delete child elements

backend/app/Element/UseCases/DeleteChildElement/DeleteChildElement.php

@@ -0,0 +1,83 @@
+<?php
+
+namespace App\Element\UseCases\DeleteChildElement;
+
+use App\Element\Element;
+use App\Element\ElementRepository;
+use App\Exceptions\BadRequestException;
+use App\Exceptions\NotFoundException;
+use App\Shared\Files\FileUploader;
+
+class DeleteChildElement
+{
+    public function __construct(
+        private ElementRepository $elementRepository,
+        private FileUploader $fileUploader,
+    ) {
+    }
+
+    /**
+     * @throws BadRequestException
+     * @throws NotFoundException
+     */
+    public function execute(DeleteChildElementRequest $request): void
+    {
+        if ($request->parentElementId === null) {
+            throw new BadRequestException('parentElementId is required');
+        }
+
+        if ($request->childElementId === null) {
+            throw new BadRequestException('childElementId is required');
+        }
+
+        $parentElement = $this->elementRepository->find(
+            $request->parentElementId
+        );
+        if ($parentElement === null) {
+            throw new NotFoundException('Parent element not found');
+        }
+
+        $childElement = $this->elementRepository->find(
+            $request->childElementId
+        );
+        if ($childElement === null) {
+            throw new NotFoundException('Child element not found');
+        }
+
+        $actualParentElement = $childElement->getParentElement();
+        if (
+            $actualParentElement === null
+            || $actualParentElement->getId() !== $parentElement->getId()
+        ) {
+            throw new BadRequestException(
+                'Child element does not belong to parent'
+            );
+        }
+
+        $this->deleteSubtree($childElement);
+    }
+
+    private function deleteSubtree(Element $element): void
+    {
+        $childElements = $this->elementRepository->findByParentElement(
+            $element
+        );
+        foreach ($childElements as $childElement) {
+            $this->deleteSubtree($childElement);
+        }
+
+        $this->deleteManagedFile($element->getIconImageUrl());
+        $this->deleteManagedFile($element->getShortPdfPath());
+        $this->deleteManagedFile($element->getLongPdfPath());
+        $this->elementRepository->delete($element);
+    }
+
+    private function deleteManagedFile(?string $path): void
+    {
+        if ($path === null) {
+            return;
+        }
+
+        $this->fileUploader->delete($path);
+    }
+}

backend/app/Element/UseCases/DeleteChildElement/DeleteChildElementRequest.php

@@ -0,0 +1,12 @@
+<?php
+
+namespace App\Element\UseCases\DeleteChildElement;
+
+class DeleteChildElementRequest
+{
+    public function __construct(
+        public ?int $parentElementId,
+        public ?int $childElementId,
+    ) {
+    }
+}