add element updates

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

@@ -0,0 +1,57 @@
+<?php
+
+namespace App\Element\UseCases\UpdateElement;
+
+use App\Element\Element;
+use App\Element\ElementRepository;
+use App\Element\UpdateElementDto;
+use App\Exceptions\BadRequestException;
+use App\Exceptions\NotFoundException;
+
+class UpdateElement
+{
+    public function __construct(private ElementRepository $elementRepository)
+    {
+    }
+
+    /**
+     * @throws BadRequestException
+     * @throws NotFoundException
+     */
+    public function execute(UpdateElementRequest $request): Element
+    {
+        if ($request->id === null) {
+            throw new BadRequestException('id is required');
+        }
+
+        if ($request->title === null || trim($request->title) === '') {
+            throw new BadRequestException('title is required');
+        }
+
+        $element = $this->elementRepository->find($request->id);
+        if ($element === null) {
+            throw new NotFoundException('Element not found');
+        }
+
+        return $this->elementRepository->update(
+            $element,
+            new UpdateElementDto(
+                title: $request->title,
+                description: $request->description ?? '',
+                iconImageUrl: $this->nullableString($request->iconImageUrl),
+                richText: $request->richText ?? '',
+                pdfPath: $this->nullableString($request->pdfPath),
+                youtubeUrl: $this->nullableString($request->youtubeUrl),
+            ),
+        );
+    }
+
+    private function nullableString(?string $value): ?string
+    {
+        if ($value === null || $value === '') {
+            return null;
+        }
+
+        return $value;
+    }
+}