<?php
/**
 * @copyright Copyright (c) 2016, ownCloud, Inc.
 * @copyright Copyright (c) 2016, Lukas Reschke <lukas@statuscode.ch>
 *
 * @author Arthur Schiwon <blizzz@arthur-schiwon.de>
 * @author Frank Karlitschek <frank@karlitschek.de>
 * @author Joas Schilling <coding@schilljs.com>
 * @author Lukas Reschke <lukas@statuscode.ch>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Robin Appelman <robin@icewind.nl>
 * @author Steffen Lindner <mail@steffen-lindner.de>
 * @author Thomas Müller <thomas.mueller@tmit.eu>
 * @author Victor Dubiniuk <dubiniuk@owncloud.com>
 * @author Vincent Petry <pvince81@owncloud.com>
 *
 * @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;

use OC\Hooks\BasicEmitter;
use OC\IntegrityCheck\Checker;
use OC_App;
use OCP\IConfig;
use OCP\ILogger;
use OCP\Util;
use Symfony\Component\EventDispatcher\GenericEvent;

/**
 * Class that handles autoupdating of ownCloud
 *
 * Hooks provided in scope \OC\Updater
 *  - maintenanceStart()
 *  - maintenanceEnd()
 *  - dbUpgrade()
 *  - failure(string $message)
 */
class Updater extends BasicEmitter {

	/** @var ILogger $log */
	private $log;

	/** @var IConfig */
	private $config;

	/** @var Checker */
	private $checker;

	/** @var bool */
	private $skip3rdPartyAppsDisable;

	private $logLevelNames = [
		0 => 'Debug',
		1 => 'Info',
		2 => 'Warning',
		3 => 'Error',
		4 => 'Fatal',
	];

	/**
	 * @param IConfig $config
	 * @param Checker $checker
	 * @param ILogger $log
	 */
	public function __construct(IConfig $config,
								Checker $checker,
								ILogger $log = null) {
		$this->log = $log;
		$this->config = $config;
		$this->checker = $checker;

		// If at least PHP 7.0.0 is used we don't need to disable apps as we catch
		// fatal errors and exceptions and disable the app just instead.
		if(version_compare(phpversion(), '7.0.0', '>=')) {
			$this->skip3rdPartyAppsDisable = true;
		}
	}

	/**
	 * Sets whether the update disables 3rd party apps.
	 * This can be set to true to skip the disable.
	 *
	 * @param bool $flag false to not disable, true otherwise
	 */
	public function setSkip3rdPartyAppsDisable($flag) {
		$this->skip3rdPartyAppsDisable = $flag;
	}

	/**
	 * runs the update actions in maintenance mode, does not upgrade the source files
	 * except the main .htaccess file
	 *
	 * @return bool true if the operation succeeded, false otherwise
	 */
	public function upgrade() {
		$this->emitRepairEvents();
		$this->logAllEvents();

		$logLevel = $this->config->getSystemValue('loglevel', Util::WARN);
		$this->emit('\OC\Updater', 'setDebugLogLevel', [ $logLevel, $this->logLevelNames[$logLevel] ]);
		$this->config->setSystemValue('loglevel', Util::DEBUG);

		$wasMaintenanceModeEnabled = $this->config->getSystemValue('maintenance', false);

		if(!$wasMaintenanceModeEnabled) {
			$this->config->setSystemValue('maintenance', true);
			$this->emit('\OC\Updater', 'maintenanceEnabled');
		}

		$installedVersion = $this->config->getSystemValue('version', '0.0.0');
		$currentVersion = implode('.', \OCP\Util::getVersion());
		$this->log->debug('starting upgrade from ' . $installedVersion . ' to ' . $currentVersion, array('app' => 'core'));

		$success = true;
		try {
			$this->doUpgrade($currentVersion, $installedVersion);
		} catch (HintException $exception) {
			$this->log->logException($exception, ['app' => 'core']);
			$this->emit('\OC\Updater', 'failure', array($exception->getMessage() . ': ' .$exception->getHint()));
			$success = false;
		} catch (\Exception $exception) {
			$this->log->logException($exception, ['app' => 'core']);
			$this->emit('\OC\Updater', 'failure', array(get_class($exception) . ': ' .$exception->getMessage()));
			$success = false;
		}

		$this->emit('\OC\Updater', 'updateEnd', array($success));

		if(!$wasMaintenanceModeEnabled && $success) {
			$this->config->setSystemValue('maintenance', false);
			$this->emit('\OC\Updater', 'maintenanceDisabled');
		} else {
			$this->emit('\OC\Updater', 'maintenanceActive');
		}

		$this->emit('\OC\Updater', 'resetLogLevel', [ $logLevel, $this->logLevelNames[$logLevel] ]);
		$this->config->setSystemValue('loglevel', $logLevel);
		$this->config->setSystemValue('installed', true);

		return $success;
	}

	/**
	 * Return version from which this version is allowed to upgrade from
	 *
	 * @return array allowed previous versions per vendor
	 */
	private function getAllowedPreviousVersions() {
		// this should really be a JSON file
		require \OC::$SERVERROOT . '/version.php';
		/** @var array $OC_VersionCanBeUpgradedFrom */
		return implode('.', $OC_VersionCanBeUpgradedFrom);
	}

	/**
	 * Return vendor from which this version was published
	 *
	 * @return string Get the vendor
	 */
	private function getVendor() {
		// this should really be a JSON file
		require \OC::$SERVERROOT . '/version.php';
		/** @var string $vendor */
		return (string) $vendor;
	}

	/**
	 * Whether an upgrade to a specified version is possible
	 * @param string $oldVersion
	 * @param string $newVersion
	 * @param array $allowedPreviousVersions
	 * @return bool
	 */
	public function isUpgradePossible($oldVersion, $newVersion, array $allowedPreviousVersions) {
		$version = explode('.', $oldVersion);
		$majorMinor = $version[0] . '.' . $version[1];

		$currentVendor = $this->config->getAppValue('core', 'vendor', '');
		if ($currentVendor === 'nextcloud') {
			return isset($allowedPreviousVersions[$currentVendor][$majorMinor])
				&& (version_compare($oldVersion, $newVersion, '<=') ||
					$this->config->getSystemValue('debug', false));
		}

		// Check if the instance can be migrated
		return isset($allowedPreviousVersions[$currentVendor][$majorMinor]);
	}

	/**
	 * runs the update actions in maintenance mode, does not upgrade the source files
	 * except the main .htaccess file
	 *
	 * @param string $currentVersion current version to upgrade to
	 * @param string $installedVersion previous version from which to upgrade from
	 *
	 * @throws \Exception
	 */
	private function doUpgrade($currentVersion, $installedVersion) {
		// Stop update if the update is over several major versions
		$allowedPreviousVersions = $this->getAllowedPreviousVersions();
		if (!$this->isUpgradePossible($installedVersion, $currentVersion, $allowedPreviousVersions)) {
			throw new \Exception('Updates between multiple major versions and downgrades are unsupported.');
		}

		// Update .htaccess files
		try {
			Setup::updateHtaccess();
			Setup::protectDataDirectory();
		} catch (\Exception $e) {
			throw new \Exception($e->getMessage());
		}

		// create empty file in data dir, so we can later find
		// out that this is indeed an ownCloud data directory
		// (in case it didn't exist before)
		file_put_contents($this->config->getSystemValue('datadirectory', \OC::$SERVERROOT . '/data') . '/.ocdata', '');

		// pre-upgrade repairs
		$repair = new Repair(Repair::getBeforeUpgradeRepairSteps(), \OC::$server->getEventDispatcher());
		$repair->run();

		$this->doCoreUpgrade();

		try {
			// TODO: replace with the new repair step mechanism https://github.com/owncloud/core/pull/24378
			Setup::installBackgroundJobs();
		} catch (\Exception $e) {
			throw new \Exception($e->getMessage());
		}

		// update all shipped apps
		$disabledApps = $this->checkAppsRequirements();
		$this->doAppUpgrade();

		// upgrade appstore apps
		$this->upgradeAppStoreApps($disabledApps);

		// install new shipped apps on upgrade
		OC_App::loadApps('authentication');
		$errors = Installer::installShippedApps(true);
		foreach ($errors as $appId => $exception) {
			/** @var \Exception $exception */
			$this->log->logException($exception, ['app' => $appId]);
			$this->emit('\OC\Updater', 'failure', [$appId . ': ' . $exception->getMessage()]);
		}

		// post-upgrade repairs
		$repair = new Repair(Repair::getRepairSteps(), \OC::$server->getEventDispatcher());
		$repair->run();

		//Invalidate update feed
		$this->config->setAppValue('core', 'lastupdatedat', 0);

		// Check for code integrity if not disabled
		if(\OC::$server->getIntegrityCodeChecker()->isCodeCheckEnforced()) {
			$this->emit('\OC\Updater', 'startCheckCodeIntegrity');
			$this->checker->runInstanceVerification();
			$this->emit('\OC\Updater', 'finishedCheckCodeIntegrity');
		}

		// only set the final version if everything went well
		$this->config->setSystemValue('version', implode('.', Util::getVersion()));
		$this->config->setAppValue('core', 'vendor', $this->getVendor());
	}

	protected function doCoreUpgrade() {
		$this->emit('\OC\Updater', 'dbUpgradeBefore');

		// do the real upgrade
		\OC_DB::updateDbFromStructure(\OC::$SERVERROOT . '/db_structure.xml');

		$this->emit('\OC\Updater', 'dbUpgrade');
	}

	/**
	 * @param string $version the oc version to check app compatibility with
	 */
	protected function checkAppUpgrade($version) {
		$apps = \OC_App::getEnabledApps();
		$this->emit('\OC\Updater', 'appUpgradeCheckBefore');

		foreach ($apps as $appId) {
			$info = \OC_App::getAppInfo($appId);
			$compatible = \OC_App::isAppCompatible($version, $info);
			$isShipped = \OC_App::isShipped($appId);

			if ($compatible && $isShipped && \OC_App::shouldUpgrade($appId)) {
				/**
				 * FIXME: The preupdate check is performed before the database migration, otherwise database changes
				 * are not possible anymore within it. - Consider this when touching the code.
				 * @link https://github.com/owncloud/core/issues/10980
				 * @see \OC_App::updateApp
				 */
				if (file_exists(\OC_App::getAppPath($appId) . '/appinfo/preupdate.php')) {
					$this->includePreUpdate($appId);
				}
				if (file_exists(\OC_App::getAppPath($appId) . '/appinfo/database.xml')) {
					$this->emit('\OC\Updater', 'appSimulateUpdate', array($appId));
					\OC_DB::simulateUpdateDbFromStructure(\OC_App::getAppPath($appId) . '/appinfo/database.xml');
				}
			}
		}

		$this->emit('\OC\Updater', 'appUpgradeCheck');
	}

	/**
	 * Includes the pre-update file. Done here to prevent namespace mixups.
	 * @param string $appId
	 */
	private function includePreUpdate($appId) {
		include \OC_App::getAppPath($appId) . '/appinfo/preupdate.php';
	}

	/**
	 * upgrades all apps within a major ownCloud upgrade. Also loads "priority"
	 * (types authentication, filesystem, logging, in that order) afterwards.
	 *
	 * @throws NeedsUpdateException
	 */
	protected function doAppUpgrade() {
		$apps = \OC_App::getEnabledApps();
		$priorityTypes = array('authentication', 'filesystem', 'logging');
		$pseudoOtherType = 'other';
		$stacks = array($pseudoOtherType => array());

		foreach ($apps as $appId) {
			$priorityType = false;
			foreach ($priorityTypes as $type) {
				if(!isset($stacks[$type])) {
					$stacks[$type] = array();
				}
				if (\OC_App::isType($appId, $type)) {
					$stacks[$type][] = $appId;
					$priorityType = true;
					break;
				}
			}
			if (!$priorityType) {
				$stacks[$pseudoOtherType][] = $appId;
			}
		}
		foreach ($stacks as $type => $stack) {
			foreach ($stack as $appId) {
				if (\OC_App::shouldUpgrade($appId)) {
					$this->emit('\OC\Updater', 'appUpgradeStarted', [$appId, \OC_App::getAppVersion($appId)]);
					\OC_App::updateApp($appId);
					$this->emit('\OC\Updater', 'appUpgrade', [$appId, \OC_App::getAppVersion($appId)]);
				}
				if($type !== $pseudoOtherType) {
					// load authentication, filesystem and logging apps after
					// upgrading them. Other apps my need to rely on modifying
					// user and/or filesystem aspects.
					\OC_App::loadApp($appId, false);
				}
			}
		}
	}

	/**
	 * check if the current enabled apps are compatible with the current
	 * ownCloud version. disable them if not.
	 * This is important if you upgrade ownCloud and have non ported 3rd
	 * party apps installed.
	 *
	 * @return array
	 * @throws \Exception
	 */
	private function checkAppsRequirements() {
		$isCoreUpgrade = $this->isCodeUpgrade();
		$apps = OC_App::getEnabledApps();
		$version = Util::getVersion();
		$disabledApps = [];
		foreach ($apps as $app) {
			// check if the app is compatible with this version of ownCloud
			$info = OC_App::getAppInfo($app);
			if(!OC_App::isAppCompatible($version, $info)) {
				if (OC_App::isShipped($app)) {
					throw new \UnexpectedValueException('The files of the app "' . $app . '" were not correctly replaced before running the update');
				}
				OC_App::disable($app);
				$this->emit('\OC\Updater', 'incompatibleAppDisabled', array($app));
			}
			// no need to disable any app in case this is a non-core upgrade
			if (!$isCoreUpgrade) {
				continue;
			}
			// shipped apps will remain enabled
			if (OC_App::isShipped($app)) {
				continue;
			}
			// authentication and session apps will remain enabled as well
			if (OC_App::isType($app, ['session', 'authentication'])) {
				continue;
			}

			// disable any other 3rd party apps if not overriden
			if(!$this->skip3rdPartyAppsDisable) {
				\OC_App::disable($app);
				$disabledApps[]= $app;
				$this->emit('\OC\Updater', 'thirdPartyAppDisabled', array($app));
			};
		}
		return $disabledApps;
	}

	/**
	 * @return bool
	 */
	private function isCodeUpgrade() {
		$installedVersion = $this->config->getSystemValue('version', '0.0.0');
		$currentVersion = implode('.', Util::getVersion());
		if (version_compare($currentVersion, $installedVersion, '>')) {
			return true;
		}
		return false;
	}

	/**
	 * @param array $disabledApps
	 * @throws \Exception
	 */
	private function upgradeAppStoreApps(array $disabledApps) {
		foreach($disabledApps as $app) {
			try {
				$installer = new Installer(
					\OC::$server->getAppFetcher(),
					\OC::$server->getHTTPClientService(),
					\OC::$server->getTempManager(),
					$this->log
				);
				if (Installer::isUpdateAvailable($app, \OC::$server->getAppFetcher())) {
					$this->emit('\OC\Updater', 'upgradeAppStoreApp', [$app]);
					$installer->updateAppstoreApp($app);
				}
			} catch (\Exception $ex) {
				$this->log->logException($ex, ['app' => 'core']);
			}
		}
	}

	/**
	 * Forward messages emitted by the repair routine
	 */
	private function emitRepairEvents() {
		$dispatcher = \OC::$server->getEventDispatcher();
		$dispatcher->addListener('\OC\Repair::warning', function ($event) {
			if ($event instanceof GenericEvent) {
				$this->emit('\OC\Updater', 'repairWarning', $event->getArguments());
			}
		});
		$dispatcher->addListener('\OC\Repair::error', function ($event) {
			if ($event instanceof GenericEvent) {
				$this->emit('\OC\Updater', 'repairError', $event->getArguments());
			}
		});
		$dispatcher->addListener('\OC\Repair::info', function ($event) {
			if ($event instanceof GenericEvent) {
				$this->emit('\OC\Updater', 'repairInfo', $event->getArguments());
			}
		});
		$dispatcher->addListener('\OC\Repair::step', function ($event) {
			if ($event instanceof GenericEvent) {
				$this->emit('\OC\Updater', 'repairStep', $event->getArguments());
			}
		});
	}

	private function logAllEvents() {
		$log = $this->log;

		$dispatcher = \OC::$server->getEventDispatcher();
		$dispatcher->addListener('\OC\DB\Migrator::executeSql', function($event) use ($log) {
			if (!$event instanceof GenericEvent) {
				return;
			}
			$log->info('\OC\DB\Migrator::executeSql: ' . $event->getSubject() . ' (' . $event->getArgument(0) . ' of ' . $event->getArgument(1) . ')', ['app' => 'updater']);
		});
		$dispatcher->addListener('\OC\DB\Migrator::checkTable', function($event) use ($log) {
			if (!$event instanceof GenericEvent) {
				return;
			}
			$log->info('\OC\DB\Migrator::checkTable: ' . $event->getSubject() . ' (' . $event->getArgument(0) . ' of ' . $event->getArgument(1) . ')', ['app' => 'updater']);
		});

		$repairListener = function($event) use ($log) {
			if (!$event instanceof GenericEvent) {
				return;
			}
			switch ($event->getSubject()) {
				case '\OC\Repair::startProgress':
					$log->info('\OC\Repair::startProgress: Starting ... ' . $event->getArgument(1) .  ' (' . $event->getArgument(0) . ')', ['app' => 'updater']);
					break;
				case '\OC\Repair::advance':
					$desc = $event->getArgument(1);
					if (empty($desc)) {
						$desc = '';
					}
					$log->info('\OC\Repair::advance: ' . $desc . ' (' . $event->getArgument(0) . ')', ['app' => 'updater']);

					break;
				case '\OC\Repair::finishProgress':
					$log->info('\OC\Repair::finishProgress', ['app' => 'updater']);
					break;
				case '\OC\Repair::step':
					$log->info('\OC\Repair::step: Repair step: ' . $event->getArgument(0), ['app' => 'updater']);
					break;
				case '\OC\Repair::info':
					$log->info('\OC\Repair::info: Repair info: ' . $event->getArgument(0), ['app' => 'updater']);
					break;
				case '\OC\Repair::warning':
					$log->warning('\OC\Repair::warning: Repair warning: ' . $event->getArgument(0), ['app' => 'updater']);
					break;
				case '\OC\Repair::error':
					$log->error('\OC\Repair::error: Repair error: ' . $event->getArgument(0), ['app' => 'updater']);
					break;
			}
		};

		$dispatcher->addListener('\OC\Repair::startProgress', $repairListener);
		$dispatcher->addListener('\OC\Repair::advance', $repairListener);
		$dispatcher->addListener('\OC\Repair::finishProgress', $repairListener);
		$dispatcher->addListener('\OC\Repair::step', $repairListener);
		$dispatcher->addListener('\OC\Repair::info', $repairListener);
		$dispatcher->addListener('\OC\Repair::warning', $repairListener);
		$dispatcher->addListener('\OC\Repair::error', $repairListener);


		$this->listen('\OC\Updater', 'maintenanceEnabled', function () use($log) {
			$log->info('\OC\Updater::maintenanceEnabled: Turned on maintenance mode', ['app' => 'updater']);
		});
		$this->listen('\OC\Updater', 'maintenanceDisabled', function () use($log) {
			$log->info('\OC\Updater::maintenanceDisabled: Turned off maintenance mode', ['app' => 'updater']);
		});
		$this->listen('\OC\Updater', 'maintenanceActive', function () use($log) {
			$log->info('\OC\Updater::maintenanceActive: Maintenance mode is kept active', ['app' => 'updater']);
		});
		$this->listen('\OC\Updater', 'updateEnd', function ($success) use($log) {
			if ($success) {
				$log->info('\OC\Updater::updateEnd: Update successful', ['app' => 'updater']);
			} else {
				$log->error('\OC\Updater::updateEnd: Update failed', ['app' => 'updater']);
			}
		});
		$this->listen('\OC\Updater', 'dbUpgradeBefore', function () use($log) {
			$log->info('\OC\Updater::dbUpgradeBefore: Updating database schema', ['app' => 'updater']);
		});
		$this->listen('\OC\Updater', 'dbUpgrade', function () use($log) {
			$log->info('\OC\Updater::dbUpgrade: Updated database', ['app' => 'updater']);
		});
		$this->listen('\OC\Updater', 'dbSimulateUpgradeBefore', function () use($log) {
			$log->info('\OC\Updater::dbSimulateUpgradeBefore: Checking whether the database schema can be updated (this can take a long time depending on the database size)', ['app' => 'updater']);
		});
		$this->listen('\OC\Updater', 'dbSimulateUpgrade', function () use($log) {
			$log->info('\OC\Updater::dbSimulateUpgrade: Checked database schema update', ['app' => 'updater']);
		});
		$this->listen('\OC\Updater', 'incompatibleAppDisabled', function ($app) use($log) {
			$log->info('\OC\Updater::incompatibleAppDisabled: Disabled incompatible app: ' . $app, ['app' => 'updater']);
		});
		$this->listen('\OC\Updater', 'thirdPartyAppDisabled', function ($app) use ($log) {
			$log->info('\OC\Updater::thirdPartyAppDisabled: Disabled 3rd-party app: ' . $app, ['app' => 'updater']);
		});
		$this->listen('\OC\Updater', 'upgradeAppStoreApp', function ($app) use($log) {
			$log->info('\OC\Updater::upgradeAppStoreApp: Update 3rd-party app: ' . $app, ['app' => 'updater']);
		});
		$this->listen('\OC\Updater', 'appUpgradeCheckBefore', function () use ($log) {
			$log->info('\OC\Updater::appUpgradeCheckBefore: Checking updates of apps', ['app' => 'updater']);
		});
		$this->listen('\OC\Updater', 'appSimulateUpdate', function ($app) use ($log) {
			$log->info('\OC\Updater::appSimulateUpdate: Checking whether the database schema for <' . $app . '> can be updated (this can take a long time depending on the database size)', ['app' => 'updater']);
		});
		$this->listen('\OC\Updater', 'appUpgradeCheck', function () use ($log) {
			$log->info('\OC\Updater::appUpgradeCheck: Checked database schema update for apps', ['app' => 'updater']);
		});
		$this->listen('\OC\Updater', 'appUpgradeStarted', function ($app) use ($log) {
			$log->info('\OC\Updater::appUpgradeStarted: Updating <' . $app . '> ...', ['app' => 'updater']);
		});
		$this->listen('\OC\Updater', 'appUpgrade', function ($app, $version) use ($log) {
			$log->info('\OC\Updater::appUpgrade: Updated <' . $app . '> to ' . $version, ['app' => 'updater']);
		});
		$this->listen('\OC\Updater', 'failure', function ($message) use($log) {
			$log->error('\OC\Updater::failure: ' . $message, ['app' => 'updater']);
		});
		$this->listen('\OC\Updater', 'setDebugLogLevel', function () use($log) {
			$log->info('\OC\Updater::setDebugLogLevel: Set log level to debug', ['app' => 'updater']);
		});
		$this->listen('\OC\Updater', 'resetLogLevel', function ($logLevel, $logLevelName) use($log) {
			$log->info('\OC\Updater::resetLogLevel: Reset log level to ' . $logLevelName . '(' . $logLevel . ')', ['app' => 'updater']);
		});
		$this->listen('\OC\Updater', 'startCheckCodeIntegrity', function () use($log) {
			$log->info('\OC\Updater::startCheckCodeIntegrity: Starting code integrity check...', ['app' => 'updater']);
		});
		$this->listen('\OC\Updater', 'finishedCheckCodeIntegrity', function () use($log) {
			$log->info('\OC\Updater::finishedCheckCodeIntegrity: Finished code integrity check', ['app' => 'updater']);
		});

	}

}