add legacy route director that should fix all forum links, fixes #5698

Closes #5698

Merge request studip/studip!4326

3 files changed, 128 insertions, 13 deletions

diff --git a/lib/classes/StudipDispatcher.php b/lib/classes/StudipDispatcher.php
index 10799c7..a54c45c 100644
--- a/lib/classes/StudipDispatcher.php
+++ b/lib/classes/StudipDispatcher.php
@@ -90,19 +90,25 @@ class StudipDispatcher extends Trails\Dispatcher
         return $this->container->make($class, ['dispatcher' => $this]);
     }
 
-    public function getRouteCallable($uri)
+    public function getRouteCallable($uri): callable
     {
-        $uri = $this->clean_request_uri((string) $uri);
-        [$controller_path, $unconsumed] = '' === $uri ? $this->default_route() : $this->parse($uri);
-        $controller = $this->load_controller($controller_path);
-        return function (
-            \Psr\Http\Message\ServerRequestInterface $request,
-            \Psr\Http\Message\ResponseInterface $response,
-            array $args
-        ) use ($controller, $unconsumed): \Psr\Http\Message\ResponseInterface {
-            $controller->injectResponse($response);
-            $response = $controller->perform($unconsumed);
-            return $response->getPsrResponse();
-        } ;
+        try {
+            $uri = $this->clean_request_uri((string) $uri);
+            [$controller_path, $unconsumed] = '' === $uri ? $this->default_route() : $this->parse($uri);
+            $controller = $this->load_controller($controller_path);
+            return function (
+                \Psr\Http\Message\ServerRequestInterface $request,
+                \Psr\Http\Message\ResponseInterface $response,
+                array $args
+            ) use ($controller, $unconsumed): \Psr\Http\Message\ResponseInterface {
+                $controller->injectResponse($response);
+                $response = $controller->perform($unconsumed);
+                return $response->getPsrResponse();
+            } ;
+        } catch (Exception $e) {
+            return function () use ($e) {
+                throw $e;
+            };
+        }
     }
 }
diff --git a/lib/middleware/LegacyRedirectorMiddleware.php b/lib/middleware/LegacyRedirectorMiddleware.php
new file mode 100644
index 0000000..5b9960c
--- /dev/null
+++ b/lib/middleware/LegacyRedirectorMiddleware.php
@@ -0,0 +1,105 @@
+<?php
+namespace Studip\Middleware;
+
+use Forum\ForumTopic;
+use NotificationCenter;
+use Psr\Http\Message\ResponseFactoryInterface;
+use Psr\Http\Message\{ResponseInterface as Response,
+    ServerRequestInterface as Request,
+    UriInterface
+};
+use Psr\Http\Server\MiddlewareInterface;
+use Psr\Http\Server\RequestHandlerInterface;
+use Slim\App;
+
+final class LegacyRedirectorMiddleware implements MiddlewareInterface
+{
+    private array $legacyRoutes = [];
+
+    public function __construct(
+        private readonly App $app,
+        private readonly ResponseFactoryInterface $response_factory
+    ) {
+        $this->addLegacyRoute(
+            '#^course/forum/index/index#',
+            [$this, 'redirectForumPost']
+        );
+
+        NotificationCenter::postNotification('LEGACY_REDIRECTOR_DID_CREATE', $this);
+    }
+
+    public function addLegacyRoute(string $route, callable $handler): void
+    {
+        $this->legacyRoutes[$route] = $handler;
+    }
+
+    public function process(Request $request, RequestHandlerInterface $handler): Response
+    {
+        $path = $this->getRelativePath($request);
+
+        foreach ($this->legacyRoutes as $legacyRoute => $routeHandler) {
+            if ($this->routeMatches($path, $legacyRoute)) {
+                /** @var UriInterface $newUri */
+                $newUri = $routeHandler($request);
+
+                $response = $this->response_factory->createResponse(301);
+                $response->getBody()->write('');
+                return $response->withHeader('Location', (string) $newUri);
+            }
+        }
+
+        return $handler->handle($request);
+    }
+
+    private function getRelativePath(Request $request): string
+    {
+        $basePath = $this->app->getBasePath();
+        $fullPath = $request->getUri()->getPath();
+
+        return ltrim(substr($fullPath, strlen($basePath)), '/');
+    }
+
+    private function routeMatches(string $path, string $route): bool
+    {
+        if (str_starts_with($route, '#') && str_ends_with($route, '#')) {
+            return preg_match($route, $path);
+        }
+
+        return str_starts_with($path, $route);
+    }
+
+    private function redirectForumPost(Request $request): UriInterface
+    {
+        $uri = $request->getUri();
+        $range_id = $request->getQueryParams()['cid'];
+        $forum_id = explode('/', $this->getRelativePath($request))[4] ?? null;
+
+        if ($forum_id === $range_id) {
+            $redirectUri = $uri->withPath(
+                str_replace(
+                    'course/forum/index/index/' . $forum_id,
+                    'course/forum/topics',
+                    $uri->getPath()
+                )
+            );
+        } elseif (ForumTopic::exists($forum_id)) {
+            $redirectUri = $uri->withPath(
+                str_replace(
+                    'course/forum/index/index',
+                    'course/forum/topics/show',
+                    $uri->getPath()
+                )
+            );
+        } else {
+            $redirectUri = $uri->withPath(
+                str_replace(
+                    'course/forum/index/index',
+                    'course/forum/discussions/show',
+                    $uri->getPath()
+                )
+            );
+        }
+
+        return $redirectUri;
+    }
+}
diff --git a/public/dispatch.php b/public/dispatch.php
index c5c2b93..d2ebdaf 100644
--- a/public/dispatch.php
+++ b/public/dispatch.php
@@ -31,6 +31,10 @@ $app->setBasePath($GLOBALS['CANONICAL_RELATIVE_PATH_STUDIP'] . 'dispatch.php');
 $studip_dispatcher = app(\Trails\Dispatcher::class);
 $route_callable = $studip_dispatcher->getRouteCallable(Request::pathInfo());
 $app->any(Request::pathInfo(), $route_callable);
+
+// Add legacy director so links shall not break
+$app->add(Studip\Middleware\LegacyRedirectorMiddleware::class);
+
 NotificationCenter::postNotification('SLIM_BEFORE_RUN', $app);
 $app->run();
 NotificationCenter::postNotification('SLIM_AFTER_RUN', $app);