refactor element updates

backend/app/Element/UseCases/UpdateElement/UpdatePdfPath.php

@@ -0,0 +1,48 @@
+<?php
+
+namespace App\Element\UseCases\UpdateElement;
+
+use App\Element\Element;
+use App\Element\ElementRepository;
+use App\Exceptions\BadRequestException;
+use App\Exceptions\NotFoundException;
+
+class UpdatePdfPath
+{
+    public function __construct(private ElementRepository $elementRepository)
+    {
+    }
+
+    /**
+     * @throws BadRequestException
+     * @throws NotFoundException
+     */
+    public function execute(UpdatePdfPathRequest $request): Element
+    {
+        if ($request->id === null) {
+            throw new BadRequestException('id is required');
+        }
+
+        if ($request->pdfPath === null) {
+            throw new BadRequestException('pdfPath is required');
+        }
+
+        $element = $this->elementRepository->find($request->id);
+        if ($element === null) {
+            throw new NotFoundException('Element not found');
+        }
+
+        $element->setPdfPath($this->nullableString($request->pdfPath));
+
+        return $this->elementRepository->update($element);
+    }
+
+    private function nullableString(string $value): ?string
+    {
+        if ($value === '') {
+            return null;
+        }
+
+        return $value;
+    }
+}