<?php
  /**
   * Copyright (c) 2013 Robin Appelman <icewind@owncloud.com>
   * This file is licensed under the Affero General Public License version 3 or
   * later.
   * See the COPYING-README file.
   */

  namespace OC;

  use OC\Hooks\BasicEmitter;
  
  /**
   * Class that handles autoupdating of ownCloud
   *
   * Hooks provided in scope \OC\Updater
   *  - maintenanceStart()
   *  - maintenanceEnd()
   *  - dbUpgrade()

   *  - failure(string $message)
   */

  class Updater extends BasicEmitter {
  
  	/**
  	 * @var \OC\Log $log
  	 */
  	private $log;

  	private $simulateStepEnabled;
  
  	private $updateStepEnabled;

  	/**
  	 * @param \OC\Log $log
  	 */
  	public function __construct($log = null) {
  		$this->log = $log;

  		$this->simulateStepEnabled = true;
  		$this->updateStepEnabled = true;
  	}
  
  	/**
  	 * Sets whether the database migration simulation must
  	 * be enabled.
  	 * This can be set to false to skip this test.
  	 *
  	 * @param bool $flag true to enable simulation, false otherwise
  	 */
  	public function setSimulateStepEnabled($flag) {
  		$this->simulateStepEnabled = $flag;
  	}
  
  	/**
  	 * Sets whether the update must be performed.
  	 * This can be set to false to skip the actual update.
  	 *
  	 * @param bool $flag true to enable update, false otherwise
  	 */
  	public function setUpdateStepEnabled($flag) {
  		$this->updateStepEnabled = $flag;

  	}

  	/**
  	 * Check if a new version is available

  	 *

  	 * @param string $updaterUrl the url to check, i.e. 'http://apps.owncloud.com/updater.php'

  	 * @return array|bool

  	 */

  	public function check($updaterUrl) {
  
  		// Look up the cache - it is invalidated all 30 minutes

  		if ((\OC_Appconfig::getValue('core', 'lastupdatedat') + 1800) > time()) {
  			return json_decode(\OC_Appconfig::getValue('core', 'lastupdateResult'), true);
  		}

  		\OC_Appconfig::setValue('core', 'lastupdatedat', time());

  		if (\OC_Appconfig::getValue('core', 'installedat', '') == '') {
  			\OC_Appconfig::setValue('core', 'installedat', microtime(true));
  		}
  
  		$version = \OC_Util::getVersion();
  		$version['installed'] = \OC_Appconfig::getValue('core', 'installedat');
  		$version['updated'] = \OC_Appconfig::getValue('core', 'lastupdatedat');

  		$version['updatechannel'] = \OC_Util::getChannel();

  		$version['edition'] = \OC_Util::getEditionString();

  		$version['build'] = \OC_Util::getBuild();

  		$versionString = implode('x', $version);
  
  		//fetch xml data from updater
  		$url = $updaterUrl . '?version=' . $versionString;
  
  		// set a sensible timeout of 10 sec to stay responsive even if the update server is down.
  		$ctx = stream_context_create(
  			array(
  				'http' => array(
  					'timeout' => 10
  				)
  			)
  		);
  		$xml = @file_get_contents($url, 0, $ctx);
  		if ($xml == false) {
  			return array();
  		}

  		$loadEntities = libxml_disable_entity_loader(true);

  		$data = @simplexml_load_string($xml);

  		libxml_disable_entity_loader($loadEntities);

  
  		$tmp = array();
  		$tmp['version'] = $data->version;
  		$tmp['versionstring'] = $data->versionstring;
  		$tmp['url'] = $data->url;
  		$tmp['web'] = $data->web;

  		// Cache the result

  		\OC_Appconfig::setValue('core', 'lastupdateResult', json_encode($data));

  		return $tmp;

  	}
  
  	/**
  	 * 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() {
  		\OC_DB::enableCaching(false);
  		\OC_Config::setValue('maintenance', true);

  		$installedVersion = \OC_Config::getValue('version', '0.0.0');
  		$currentVersion = implode('.', \OC_Util::getVersion());

  		if ($this->log) {
  			$this->log->debug('starting upgrade from ' . $installedVersion . ' to ' . $currentVersion, array('app' => 'core'));
  		}
  		$this->emit('\OC\Updater', 'maintenanceStart');

  		try {
  			$this->doUpgrade($currentVersion, $installedVersion);
  		} catch (\Exception $exception) {
  			$this->emit('\OC\Updater', 'failure', array($exception->getMessage()));
  		}
  
  		\OC_Config::setValue('maintenance', false);
  		$this->emit('\OC\Updater', 'maintenanceEnd');
  	}
  
  	/**
  	 * 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 $installedVersion previous version from which to upgrade from
  	 *
  	 * @return bool true if the operation succeeded, false otherwise
  	 */
  	private function doUpgrade($currentVersion, $installedVersion) {
  		// Update htaccess files for apache hosts
  		if (isset($_SERVER['SERVER_SOFTWARE']) && strstr($_SERVER['SERVER_SOFTWARE'], 'Apache')) {
  			\OC_Setup::updateHtaccess();
  		}

  		// 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(\OC_Config::getValue('datadirectory', \OC::$SERVERROOT . '/data') . '/.ocdata', '');

  		/*
  		 * START CONFIG CHANGES FOR OLDER VERSIONS
  		 */

  		if (!\OC::$CLI && version_compare($installedVersion, '6.90.1', '<')) {

  			// Add the trusted_domains config if it is not existant

  			// This is added to prevent host header poisoning

  			\OC_Config::setValue('trusted_domains', \OC_Config::getValue('trusted_domains', array(\OC_Request::serverHost())));

  		}

  		/*
  		 * STOP CONFIG CHANGES FOR OLDER VERSIONS
  		 */

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

  		// simulate DB upgrade
  		if ($this->simulateStepEnabled) {

  			$this->checkCoreUpgrade();

  
  			// simulate apps DB upgrade

  			$this->checkAppUpgrade($currentVersion);

  		}

  		// upgrade from OC6 to OC7
  		// TODO removed it again for OC8
  		$sharePolicy = \OC_Appconfig::getValue('core', 'shareapi_share_policy', 'global');
  		if ($sharePolicy === 'groups_only') {
  			\OC_Appconfig::setValue('core', 'shareapi_only_share_with_group_members', 'yes');
  		}

  		if ($this->updateStepEnabled) {

  			$this->doCoreUpgrade();

  			$disabledApps = \OC_App::checkAppsRequirements();
  			if (!empty($disabledApps)) {
  				$this->emit('\OC\Updater', 'disabledApps', array($disabledApps));

  			}

  
  			$this->doAppUpgrade();

  
  			// post-upgrade repairs
  			$repair = new \OC\Repair(\OC\Repair::getRepairSteps());
  			$repair->run();
  
  			//Invalidate update feed
  			\OC_Appconfig::setValue('core', 'lastupdatedat', 0);
  
  			// only set the final version if everything went well
  			\OC_Config::setValue('version', implode('.', \OC_Util::getVersion()));

  		}

  	}

  
  	protected function checkCoreUpgrade() {
  		// simulate core DB upgrade
  		\OC_DB::simulateUpdateDbFromStructure(\OC::$SERVERROOT . '/db_structure.xml');
  
  		$this->emit('\OC\Updater', 'dbSimulateUpgrade');
  	}
  
  	protected function doCoreUpgrade() {
  		// do the real upgrade
  		\OC_DB::updateDbFromStructure(\OC::$SERVERROOT . '/db_structure.xml');
  
  		$this->emit('\OC\Updater', 'dbUpgrade');
  	}
  
  	/**
  	 * @param string $version the oc version to check app compatibilty with
  	 */
  	protected function checkAppUpgrade($version) {
  		$apps = \OC_App::getEnabledApps();
  
  
  		foreach ($apps as $appId) {
  			if ($version) {
  				$info = \OC_App::getAppInfo($appId);
  				$compatible = \OC_App::isAppCompatible($version, $info);
  			} else {
  				$compatible = true;
  			}
  
  			if ($compatible && \OC_App::shouldUpgrade($appId)) {
  				if (file_exists(\OC_App::getAppPath($appId) . '/appinfo/database.xml')) {
  					\OC_DB::simulateUpdateDbFromStructure(\OC_App::getAppPath($appId) . '/appinfo/database.xml');
  				}
  			}
  		}
  
  		$this->emit('\OC\Updater', 'appUpgradeCheck');
  	}
  
  	protected function doAppUpgrade() {
  		$apps = \OC_App::getEnabledApps();
  
  		foreach ($apps as $appId) {
  			if (\OC_App::shouldUpgrade($appId)) {
  				\OC_App::updateApp($appId);
  				$this->emit('\OC\Updater', 'appUpgrade', array($appId, \OC_App::getAppVersion($appId)));
  			}
  		}
  	}

  }