webmentions/src/Webmention.php

<?php

namespace Lewisdale\Webmentions;

use Symfony\Component\DomCrawler\Crawler;
use Symfony\Component\HttpClient\HttpClient;
use Symfony\Contracts\HttpClient\HttpClientInterface;

class Webmention {
    private readonly HttpClientInterface $client;

    function __construct()
    {
        $this->client = HttpClient::create();
    }

    public function sendForPage(string $source) : void {
        $urls = $this->getUrls($source);

        foreach($urls as $target) {
            $this->sendWebmention($source, $target);
        }
    }

    private function getUrls(string $url) : array {
        $page = file_get_contents($url);
        $doc = new Crawler($page);

        $urls = [];
        foreach ($doc->filter('.h-entry a') as $anchor) {
            $target_url = $anchor->attributes->getNamedItem('href')->textContent;

            if ($target_url !== null && strlen($target_url)) {
              $urls[] = $target_url;
            } 
        }
        return $urls;
    }

    private function sendWebmention(string $source, string $target) {
        $endpoint = $this->getWebmentionEndpoint($target);
        
        if ($endpoint) {
            echo "Sending for " . $endpoint . "<br />";
            $this->client->request('POST', $endpoint,
            [
                "body" => [
                    "source" => $source,
                    "target" => $target
                ]
            ]);
        }
    }

    private function getWebmentionEndpoint(string $url) : string | null {
        $response = $this->client->request('GET', $url);
        return EndpointParser::parse($response);
    }
}