add set deletion

backend/app/Set/UseCases/DeleteSet/DeleteSet.php

@@ -0,0 +1,115 @@
+<?php
+
+namespace App\Set\UseCases\DeleteSet;
+
+use App\Element\Element;
+use App\Element\ElementRepository;
+use App\Exceptions\BadRequestException;
+use App\Exceptions\NotFoundException;
+use App\Set\SetRepository;
+use App\Shared\Files\Filesystem;
+
+class DeleteSet
+{
+    /**
+     * @var array<string, true>
+     */
+    private array $managedFilePaths = [];
+
+    public function __construct(
+        private SetRepository $setRepository,
+        private ElementRepository $elementRepository,
+        private Filesystem $filesystem,
+    ) {
+    }
+
+    /**
+     * @throws BadRequestException
+     * @throws NotFoundException
+     */
+    public function execute(DeleteSetRequest $request): void
+    {
+        if ($request->id === null) {
+            throw new BadRequestException('setId is required');
+        }
+
+        $set = $this->setRepository->find($request->id);
+        if ($set === null) {
+            throw new NotFoundException('Set not found');
+        }
+
+        $this->managedFilePaths = [];
+        $this->rememberManagedFile($set->getIconImageUrl());
+
+        $elements = $this->elementRepository->findBySet($set);
+        foreach ($elements as $element) {
+            $this->rememberManagedFile($element->getIconImageUrl());
+            $this->rememberManagedFile($element->getShortPdfPath());
+            $this->rememberManagedFile($element->getLongPdfPath());
+        }
+
+        foreach ($this->deepestElementsFirst($elements) as $element) {
+            $this->elementRepository->delete($element);
+        }
+
+        $this->setRepository->delete($set);
+        foreach (array_keys($this->managedFilePaths) as $path) {
+            $this->filesystem->delete($path);
+        }
+    }
+
+    /**
+     * @param Element[] $elements
+     * @return Element[]
+     */
+    private function deepestElementsFirst(array $elements): array
+    {
+        usort($elements, function (
+            Element $firstElement,
+            Element $secondElement,
+        ): int {
+            $firstDepth = $this->elementDepth($firstElement);
+            $secondDepth = $this->elementDepth($secondElement);
+            if ($firstDepth === $secondDepth) {
+                return $secondElement->getId() <=> $firstElement->getId();
+            }
+
+            return $secondDepth <=> $firstDepth;
+        });
+
+        return $elements;
+    }
+
+    private function elementDepth(Element $element): int
+    {
+        $depth = 0;
+        $parentElement = $element->getParentElement();
+        while ($parentElement !== null) {
+            $depth++;
+            $parentElement = $parentElement->getParentElement();
+        }
+
+        return $depth;
+    }
+
+    private function rememberManagedFile(?string $path): void
+    {
+        if ($path === null) {
+            return;
+        }
+
+        if (! $this->isManagedFilePath($path)) {
+            return;
+        }
+
+        $this->managedFilePaths[$path] = true;
+    }
+
+    private function isManagedFilePath(string $path): bool
+    {
+        return str_starts_with($path, 'set-icons/')
+            || str_starts_with($path, 'element-icons/')
+            || str_starts_with($path, 'element-pdfs/short/')
+            || str_starts_with($path, 'element-pdfs/long/');
+    }
+}