webmentions/src/Endpoint.php

<?php declare(strict_types=1);

namespace Lewisdale\Webmentions;

use Lewisdale\Webmentions\Gateways\WebmentionGatewayInterface;

class Endpoint {
    private readonly WebmentionGatewayInterface $gateway;

    public function validateUrl(string $url) : bool {
        return !!filter_var($url, FILTER_VALIDATE_URL);
    }

    public function receiveWebmention(string $source, string $target) : void
    {
        // Validate that both source and target are actual domains
        if (!$this->validateUrl($source) || !$this->validateUrl($target))
        {
            return;
        }

        // Validate that the webmention target is a domain I care about
        if (!str_contains($target, "https://lewisdale.dev")) {
            // Should throw a Bad Request error
            return;  
        }

        // Parse content from the source

        // Store the webmention

        // Send the appropriate response
    }
}