<?php

chdir(__DIR__);

$options = getopt('c:');

$config = parse_ini_file($options['c'] ?? 'config.ini', true);

$debug = (bool) ($config['debug'] ?? false);
$feedUrl = $config['feed']['url'];
$hookUrl = $config['mattermost']['hook_url'];
$cacheFile = $config['cache']['file'];
$template = $config['mattermost']['message_template'];
$cache = [];
$commands = [];

if (file_exists($cacheFile)) {
    $cache = json_decode(file_get_contents($cacheFile), true);

    if (null === $cache) {
        $cache = [];
    }
}

$xml = simplexml_load_file($feedUrl);
$entries = array_merge($xml->xpath('//entry'), $xml->xpath('//item'));

foreach ($entries as $entry) {
    $title = (string) $entry->title;
    $url = null;

    foreach ($entry->link as $link) {
        if (null !== $url) {
            continue;
        }

        $attributes = $link->attributes();
        $content = (string) $link;
        $href = (string) ($attributes['href'] ?? '');
        $type = (string) ($attributes['type'] ?? '');

        if ('' !== $type && 'text/html' !== $type) {
            continue;
        }

        if ('' !== $href) {
            $url = $href;
        } elseif ('' !== $content) {
            $url = $content;
        }
    }

    if (empty($url)) {
        continue;
    }

    $hash = md5($title.$url);

    if (!isset($cache[$hash])) {
        $cache[$hash] = true;

        $json = json_encode([
            'text' => sprintf($template, $title, $url),
        ]);

        $commands[] = sprintf(
            'curl -i -X POST -H "Content-Type: application/json" -d %s %s',
            escapeshellarg($json),
            escapeshellarg($hookUrl)
        );
    }
}

if (!$debug) {
    file_put_contents($cacheFile, json_encode($cache));
}

foreach ($commands as $command) {
    if ($debug) {
        echo $command, "\n";
    } else {
        shell_exec($command);
    }
}