added frontend and made it usable

frontend/src/Controller/EventController.php

@@ -0,0 +1,52 @@
+<?php
+
+namespace App\Controller;
+
+use App\Repository\CategoryRepository;
+use App\Repository\EventRepository;
+use App\Service\EventMapSerializer;
+use Symfony\Bundle\FrameworkBundle\Controller\AbstractController;
+use Symfony\Component\HttpFoundation\Request;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\Routing\Attribute\Route;
+
+class EventController extends AbstractController
+{
+    private const PER_PAGE = 24;
+
+    #[Route('/events', name: 'event_list')]
+    public function list(Request $request, EventRepository $events, CategoryRepository $categories): Response
+    {
+        $page = max(1, $request->query->getInt('page', 1));
+        $category = $request->query->get('category') ?: null;
+        $offset = (($page ?: 1) - 1) * self::PER_PAGE;
+
+        $items = $events->findPage(self::PER_PAGE, $offset, $category);
+        $total = $events->countPage($category);
+
+        return $this->render('events/list.html.twig', [
+            'activeNav' => 'events',
+            'events' => $items,
+            'categories' => $categories->findUsedNames(),
+            'activeCategory' => $category,
+            'page' => $page,
+            'totalPages' => max(1, (int) ceil($total / self::PER_PAGE)),
+            'total' => $total,
+        ]);
+    }
+
+    #[Route('/events/{id}', name: 'event_show', requirements: ['id' => '\d+'])]
+    public function show(int $id, EventRepository $events, EventMapSerializer $mapSerializer): Response
+    {
+        $event = $events->findOneNotDeleted($id);
+        if (!$event) {
+            throw $this->createNotFoundException('Event nicht gefunden.');
+        }
+
+        return $this->render('events/show.html.twig', [
+            'activeNav' => 'events',
+            'event' => $event,
+            'mapEventJson' => $event->hasCoordinates() ? $mapSerializer->toJson([$event]) : '[]',
+        ]);
+    }
+}