<?php

declare(strict_types=1);

namespace Esun\Translation\Model\Ai;

class ProtectedTextProcessor
{
    /**
     * @return array{0: string, 1: array<string, string>}
     */
    public function protect(string $text): array
    {
        $placeholders = [];
        $index = 0;
        $protected = preg_replace_callback(
            '/\{\{.*?\}\}|https?:\/\/[^\s<>"\']+|%[0-9]*\$?[a-zA-Z]|\{[A-Za-z0-9_.-]+\}/',
            function (array $matches) use (&$placeholders, &$index): string {
                $token = '__ESUN_TRANSLATION_PRESERVE_' . $index++ . '__';
                $placeholders[$token] = $matches[0];

                return $token;
            },
            $text
        );

        return [$protected ?? $text, $placeholders];
    }

    /**
     * @param array<string, string> $placeholders
     */
    public function restore(string $text, array $placeholders): string
    {
        foreach ($placeholders as $token => $original) {
            if (!str_contains($text, $token)) {
                throw new \RuntimeException(sprintf('Protected token "%s" was not preserved by AI response.', $token));
            }
        }

        return strtr($text, $placeholders);
    }
}