<?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\Filesystem;

class DeleteChildElement
{
    public function __construct(
        private ElementRepository $elementRepository,
        private Filesystem $filesystem,
    ) {
    }

    /**
     * @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;
        }

        $this->filesystem->delete($path);
    }
}