<?php

namespace App\Node\UseCases;

use App\Exceptions\BadRequestException;
use App\Node\Node;
use App\Node\CreateNodeDto;
use App\Node\NodeRepository;
use App\Text\TextRepository;
use DomainException;

class CreateNode
{
    public function __construct(
        private NodeRepository $nodeRepo,
        private TextRepository $textRepo,
    ) {}

    /**
     * @throws BadRequestException
     * @throws DomainException
     */
    public function execute(CreateNodeRequest $request): Node
    {
        if ($request->textId === null) {
            throw new BadRequestException('textId is required');
        }

        if ($request->title === null) {
            throw new BadRequestException('title is required');
        }

        $textId = $request->textId;
        $text = $this->textRepo->find($textId);
        if ($text === null) {
            throw new DomainException("Text with id: $textId doesnt exist");
        }
        if ($request->parentNodeId === null) {
            $this->validateNoOtherRootNodeExists($textId);
            return $this->nodeRepo->create(new CreateNodeDto(
                text: $text,
                title: $request->title,
                parentNode: null,
            ));
        }
        $parentNodeId = $request->parentNodeId;
        $parentNode = $this->nodeRepo->find($parentNodeId);
        if ($parentNode === null) {
            throw new DomainException("Node with id: $parentNodeId doesnt exist");
        }

        return $this->nodeRepo->create(new CreateNodeDto(
            text: $text,
            title: $request->title,
            parentNode: $parentNode,
        ));
    }

    /**
     * @throws DomainException
     */
    private function validateNoOtherRootNodeExists(int $textId): void
    {
        $nodesOfText = $this->nodeRepo->findByTextId($textId);
        $exists = array_find(
            $nodesOfText,
            function (Node $node) {
                return $node->getParentNode() === null;
            }
        );
        if ($exists) {
            throw new DomainException('A root node already exists for this text');
        }
    }
}