<?php
declare(strict_types=1);

/**
 * TKLM Translate V3: klient PHP -> https://translate.tklm.pl.
 * Wywoluj TYLKO po stronie serwera (np. z panelu administracyjnego / zadania cron).
 * Nigdy nie ujawniaj klucza w HTML, JavaScript, JSON ani przegladarce.
 */
final class TklmTranslateClient
{
    private string $key;
    private string $endpoint = 'https://translate.tklm.pl';

    public function __construct(string $key)
    {
        if (!preg_match('/^[a-f0-9]{48}$/', $key)) {
            throw new InvalidArgumentException('Nieprawidlowy klucz API TKLM');
        }
        if (!extension_loaded('curl')) {
            throw new RuntimeException('Brak rozszerzenia cURL w PHP');
        }
        $this->key = $key;
    }

    public function languages(): array
    {
        return $this->request('/languages', null);
    }

    public function translate(string $text, string $source = 'pl', string $target = 'en'): array
    {
        $text = trim($text);
        if ($text === '' || strlen($text) > 50000) {
            throw new InvalidArgumentException('Tekst musi miec 1-50000 bajtow');
        }
        if (!preg_match('/^(auto|[a-z]{2,3}(?:-[A-Za-z0-9]+)?)$/', $source) ||
            !preg_match('/^[a-z]{2,3}(?:-[A-Za-z0-9]+)?$/', $target)) {
            throw new InvalidArgumentException('Niepoprawny kod jezyka');
        }
        return $this->request('/translate', [
            'q' => $text, 'source' => $source, 'target' => $target, 'format' => 'text'
        ]);
    }

    public function detect(string $text): array
    {
        if (trim($text) === '' || strlen($text) > 50000) {
            throw new InvalidArgumentException('Niepoprawna dlugosc tekstu');
        }
        return $this->request('/detect', ['q' => $text]);
    }

    private function request(string $path, ?array $data): array
    {
        $ch = curl_init($this->endpoint . $path);
        if ($ch === false) {
            throw new RuntimeException('Nie udalo sie uruchomic cURL');
        }
        $opts = [
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_CONNECTTIMEOUT => 10,
            CURLOPT_TIMEOUT => 120,
            CURLOPT_FOLLOWLOCATION => false,
            CURLOPT_SSL_VERIFYPEER => true,
            CURLOPT_SSL_VERIFYHOST => 2,
            CURLOPT_HTTPHEADER => [
                'X-TKLM-Translate-Key: ' . $this->key,
                'Accept: application/json',
                'Content-Type: application/x-www-form-urlencoded',
            ],
        ];
        if (defined('CURLOPT_PROTOCOLS_STR')) {
            $opts[CURLOPT_PROTOCOLS_STR] = 'https';
        } elseif (defined('CURLOPT_PROTOCOLS')) {
            $opts[CURLOPT_PROTOCOLS] = CURLPROTO_HTTPS;
        }
        if ($data !== null) {
            $opts[CURLOPT_POST] = true;
            $opts[CURLOPT_POSTFIELDS] = http_build_query($data, '', '&', PHP_QUERY_RFC3986);
        }
        curl_setopt_array($ch, $opts);
        $body = curl_exec($ch);
        $code = (int)curl_getinfo($ch, CURLINFO_RESPONSE_CODE);
        if ($body === false) {
            $err = curl_error($ch);
            curl_close($ch);
            throw new RuntimeException('Polaczenie Translate nieudane: ' . $err);
        }
        curl_close($ch);
        if ($code !== 200) {
            throw new RuntimeException('API Translate zwrocilo HTTP ' . $code);
        }
        $json = json_decode($body, true);
        if (!is_array($json)) {
            throw new RuntimeException('Niepoprawny JSON z Translate');
        }
        return $json;
    }
}