rssmonster/rssmonster.php

<?php
declare(strict_types = 1);

// Some dependencies haven't been updated for PHP 8
// This can probably be removed for PHP 7.3
error_reporting(E_ALL & ~E_DEPRECATED);

require('vendor/autoload.php');

use GuzzleHttp\Client as HTTPClient;
use PHPHtmlParser\Dom as DOM;

class Log {
    private static $enabled = [
        'silly' => false,
        'debug' => true,
        'info' => true
    ];
    
    private static function emit(string $level, $message) {
        if (!Log::$enabled[$level]) {
            return;
        };
        $now = date("c");
        print("$now [$level] $message\n");
    }

    public static function silly($message) {
        Log::emit('silly', $message);
    }

    public static function debug($message) {
        Log::emit('debug', $message);
    }

    public static function info($message) {
        Log::emit('info', $message);
    }
};

function fetchUrl(string $url) {
    $client = new HTTPClient();

    $res = $client->request(
        'GET', $url, [
            'http_errors' => false,
            'headers' => [
                'User-Agent' => 'Lexie\'s RSS Monster (for Cial) (lexie@alexis-marie-wright.me)'
            ]
        ]
    );

    if ($res->getStatusCode() !== 200) {
        Log::debug($res->getBody());
        throw "Request for $url returned {$res->getStatusCode()}";
    };

    return strval($res->getBody());
};

$baseUrl = 'http://inhuman-comic.com';

$nextLinkSelector = 'div.body a.prev';
$urls = [$baseUrl];
$fetchedUrls = [];

while (count($urls) > 0) {
    $url = array_shift($urls);
    
    $res = fetchUrl($url);
    Log::info("$url: fetched " . strlen($res) . " bytes");

    Log::silly($res);
    
    array_push($fetchedUrls, $url);

    $dom = new DOM;
    $dom->loadStr($res);

    foreach (array($dom->find($nextLinkSelector)) as $el) {
        $nextUrl = $baseUrl . '/' . $el->href;
        
        if (array_search($nextUrl, $fetchedUrls)) {
            Log::debug("$url: already fetched next link $nextUrl");
            continue;
        };

        if (array_search($nextUrl, $urls)) {
            Log::debug("$url: duplicate next link $nextUrl");
            continue;
        };
        
        Log::info("$url: next link $nextUrl");
        array_push($urls, $nextUrl);
    };

    usleep(500000); // wait half a second, to be minimally polite
};
Log::info("Out of next links!");