Add app and category whitelisting and blacklisting to Nextcloud

appstore.php

<?php
/**
 * @copyright Copyright (c) 2021, Platypus Innovations LLC
 *
 * @author Andrew Summers
 *
 * This snippet provides a way to implement app and category whitelists/
 * blacklists on Nextcloud. This is accomplished by creating a dummy
 * "appstore" on the local system:
 * - Download the official listings from the Nextcloud servers
 * - Filter out the apps/categories based on the provided configuration
 * - Save the app/category files to the webroot
 * - Modify `config.php` to point `appstoreurl` to localhost
 *
 * To use this script:
 * 1. Save the file to the Nextcloud webroot
 * 2. Make sure to set the proper permissions and ownership (usually by
 *    running `chown www-data:www-data appstore.php`)
 * 3. From your browser, go to: 
 *    https://your-Nextcloud-url.com/appstore.php?clearappcache
 *    This will automatically set up values in your `config.php`
 * 4. Open up `config.php` and edit the whitelist/blacklist values as
 *    you see fit
 * 5. Reload the page from step 3
 * 
 * You will need to set up a cron job or other scheduled tast to call
 * the script on a regular basis in order to refresh the listings on
 * your server. Also, Nextcloud caches the app and category listings,
 * so if you want to force your system to refresh the files, make sure
 * to append the `?clearappcache` URL parameter.
 *
 * In addition to a whitelist/blacklist, this script provides a few
 * other features:
 * - If you need to get a list of all available apps and categories,
 *   include the URL parameter `applist` or `categorylist`, respectively
 * - Add an "All Apps" category to the app manager page.
 * - Hide untested apps. This checks `version` value in `config.php` to
 *   determine if apps are compatible or not. Note that it only checks
 *   the maximum version value of an app, not the minimum. Also, it
 *   only checks whole-number values, not dot-revisions (i.e. 20.0.6 or
 *   15.3.8)
 */

<?php

<?php

require './lib/private/Config.php';

$config = new \OC\Config('./config/');
$config_keys = $config->getKeys();

if (isset($_GET['clearappcache'])) {
	unlink($config->getValue('datadirectory') . '/appdata_' . $config->getValue('instanceid') . '/appstore/apps.json');
	unlink($config->getValue('datadirectory') . '/appdata_' . $config->getValue('instanceid') . '/appstore/categories.json');
}

$app_whitelist = array();
$app_blacklist = array();
$category_whitelist = array();
$category_blacklist = array();
$hide_untested_apps = false;
$hide_invalid_urls = false;
$add_all_apps_category = false;

if (in_array('appwhitelist', $config_keys)) {
	$app_whitelist = $config->getValue('appwhitelist');
}
if (in_array('appblacklist', $config_keys)) {
	$app_blacklist = $config->getValue('appblacklist');
}
if (in_array('categorywhitelist', $config_keys)) {
	$category_whitelist = $config->getValue('categorywhitelist');
}
if (in_array('categoryblacklist', $config_keys)) {
	$category_blacklist = $config->getValue('categoryblacklist');
}
if (in_array('hideuntestedapps', $config_keys)) {
	$hide_untested_apps = $config->getValue('hideuntestedapps');
}
if (in_array('hideinvalidurls', $config_keys)) {
	$hide_invalid_urls = $config->getValue('hideinvalidurls');
}
if (in_array('addallappscategory', $config_keys)) {
	$add_all_apps_category = $config->getValue('addallappscategory');
}

if (! in_array('appstoreenabled', $config_keys)) {
	$config->setValue('appstoreenabled', true);
}
if (! in_array('appstoreurl', $config_keys)) {
	$config->setValue('appstoreurl', $config->getValue('overwrite.cli.url'));
}

$apps = json_decode(file_get_contents('https://apps.nextcloud.com/api/v1/apps.json'),1);
$categories = json_decode(file_get_contents('https://apps.nextcloud.com/api/v1/categories.json'),1);

if (isset($_GET['applist']) && $_GET['applist'] != 'filtered') {
	printAppList($apps);
}

if (isset($_GET['categorylist'])) {
	printCategoryList($categories);
}

if (sizeof($app_whitelist) > 0) {
	$apps = array_filter($apps, function($var) use ($app_whitelist) {
		return in_array($var['id'], $app_whitelist);
	});
}

if (sizeof($app_blacklist) > 0) {
	$apps = array_filter($apps, function($var) use ($app_blacklist) {
		return ! in_array($var['id'], $app_blacklist);
	});
}

if (sizeof($category_whitelist) > 0) {
	$categories = array_filter($categories, function($var) use ($category_whitelist) {
		return in_array($var['id'], $category_whitelist);
	});
}

if (sizeof($category_blacklist) > 0) {
	$categories = array_filter($categories, function($var) use ($category_blacklist) {
		return ! in_array($var['id'], $category_blacklist);
	});
}

if ($add_all_apps_category) {
	$all_apps_array = [
		'id' => 'all',
		'translations' => [
			'en' => [
				'description' => 'All available Nextcloud apps',
				'name' => 'All Apps',
			],
		],
	];
	array_push($categories, $all_apps_array);

	foreach ($apps as $key=>$app) {
		array_push($apps[$key]['categories'], 'all');
	}
}

if ($hide_untested_apps) {
	foreach ($apps as $app_key=>$app) {
		if (isset($app['releases']) || array_key_exists('releases', $app)) {
			foreach ($app['releases'] as $release_key=>$release) {
				$versions = explode(' ', $release['platformVersionSpec']);

				if (sizeof($versions) != 2) {
					$version_max = PHP_INT_MAX;
					$versions[1] = '<' . PHP_INT_MAX;
				}

				$version_min = ltrim($versions[0], '=><');
				$version_max = ltrim($versions[1], '=><');

				$version_min_comp = explode($version_min, $versions[0])[0];
				$version_max_comp = explode($version_max, $versions[1])[0];

				if (
					! version_compare($config->getValue('version'), $version_min, $version_min_comp) ||
					! version_compare($config->getValue('version'), $version_max, $version_max_comp)
				) {
					unset($apps[$app_key]['releases'][$release_key]);
				}
				else {
					$head = @get_headers($release['download']);

					if ($head && is_array($head) && sizeof($head) > 0) {
						$response_code = explode(' ', $head[0])[1];
						if ($response_code > 399) {
							unset($apps[$app_key]['releases'][$release_key]);
						}
					}
					else {
						unset($apps[$app_key]['releases'][$release_key]);
					}
				}
			}
			if (sizeof($apps[$app_key]['releases']) == 0) {
				unset($apps[$app_key]);
			}
			else {
				$apps[$app_key]['releases'] = array_values($apps[$app_key]['releases']);
			}
		}
	}
	$apps = array_values($apps);
}

if ($hide_invalid_urls) {
	foreach ($apps as $app_key=>$app) {
		if (isset($app['releases']) || array_key_exists('releases', $app)) {
			foreach ($app['releases'] as $release_key=>$release) {
				$head = @get_headers($release['download']);

				if ($head && is_array($head) && sizeof($head) > 0) {
					$response_code = explode(' ', $head[0])[1];
					if ($response_code > 399) {
						unset($apps[$app_key]['releases'][$release_key]);
					}
				}
				else {
					unset($apps[$app_key]['releases'][$release_key]);
				}
			}
			if (sizeof($apps[$app_key]['releases']) == 0) {
				unset($apps[$app_key]);
			}
			else {
				$apps[$app_key]['releases'] = array_values($apps[$app_key]['releases']);
			}
		}
	}
	$apps = array_values($apps);
}

if (isset($_GET['applist']) && $_GET['applist'] == 'filtered') {
	printAppList($apps);
}

file_put_contents('apps.json', json_encode($apps));
file_put_contents('categories.json', json_encode($categories));

function printAppList($apps) {
	echo '<style>table,th,td{border:1px solid black; border-collapse:collapse;}</style>';
	echo '<table>';
	foreach ($apps as $app) {
		if (sizeof($app['releases']) > 0) {
			echo '<tr>';
			echo	'<td>' . $app['id'] .  '</td>';
			echo	'<td>' . $app['translations']['en']['name'] . '</td>';
			echo '</tr>';
		}
	}
	echo '</table>';
}

function printCategoryList($categories) {
	echo '<style>table,th,td{border:1px solid black; border-collapse:collapse;}</style>';
	echo '<table>';
	foreach ($categories as $category) {
		echo '<tr>';
		echo	'<td>' . $category['id'] .  '</td>';
		echo	'<td>' . $category['translations']['en']['name'] . '</td>';
		echo '</tr>';
	}
	echo '</table>';
}

?>