component\ErrorHandler\ErrorRenderer\HtmlErrorRenderer;
 use Throwable;
@@ -345,4 +346,24 @@ class FrontController extends BaseController
             return $this->displayError($request, $response, $message);
         }
     }
+
+    /**
+     * Route that mimics YouTube video URLs ("/watch?v=foo")
+     *
+     * @param Request $request
+     * @param Response $response
+     * @return Response
+     */
+    public function watch(Request $request, Response $response): Response
+    {
+        // We build a full YouTube URL from the video ID.
+        $youtubeUri = Uri::createFromString('https://www.youtube.com/watch')
+            ->withQuery(http_build_query(['v' => $request->getQueryParam('v')]));
+
+        // Then pass it to the info route.
+        return $response->withRedirect(
+            Uri::createFromString($this->router->pathFor('info'))
+                ->withQuery(http_build_query(['url' => strval($youtubeUri)]))
+        );
+    }
 }