<?php

namespace App\Node;

use App\Node\Node;
use App\Node\CreateNodeDto;
use App\Node\NodeRepository;
use App\Text\TextRepository;

class JsonNodeRepository implements NodeRepository
{
    private string $filePath;

    public function __construct(
        private TextRepository $textRepository,
    ) {
        $this->filePath = __DIR__ . '/../../data/nodes.json';
    }

    public function create(CreateNodeDto $dto): Node
    {
        $nodes = $this->readNodes();
        $id = $this->getNextId($nodes);

        $nodes[] = [
            'id' => $id,
            'title' => $dto->title,
            'textId' => $dto->text->getId(),
            'parentNodeId' => $dto->parentNode?->getId(),
        ];

        $this->writeNodes($nodes);

        return new Node(
            id: $id,
            title: $dto->title,
            text: $dto->text,
            parentNode: $dto->parentNode,
        );
    }

    public function find(int $id): ?Node
    {
        $nodes = $this->readNodes();

        foreach ($nodes as $data) {
            if ($data['id'] === $id) {
                return $this->hydrateNode($data, $nodes);
            }
        }

        return null;
    }

    /**
     * @return Node[]
     */
    public function findByTextId(int $id): array
    {
        $nodes = $this->readNodes();

        $matching = array_filter(
            $nodes,
            fn(array $data) => $data['textId'] === $id
        );

        return array_values(array_map(
            fn(array $data) => $this->hydrateNode($data, $nodes),
            $matching
        ));
    }

    private function hydrateNode(array $data, array $allNodes): Node
    {
        $text = $this->textRepository->find($data['textId']);

        $parentNode = null;
        if ($data['parentNodeId'] !== null) {
            foreach ($allNodes as $parentData) {
                if ($parentData['id'] === $data['parentNodeId']) {
                    $parentNode = $this->hydrateNode($parentData, $allNodes);
                    break;
                }
            }
        }

        return new Node(
            id: $data['id'],
            title: $data['title'],
            text: $text,
            parentNode: $parentNode,
        );
    }

    private function readNodes(): array
    {
        if (!file_exists($this->filePath)) {
            return [];
        }

        $content = file_get_contents($this->filePath);

        return json_decode($content, true) ?? [];
    }

    private function writeNodes(array $nodes): void
    {
        file_put_contents(
            $this->filePath,
            json_encode($nodes, JSON_PRETTY_PRINT)
        );
    }

    private function getNextId(array $nodes): int
    {
        if (empty($nodes)) {
            return 1;
        }

        $maxId = 0;
        foreach ($nodes as $node) {
            if ($node['id'] > $maxId) {
                $maxId = $node['id'];
            }
        }

        return $maxId + 1;
    }
}