<?php

namespace App\Services\Crawl;

use App\Models\CrawlSource;

class CrawlSourceResolver
{
    public function resolve(string $requestUrl, string $targetType): ?CrawlSource
    {
        $host = strtolower((string) parse_url($requestUrl, PHP_URL_HOST));
        if ($host === '') {
            return null;
        }

        $sources = CrawlSource::query()
            ->where('status', 1)
            ->where('target_type', $targetType)
            ->orderBy('sort')
            ->get();

        $wildcard = null;

        foreach ($sources as $source) {
            foreach ($source->match_domains ?? [] as $domain) {
                $domain = strtolower(trim((string) $domain));
                if ($domain === '*' || $domain === 'any') {
                    $wildcard ??= $source;

                    continue;
                }
                if ($this->hostMatchesDomain($host, $domain)) {
                    return $source;
                }
            }
        }

        $hint = $this->resolveByUrlHint($requestUrl, $targetType, $sources);
        if ($hint) {
            return $hint;
        }

        return $wildcard;
    }

    protected function hostMatchesDomain(string $host, string $domain): bool
    {
        $host = $this->normalizeHost($host);
        $domain = strtolower(trim($domain));
        if ($domain === '' || $domain === '*' || $domain === 'any') {
            return false;
        }

        if (str_starts_with($domain, '*.')) {
            $suffix = substr($domain, 1);

            return $host === substr($domain, 2) || str_ends_with($host, $suffix);
        }

        $domain = $this->normalizeHost($domain);

        return $host === $domain || str_ends_with($host, '.'.$domain);
    }

    protected function normalizeHost(string $host): string
    {
        $host = strtolower(trim($host));
        if (str_starts_with($host, 'www.')) {
            return substr($host, 4);
        }

        return $host;
    }

    /**
     * 域名未精确命中时，按 URL 特征回退（如 pedaily 子域、arxiv 路径）。
     *
     * @param  \Illuminate\Support\Collection<int, CrawlSource>  $sources
     */
    protected function resolveByUrlHint(string $requestUrl, string $targetType, $sources): ?CrawlSource
    {
        $lower = strtolower($requestUrl);

        if ($targetType === 'industry_news' && str_contains($lower, 'pedaily')) {
            return $sources->firstWhere('adapter_code', 'pedaily_html');
        }

        if ($targetType === 'paper' && (str_contains($lower, 'arxiv.org') || str_contains($lower, 'arxiv'))) {
            return $sources->firstWhere('adapter_code', 'arxiv_api');
        }

        return null;
    }
}