nextcloud/lib/private/l10n/factory.php

<?php
/**
 * @author Bart Visscher <bartv@thisnet.nl>
 * @author Joas Schilling <nickvergessen@owncloud.com>
 * @author Morris Jobke <hey@morrisjobke.de>
 * @author Robin Appelman <icewind@owncloud.com>
 * @author Robin McCorkell <robin@mccorkell.me.uk>
 *
 * @copyright Copyright (c) 2016, ownCloud, Inc.
 * @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\L10N;

use OCP\IConfig;
use OCP\IRequest;
use OCP\L10N\IFactory;

/**
 * A factory that generates language instances
 */
class Factory implements IFactory {

	/** @var string */
	protected $requestLanguage = '';

	/**
	 * cached instances
	 * @var array Structure: Lang => App => \OCP\IL10N
	 */
	protected $instances = [];

	/**
	 * @var array Structure: App => string[]
	 */
	protected $availableLanguages = [];

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

	/** @var IRequest */
	protected $request;

	/**
	 * @param IConfig $config
	 * @param IRequest $request
	 */
	public function __construct(IConfig $config, IRequest $request) {
		$this->config = $config;
		$this->request = $request;
	}

	/**
	 * Get a language instance
	 *
	 * @param string $app
	 * @param string|null $lang
	 * @return \OCP\IL10N
	 */
	public function get($app, $lang = null) {
		$app = \OC_App::cleanAppId($app);
		if ($lang !== null) {
			$lang = str_replace(array('\0', '/', '\\', '..'), '', (string) $lang);
		}
		$key = $lang;
		if ($key === null || !$this->languageExists($app, $lang)) {
			$key = 'null';
			$lang = $this->findLanguage($app);
		}

		if (!isset($this->instances[$key][$app])) {
			$this->instances[$key][$app] = new \OC_L10N($app, $lang);
		}

		return $this->instances[$key][$app];
	}

	/**
	 * Find the best language
	 *
	 * @param string|null $app App id or null for core
	 * @return string language If nothing works it returns 'en'
	 */
	public function findLanguage($app = null) {
		if ($this->requestLanguage !== '' && $this->languageExists($app, $this->requestLanguage)) {
			return $this->requestLanguage;
		}

		$userId = \OC_User::getUser(); // FIXME not available in non-static?

		if ($userId && $this->config->getUserValue($userId, 'core', 'lang')) {
			$lang = $this->config->getUserValue($userId, 'core', 'lang');
			$this->requestLanguage = $lang;
			if ($this->languageExists($app, $lang)) {
				return $lang;
			}
		}

		$defaultLanguage = $this->config->getSystemValue('default_language', false);

		if ($defaultLanguage !== false) {
			return $defaultLanguage;
		}

		$lang = $this->setLanguageFromRequest($app);
		if ($userId && $app === null && !$this->config->getUserValue($userId, 'core', 'lang')) {
			$this->config->setUserValue($userId, 'core', 'lang', $lang);
		}

		return $lang;
	}

	/**
	 * Find all available languages for an app
	 *
	 * @param string|null $app App id or null for core
	 * @return array an array of available languages
	 */
	public function findAvailableLanguages($app = null) {
		$key = $app;
		if ($key === null) {
			$key = 'null';
		}

		// also works with null as key
		if (!empty($this->availableLanguages[$key])) {
			return $this->availableLanguages[$key];
		}

		$available = ['en']; //english is always available
		$dir = $this->findL10nDir($app);
		if (is_dir($dir)) {
			$files = scandir($dir);
			if ($files !== false) {
				foreach ($files as $file) {
					if (substr($file, -5) === '.json' && substr($file, 0, 4) !== 'l10n') {
						$available[] = substr($file, 0, -5);
					}
				}
			}
		}

		$this->availableLanguages[$key] = $available;
		return $available;
	}

	/**
	 * @param string|null $app App id or null for core
	 * @param string $lang
	 * @return bool
	 */
	public function languageExists($app, $lang) {
		if ($lang === 'en') {//english is always available
			return true;
		}

		$languages = $this->findAvailableLanguages($app);
		return array_search($lang, $languages);
	}

	/**
	 * @param string|null $app App id or null for core
	 * @return string
	 */
	public function setLanguageFromRequest($app = null) {
		$header = $this->request->getHeader('ACCEPT_LANGUAGE');
		if ($header) {
			$available = $this->findAvailableLanguages($app);

			// E.g. make sure that 'de' is before 'de_DE'.
			sort($available);

			$preferences = preg_split('/,\s*/', strtolower($header));
			foreach ($preferences as $preference) {
				list($preferred_language) = explode(';', $preference);
				$preferred_language = str_replace('-', '_', $preferred_language);

				foreach ($available as $available_language) {
					if ($preferred_language === strtolower($available_language)) {
						if ($app === null && !$this->requestLanguage) {
							$this->requestLanguage = $available_language;
						}
						return $available_language;
					}
				}

				// Fallback from de_De to de
				foreach ($available as $available_language) {
					if (substr($preferred_language, 0, 2) === $available_language) {
						if ($app === null && !$this->requestLanguage) {
							$this->requestLanguage = $available_language;
						}
						return $available_language;
					}
				}
			}
		}

		if (!$this->requestLanguage) {
			$this->requestLanguage = 'en';
		}
		return 'en'; // Last try: English
	}

	/**
	 * find the l10n directory
	 *
	 * @param string $app App id or empty string for core
	 * @return string directory
	 */
	protected function findL10nDir($app = '') {
		if ($app !== '') {
			// Check if the app is in the app folder
			if (file_exists(\OC_App::getAppPath($app) . '/l10n/')) {
				return \OC_App::getAppPath($app) . '/l10n/';
			} else {
				return \OC::$SERVERROOT . '/' . $app . '/l10n/';
			}
		}
		return \OC::$SERVERROOT.'/core/l10n/';
	}
}