feat: streamlined filenames of downloaded teamer documents

addresses #8698updx6

src/Service/Upload/DownloadNamer.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace App\Service\Upload;
+
+use App\Entity\Teamer;
+use App\Entity\Upload;
+use Symfony\Component\String\Slugger\AsciiSlugger;
+
+class DownloadNamer
+{
+    public function nameForTeamer(Upload $upload, Teamer $teamer): string
+    {
+        $pattern = match($upload->getType()) {
+            Upload::TYPE_INVOICE => 'hn-%d-%s-%s.pdf',
+            Upload::TYPE_CONTRACT => 'hv-%d-%s-%s.pdf',
+            default => null,
+        };
+
+        if (null === $pattern) {
+            return $upload->getOriginalFilename();
+        }
+
+        $slugger = new AsciiSlugger('de');
+        $teamerName = strtolower($slugger->slug($teamer->getFullName(true), '_'));
+
+        return sprintf(
+            $pattern,
+            $upload->getId(),
+            $teamerName,
+            $upload->getCreatedAt()->format('Ymd')
+        );
+    }
+}