<?php

declare(strict_types=1);

namespace App\Services;

use Illuminate\Http\Client\ConnectionException;
use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\Http;
use Spatie\Robots\RobotsTxt;

class RobotsService
{
    public function __construct(
        private UrlService $urlService,
    ) {}

    public function isAllowed(string $url, ?string $userAgent = null): bool
    {
        $host = $this->urlService->host($url);
        $path = parse_url($url, PHP_URL_PATH) ?? '/';

        $body = Cache::remember(
            "crawler:robots:{$host}",
            config('crawler.robots_cache_ttl_seconds'),
            function () use ($host) {
                try {
                    $response = Http::get("https://{$host}/robots.txt");

                    return $response->successful() ? $response->body() : '';
                } catch (ConnectionException) {
                    return '';
                }
            }
        );

        return (new RobotsTxt($body))->allows($path, $userAgent);
    }

    public function crawlDelayFor(string $host, string $userAgent): ?int
    {
        $body = Cache::remember(
            "crawler:robots:{$host}",
            config('crawler.robots_cache_ttl_seconds'),
            function () use ($host) {
                try {
                    $response = Http::get("https://{$host}/robots.txt");

                    return $response->successful() ? $response->body() : '';
                } catch (ConnectionException) {
                    return '';
                }
            }
        );

        $delay = (new RobotsTxt($body))->crawlDelay($userAgent);

        return $delay !== null ? (int) $delay : null;
    }
}