<?php

declare(strict_types=1);

namespace App\Services\Crawler;

use App\Models\CrawlRule;
use Illuminate\Http\Client\PendingRequest;
use Illuminate\Support\Facades\Http;

class CrawlFetcherService
{
    /**
     * @return array{ok: bool, http_code: int|null, body: string, error: string|null, latency_ms: int}
     */
    public function fetch(CrawlRule $rule, string $url): array
    {
        $startedAt = microtime(true);

        try {
            if ($rule->render_js && is_string(config('crawler.browserless_endpoint')) && config('crawler.browserless_endpoint') !== '') {
                $response = $this->browserlessRequest($rule)->post((string) config('crawler.browserless_endpoint'), [
                    'url' => $url,
                    'waitUntil' => 'networkidle2',
                ]);
            } else {
                $response = $this->httpRequest($rule)->get($url);
            }

            return [
                'ok' => $response->successful(),
                'http_code' => $response->status(),
                'body' => $response->body(),
                'error' => $response->successful() ? null : sprintf('HTTP %d', $response->status()),
                'latency_ms' => (int) ((microtime(true) - $startedAt) * 1000),
            ];
        } catch (\Throwable $exception) {
            return [
                'ok' => false,
                'http_code' => null,
                'body' => '',
                'error' => $exception->getMessage(),
                'latency_ms' => (int) ((microtime(true) - $startedAt) * 1000),
            ];
        }
    }

    private function httpRequest(CrawlRule $rule): PendingRequest
    {
        $headers = is_array($rule->headers) ? $rule->headers : [];
        $cookies = is_array($rule->cookies) ? $rule->cookies : [];
        $timeout = max((int) config('crawler.request_timeout_seconds', 20), 5);

        $request = Http::timeout($timeout)
            ->withHeaders($headers)
            ->withUserAgent((string) ($rule->user_agent ?: config('crawler.default_user_agent')));

        if (! (bool) config('crawler.verify_ssl', true)) {
            $request = $request->withoutVerifying();
        }

        $request = $this->applyNetworkOptions($request);

        if ($cookies !== []) {
            $request = $request->withCookies($cookies, parse_url((string) ($rule->entry_urls[0] ?? ''), PHP_URL_HOST) ?: '');
        }

        return $request;
    }

    private function applyNetworkOptions(PendingRequest $request): PendingRequest
    {
        $options = [];

        if ((bool) config('crawler.force_ipv4', false)) {
            $options['force_ip_resolve'] = 'v4';
        }

        $dnsServers = trim((string) config('crawler.dns_servers', ''));
        if ($dnsServers !== '' && defined('CURLOPT_DNS_SERVERS')) {
            $options['curl'][CURLOPT_DNS_SERVERS] = $dnsServers;
        }

        if ($options === []) {
            return $request;
        }

        return $request->withOptions($options);
    }

    private function browserlessRequest(CrawlRule $rule): PendingRequest
    {
        $request = $this->httpRequest($rule);
        $token = (string) config('crawler.browserless_token', '');

        if ($token !== '') {
            $request = $request->withToken($token);
        }

        return $request;
    }
}