<?php
/**
 * @copyright Copyright (c) 2016, ownCloud, Inc.
 *
 * @author Joas Schilling <coding@schilljs.com>
 * @author Lukas Reschke <lukas@statuscode.ch>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Robin McCorkell <robin@mccorkell.me.uk>
 * @author Roeland Jago Douma <roeland@famdouma.nl>
 *
 * @license AGPL-3.0
 *
 * This code is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License, version 3,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License, version 3,
 * along with this program.  If not, see <http://www.gnu.org/licenses/>
 *
 */

namespace OC\Settings\Controller;

use GuzzleHttp\Exception\ClientException;
use OC\AppFramework\Http;
use OC\IntegrityCheck\Checker;
use OCP\AppFramework\Controller;
use OCP\AppFramework\Http\DataDisplayResponse;
use OCP\AppFramework\Http\DataResponse;
use OCP\AppFramework\Http\RedirectResponse;
use OCP\Http\Client\IClientService;
use OCP\IConfig;
use OCP\IL10N;
use OCP\ILogger;
use OCP\IRequest;
use OC_Util;
use OCP\IURLGenerator;

/**
 * @package OC\Settings\Controller
 */
class CheckSetupController extends Controller {
	/** @var IConfig */
	private $config;
	/** @var IClientService */
	private $clientService;
	/** @var \OC_Util */
	private $util;
	/** @var IURLGenerator */
	private $urlGenerator;
	/** @var IL10N */
	private $l10n;
	/** @var Checker */
	private $checker;
	/** @var ILogger */
	private $logger;

	/**
	 * @param string $AppName
	 * @param IRequest $request
	 * @param IConfig $config
	 * @param IClientService $clientService
	 * @param IURLGenerator $urlGenerator
	 * @param \OC_Util $util
	 * @param IL10N $l10n
	 * @param Checker $checker
	 * @param ILogger $logger
	 */
	public function __construct($AppName,
								IRequest $request,
								IConfig $config,
								IClientService $clientService,
								IURLGenerator $urlGenerator,
								\OC_Util $util,
								IL10N $l10n,
								Checker $checker,
								ILogger $logger) {
		parent::__construct($AppName, $request);
		$this->config = $config;
		$this->clientService = $clientService;
		$this->util = $util;
		$this->urlGenerator = $urlGenerator;
		$this->l10n = $l10n;
		$this->checker = $checker;
		$this->logger = $logger;
	}

	/**
	 * Checks if the ownCloud server can connect to the internet using HTTPS and HTTP
	 * @return bool
	 */
	private function isInternetConnectionWorking() {
		if ($this->config->getSystemValue('has_internet_connection', true) === false) {
			return false;
		}

		$siteArray = ['www.nextcloud.com',
						'www.google.com',
						'www.github.com'];

		foreach($siteArray as $site) {
			if ($this->isSiteReachable($site)) {
				return true;
			}
		}
		return false;
	}

	/**
	* Chceks if the ownCloud server can connect to a specific URL using both HTTPS and HTTP
	* @return bool
	*/
	private function isSiteReachable($sitename) {
		$httpSiteName = 'http://' . $sitename . '/';
		$httpsSiteName = 'https://' . $sitename . '/';

		try {
			$client = $this->clientService->newClient();
			$client->get($httpSiteName);
			$client->get($httpsSiteName);
		} catch (\Exception $e) {
			$this->logger->logException($e, ['app' => 'internet_connection_check']);
			return false;
		}
		return true;
	}

	/**
	 * Checks whether a local memcache is installed or not
	 * @return bool
	 */
	private function isMemcacheConfigured() {
		return $this->config->getSystemValue('memcache.local', null) !== null;
	}

	/**
	 * Whether /dev/urandom is available to the PHP controller
	 *
	 * @return bool
	 */
	private function isUrandomAvailable() {
		if(@file_exists('/dev/urandom')) {
			$file = fopen('/dev/urandom', 'rb');
			if($file) {
				fclose($file);
				return true;
			}
		}

		return false;
	}

	/**
	 * Public for the sake of unit-testing
	 *
	 * @return array
	 */
	protected function getCurlVersion() {
		return curl_version();
	}

	/**
	 * Check if the used  SSL lib is outdated. Older OpenSSL and NSS versions do
	 * have multiple bugs which likely lead to problems in combination with
	 * functionality required by ownCloud such as SNI.
	 *
	 * @link https://github.com/owncloud/core/issues/17446#issuecomment-122877546
	 * @link https://bugzilla.redhat.com/show_bug.cgi?id=1241172
	 * @return string
	 */
	private function isUsedTlsLibOutdated() {
		// Don't run check when:
		// 1. Server has `has_internet_connection` set to false
		// 2. AppStore AND S2S is disabled
		if(!$this->config->getSystemValue('has_internet_connection', true)) {
			return '';
		}
		if(!$this->config->getSystemValue('appstoreenabled', true)
			&& $this->config->getAppValue('files_sharing', 'outgoing_server2server_share_enabled', 'yes') === 'no'
			&& $this->config->getAppValue('files_sharing', 'incoming_server2server_share_enabled', 'yes') === 'no') {
			return '';
		}

		$versionString = $this->getCurlVersion();
		if(isset($versionString['ssl_version'])) {
			$versionString = $versionString['ssl_version'];
		} else {
			return '';
		}

		$features = (string)$this->l10n->t('installing and updating apps via the app store or Federated Cloud Sharing');
		if(!$this->config->getSystemValue('appstoreenabled', true)) {
			$features = (string)$this->l10n->t('Federated Cloud Sharing');
		}

		// Check if at least OpenSSL after 1.01d or 1.0.2b
		if(strpos($versionString, 'OpenSSL/') === 0) {
			$majorVersion = substr($versionString, 8, 5);
			$patchRelease = substr($versionString, 13, 6);

			if(($majorVersion === '1.0.1' && ord($patchRelease) < ord('d')) ||
				($majorVersion === '1.0.2' && ord($patchRelease) < ord('b'))) {
				return (string) $this->l10n->t('cURL is using an outdated %s version (%s). Please update your operating system or features such as %s will not work reliably.', ['OpenSSL', $versionString, $features]);
			}
		}

		// Check if NSS and perform heuristic check
		if(strpos($versionString, 'NSS/') === 0) {
			try {
				$firstClient = $this->clientService->newClient();
				$firstClient->get('https://nextcloud.com/');

				$secondClient = $this->clientService->newClient();
				$secondClient->get('https://nextcloud.com/');
			} catch (ClientException $e) {
				if($e->getResponse()->getStatusCode() === 400) {
					return (string) $this->l10n->t('cURL is using an outdated %s version (%s). Please update your operating system or features such as %s will not work reliably.', ['NSS', $versionString, $features]);
				}
			}
		}

		return '';
	}

	/**
	 * Whether the version is outdated
	 *
	 * @return bool
	 */
	protected function isPhpOutdated() {
		if (version_compare(PHP_VERSION, '5.5.0') === -1) {
			return true;
		}

		return false;
	}

	/**
	 * Whether the php version is still supported (at time of release)
	 * according to: https://secure.php.net/supported-versions.php
	 *
	 * @return array
	 */
	private function isPhpSupported() {
		return ['eol' => $this->isPhpOutdated(), 'version' => PHP_VERSION];
	}

	/**
	 * Check if the reverse proxy configuration is working as expected
	 *
	 * @return bool
	 */
	private function forwardedForHeadersWorking() {
		$trustedProxies = $this->config->getSystemValue('trusted_proxies', []);
		$remoteAddress = $this->request->getRemoteAddress();

		if (is_array($trustedProxies) && in_array($remoteAddress, $trustedProxies)) {
			return false;
		}

		// either not enabled or working correctly
		return true;
	}

	/**
	 * Checks if the correct memcache module for PHP is installed. Only
	 * fails if memcached is configured and the working module is not installed.
	 *
	 * @return bool
	 */
	private function isCorrectMemcachedPHPModuleInstalled() {
		if ($this->config->getSystemValue('memcache.distributed', null) !== '\OC\Memcache\Memcached') {
			return true;
		}

		// there are two different memcached modules for PHP
		// we only support memcached and not memcache
		// https://code.google.com/p/memcached/wiki/PHPClientComparison
		return !(!extension_loaded('memcached') && extension_loaded('memcache'));
	}

	/**
	 * @return RedirectResponse
	 */
	public function rescanFailedIntegrityCheck() {
		$this->checker->runInstanceVerification();
		return new RedirectResponse(
			$this->urlGenerator->linkToRoute('settings.AdminSettings.index')
		);
	}

	/**
	 * @NoCSRFRequired
	 * @return DataResponse
	 */
	public function getFailedIntegrityCheckFiles() {
		if(!$this->checker->isCodeCheckEnforced()) {
			return new DataDisplayResponse('Integrity checker has been disabled. Integrity cannot be verified.');
		}

		$completeResults = $this->checker->getResults();

		if(!empty($completeResults)) {
			$formattedTextResponse = 'Technical information
=====================
The following list covers which files have failed the integrity check. Please read
the previous linked documentation to learn more about the errors and how to fix
them.

Results
=======
';
			foreach($completeResults as $context => $contextResult) {
				$formattedTextResponse .= "- $context\n";

				foreach($contextResult as $category => $result) {
					$formattedTextResponse .= "\t- $category\n";
					if($category !== 'EXCEPTION') {
						foreach ($result as $key => $results) {
							$formattedTextResponse .= "\t\t- $key\n";
						}
					} else {
						foreach ($result as $key => $results) {
							$formattedTextResponse .= "\t\t- $results\n";
						}
					}

				}
			}

			$formattedTextResponse .= '
Raw output
==========
';
			$formattedTextResponse .= print_r($completeResults, true);
		} else {
			$formattedTextResponse = 'No errors have been found.';
		}


		$response = new DataDisplayResponse(
			$formattedTextResponse,
			Http::STATUS_OK,
			[
				'Content-Type' => 'text/plain',
			]
		);

		return $response;
	}

	/**
	 * @return DataResponse
	 */
	public function check() {
		return new DataResponse(
			[
				'serverHasInternetConnection' => $this->isInternetConnectionWorking(),
				'isMemcacheConfigured' => $this->isMemcacheConfigured(),
				'memcacheDocs' => $this->urlGenerator->linkToDocs('admin-performance'),
				'isUrandomAvailable' => $this->isUrandomAvailable(),
				'securityDocs' => $this->urlGenerator->linkToDocs('admin-security'),
				'isUsedTlsLibOutdated' => $this->isUsedTlsLibOutdated(),
				'phpSupported' => $this->isPhpSupported(),
				'forwardedForHeadersWorking' => $this->forwardedForHeadersWorking(),
				'reverseProxyDocs' => $this->urlGenerator->linkToDocs('admin-reverse-proxy'),
				'isCorrectMemcachedPHPModuleInstalled' => $this->isCorrectMemcachedPHPModuleInstalled(),
				'hasPassedCodeIntegrityCheck' => $this->checker->hasPassedCheck(),
				'codeIntegrityCheckerDocumentation' => $this->urlGenerator->linkToDocs('admin-code-integrity'),
			]
		);
	}
}