<?php
  /**
   * ownCloud
   *

   * @author Frank Karlitschek

   * @author Jakob Sack
   * @copyright 2012 Frank Karlitschek frank@owncloud.org

   * @copyright 2013 Jakob Sack

   *
   * This library is free software; you can redistribute it and/or
   * modify it under the terms of the GNU AFFERO GENERAL PUBLIC LICENSE
   * License as published by the Free Software Foundation; either
   * version 3 of the License, or any later version.
   *
   * This library 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 along with this library.  If not, see <http://www.gnu.org/licenses/>.
   *
   */
  
  /**
   * This class is for i18n and l10n
   */

  class OC_L10N implements \OCP\IL10N {

  	/**
  	 * cache
  	 */
  	protected static $cache = array();
  
  	/**
  	 * The best language
  	 */
  	protected static $language = '';
  
  	/**
  	 * App of this object
  	 */
  	protected $app;
  
  	/**
  	 * Language of this object
  	 */
  	protected $lang;
  
  	/**
  	 * Translations
  	 */
  	private $translations = array();
  
  	/**

  	 * Plural forms (string)
  	 */
  	private $plural_form_string = 'nplurals=2; plural=(n != 1);';
  
  	/**
  	 * Plural forms (function)
  	 */
  	private $plural_form_function = null;
  
  	/**

  	 * Localization
  	 */
  	private $localizations = array(
  		'jsdate' => 'dd.mm.yy',
  		'date' => '%d.%m.%Y',
  		'datetime' => '%d.%m.%Y %H:%M:%S',
  		'time' => '%H:%M:%S',
  		'firstday' => 0);
  
  	/**
  	 * get an L10N instance

  	 * @param $app string
  	 * @param $lang string|null

  	 * @return OC_L10N
  	 */
  	public static function get($app, $lang=null) {

  		if (is_null($lang)) {
  			return OC::$server->getL10N($app);
  		} else {
  			return new \OC_L10N($app, $lang);

  		}
  	}
  
  	/**
  	 * @brief The constructor

  	 * @param $app string app requesting l10n
  	 * @param $lang string default: null Language

  	 * @returns OC_L10N-Object
  	 *
  	 * If language is not set, the constructor tries to find the right
  	 * language.
  	 */
  	public function __construct($app, $lang = null) {
  		$this->app = $app;
  		$this->lang = $lang;
  	}

  	public function load($transFile) {
  		$this->app = true;
  		include $transFile;
  		if(isset($TRANSLATIONS) && is_array($TRANSLATIONS)) {
  			$this->translations = $TRANSLATIONS;
  		}
  		if(isset($PLURAL_FORMS)) {
  			$this->plural_form_string = $PLURAL_FORMS;
  		}
  	}

  	protected function init() {
  		if ($this->app === true) {
  			return;
  		}
  		$app = OC_App::cleanAppId($this->app);
  		$lang = $this->lang;
  		$this->app = true;
  		// Find the right language
  		if(is_null($lang) || $lang == '') {
  			$lang = self::findLanguage($app);
  		}
  
  		// Use cache if possible
  		if(array_key_exists($app.'::'.$lang, self::$cache)) {
  
  			$this->translations = self::$cache[$app.'::'.$lang]['t'];
  			$this->localizations = self::$cache[$app.'::'.$lang]['l'];
  		}
  		else{
  			$i18ndir = self::findI18nDir($app);
  			// Localization is in /l10n, Texts are in $i18ndir
  			// (Just no need to define date/time format etc. twice)
  			if((OC_Helper::issubdirectory($i18ndir.$lang.'.php', OC_App::getAppPath($app).'/l10n/')
  				|| OC_Helper::issubdirectory($i18ndir.$lang.'.php', OC::$SERVERROOT.'/core/l10n/')
  				|| OC_Helper::issubdirectory($i18ndir.$lang.'.php', OC::$SERVERROOT.'/lib/l10n/')
  				|| OC_Helper::issubdirectory($i18ndir.$lang.'.php', OC::$SERVERROOT.'/settings')
  				)
  				&& file_exists($i18ndir.$lang.'.php')) {
  				// Include the file, save the data from $CONFIG

  				$transFile = strip_tags($i18ndir).strip_tags($lang).'.php';
  				include $transFile;

  				if(isset($TRANSLATIONS) && is_array($TRANSLATIONS)) {
  					$this->translations = $TRANSLATIONS;

  					//merge with translations from theme
  					$theme = OC_Config::getValue( "theme" );
  					if (!is_null($theme)) {
  						$transFile = OC::$SERVERROOT.'/themes/'.$theme.substr($transFile, strlen(OC::$SERVERROOT));
  						if (file_exists($transFile)) {
  							include $transFile;
  							if (isset($TRANSLATIONS) && is_array($TRANSLATIONS)) {
  								$this->translations = array_merge($this->translations, $TRANSLATIONS);
  							}
  						}
  					}
  				}
  				if(isset($PLURAL_FORMS)) {
  					$this->plural_form_string = $PLURAL_FORMS;

  				}
  			}
  
  			if(file_exists(OC::$SERVERROOT.'/core/l10n/l10n-'.$lang.'.php')) {
  				// Include the file, save the data from $CONFIG
  				include OC::$SERVERROOT.'/core/l10n/l10n-'.$lang.'.php';
  				if(isset($LOCALIZATIONS) && is_array($LOCALIZATIONS)) {
  					$this->localizations = array_merge($this->localizations, $LOCALIZATIONS);
  				}
  			}
  
  			self::$cache[$app.'::'.$lang]['t'] = $this->translations;
  			self::$cache[$app.'::'.$lang]['l'] = $this->localizations;
  		}
  	}
  
  	/**

  	 * @brief Creates a function that The constructor
  	 *
  	 * If language is not set, the constructor tries to find the right
  	 * language.
  	 *
  	 * Parts of the code is copied from Habari:
  	 * https://github.com/habari/system/blob/master/classes/locale.php
  	 * @param $string string
  	 * @return string
  	 */
  	protected function createPluralFormFunction($string){
  		if(preg_match( '/^\s*nplurals\s*=\s*(\d+)\s*;\s*plural=(.*)$/u', $string, $matches)) {
  			// sanitize
  			$nplurals = preg_replace( '/[^0-9]/', '', $matches[1] );
  			$plural = preg_replace( '#[^n0-9:\(\)\?\|\&=!<>+*/\%-]#', '', $matches[2] );
  
  			$body = str_replace(
  				array( 'plural', 'n', '$n$plurals', ),
  				array( '$plural', '$n', '$nplurals', ),
  				'nplurals='. $nplurals . '; plural=' . $plural
  			);
  
  			// add parents
  			// important since PHP's ternary evaluates from left to right
  			$body .= ';';
  			$res = '';
  			$p = 0;
  			for($i = 0; $i < strlen($body); $i++) {
  				$ch = $body[$i];
  				switch ( $ch ) {
  				case '?':
  					$res .= ' ? (';
  					$p++;
  					break;
  				case ':':
  					$res .= ') : (';
  					break;
  				case ';':
  					$res .= str_repeat( ')', $p ) . ';';
  					$p = 0;
  					break;
  				default:
  					$res .= $ch;
  				}
  			}
  
  			$body = $res . 'return ($plural>=$nplurals?$nplurals-1:$plural);';
  			return create_function('$n', $body);
  		}
  		else {
  			// default: one plural form for all cases but n==1 (english)
  			return create_function(
  				'$n',
  				'$nplurals=2;$plural=($n==1?0:1);return ($plural>=$nplurals?$nplurals-1:$plural);'
  			);
  		}
  	}
  
  	/**

  	 * @brief Translating
  	 * @param $text String The text we need a translation for
  	 * @param array $parameters default:array() Parameters for sprintf
  	 * @return \OC_L10N_String Translation or the same text
  	 *
  	 * Returns the translation. If no translation is found, $text will be
  	 * returned.
  	 */
  	public function t($text, $parameters = array()) {
  		return new OC_L10N_String($this, $text, $parameters);
  	}
  
  	/**
  	 * @brief Translating

  	 * @param $text_singular String the string to translate for exactly one object
  	 * @param $text_plural String the string to translate for n objects
  	 * @param $count Integer Number of objects
  	 * @param array $parameters default:array() Parameters for sprintf
  	 * @return \OC_L10N_String Translation or the same text
  	 *
  	 * Returns the translation. If no translation is found, $text will be
  	 * returned. %n will be replaced with the number of objects.
  	 *
  	 * The correct plural is determined by the plural_forms-function
  	 * provided by the po file.
  	 *
  	 */
  	public function n($text_singular, $text_plural, $count, $parameters = array()) {
  		$this->init();

  		$identifier = "_${text_singular}_::_${text_plural}_";

  		if( array_key_exists($identifier, $this->translations)) {
  			return new OC_L10N_String( $this, $identifier, $parameters, $count );
  		}
  		else{
  			if($count === 1) {
  				return new OC_L10N_String($this, $text_singular, $parameters, $count);
  			}
  			else{
  				return new OC_L10N_String($this, $text_plural, $parameters, $count);
  			}
  		}
  	}
  
  	/**
  	 * @brief Translating

  	 * @param $textArray The text array we need a translation for
  	 * @returns Translation or the same text
  	 *
  	 * Returns the translation. If no translation is found, $textArray will be
  	 * returned.
  	 *
  	 *
  	 * @deprecated deprecated since ownCloud version 5.0
  	 * This method will probably be removed with ownCloud 6.0
  	 *
  	 *
  	 */
  	public function tA($textArray) {
  		OC_Log::write('core', 'DEPRECATED: the method tA is deprecated and will be removed soon.', OC_Log::WARN);
  		$result = array();
  		foreach($textArray as $key => $text) {
  			$result[$key] = (string)$this->t($text);
  		}
  		return $result;
  	}
  
  	/**
  	 * @brief getTranslations
  	 * @returns Fetch all translations
  	 *
  	 * Returns an associative array with all translations
  	 */
  	public function getTranslations() {
  		$this->init();
  		return $this->translations;
  	}
  
  	/**

  	 * @brief getPluralFormString
  	 * @returns string containing the gettext "Plural-Forms"-string
  	 *
  	 * Returns a string like "nplurals=2; plural=(n != 1);"
  	 */
  	public function getPluralFormString() {
  		$this->init();
  		return $this->plural_form_string;
  	}
  
  	/**
  	 * @brief getPluralFormFunction
  	 * @returns string the plural form function
  	 *
  	 * returned function accepts the argument $n
  	 */
  	public function getPluralFormFunction() {
  		$this->init();
  		if(is_null($this->plural_form_function)) {
  			$this->plural_form_function = $this->createPluralFormFunction($this->plural_form_string);
  		}
  		return $this->plural_form_function;
  	}
  
  	/**
  	 * @brief get localizations
  	 * @returns Fetch all localizations
  	 *
  	 * Returns an associative array with all localizations
  	 */
  	public function getLocalizations() {
  		$this->init();
  		return $this->localizations;
  	}
  
  	/**

  	 * @brief Localization
  	 * @param $type Type of localization
  	 * @param $params parameters for this localization
  	 * @returns String or false
  	 *
  	 * Returns the localized data.
  	 *
  	 * Implemented types:
  	 *  - date
  	 *    - Creates a date
  	 *    - l10n-field: date
  	 *    - params: timestamp (int/string)
  	 *  - datetime
  	 *    - Creates date and time
  	 *    - l10n-field: datetime
  	 *    - params: timestamp (int/string)
  	 *  - time
  	 *    - Creates a time
  	 *    - l10n-field: time
  	 *    - params: timestamp (int/string)
  	 */
  	public function l($type, $data) {
  		$this->init();
  		switch($type) {
  			// If you add something don't forget to add it to $localizations
  			// at the top of the page
  			case 'date':
  			case 'datetime':
  			case 'time':
  				if($data instanceof DateTime) {
  					return $data->format($this->localizations[$type]);
  				} elseif(is_string($data) && !is_numeric($data)) {
  					$data = strtotime($data);
  				}
  				$locales = array(self::findLanguage());
  				if (strlen($locales[0]) == 2) {
  					$locales[] = $locales[0].'_'.strtoupper($locales[0]);
  				}
  				setlocale(LC_TIME, $locales);
  				$format = $this->localizations[$type];
  				// Check for Windows to find and replace the %e modifier correctly
  				if (strtoupper(substr(PHP_OS, 0, 3)) == 'WIN') {
  					$format = preg_replace('#(?<!%)((?:%%)*)%e#', '\1%#d', $format);
  				}
  				return strftime($format, $data);
  				break;
  			case 'firstday':
  			case 'jsdate':
  				return $this->localizations[$type];
  			default:
  				return false;
  		}
  	}
  
  	/**
  	 * @brief Choose a language
  	 * @param $texts Associative Array with possible strings
  	 * @returns String
  	 *
  	 * $text is an array 'de' => 'hallo welt', 'en' => 'hello world', ...
  	 *
  	 * This function is useful to avoid loading thousands of files if only one
  	 * simple string is needed, for example in appinfo.php
  	 */
  	public static function selectLanguage($text) {
  		$lang = self::findLanguage(array_keys($text));
  		return $text[$lang];
  	}
  
  	/**
  	 * @brief find the best language
  	 * @param $app Array or string, details below

  	 * @returns string language

  	 *
  	 * If $app is an array, ownCloud assumes that these are the available
  	 * languages. Otherwise ownCloud tries to find the files in the l10n
  	 * folder.
  	 *
  	 * If nothing works it returns 'en'
  	 */
  	public static function findLanguage($app = null) {
  		if(!is_array($app) && self::$language != '') {
  			return self::$language;
  		}
  
  		if(OC_User::getUser() && OC_Preferences::getValue(OC_User::getUser(), 'core', 'lang')) {
  			$lang = OC_Preferences::getValue(OC_User::getUser(), 'core', 'lang');
  			self::$language = $lang;
  			if(is_array($app)) {
  				$available = $app;
  				$lang_exists = array_search($lang, $available) !== false;

  			} else {

  				$lang_exists = self::languageExists($app, $lang);
  			}
  			if($lang_exists) {
  				return $lang;
  			}
  		}
  
  		$default_language = OC_Config::getValue('default_language', false);

  		if($default_language !== false) {

  			return $default_language;
  		}
  
  		if(isset($_SERVER['HTTP_ACCEPT_LANGUAGE'])) {

  			if(is_array($app)) {
  				$available = $app;

  			} else {

  				$available = self::findAvailableLanguages($app);
  			}

  
  			// E.g. make sure that 'de' is before 'de_DE'.
  			sort($available);
  
  			$preferences = preg_split('/,\s*/', strtolower($_SERVER['HTTP_ACCEPT_LANGUAGE']));
  			foreach($preferences as $preference) {
  				list($preferred_language) = explode(';', $preference);
  				$preferred_language = str_replace('-', '_', $preferred_language);
  				foreach($available as $available_language) {
  					if ($preferred_language === strtolower($available_language)) {
  						if (is_null($app)) {
  							self::$language = $available_language;
  						}
  						return $available_language;
  					}

  				}

  				foreach($available as $available_language) {
  					if (substr($preferred_language, 0, 2) === $available_language) {
  						if (is_null($app)) {
  							self::$language = $available_language;
  						}
  						return $available_language;

  					}
  				}
  			}
  		}
  
  		// Last try: English
  		return 'en';
  	}
  
  	/**
  	 * @brief find the l10n directory
  	 * @param $app App that needs to be translated
  	 * @returns directory
  	 */
  	protected static function findI18nDir($app) {
  		// find the i18n dir
  		$i18ndir = OC::$SERVERROOT.'/core/l10n/';
  		if($app != '') {
  			// Check if the app is in the app folder
  			if(file_exists(OC_App::getAppPath($app).'/l10n/')) {
  				$i18ndir = OC_App::getAppPath($app).'/l10n/';
  			}
  			else{
  				$i18ndir = OC::$SERVERROOT.'/'.$app.'/l10n/';
  			}
  		}
  		return $i18ndir;
  	}
  
  	/**
  	 * @brief find all available languages for an app
  	 * @param $app App that needs to be translated
  	 * @returns array an array of available languages
  	 */
  	public static function findAvailableLanguages($app=null) {
  		$available=array('en');//english is always available
  		$dir = self::findI18nDir($app);
  		if(is_dir($dir)) {
  			$files=scandir($dir);
  			foreach($files as $file) {
  				if(substr($file, -4, 4) === '.php' && substr($file, 0, 4) !== 'l10n') {
  					$i = substr($file, 0, -4);
  					$available[] = $i;
  				}
  			}
  		}
  		return $available;
  	}
  
  	public static function languageExists($app, $lang) {
  		if ($lang == 'en') {//english is always available
  			return true;
  		}
  		$dir = self::findI18nDir($app);
  		if(is_dir($dir)) {
  			return file_exists($dir.'/'.$lang.'.php');
  		}
  		return false;
  	}
  }