<?php
namespace Fisharebest\Webtrees;

/**
 * webtrees: online genealogy
 * Copyright (C) 2015 webtrees development team
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 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 General Public License for more details.
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */

use Fisharebest\Localization\Locale;
use Patchwork\TurkishUtf8;
use Zend_Cache;
use Zend_Cache_Core;
use Zend_Registry;
use Zend_Translate;

/**
 * Class I18N - Functions to support internationalization (i18n) functionality.
 */
class I18N {
	/** @var Locale The current locale (e.g. LocaleEnGb) */
	private static $locale;

	// Digits are always rendered LTR, even in RTL text.
	const DIGITS = '0123456789٠١٢٣٤٥٦٧٨٩۰۱۲۳۴۵۶۷۸۹';

	// Reversable character conversions from the UNICODE 5.1 database.
	// It excludes ambiguous (turkish dotless i) and mixed-case (Dz) characters.
	// The characters should be arranged in default unicode-collation order.
	const ALPHABET_LOWER = 'aàáâãäåāăąǎǟǡǻȁȃȧḁạảấầẩẫậắằẳẵặⓐａæǣǽbḃḅḇⓑｂƀɓƃcçćĉċčḉⅽⓒｃƈdďḋḍḏḑḓⅾⓓｄǆǳđɖɗƌðeèéêëēĕėęěȅȇȩḕḗḙḛḝẹẻẽếềểễệⓔｅǝəɛfḟⓕｆƒgĝğġģǧǵḡⓖｇǥɠɣƣhĥȟḣḥḧḩḫⓗｈƕħiìíîïĩīĭįǐȉȋḭḯỉịⅰⓘｉⅱⅲĳⅳⅸɨɩjĵⓙｊkķǩḱḳḵⓚｋƙlĺļľḷḹḻḽⅼⓛｌŀǉłƚmḿṁṃⅿⓜｍnñńņňǹṅṇṉṋⓝｎǌɲƞŋoòóôõöōŏőơǒǫǭȍȏȫȭȯȱṍṏṑṓọỏốồổỗộớờởỡợⓞｏœøǿɔɵȣpṕṗⓟｐƥqⓠｑrŕŗřȑȓṙṛṝṟⓡｒʀsśŝşšșṡṣṥṧṩⓢｓʃtţťțṫṭṯṱⓣｔŧƭʈuùúûüũūŭůűųưǔǖǘǚǜȕȗṳṵṷṹṻụủứừửữựⓤｕʉɯʊvṽṿⅴⓥｖⅵⅶⅷʋʌwŵẁẃẅẇẉⓦｗxẋẍⅹⓧｘⅺⅻyýÿŷȳẏỳỵỷỹⓨｙƴzźżžẑẓẕⓩｚƶȥǯʒƹȝþƿƨƽƅάαἀἁἂἃἄἅἆἇὰάᾀᾁᾂᾃᾄᾅᾆᾇᾰᾱᾳβγδέεἐἑἒἓἔἕὲέϝϛζήηἠἡἢἣἤἥἦἧὴήᾐᾑᾒᾓᾔᾕᾖᾗῃθϊἰἱἲἳἴἵἶἷὶίῐῑκϗλμνξοόὀὁὂὃὄὅὸόπϟϙρῥσϲτυϋύὑὓὕὗὺύῠῡφχψωώὠὡὢὣὤὥὦὧὼώᾠᾡᾢᾣᾤᾥᾦᾧῳϡϸϻϣϥϧϩϫϭϯаӑӓәӛӕбвгґғҕдԁђԃѓҙеѐёӗєжӂӝҗзԅӟѕӡԇиѝӣҋӥіїйјкқӄҡҟҝлӆљԉмӎнӊңӈҥњԋоӧөӫпҧҁрҏсԍҫтԏҭћќуӯўӱӳүұѹфхҳһѡѿѽѻцҵчӵҷӌҹҽҿџшщъыӹьҍѣэӭюяѥѧѫѩѭѯѱѳѵѷҩաբգդեզէըթժիլխծկհձղճմյնշոչպջռսվտրցւփքօֆȼɂɇɉɋɍɏͱͳͷͻͼͽӏӷӻӽӿԑԓԕԗԙԛԝԟԡԣԥᵹᵽỻỽỿⅎↄⰰⰱⰲⰳⰴⰵⰶⰷⰸⰹⰺⰻⰼⰽⰾⰿⱀⱁⱂⱃⱄⱅⱆⱇⱈⱉⱊⱋⱌⱍⱎⱏⱐⱑⱒⱓⱔⱕⱖⱗⱘⱙⱚⱛⱜⱝⱞⱡⱨⱪⱬⱳⱶⲁⲃⲅⲇⲉⲋⲍⲏⲑⲓⲕⲗⲙⲛⲝⲟⲡⲣⲥⲧⲩⲫⲭⲯⲱⲳⲵⲷⲹⲻⲽⲿⳁⳃⳅⳇⳉⳋⳍⳏⳑⳓⳕⳗⳙⳛⳝⳟⳡⳣⳬⳮⴀⴁⴂⴃⴄⴅⴆⴇⴈⴉⴊⴋⴌⴍⴎⴏⴐⴑⴒⴓⴔⴕⴖⴗⴘⴙⴚⴛⴜⴝⴞⴟⴠⴡⴢⴣⴤⴥꙁꙃꙅꙇꙉꙋꙍꙏꙑꙓꙕꙗꙙꙛꙝꙟꙣꙥꙧꙩꙫꙭꚁꚃꚅꚇꚉꚋꚍꚏꚑꚓꚕꚗꜣꜥꜧꜩꜫꜭꜯꜳꜵꜷꜹꜻꜽꜿꝁꝃꝅꝇꝉꝋꝍꝏꝑꝓꝕꝗꝙꝛꝝꝟꝡꝣꝥꝧꝩꝫꝭꝯꝺꝼꝿꞁꞃꞅꞇꞌ';
	const ALPHABET_UPPER = 'AÀÁÂÃÄÅĀĂĄǍǞǠǺȀȂȦḀẠẢẤẦẨẪẬẮẰẲẴẶⒶＡÆǢǼBḂḄḆⒷＢɃƁƂCÇĆĈĊČḈⅭⒸＣƇDĎḊḌḎḐḒⅮⒹＤǄǱĐƉƊƋÐEÈÉÊËĒĔĖĘĚȄȆȨḔḖḘḚḜẸẺẼẾỀỂỄỆⒺＥƎƏƐFḞⒻＦƑGĜĞĠĢǦǴḠⒼＧǤƓƔƢHĤȞḢḤḦḨḪⒽＨǶĦIÌÍÎÏĨĪĬĮǏȈȊḬḮỈỊⅠⒾＩⅡⅢĲⅣⅨƗƖJĴⒿＪKĶǨḰḲḴⓀＫƘLĹĻĽḶḸḺḼⅬⓁＬĿǇŁȽMḾṀṂⅯⓂＭNÑŃŅŇǸṄṆṈṊⓃＮǊƝȠŊOÒÓÔÕÖŌŎŐƠǑǪǬȌȎȪȬȮȰṌṎṐṒỌỎỐỒỔỖỘỚỜỞỠỢⓄＯŒØǾƆƟȢPṔṖⓅＰƤQⓆＱRŔŖŘȐȒṘṚṜṞⓇＲƦSŚŜŞŠȘṠṢṤṦṨⓈＳƩTŢŤȚṪṬṮṰⓉＴŦƬƮUÙÚÛÜŨŪŬŮŰŲƯǓǕǗǙǛȔȖṲṴṶṸṺỤỦỨỪỬỮỰⓊＵɄƜƱVṼṾⅤⓋＶⅥⅦⅧƲɅWŴẀẂẄẆẈⓌＷXẊẌⅩⓍＸⅪⅫYÝŸŶȲẎỲỴỶỸⓎＹƳZŹŻŽẐẒẔⓏＺƵȤǮƷƸȜÞǷƧƼƄΆΑἈἉἊἋἌἍἎἏᾺΆᾈᾉᾊᾋᾌᾍᾎᾏᾸᾹᾼΒΓΔΈΕἘἙἚἛἜἝῈΈϜϚΖΉΗἨἩἪἫἬἭἮἯῊΉᾘᾙᾚᾛᾜᾝᾞᾟῌΘΪἸἹἺἻἼἽἾἿῚΊῘῙΚϏΛΜΝΞΟΌὈὉὊὋὌὍῸΌΠϞϘΡῬΣϹΤΥΫΎὙὛὝὟῪΎῨῩΦΧΨΩΏὨὩὪὫὬὭὮὯῺΏᾨᾩᾪᾫᾬᾭᾮᾯῼϠϷϺϢϤϦϨϪϬϮАӐӒӘӚӔБВГҐҒҔДԀЂԂЃҘЕЀЁӖЄЖӁӜҖЗԄӞЅӠԆИЍӢҊӤІЇЙЈКҚӃҠҞҜЛӅЉԈМӍНӉҢӇҤЊԊОӦӨӪПҦҀРҎСԌҪТԎҬЋЌУӮЎӰӲҮҰѸФХҲҺѠѾѼѺЦҴЧӴҶӋҸҼҾЏШЩЪЫӸЬҌѢЭӬЮЯѤѦѪѨѬѮѰѲѴѶҨԱԲԳԴԵԶԷԸԹԺԻԼԽԾԿՀՁՂՃՄՅՆՇՈՉՊՋՌՍՎՏՐՑՒՓՔՕՖȻɁɆɈɊɌɎͰͲͶϽϾϿӀӶӺӼӾԐԒԔԖԘԚԜԞԠԢԤꝽⱣỺỼỾℲↃⰀⰁⰂⰃⰄⰅⰆⰇⰈⰉⰊⰋⰌⰍⰎⰏⰐⰑⰒⰓⰔⰕⰖⰗⰘⰙⰚⰛⰜⰝⰞⰟⰠⰡⰢⰣⰤⰥⰦⰧⰨⰩⰪⰫⰬⰭⰮⱠⱧⱩⱫⱲⱵⲀⲂⲄⲆⲈⲊⲌⲎⲐⲒⲔⲖⲘⲚⲜⲞⲠⲢⲤⲦⲨⲪⲬⲮⲰⲲⲴⲶⲸⲺⲼⲾⳀⳂⳄⳆⳈⳊⳌⳎⳐⳒⳔⳖⳘⳚⳜⳞⳠⳢⳫⳭႠႡႢႣႤႥႦႧႨႩႪႫႬႭႮႯႰႱႲႳႴႵႶႷႸႹႺႻႼႽႾႿჀჁჂჃჄჅꙀꙂꙄꙆꙈꙊꙌꙎꙐꙒꙔꙖꙘꙚꙜꙞꙢꙤꙦꙨꙪꙬꚀꚂꚄꚆꚈꚊꚌꚎꚐꚒꚔꚖꜢꜤꜦꜨꜪꜬꜮꜲꜴꜶꜸꜺꜼꜾꝀꝂꝄꝆꝈꝊꝌꝎꝐꝒꝔꝖꝘꝚꝜꝞꝠꝢꝤꝦꝨꝪꝬꝮꝹꝻꝾꞀꞂꞄꞆꞋ';

	// Alphabet for the currently selected locale
	private static $alphabet_lower = 'abcdefghijklmnopqrstuvwxyz';
	private static $alphabet_upper = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ';

	// Lookup table to convert unicode code-points into scripts.
	// See https://en.wikipedia.org/wiki/Unicode_block
	// Note: we only need details for scripts of languages into which webtrees is translated.
	private static $scripts = array(
		array('Latn', 0x0041, 0x005A), // a-z
		array('Latn', 0x0061, 0x007A), // A-Z
		array('Latn', 0x0100, 0x02AF),
		array('Grek', 0x0370, 0x03FF),
		array('Cyrl', 0x0400, 0x052F),
		array('Hebr', 0x0590, 0x05FF),
		array('Arab', 0x0600, 0x06FF),
		array('Arab', 0x0750, 0x077F),
		array('Arab', 0x08A0, 0x08FF),
		array('Deva', 0x0900, 0x097F),
		array('Taml', 0x0B80, 0x0BFF),
		array('Sinh', 0x0D80, 0x0DFF),
		array('Thai', 0x0E00, 0x0E7F),
		array('Geor', 0x10A0, 0x10FF),
		array('Grek', 0x1F00, 0x1FFF),
		array('Deva', 0xA8E0, 0xA8FF),
		array('Hans', 0x3000, 0x303F), // Mixed CJK, not just Hans
		array('Hans', 0x3400, 0xFAFF), // Mixed CJK, not just Hans
		array('Hans', 0x20000, 0x2FA1F), // Mixed CJK, not just Hans
	);

	// Characters that are displayed in mirror form in RTL text.
	private static $mirror_characters = array(
		'(' => ')',
		')' => '(',
		'[' => ']',
		']' => '[',
		'{' => '}',
		'}' => '{',
		'<' => '>',
		'>' => '<',
		'‹' => '›',
		'›' => '‹',
		'«' => '»',
		'»' => '«',
		'﴾' => '﴿',
		'﴿' => '﴾',
		'“' => '”',
		'”' => '“',
		'‘' => '’',
		'’' => '‘',
	);

	/** @var string The MySQL collation sequence used by this language, typically utf8_unicode_ci */
	public static $collation;

	/** @var string Punctuation used to separate list items, typically a comma */
	public static $list_separator;

	/** @var Zend_Cache_Core */
	private static $cache;

	/** @var Zend_Translate */
	private static $translation_adapter;

	/**
	 * Initialise the translation adapter with a locale setting.
	 *
	 * @param string|null $locale If no locale specified, choose one automatically
	 *
	 * @return string $string
	 */
	public static function init($locale = null) {
		global $WT_SESSION, $WT_TREE;

		// The translation libraries only work with a cache.
		$cache_options = array(
			'automatic_serialization' => true,
			'cache_id_prefix'         => md5(WT_BASE_URL),
		);

		if (ini_get('apc.enabled')) {
			self::$cache = Zend_Cache::factory('Core', 'Apc', $cache_options, array());
		} elseif (File::mkdir(WT_DATA_DIR . 'cache')) {
			self::$cache = Zend_Cache::factory('Core', 'File', $cache_options, array('cache_dir' => WT_DATA_DIR . 'cache'));
		} else {
			self::$cache = Zend_Cache::factory('Core', 'Zend_Cache_Backend_BlackHole', $cache_options, array(), false, true);
		}

		Zend_Translate::setCache(self::$cache);


		$installed_locales = array();
		foreach (self::installedLocales() as $installed_locale) {
			$installed_locales[$installed_locale->languageTag()] = $installed_locale->endonym();
		}

		if (is_null($locale) || !array_key_exists($locale, $installed_locales)) {
			// Automatic locale selection.
			if (array_key_exists(Filter::get('lang'), $installed_locales)) {
				// Requested in the URL?
				$locale = Filter::get('lang');
			} elseif (array_key_exists($WT_SESSION->locale, $installed_locales)) {
				// Rembered from a previous visit?
				$locale = $WT_SESSION->locale;
			} else {
				// Browser preference takes priority over gedcom default
				if (empty($_SERVER['HTTP_ACCEPT_LANGUAGE'])) {
					$prefs = array();
				} else {
					$prefs = explode(',', str_replace(' ', '', $_SERVER['HTTP_ACCEPT_LANGUAGE']));
				}
				if ($WT_TREE) {
					// Add the tree’s default language as a low-priority
					$locale  = $WT_TREE->getPreference('LANGUAGE');
					$prefs[] = $locale . ';q=0.2';
				}
				$prefs2 = array();
				foreach ($prefs as $pref) {
					list($l, $q) = explode(';q=', $pref . ';q=1.0');
					$l = preg_replace_callback(
						'/_[a-z][a-z]$/',
						function($x) { return strtoupper($x[0]); },
						str_replace('-', '_', $l)
					); // en-gb => en_GB
					if (array_key_exists($l, $prefs2)) {
						$prefs2[$l] = max((float) $q, $prefs2[$l]);
					} else {
						$prefs2[$l] = (float) $q;
					}
				}
				// Ensure there is a fallback.
				if (!array_key_exists('en-US', $prefs2)) {
					$prefs2['en-US'] = 0.01;
				}
				arsort($prefs2);
				foreach (array_keys($prefs2) as $pref) {
					if (array_key_exists($pref, $installed_locales)) {
						$locale = $pref;
						break;
					}
				}
			}
		}

		// Load the translation file
		self::$translation_adapter = new Zend_Translate('gettext', WT_ROOT . 'language/' . $locale . '.mo', $locale);

		// Deprecated - some custom modules use this to add translations
		Zend_Registry::set('Zend_Translate', self::$translation_adapter);

		// Load any local user translations
		if (is_dir(WT_DATA_DIR . 'language')) {
			if (file_exists(WT_DATA_DIR . 'language/' . $locale . '.mo')) {
				self::addTranslation(
					new Zend_Translate('gettext', WT_DATA_DIR . 'language/' . $locale . '.mo', $locale)
				);
			}
			if (file_exists(WT_DATA_DIR . 'language/' . $locale . '.php')) {
				self::addTranslation(
					new Zend_Translate('array', WT_DATA_DIR . 'language/' . $locale . '.php', $locale)
				);
			}
			if (file_exists(WT_DATA_DIR . 'language/' . $locale . '.csv')) {
				self::addTranslation(
					new Zend_Translate('csv', WT_DATA_DIR . 'language/' . $locale . '.csv', $locale)
				);
			}
		}

		// Extract language settings from the translation file
		global $DATE_FORMAT; // I18N: This is the format string for full dates.  See http://php.net/date for codes
		$DATE_FORMAT = self::noop('%j %F %Y');

		global $TIME_FORMAT; // I18N: This is the format string for the time-of-day.  See http://php.net/date for codes
		$TIME_FORMAT = self::noop('%H:%i:%s');

		// Alphabetic sorting sequence (upper-case letters), used by webtrees to sort strings
		list(, self::$alphabet_upper) = explode('=', self::noop('ALPHABET_upper=ABCDEFGHIJKLMNOPQRSTUVWXYZ'));
		// Alphabetic sorting sequence (lower-case letters), used by webtrees to sort strings
		list(, self::$alphabet_lower) = explode('=', self::noop('ALPHABET_lower=abcdefghijklmnopqrstuvwxyz'));

		global $WEEK_START; // I18N: This is the first day of the week on calendars. 0=Sunday, 1=Monday...
		list(, $WEEK_START) = explode('=', self::noop('WEEK_START=0'));


		// Save the current locale, and some attributes of it
		self::$locale = Locale::create($locale);

		self::$list_separator = /* I18N: This punctuation is used to separate lists of items */ self::translate(', ');
		self::$collation      = /* I18N: This is the name of the MySQL collation that applies to your language.  A list is available at http://dev.mysql.com/doc/refman/5.0/en/charset-unicode-sets.html */ self::translate('utf8_unicode_ci');

		return self::$locale->languageTag();
	}

	/**
	 * Add a translation file
	 *
	 * @param Zend_Translate $translation
	 */
	public static function addTranslation(Zend_Translate $translation) {
		self::$translation_adapter->getAdapter()->addTranslation(array('content' => $translation));
	}

	/**
	 * The prefered locales for this site, or a default list if no preference.
	 *
	 * @return Locale[]
	 */
	public static function activeLocales() {
		$code_list = Site::getPreference('LANGUAGES');

		if ($code_list) {
			$codes = explode(',', $code_list);
		} else {
			$codes = array(
				'ar', 'bg', 'bs', 'ca', 'cs', 'da', 'de', 'el', 'en-GB', 'en-US', 'es',
				'et', 'fi', 'fr', 'he', 'hr', 'hu', 'is', 'it', 'ka', 'lt', 'mr', 'nb',
				'nl', 'nn', 'pl', 'pt', 'ru', 'sk', 'sv', 'tr', 'uk', 'vi', 'zh-Hans',
			);
		}

		$locales = array();
		foreach ($codes as $code) {
			if (file_exists(WT_ROOT . 'language/' . $code . '.mo')) {
				try {
					$locales[] = Locale::create($code);
				} catch (\Exception $ex) {
					// No such locale exists?
				}
			}
		}
		usort($locales, '\Fisharebest\Localization\Locale::compare');

		return $locales;
	}

	/**
	 * All locales for which a translation file exists.
	 *
	 * @return Locale[]
	 */
	public static function installedLocales() {
		$locales = array();
		foreach (glob(WT_ROOT . 'language/*.mo') as $file) {
			try {
				$locales[] = Locale::create(basename($file, '.mo'));
			} catch (\Exception $ex) {
				// No such locale exists?
			}
		}
		usort($locales, '\Fisharebest\Localization\Locale::compare');

		return $locales;
	}

	/**
	 * Generate i18n markup for the <html> tag, e.g. lang="ar" dir="rtl"
	 *
	 * @return string
	 */
	public static function htmlAttributes() {
		return self::$locale->htmlAttributes();
	}

	/**
	 * Translate a number into the local representation.
	 *
	 * e.g. 12345.67 becomes
	 * en: 12,345.67
	 * fr: 12 345,67
	 * de: 12.345,67
	 *
	 * @param float   $n
	 * @param integer $precision
	 *
	 * @return string
	 */
	public static function number($n, $precision = 0) {
		return self::$locale->number(round($n, $precision));
	}

	/**
	 * Convert the digits 0-9 into the local script
	 *
	 * Used for years, etc., where we do not want thousands-separators, decimals, etc.
	 *
	 * @param integer $n
	 *
	 * @return string
	 */
	public static function digits($n) {
		return self::$locale->digits($n);
	}

	/**
	 * Translate a fraction into a percentage.
	 *
	 * e.g. 0.123 becomes
	 * en: 12.3%
	 * fr: 12,3 %
	 * de: 12,3%
	 *
	 * @param float   $n
	 * @param integer $precision
	 *
	 * @return string
	 */
	public static function percentage($n, $precision = 0) {
		return
			/* I18N: This is a percentage, such as “32.5%”. “%s” is the number, “%%” is the percent symbol.  Some languages require a (non-breaking) space between the two, or a different symbol. */
			self::translate('%s%%', self::number($n * 100.0, $precision));
	}

	/**
	 * What is the direction of the current locale
	 *
	 * @return string "ltr" or "rtl"
	 */
	public static function direction() {
		return self::$locale->direction();
	}

	/**
	 * Translate a string, and then substitute placeholders
	 *
	 * echo I18N::translate('Hello World!');
	 * echo I18N::translate('The %s sat on the mat', 'cat');
	 *
	 * @return string
	 */
	public static function translate(/* var_args */) {
		$args = func_get_args();
		$args[0] = self::$translation_adapter->getAdapter()->_($args[0]);

		return call_user_func_array('sprintf', $args);
	}

	/**
	 * Context sensitive version of translate.
	 *
	 * echo I18N::translate_c('NOMINATIVE', 'January');
	 * echo I18N::translate_c('GENITIVE',   'January');
	 *
	 * @return string
	 */
	public static function translateContext(/* var_args */) {
		$args = func_get_args();
		$msgid = $args[0] . "\x04" . $args[1];
		$msgtxt = self::$translation_adapter->getAdapter()->_($msgid);
		if ($msgtxt === $msgid) {
			$msgtxt = $args[1];
		}
		$args[0] = $msgtxt;
		unset($args[1]);

		return call_user_func_array('sprintf', $args);
	}

	/**
	 * Similar to translate, but do perform "no operation" on it.
	 *
	 * This is necessary to fetch a format string (containing % characters) without
	 * performing sustitution of arguments.
	 *
	 * @param string $string
	 *
	 * @return string
	 */
	public static function noop($string) {
		return self::$translation_adapter->getAdapter()->_($string);
	}

	/**
	 * Translate a plural string
	 *
	 * echo self::plural('There is an error', 'There are errors', $num_errors);
	 * echo self::plural('There is one error', 'There are %s errors', $num_errors);
	 * echo self::plural('There is %1$d %2$s cat', 'There are %1$d %2$s cats', $num, $num, $colour);
	 *
	 * @return string
	 */
	public static function plural(/* var_args */) {
		$args = func_get_args();
		$string = self::$translation_adapter->getAdapter()->plural($args[0], $args[1], $args[2]);
		array_splice($args, 0, 3, array($string));

		return call_user_func_array('sprintf', $args);
	}

	/**
	 * Convert a GEDCOM age string into translated_text
	 *
	 * NB: The import function will have normalised this, so we don't need
	 * to worry about badly formatted strings
	 * NOTE: this function is not yet complete - eventually it will replace get_age_at_event()
	 *
	 * @param $string
	 *
	 * @return string
	 */
	public static function gedcomAge($string) {
		switch ($string) {
		case 'STILLBORN':
			// I18N: Description of an individual’s age at an event.  For example, Died 14 Jan 1900 (stillborn)
			return self::translate('(stillborn)');
		case 'INFANT':
			// I18N: Description of an individual’s age at an event.  For example, Died 14 Jan 1900 (in infancy)
			return self::translate('(in infancy)');
		case 'CHILD':
			// I18N: Description of an individual’s age at an event.  For example, Died 14 Jan 1900 (in childhood)
			return self::translate('(in childhood)');
		}
		$age = array();
		if (preg_match('/(\d+)y/', $string, $match)) {
			// I18N: Part of an age string. e.g. 5 years, 4 months and 3 days
			$years = $match[1];
			$age[] = self::plural('%s year', '%s years', $years, self::number($years));
		} else {
			$years = -1;
		}
		if (preg_match('/(\d+)m/', $string, $match)) {
			// I18N: Part of an age string. e.g. 5 years, 4 months and 3 days
			$age[] = self::plural('%s month', '%s months', $match[1], self::number($match[1]));
		}
		if (preg_match('/(\d+)w/', $string, $match)) {
			// I18N: Part of an age string. e.g. 7 weeks and 3 days
			$age[] = self::plural('%s week', '%s weeks', $match[1], self::number($match[1]));
		}
		if (preg_match('/(\d+)d/', $string, $match)) {
			// I18N: Part of an age string. e.g. 5 years, 4 months and 3 days
			$age[] = self::plural('%s day', '%s days', $match[1], self::number($match[1]));
		}
		// If an age is just a number of years, only show the number
		if (count($age) === 1 && $years >= 0) {
			$age = $years;
		}
		if ($age) {
			if (!substr_compare($string, '<', 0, 1)) {
				// I18N: Description of an individual’s age at an event.  For example, Died 14 Jan 1900 (aged less than 21 years)
				return self::translate('(aged less than %s)', $age);
			} elseif (!substr_compare($string, '>', 0, 1)) {
				// I18N: Description of an individual’s age at an event.  For example, Died 14 Jan 1900 (aged more than 21 years)
				return self::translate('(aged more than %s)', $age);
			} else {
				// I18N: Description of an individual’s age at an event.  For example, Died 14 Jan 1900 (aged 43 years)
				return self::translate('(aged %s)', $age);
			}
		} else {
			// Not a valid string?
			return self::translate('(aged %s)', $string);
		}
	}

	/**
	 * Convert a number of seconds into a relative time.  For example, 630 => "10 hours, 30 minutes ago"
	 *
	 * @param integer $seconds
	 *
	 * @return string
	 */
	public static function timeAgo($seconds) {
		$minute = 60;
		$hour   = 60 * $minute;
		$day    = 24 * $hour;
		$month  = 30 * $day;
		$year   = 365 * $day;

		if ($seconds > $year) {
			$years = (int) ($seconds / $year);
			return self::plural('%s year ago', '%s years ago', $years, self::number($years));
		} elseif ($seconds > $month) {
			$months = (int) ($seconds / $month);
			return self::plural('%s month ago', '%s months ago', $months, self::number($months));
		} elseif ($seconds > $day) {
			$days = (int) ($seconds / $day);
			return self::plural('%s day ago', '%s days ago', $days, self::number($days));
		} elseif ($seconds > $hour) {
			$hours = (int) ($seconds / $hour);
			return self::plural('%s hour ago', '%s hours ago', $hours, self::number($hours));
		} elseif ($seconds > $minute) {
			$minutes = (int) ($seconds / $minute);
			return self::plural('%s minute ago', '%s minutes ago', $minutes, self::number($minutes));
		} else {
			return self::plural('%s second ago', '%s seconds ago', $seconds, self::number($seconds));
		}
	}

	/**
	 * Return the endonym for a given language - as per http://cldr.unicode.org/
	 * 
	 * @param string $locale
	 *
	 * @return string
	 */
	public static function languageName($locale) {
		return Locale::create($locale)->endonym();
	}

	/**
	 * Return the script used by a given language
	 *
	 * @param string $locale
	 *
	 * @return string
	 */
	public static function languageScript($locale) {
		return Locale::create($locale)->script()->code();
	}

	/**
	 * Identify the script used for a piece of text
	 *
	 * @param $string
	 *
	 * @return string
	 */
	public static function textScript($string) {
		$string = strip_tags($string); // otherwise HTML tags show up as latin
		$string = html_entity_decode($string, ENT_QUOTES, 'UTF-8'); // otherwise HTML entities show up as latin
		$string = str_replace(array('@N.N.', '@P.N.'), '', $string); // otherwise unknown names show up as latin
		$pos = 0;
		$strlen = strlen($string);
		while ($pos < $strlen) {
			// get the Unicode Code Point for the character at position $pos
			$byte1 = ord($string[$pos]);
			if ($byte1 < 0x80) {
				$code_point = $byte1;
				$chrlen = 1;
			} elseif ($byte1 < 0xC0) {
				// Invalid continuation character
				return 'Latn';
			} elseif ($byte1 < 0xE0) {
				$code_point = (($byte1 & 0x1F) << 6) + (ord($string[$pos + 1]) & 0x3F);
				$chrlen = 2;
			} elseif ($byte1 < 0xF0) {
				$code_point = (($byte1 & 0x0F) << 12) + ((ord($string[$pos + 1]) & 0x3F) << 6) + (ord($string[$pos + 2]) & 0x3F);
				$chrlen = 3;
			} elseif ($byte1 < 0xF8) {
				$code_point = (($byte1 & 0x07) << 24) + ((ord($string[$pos + 1]) & 0x3F) << 12) + ((ord($string[$pos + 2]) & 0x3F) << 6) + (ord($string[$pos + 3]) & 0x3F);
				$chrlen = 3;
 			} else {
				// Invalid UTF
				return 'Latn';
			}

			foreach (self::$scripts as $range) {
				if ($code_point >= $range[1] && $code_point <= $range[2]) {
					return $range[0];
				}
			}
			// Not a recognised script.  Maybe punctuation, spacing, etc.  Keep looking.
			$pos += $chrlen;
		}

		return 'Latn';
	}

	/**
	 * Return the direction (ltr or rtl) for a given script
	 *
	 * The PHP/intl library does not provde this information, so we need
	 * our own lookup table.
	 *
	 * @param string $script
	 *
	 * @return string
	 */
	public static function scriptDirection($script) {
		switch ($script) {
		case 'Arab':
		case 'Hebr':
		case 'Mong':
		case 'Thaa':
			return 'rtl';
		default:
			return 'ltr';
		}
	}

	/**
	 * UTF8 version of PHP::strtoupper()
	 *
	 * Convert a string to upper case, using the rules from the current locale
	 *
	 * @param string $string
	 *
	 * @return string
	 */
	public static function strtoupper($string) {
		if (self::$locale->language()->code() === 'tr' || self::$locale->language()->code() === 'az') {
			return TurkishUtf8::strtoupper($string);
		} else {
			return mb_strtoupper($string);
		}
	}

	/**
	 * UTF8 version of PHP::strtolower()
	 *
	 * Convert a string to lower case, using the rules from the current locale
	 *
	 * @param string $string
	 *
	 * @return string
	 */
	public static function strtolower($string) {
		if (self::$locale->language()->code() === 'tr' || self::$locale->language()->code() === 'az') {
			return TurkishUtf8::strtolower($string);
		} else {
			return mb_strtolower($string);
		}
	}

	/**
	 * UTF8 version of PHP::strcasecmp()
	 *
	 * Perform a case-insensitive comparison of two strings, using rules from the current locale
	 *
	 * @param string $string1
	 * @param string $string2
	 *
	 * @return integer
	 */
	public static function strcasecmp($string1, $string2) {
		$strpos1 = 0;
		$strpos2 = 0;
		$strlen1 = strlen($string1);
		$strlen2 = strlen($string2);
		while ($strpos1 < $strlen1 && $strpos2 < $strlen2) {
			$byte1 = ord($string1[$strpos1]);
			$byte2 = ord($string2[$strpos2]);
			if (($byte1 & 0xE0) === 0xC0) {
				$chr1 = $string1[$strpos1++] . $string1[$strpos1++];
			} elseif (($byte1 & 0xF0) === 0xE0) {
				$chr1 = $string1[$strpos1++] . $string1[$strpos1++] . $string1[$strpos1++];
			} else {
				$chr1 = $string1[$strpos1++];
			}
			if (($byte2 & 0xE0) === 0xC0) {
				$chr2 = $string2[$strpos2++] . $string2[$strpos2++];
			} elseif (($byte2 & 0xF0) === 0xE0) {
				$chr2 = $string2[$strpos2++] . $string2[$strpos2++] . $string2[$strpos2++];
			} else {
				$chr2 = $string2[$strpos2++];
			}
			if ($chr1 === $chr2) {
				continue;
			}
			// Try the local alphabet first
			$offset1 = strpos(self::$alphabet_lower, $chr1);
			if ($offset1 === false) {
				$offset1 = strpos(self::$alphabet_upper, $chr1);
			}
			$offset2 = strpos(self::$alphabet_lower, $chr2);
			if ($offset2 === false) {
				$offset2 = strpos(self::$alphabet_upper, $chr2);
			}
			if ($offset1 !== false && $offset2 !== false) {
				if ($offset1 === $offset2) {
					continue;
				} else {
					return $offset1 - $offset2;
				}
			}
			// Try the global alphabet next
			$offset1 = strpos(self::ALPHABET_LOWER, $chr1);
			if ($offset1 === false) {
				$offset1 = strpos(self::ALPHABET_UPPER, $chr1);
			}
			$offset2 = strpos(self::ALPHABET_LOWER, $chr2);
			if ($offset2 === false) {
				$offset2 = strpos(self::ALPHABET_UPPER, $chr2);
			}
			if ($offset1 !== false && $offset2 !== false) {
				if ($offset1 === $offset2) {
					continue;
				} else {
					return $offset1 - $offset2;
				}
			}
			// Just compare by unicode order
			return strcmp($chr1, $chr2);
		}
		// Shortest string comes first.
		return ($strlen1 - $strpos1) - ($strlen2 - $strpos2);
	}

	/**
	 * UTF8 version of PHP::strrev()
	 *
	 * Reverse RTL text for third-party libraries such as GD2 and googlechart.
	 *
	 * These do not support UTF8 text direction, so we must mimic it for them.
	 *
	 * Numbers are always rendered LTR, even in RTL text.
	 * The visual direction of characters such as parentheses should be reversed.
	 *
	 * @param string $text Text to be reversed
	 *
	 * @return string
	 */
	public static function reverseText($text) {
		// Remove HTML markup - we can't display it and it is LTR.
		$text = Filter::unescapeHtml($text);

		// LTR text doesn't need reversing
		if (self::scriptDirection(self::textScript($text)) === 'ltr') {
			return $text;
		}

		// Mirrored characters
		$text = strtr($text, self::$mirror_characters);

		$reversed = '';
		$digits = '';
		while ($text != '') {
			$letter = mb_substr($text, 0, 1);
			$text = mb_substr($text, 1);
			if (strpos(self::DIGITS, $letter) !== false) {
				$digits .= $letter;
			} else {
				$reversed = $letter . $digits . $reversed;
				$digits = '';
			}
		}

		return $digits . $reversed;
	}

	/**
	 * Generate consistent I18N for datatables.js
	 *
	 * @param array|null $lengths An optional array of page lengths
	 *
	 * @return string
	 */
	public static function datatablesI18N(array $lengths = null) {
		if ($lengths === null) {
			$lengths = array(10, 20, 30, 50, 100, -1);
		}

		$length_menu = '';
		foreach ($lengths as $length) {
			$length_menu .=
				'<option value="' . $length . '">' .
				($length === -1 ? /* I18N: listbox option, e.g. “10,25,50,100,all” */ self::translate('All') : self::number($length)) .
				'</option>';
		}
		$length_menu = '<select>' . $length_menu . '</select>';
		$length_menu = /* I18N: Display %s [records per page], %s is a placeholder for listbox containing numeric options */ self::translate('Display %s', $length_menu);

		$digits = self::$locale->digits('0123456789');
		if ($digits === '0123456789') {
			$callback = '';
		} else {
			$callback = ',
				"infoCallback": function(oSettings, iStart, iEnd, iMax, iTotal, sPre) {
					return sPre
						.replace(/0/g, "' . mb_substr($digits, 0, 1) . '")
						.replace(/1/g, "' . mb_substr($digits, 1, 1) . '")
						.replace(/2/g, "' . mb_substr($digits, 2, 1) . '")
						.replace(/3/g, "' . mb_substr($digits, 3, 1) . '")
						.replace(/4/g, "' . mb_substr($digits, 4, 1) . '")
						.replace(/5/g, "' . mb_substr($digits, 5, 1) . '")
						.replace(/6/g, "' . mb_substr($digits, 6, 1) . '")
						.replace(/7/g, "' . mb_substr($digits, 7, 1) . '")
						.replace(/8/g, "' . mb_substr($digits, 8, 1) . '")
						.replace(/9/g, "' . mb_substr($digits, 9, 1) . '");
				},
				"formatNumber": function(iIn) {
					return String(iIn)
						.replace(/0/g, "' . mb_substr($digits, 0, 1) . '")
						.replace(/1/g, "' . mb_substr($digits, 1, 1) . '")
						.replace(/2/g, "' . mb_substr($digits, 2, 1) . '")
						.replace(/3/g, "' . mb_substr($digits, 3, 1) . '")
						.replace(/4/g, "' . mb_substr($digits, 4, 1) . '")
						.replace(/5/g, "' . mb_substr($digits, 5, 1) . '")
						.replace(/6/g, "' . mb_substr($digits, 6, 1) . '")
						.replace(/7/g, "' . mb_substr($digits, 7, 1) . '")
						.replace(/8/g, "' . mb_substr($digits, 8, 1) . '")
						.replace(/9/g, "' . mb_substr($digits, 9, 1) . '");
				}
			';
		}

		return
			'"language": {' .
			' "paginate": {' .
			'  "first":    "' . /* I18N: button label, first page    */ self::translate('first') . '",' .
			'  "last":     "' . /* I18N: button label, last page     */ self::translate('last') . '",' .
			'  "next":     "' . /* I18N: button label, next page     */ self::translate('next') . '",' .
			'  "previous": "' . /* I18N: button label, previous page */ self::translate('previous') . '"' .
			' },' .
			' "emptyTable":     "' . self::translate('No records to display') . '",' .
			' "info":           "' . /* I18N: %s are placeholders for numbers */ self::translate('Showing %1$s to %2$s of %3$s', '_START_', '_END_', '_TOTAL_') . '",' .
			' "infoEmpty":      "' . self::translate('Showing %1$s to %2$s of %3$s', 0, 0, 0) . '",' .
			' "infoFiltered":   "' . /* I18N: %s is a placeholder for a number */ self::translate('(filtered from %s total entries)', '_MAX_') . '",' .
			' "infoPostfix":    "",' .
			' "lengthMenu":     "' . Filter::escapeJs($length_menu) . '",' .
			' "loadingRecords": "' . self::translate('Loading…') . '",' .
			' "processing":     "' . self::translate('Loading…') . '",' .
			' "search":         "' . self::translate('Filter') . '",' .
			' "url":            "",' .
			' "zeroRecords":    "' . self::translate('No records to display') . '"' .
			'}' .
			$callback;
	}
}