<?php

declare(strict_types=1);

namespace App\Services;

use LanguageDetection\Language;

class LanguageDetectionService
{
    private Language $language;

    public function __construct()
    {
        $this->language = new Language;
    }

    /**
     * @return array{0: string, 1: float}|null
     */
    public function detect(string $text): ?array
    {
        if (trim($text) === '') {
            return null;
        }

        $languages = $this->language->detect($text)->bestResults()->close();

        if ($languages === []) {
            return null;
        }

        // bestResults() keeps every candidate within 0.025 of the top score.
        // array_key_first picks the highest-ranked one (arsort'd by the library).
        $code = array_key_first($languages);

        return [$code, $languages[$code]];
    }
}