<?php

    // https://pubsubhubbub.appspot.com/
    // https://pubsubhubbub.github.io/PubSubHubbub/pubsubhubbub-core-0.4.html
    // https://developers.google.com/youtube/v3/guides/push_notifications
    // https://indieweb.org/How_to_publish_and_consume_WebSub#How_to_Subscribe

    if(isset($_GET['hub_challenge'])){
        // Resposta para verificação do webhook
        echo $_GET['hub_challenge'];

        // Registra em arquivo de logs
        $file = fopen(__DIR__ . '/video_logs.txt','a+');
        fwrite($file, "\r\n ============================== \r\n\r\n");
        fwrite($file, json_encode($_GET));
        fclose($file);
    } else {
        // Faz o tratamento das atualizações recebidas
        $data = file_get_contents('php://input');
        parseYouTubeUpdate($data);
    }

    function parseYoutubeUpdate($data) {
        $xml = simplexml_load_string($data, 'SimpleXMLElement', LIBXML_NOCDATA);

        // Organizando dados recebidos
        $video_data = [
            "xml"          => $xml,
            "id"           => substr((string)$xml->entry->id, 9),
            "title"        => (string)$xml->entry->title,
            "channel_id"   => substr((string)$xml->entry->author->uri, 32),
            "channel_url"  => (string)$xml->entry->author->uri,
            "author"       => (string)$xml->entry->author->name,
            "published"    => (string)$xml->entry->published,
            "updated"      => (string)$xml->entry->updated
        ];

        // Registra em arquivo de logs
        $file = fopen(__DIR__ . '/video_logs.txt','a+');
        fwrite($file, "\r\n ============================== \r\n\r\n");
        fwrite($file, json_encode($video_data));
        fclose($file);

        return;
    }

?>