diff --git a/4dev/locale/en_US.admin.UTF-8.po b/4dev/locale/en_US.admin.UTF-8.po
index e6241638..b6c191f3 100644
--- a/4dev/locale/en_US.admin.UTF-8.po
+++ b/4dev/locale/en_US.admin.UTF-8.po
@@ -3,21 +3,22 @@
 # CREATED: 2005/08/09
 # SHORT DESCRIPTION:
 # Backned English Messages file for gettext
-# to craete: msgfmt -o ja.mo messages_en.po
-# HISTORY:
+# to craete: msgfmt -o <output.po> <input.mo>
 # ********************************************************************/
 
 msgid ""
 msgstr ""
-"Project-Id-Version: Project Version\n"
+"Project-Id-Version: en_US.UTF-8 LC_MESSAGES admin\n"
 "Report-Msgid-Bugs-To: clemens.schwaighofer@egplusww.com\n"
 "POT-Creation-Date: 2018-03-28 10:40+0900\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
-"Last-Translator: \n"
+"Last-Translator: clemens.schwaighofer@egplusww.co\n"
 "Language-Team: E-GRAPHICS COMMUNICATIONS Japan <info.jp@egplusww.com>\n"
+"Language: en_US\n"
 "MIME-Version: 1.0\n"
 "Content-Type: text/plain; charset=UTF-8\n"
 "Content-Transfer-Encoding: 8bit\n"
+"Plural-Forms: nplurals=2; plural=n != 1;\n"
 
 msgid "Year"
 msgstr "Year"
@@ -28,6 +29,24 @@ msgstr "Month"
 msgid "INPUT TEST"
 msgstr "OUTPUT TEST ADMIN EN"
 
+# testing multi
+msgid "single"
+msgid_plural "multi"
+msgstr[0] "Multi Admin en_US 0"
+msgstr[1] "Multi Admin en_US 1"
+msgstr[2] "Multi Admin en_US 2"
+
+msgctxt "month name"
+msgid "May"
+msgstr "May Admin en_US"
+
+msgctxt "month name"
+msgid "single"
+msgid_plural "multi"
+msgstr[0] "Multi Admin month en_US 0"
+msgstr[1] "Multi Admin month en_US 1"
+msgstr[2] "Multi Admin month en_US 2"
+
 msgid "I should be translated"
 msgstr "I should be translated: I WAS TRANSLATED"
 
diff --git a/4dev/locale/en_US.frontend.UTF-8.po b/4dev/locale/en_US.frontend.UTF-8.po
index 6e9f76f2..765359d0 100644
--- a/4dev/locale/en_US.frontend.UTF-8.po
+++ b/4dev/locale/en_US.frontend.UTF-8.po
@@ -1,2 +1,24 @@
+# to craete: msgfmt -o <output.po> <input.mo>
+
+msgid ""
+msgstr ""
+"Project-Id-Version: en_US.UTF-8 LC_MESSAGES frontend\n"
+"Report-Msgid-Bugs-To: clemens.schwaighofer@egplusww.com\n"
+"POT-Creation-Date: 2018-03-28 10:40+0900\n"
+"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
+"Last-Translator: clemens.schwaighofer@egplusww.co\n"
+"Language-Team: E-GRAPHICS COMMUNICATIONS Japan <info.jp@egplusww.com>\n"
+"Language: en_US\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"Plural-Forms: nplurals=2; plural=n != 1;\n"
+
 msgid "INPUT TEST"
 msgstr "OUTPUT TEST FRONTEND EN"
+
+msgid "single"
+msgid_plural "multi"
+msgstr[0] "Multi frontend en_US 0"
+msgstr[1] "Multi frontend en_US 1"
+msgstr[2] "Multi frontend en_US 2"
diff --git a/4dev/locale/ja_JP.admin.UTF-8.po b/4dev/locale/ja_JP.admin.UTF-8.po
index 4d49c4a9..35e08f80 100644
--- a/4dev/locale/ja_JP.admin.UTF-8.po
+++ b/4dev/locale/ja_JP.admin.UTF-8.po
@@ -3,21 +3,22 @@
 # CREATED: 2018/03/28
 # SHORT DESCRIPTION:
 # Backend Japanese Messages file for gettext
-# to craete: msgfmt -o ja.mo messages_ja.po
-# HISTORY:
+# to craete: msgfmt -o <output.po> <input.mo>
 # ********************************************************************/
 
 msgid ""
 msgstr ""
-"Project-Id-Version: Project Version\n"
+"Project-Id-Version: ja_JP.UTF-8 LC_MESSAGES admin\n"
 "Report-Msgid-Bugs-To: clemens.schwaighofer@egplusww.com\n"
 "POT-Creation-Date: 2018-03-28 10:40+0900\n"
 "PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
-"Last-Translator: \n"
+"Last-Translator: clemens.schwaighofer@egplusww.com\n"
 "Language-Team: E-GRAPHICS COMMUNICATIONS Japan <info.jp@egplusww.com>\n"
+"Language: ja\n"
 "MIME-Version: 1.0\n"
 "Content-Type: text/plain; charset=UTF-8\n"
 "Content-Transfer-Encoding: 8bit\n"
+"Plural-Forms: nplurals=3; plural=n%10==1 && n%100!=11 ? 0 : n%10>=2 && n%10<=4 && (n%100<10 || n%100>=20) ? 1 : 2;\n"
 
 msgid "Yes"
 msgstr "はい"
@@ -65,6 +66,13 @@ msgstr "日"
 msgid "INPUT TEST"
 msgstr "OUTPUT TEST ADMIN JA"
 
+# testing multi
+msgid "single"
+msgid_plural "multi"
+msgstr[0] "Multi Admin ja_JP 0"
+msgstr[1] "Multi Admin ja_JP 1"
+msgstr[2] "Multi Admin ja_JP 2"
+
 # login string
 msgid "Hello %s"
 msgstr "こにちは %s"
diff --git a/4dev/locale/ja_JP.frontend.UTF-8.po b/4dev/locale/ja_JP.frontend.UTF-8.po
index 91c739b2..049707a1 100644
--- a/4dev/locale/ja_JP.frontend.UTF-8.po
+++ b/4dev/locale/ja_JP.frontend.UTF-8.po
@@ -1,2 +1,8 @@
+# to craete: msgfmt -o <output.po> <input.mo>
+
+msgid ""
+msgstr ""
+"Plural-Forms: nplurals=2; plural=(n != 1)\n"
+
 msgid "INPUT TEST"
 msgstr "OUTPUT TEST FRONTEND JA"
diff --git a/4dev/tests/CoreLibsLanguageL10nTest.php b/4dev/tests/CoreLibsLanguageL10nTest.php
index 57adf084..ac866c06 100644
--- a/4dev/tests/CoreLibsLanguageL10nTest.php
+++ b/4dev/tests/CoreLibsLanguageL10nTest.php
@@ -1,4 +1,4 @@
-<?php
+<?php // phpcs:disable Generic.Files.LineLength
 
 declare(strict_types=1);
 
@@ -16,17 +16,1027 @@ use PHPUnit\Framework\TestCase;
 final class CoreLibsLanguageL10nTest extends TestCase
 {
 	/**
-	 * Undocumented function
-	 *
-	 * @testdox Language\L10n Class tests
+	 * set all constant variables that must be set before call
 	 *
 	 * @return void
 	 */
-	public function testLanguageEncoding()
+	public static function setUpBeforeClass(): void
 	{
-		$this->assertTrue(true, 'Language L10n Tests not implemented');
-		$this->markTestIncomplete(
-			'Language\L10n Tests have not yet been implemented'
+		define('DEFAULT_LANG', 'en_US');
+		// default web page encoding setting
+		define('DEFAULT_ENCODING', 'UTF-8');
+		// default lang + encoding
+		define('DEFAULT_LOCALE', 'en_US.UTF-8');
+		// site
+		define('SITE_LANG', DEFAULT_LANG);
+		// just set
+		define('BASE', str_replace('/configs', '', __DIR__) . DIRECTORY_SEPARATOR);
+		define('INCLUDES', 'includes' . DIRECTORY_SEPARATOR);
+		define('LANG', 'lang' . DIRECTORY_SEPARATOR);
+		define('LOCALE', 'locale' . DIRECTORY_SEPARATOR);
+		define('CONTENT_PATH', 'frontend' . DIRECTORY_SEPARATOR);
+	}
+
+	/**
+	 * get instance self type check
+	 *
+	 * @covers ::getInstance
+	 * @testdox check that getInstance() returns valid instance
+	 *
+	 * @return void
+	 */
+	public function testGetInstance(): void
+	{
+		$l10n_obj = \CoreLibs\Language\L10n::getInstance();
+		$this->assertIsObject(
+			$l10n_obj
+		);
+		$this->assertInstanceOf(
+			'\CoreLibs\Language\L10n',
+			$l10n_obj
+		);
+	}
+
+	/**
+	 * get current translator class type check
+	 *
+	 * @covers ::getTranslatorClass
+	 * @testdox check that getTranslatorClass() returns valid instance
+	 *
+	 * @return void
+	 */
+	public function testGetTranslatorClass(): void
+	{
+		$l10n = new \CoreLibs\Language\L10n();
+		$translator = $l10n->getTranslatorClass();
+		$this->assertIsObject(
+			$translator
+		);
+		$this->assertInstanceOf(
+			'\CoreLibs\Language\Core\GetTextReader',
+			$translator
+		);
+	}
+
+	/**
+	 * provider for class load parameters
+	 *
+	 * @return array
+	 */
+	public function l10nObjectProvider(): array
+	{
+		return [
+			// 0: locale
+			// 1: path
+			// 2: domain
+			// 3: legacy load (Default true)
+			// 4: locale expected
+			// 5: domain exepcted
+			// 6: context (null for none)
+			// 7: test string in
+			// 8: test translated
+			'legacy load en' => [
+				'en_utf8',
+				null,
+				null,
+				null,
+				//
+				'en_utf8',
+				'',
+				//
+				null,
+				'Original',
+				'Translated frontend en_US',
+			],
+			'legacy load ja' => [
+				'ja_utf8',
+				null,
+				null,
+				null,
+				'ja_utf8',
+				'',
+				null,
+				'Original',
+				'Translated frontend ja_JP',
+			],
+			// new style load
+			'gettext load en' => [
+				'en_US.UTF-8',
+				__DIR__ . 'includes/locale/',
+				'frontend',
+				false,
+				'en_US.UTF-8',
+				'frontend',
+				null,
+				'Original',
+				'Translated frontend en_US',
+			],
+			'gettext load en' => [
+				'en_US.UTF-8',
+				__DIR__ . 'includes/locale/',
+				'frontend',
+				false,
+				'en_US.UTF-8',
+				'frontend',
+				'context',
+				'Original',
+				'Original context frontend en_US',
+			],
+			'gettext load ja' => [
+				'ja_JP.UTF-8',
+				__DIR__ . 'includes/locale/',
+				'admin',
+				false,
+				'ja_JP.UTF-8',
+				'admin',
+				null,
+				'Original',
+				'Translated admin ja_JP',
+			],
+			// null set locale legacy
+			'empty load legacy' => [
+				null,
+				null,
+				null,
+				null,
+				'',
+				'',
+				null,
+				'Original',
+				'Original',
+			],
+			'empty load new ' => [
+				'',
+				'',
+				'',
+				false,
+				'',
+				'',
+				null,
+				'Original',
+				'Original',
+			]
+		];
+	}
+
+	/**
+	 * new class load test (basic test)
+	 *
+	 * @covers ::__construct
+	 * @dataProvider l10nObjectProvider
+	 * @testdox check l10n init with Locale $locale, Path $path, Domain $domain, Legacy: $legacy with $context [$_dataName]
+	 *
+	 * @param  string|null $locale
+	 * @param  string|null $path
+	 * @param  string|null $domain
+	 * @param  bool|null   $legacy
+	 * @param  string      $locale_expected
+	 * @param  string      $domain_expected
+	 * @param  ?string     $context
+	 * @param  string      $original
+	 * @param  string      $translated
+	 * @return void
+	 */
+	public function testL10nObject(
+		?string $locale,
+		?string $path,
+		?string $domain,
+		?bool $legacy,
+		string $locale_expected,
+		string $domain_expected,
+		?string $context,
+		string $original,
+		string $translated,
+	): void {
+		if ($locale === null) {
+			$l10n = new \CoreLibs\Language\L10n();
+		} elseif ($path === null) {
+			$l10n = new \CoreLibs\Language\L10n($locale);
+		} elseif ($domain === null) {
+			$l10n = new \CoreLibs\Language\L10n($locale, $path);
+		} elseif ($legacy === null) {
+			$l10n = new \CoreLibs\Language\L10n($locale, $path, $domain);
+		} else {
+			$l10n = new \CoreLibs\Language\L10n($locale, $path, $domain, $legacy);
+		}
+		// print "LOC: " . $locale . ", " . $l10n->getLocale() . ", " . $locale_expected . "\n";
+		// print "MO: " . $l10n->getMoFile() . "\n";
+		$this->assertEquals(
+			$locale_expected,
+			$l10n->getLocale(),
+			'Locale assert failed'
+		);
+		$this->assertEquals(
+			$domain_expected,
+			$l10n->getDomain(),
+			'Domain assert failed'
+		);
+		if (empty($context)) {
+			$this->assertEquals(
+				$translated,
+				$l10n->__($original),
+				'Translated string assert failed'
+			);
+		} else {
+			$this->assertEquals(
+				$translated,
+				$l10n->__p($context, $original),
+				'Translated string assert failed in context: ' . $context
+			);
+		}
+	}
+
+	// l10nReloadMOfile and getTranslator
+	// null init with loader
+	// loader with reload (change type)
+
+	/**
+	 * Undocumented function
+	 *
+	 * @return array
+	 */
+	public function getTranslatorProvider(): array
+	{
+		return [
+			// 0: locale
+			// 1: path
+			// 2: domain
+			// 3: legacy flag
+			// 4: input string to translated
+			// 5: expected locale
+			// 6: expected domain
+			// 7: expected translation
+			// 8: change locale
+			// 9: change path
+			// 10: change domain
+			// 11: legacy flag
+			// 12: expected locale
+			// 13: expected domain
+			// 14: expected translation
+			'legacy load and change (en->ja)' => [
+				// set 0-3
+				'en_utf8',
+				null,
+				null,
+				null,
+				// status 4
+				false,
+				// to translate 5
+				'Original',
+				// check setter 6-8
+				'en_utf8',
+				'',
+				'Translated frontend en_US',
+				// set new 9-12
+				'ja_utf8',
+				null,
+				null,
+				null,
+				// status new 13
+				false,
+				// check new setter 14-16
+				'ja_utf8',
+				'',
+				'Translated frontend ja_JP',
+			],
+			'load and change (en->ja)' => [
+				// set 0-3
+				'en_US.UTF-8',
+				__DIR__ . 'includes/locale/',
+				'frontend',
+				false,
+				// status 4
+				false,
+				// to translate 5
+				'Original',
+				// check setter 6-8
+				'en_US.UTF-8',
+				'frontend',
+				'Translated frontend en_US',
+				// set new 9-12
+				'ja_JP.UTF-8',
+				__DIR__ . 'includes/locale/',
+				'frontend',
+				false,
+				// status new 13
+				false,
+				// check new setter 14-16
+				'ja_JP.UTF-8',
+				'frontend',
+				'Translated frontend ja_JP',
+			],
+			'empty load and change to en' => [
+				// set 0-3
+				'',
+				'',
+				'',
+				false,
+				// status 4
+				false,
+				// to translate 5
+				'Original',
+				// check setter 6-8
+				'',
+				'',
+				'Original',
+				// set new 9-12
+				'en_US.UTF-8',
+				__DIR__ . 'includes/locale/',
+				'frontend',
+				false,
+				// status new 13
+				false,
+				// check new setter 14-16
+				'en_US.UTF-8',
+				'frontend',
+				'Translated frontend en_US',
+			]
+		];
+	}
+
+	/**
+	 * init check and connected change translation
+	 *
+	 * @covers ::getTranslator
+	 * @covers ::l10nReloadMOfile
+	 * @dataProvider getTranslatorProvider
+	 * @testdox change locale from $locale and domain $domain to locale $locale_new and domain $domain_new [$_dataName]
+	 *
+	 * @param  string|null $locale
+	 * @param  string|null $path
+	 * @param  string|null $domain
+	 * @param  bool|null   $legacy
+	 * @param  bool        $load_error
+	 * @param  string      $original
+	 * @param  string      $locale_expected_a
+	 * @param  string      $domain_expected_a
+	 * @param  string      $translated_a
+	 * @param  string|null $locale_new
+	 * @param  string|null $path_new
+	 * @param  string|null $domain_new
+	 * @param  bool|null   $legacy_new
+	 * @param  bool        $load_error_new
+	 * @param  string      $locale_expected_b
+	 * @param  string      $domain_expected_b
+	 * @param  string      $translated_b
+	 * @return void
+	 */
+	public function testGetTranslator(
+		// 0-3
+		?string $locale,
+		?string $path,
+		?string $domain,
+		?bool $legacy,
+		// 4
+		bool $load_error,
+		// 5
+		string $original,
+		// 6-8
+		string $locale_expected_a,
+		string $domain_expected_a,
+		string $translated_a,
+		// 9-12
+		?string $locale_new,
+		?string $path_new,
+		?string $domain_new,
+		?bool $legacy_new,
+		// 13
+		bool $load_error_new,
+		// 14-16
+		string $locale_expected_b,
+		string $domain_expected_b,
+		string $translated_b,
+	): void {
+		if ($locale === null) {
+			$l10n = new \CoreLibs\Language\L10n();
+		} elseif ($path === null) {
+			$l10n = new \CoreLibs\Language\L10n($locale);
+		} elseif ($domain === null) {
+			$l10n = new \CoreLibs\Language\L10n($locale, $path);
+		} elseif ($legacy === null) {
+			$l10n = new \CoreLibs\Language\L10n($locale, $path, $domain);
+		} else {
+			$l10n = new \CoreLibs\Language\L10n($locale, $path, $domain, $legacy);
+		}
+		// print "LOC: " . $locale . ", " . $l10n->getLocale() . ", " . $locale_expected . "\n";
+		// status check
+		$this->assertEquals(
+			$load_error,
+			$l10n->getLoadError(),
+			'Legacy method load error init check'
+		);
+		$this->assertEquals(
+			$locale_expected_a,
+			$l10n->getLocale(),
+			'Locale init assert failed'
+		);
+		$this->assertEquals(
+			$domain_expected_a,
+			$l10n->getDomain(),
+			'Domain init assert failed'
+		);
+		$this->assertEquals(
+			$translated_a,
+			$l10n->__($original),
+			'Translated string init assert failed'
+		);
+
+		// do reload with legacy l10nReloadMOfile IF legacy is null or true
+		// use getTranslator if legacy is false
+		if ($legacy === null || $legacy === true) {
+			// there is no null/empty locale allowed directly
+			// if empty will set previous one
+			if ($path_new === null) {
+				$ret_status = $l10n->l10nReloadMOfile($locale_new);
+			} elseif ($domain_new === null) {
+				$ret_status = $l10n->l10nReloadMOfile($locale_new, $path_new);
+			} elseif ($legacy_new === null) {
+				$ret_status = $l10n->l10nReloadMOfile($locale_new, $path_new, $domain_new);
+			} else {
+				$ret_status = $l10n->l10nReloadMOfile($locale_new, $path_new, $domain_new, $legacy_new);
+			}
+			// status check
+			$this->assertEquals(
+				$load_error_new,
+				$l10n->getLoadError(),
+				'Legacy method load error change check'
+			);
+			// retun status check is inverted to load error check
+			$this->assertEquals(
+				$load_error_new ? false : true,
+				$ret_status,
+				'Legacy return load error change check'
+			);
+		} else {
+			if ($locale_new === null) {
+				$translator = $l10n->getTranslator();
+			} elseif ($path_new === null) {
+				$translator = $l10n->getTranslator($locale_new);
+			} elseif ($domain_new === null) {
+				$translator = $l10n->getTranslator($locale_new, $path_new);
+			} elseif ($legacy_new === null) {
+				$translator = $l10n->getTranslator($locale_new, $path_new, $domain_new);
+			} else {
+				$translator = $l10n->getTranslator($locale_new, $path_new, $domain_new, $legacy_new);
+			}
+			// status check
+			$this->assertEquals(
+				$load_error_new,
+				$l10n->getLoadError(),
+				'Translate method load error change check'
+			);
+			// check that returned is class GetTextReader and object
+			$this->assertIsObject(
+				$translator,
+				'translater class is object assert failed'
+			);
+			$this->assertInstanceOf(
+				'\CoreLibs\Language\Core\GetTextReader',
+				$translator,
+				'translator class is correct instance assert failed'
+			);
+			// translator class
+			$this->assertEquals(
+				$translated_b,
+				$translator->gettext($original),
+				'Translated string change assert failed from returned class'
+			);
+		}
+		// new set check
+		$this->assertEquals(
+			$locale_expected_b,
+			$l10n->getLocale(),
+			'Locale change assert failed'
+		);
+		$this->assertEquals(
+			$domain_expected_b,
+			$l10n->getDomain(),
+			'Domain change assert failed'
+		);
+		$this->assertEquals(
+			$translated_b,
+			$l10n->__($original),
+			'Translated string change assert failed'
+		);
+	}
+
+	// TODO: test all translation types
+	// __/gettext
+	// __n/ngettext
+	// ->dgettext
+	// ->dngettext
+	// ->dpgettext
+	// ->dpngettext
+
+	/**
+	 * Undocumented function
+	 *
+	 * @return array
+	 */
+	public function ngettextProvider(): array
+	{
+		return [
+			// 0: locale
+			// 1: path
+			// 2: domain
+			// 3: context (null for none)
+			// 4: single string
+			// 5: plural string
+			// 6: array for each n value expected string
+			'plural text en' => [
+				'en_US',
+				__DIR__ . 'includes/locale/',
+				'admin',
+				// context
+				null,
+				// text single/multi in
+				'single',
+				'multi',
+				// confirm translation, pos in array equal n
+				[
+					0 => 'Multi admin en_US 1',
+					1 => 'Multi admin en_US 0',
+					2 => 'Multi admin en_US 1',
+				]
+			],
+			'plural text context en' => [
+				'en_US',
+				__DIR__ . 'includes/locale/',
+				'admin',
+				// context
+				'context',
+				// text single/multi in
+				'single',
+				'multi',
+				// confirm translation, pos in array equal n
+				[
+					0 => 'Multi context admin en_US 1',
+					1 => 'Multi context admin en_US 0',
+					2 => 'Multi context admin en_US 1',
+				]
+				],
+		];
+	}
+
+	/**
+	 * Undocumented function
+	 *
+	 * @covers ::__n
+	 * @dataProvider ngettextProvider
+	 * @testdox plural string test for locale $locale and domain $domain with $context [$_dataName]
+	 *
+	 * @param  string  $locale
+	 * @param  string  $path
+	 * @param  string  $domain
+	 * @param  ?string $context
+	 * @param  string  $original_single
+	 * @param  string  $original_plural
+	 * @param  array   $expected_strings
+	 * @return void
+	 */
+	public function testNgettext(
+		// config 0-3
+		string $locale,
+		string $path,
+		string $domain,
+		// context string
+		?string $context,
+		// input strings
+		string $original_single,
+		string $original_plural,
+		// expected
+		array $expected_strings
+	): void {
+		$l10n = new \CoreLibs\Language\L10n($locale, $path, $domain, false);
+
+		foreach ($expected_strings as $n => $expected) {
+			if (empty($context)) {
+				$this->assertEquals(
+					$expected,
+					$l10n->__n($original_single, $original_plural, $n),
+					'assert failed for plural: ' . $n
+				);
+			} else {
+				$this->assertEquals(
+					$expected,
+					$l10n->__pn($context, $original_single, $original_plural, $n),
+					'assert failed for plural: ' . $n . ' in context: ' . $context
+				);
+			}
+		}
+	}
+
+	/**
+	 * locales list for testing locale folder lookup
+	 *
+	 * @return array
+	 */
+	public function localesProvider(): array
+	{
+		return [
+			// 0: locale
+			// 1: return array
+			'en' => [
+				'en',
+				[
+					'en',
+				]
+			],
+			'en.UTF-8' => [
+				'en.UTF-8',
+				[
+					'en.UTF-8',
+					'en',
+				]
+			],
+			'en_US' => [
+				'en_US',
+				[
+					'en_US',
+					'en',
+				]
+			],
+			'en_US.UTF-8' => [
+				'en_US.UTF-8',
+				[
+					'en_US.UTF-8',
+					'en_US',
+					'en',
+				]
+			],
+			'en_US@subtext' => [
+				'en_US@subtext',
+				[
+					'en_US@subtext',
+					'en@subtext',
+					'en_US',
+					'en',
+				]
+			],
+			'en_US.UTF-8@subtext' => [
+				'en_US.UTF-8@subtext',
+				[
+					'en_US.UTF-8@subtext',
+					'en_US@subtext',
+					'en@subtext',
+					'en_US.UTF-8',
+					'en_US',
+					'en',
+				]
+			]
+		];
+	}
+
+	/**
+	 * test locales array return
+	 *
+	 * @covers ::listLocales
+	 * @dataProvider localesProvider
+	 * @testdox check $locale [$_dataName]
+	 *
+	 * @param string $locale
+	 * @param array $expected
+	 * @return void
+	 */
+	public function testListLocales(string $locale, array $expected): void
+	{
+		$locale_list = \CoreLibs\Language\L10n::listLocales($locale);
+		// print "LOCALES: " . print_r($locale_list, true) . "\n";
+		$this->assertEquals(
+			$expected,
+			$locale_list
+		);
+	}
+
+	// @covers ::detectLocale
+
+	/**
+	 * Undocumented function
+	 *
+	 * @return array
+	 */
+	public function detectLocaleProvider(): array
+	{
+		return [
+			// 0: type: global | env
+			// 1: global variable name or enviroment var
+			// 2: value to set
+			// 3: value to expect back
+			'global locale' => [
+				'global',
+				'LOCALE',
+				'ja_JP.UTF-8',
+				'ja_JP.UTF-8',
+			],
+			'env LC_ALL' => [
+				'env',
+				'LC_ALL',
+				'ja_JP.UTF-8',
+				'ja_JP.UTF-8',
+			],
+			'env LANG' => [
+				'env',
+				'LANG',
+				'ja_JP.UTF-8',
+				'ja_JP.UTF-8',
+			],
+			'default return' => [
+				'env',
+				'LC_ALL',
+				'',
+				'en',
+			]
+		];
+	}
+
+	/**
+	 * Undocumented function
+	 * @covers ::detectLocale
+	 * @dataProvider detectLocaleProvider
+	 * @testdox check detectLocale for $type with $var and $value is $expected [$_dataName]
+	 *
+	 * @return void
+	 */
+	public function testDetectLocale(
+		string $type,
+		string $var,
+		string $value,
+		string $expected,
+	): void {
+		switch ($type) {
+			case 'global':
+				$GLOBALS[$var] = $value;
+				break;
+			case 'env':
+				$old_value = getenv("$var");
+				putenv("$var=$value");
+				// unset all other env vars
+				foreach (['LC_ALL', 'LC_MESSAGES', 'LANG'] as $env) {
+					if ($env != $var) {
+						putenv("$env=");
+					}
+				}
+				break;
+		}
+		$locale = \CoreLibs\Language\L10n::detectLocale();
+		$this->assertEquals(
+			$expected,
+			$locale
+		);
+		// reset post run
+		switch ($type) {
+			case 'global':
+				unset($GLOBALS[$var]);
+				break;
+			case 'env':
+				putenv("$var=$old_value");
+				break;
+		}
+	}
+
+	// set/get text domain, domain, locale
+
+	/**
+	 * Undocumented function
+	 *
+	 * @return array
+	 */
+	public function textDomainProvider(): array
+	{
+		return [
+			// 0: set domain
+			// 1: set path
+			// 2: get domain
+			// 3: expected path
+			'valid set and get' => [
+				'foo',
+				'foo/bar',
+				'foo',
+				'foo/bar',
+			],
+			'invalid set and get' => [
+				'foo',
+				'foo/bar',
+				'iamnotset',
+				false
+			]
+		];
+	}
+
+	/**
+	 * Undocumented function
+	 *
+	 * @covers ::setTextDomain
+	 * @covers ::getTextDomain
+	 * @dataProvider textDomainProvider
+	 * @testdox set $domain with $path and get $get_domain and expect $expected [$_dataName]
+	 *
+	 * @param  string $domain
+	 * @param  string $path
+	 * @param  string $get_domain
+	 * @param  string|bool $expected
+	 * @return void
+	 */
+	public function testSetGetTextDomain(string $domain, string $path, string $get_domain, $expected): void
+	{
+		$l10n = new \CoreLibs\Language\L10n();
+		$l10n->setTextDomain($domain, $path);
+		$this->assertEquals(
+			$expected,
+			$l10n->getTextDomain($get_domain)
+		);
+	}
+
+	/**
+	 * Undocumented function
+	 *
+	 * @return array
+	 */
+	public function domainProvider(): array
+	{
+		return [
+			// 0: set domain
+			// 1: expected domain from get
+			'valid domain' => [
+				'foo',
+				'foo',
+			],
+			'empty domain' => [
+				'',
+				'',
+			]
+		];
+	}
+
+	/**
+	 * Undocumented function
+	 *
+	 * @covers ::setDomain
+	 * @covers ::getDomain
+	 * @dataProvider domainProvider
+	 * @testdox set $domain and expect $expected [$_dataName]
+	 *
+	 * @param  string $domain
+	 * @param  string $expected
+	 * @return void
+	 */
+	public function testSetGetDomain(string $domain, string $expected): void
+	{
+		$l10n = new \CoreLibs\Language\L10n();
+		$l10n->setDomain($domain);
+		$this->assertEquals(
+			$expected,
+			$l10n->getDomain()
+		);
+	}
+
+	/**
+	 * Undocumented function
+	 *
+	 * @return array
+	 */
+	public function localeProvider(): array
+	{
+		return [
+			// 0: set locale
+			// 1: pre set if not null or not empty
+			// 2: expected return from set
+			// 3: expected from get
+			'valid locale' => [
+				'foo',
+				null,
+				'foo',
+				'foo',
+			],
+			'empty locale' => [
+				'',
+				null,
+				'',
+				'',
+			],
+			'empty locale, pre set' => [
+				'',
+				'foo',
+				'foo',
+				'foo',
+			],
+		];
+	}
+
+	/**
+	 * Undocumented function
+	 *
+	 * @covers ::setLocale
+	 * @covers ::getLocale
+	 * @dataProvider localeProvider
+	 * @testdox set $locale with $expected_return and expect $expected [$_dataName]
+	 *
+	 * @param  string $locale
+	 * @param  string $pre_locale
+	 * @param  string $expected_return
+	 * @param  string $expected
+	 * @return void
+	 */
+	public function testSetGetLocale(
+		string $locale,
+		?string $pre_locale,
+		string $expected_return,
+		string $expected
+	): void {
+		$l10n = new \CoreLibs\Language\L10n();
+		if (!empty($pre_locale)) {
+			$l10n->setLocale($pre_locale);
+		}
+		$returned = $l10n->setLocale($locale);
+		$this->assertEquals(
+			$expected_return,
+			$returned,
+			'Set locale return assert failed'
+		);
+		$this->assertEquals(
+			$expected,
+			$l10n->getLocale(),
+			'Get locale aszert failed'
+		);
+	}
+
+	// static load
+
+	/**
+	 * Undocumented function
+	 *
+	 * @return array
+	 */
+	public function functionsProvider(): array
+	{
+		return [
+			// 0: lang/locale
+			// 1: path
+			// 2: domain
+			// 3: encoding
+			// 4: string
+			// 5: translated string
+			'standard en' => [
+				'en_US.UTF-8',
+				__DIR__ . 'includes/locale/',
+				'frontend',
+				'UTF-8',
+				'Original',
+				'Translated frontend en_US',
+			],
+			'standard ja' => [
+				'ja_JP.UTF-8',
+				__DIR__ . 'includes/locale/',
+				'admin',
+				'UTF-8',
+				'Original',
+				'Translated admin ja_JP',
+			]
+		];
+	}
+
+	/**
+	 * fuctions check
+	 * TODO: others d/dn/dp/dpn gettext functions
+	 *
+	 * @covers __setlocale
+	 * @covers __bindtextdomain
+	 * @covers __bind_textdomain_codeset
+	 * @covers __textdomain
+	 * @covers __gettext
+	 * @covers __
+	 * @dataProvider functionsProvider
+	 * @testdox check functions with locale $locale and domain $domain [$_dataName]
+	 * @param  string $locale
+	 * @param  string $path
+	 * @param  string $domain
+	 * @param  string $encoding
+	 * @param  string $original
+	 * @param  string $translated
+	 * @return void
+	 */
+	public function testFunctions(
+		string $locale,
+		string $path,
+		string $domain,
+		string $encoding,
+		string $original,
+		string $translated
+	): void {
+		\CoreLibs\Language\L10n::loadFunctions();
+		__setlocale(LC_MESSAGES, $locale);
+		__textdomain($domain);
+		__bindtextdomain($domain, $path);
+		__bind_textdomain_codeset($domain, $encoding);
+		$this->assertEquals(
+			$translated,
+			__($original),
+			'function __ assert failed'
+		);
+		$this->assertEquals(
+			$translated,
+			__gettext($original),
+			'function gettext assert failed'
 		);
 	}
 }
diff --git a/4dev/tests/includes/create_po.sh b/4dev/tests/includes/create_po.sh
new file mode 100755
index 00000000..d549d19a
--- /dev/null
+++ b/4dev/tests/includes/create_po.sh
@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+
+# if we don't have one base file we are in the wrong folder
+if [ ! -f "locale/en_US/LC_MESSAGES/admin.mo" ]; then
+	echo "Locale file is missing, wrong base folder?"
+	echo "Should be: 4dev/tests/includes/"
+	exit;
+fi;
+
+msgfmt -o locale/en_US/LC_MESSAGES/admin.mo locale/en_US.admin.UTF-8.po
+msgfmt -o locale/en_US/LC_MESSAGES/frontend.mo locale/en_US.frontend.UTF-8.po
+msgfmt -o locale/ja_JP/LC_MESSAGES/admin.mo locale/ja_JP.admin.UTF-8.po
+msgfmt -o locale/ja_JP/LC_MESSAGES/frontend.mo locale/ja_JP.frontend.UTF-8.po
diff --git a/4dev/tests/includes/locale/en_US.admin.UTF-8.po b/4dev/tests/includes/locale/en_US.admin.UTF-8.po
index af91eed8..c35caf23 100644
--- a/4dev/tests/includes/locale/en_US.admin.UTF-8.po
+++ b/4dev/tests/includes/locale/en_US.admin.UTF-8.po
@@ -1,2 +1,34 @@
+
+msgid ""
+msgstr ""
+"Project-Id-Version: en_US.UTF-8 LC_MESSAGES admin\n"
+"Report-Msgid-Bugs-To: clemens.schwaighofer@egplusww.com\n"
+"POT-Creation-Date: 2018-03-28 10:40+0900\n"
+"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
+"Last-Translator: clemens.schwaighofer@egplusww.co\n"
+"Language-Team: E-GRAPHICS COMMUNICATIONS Japan <info.jp@egplusww.com>\n"
+"Language: en_US\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"Plural-Forms: nplurals=2; plural=n != 1;\n"
+
 msgid "Original"
 msgstr "Translated admin en_US"
+
+msgid "single"
+msgid_plural "multi"
+msgstr[0] "Multi admin en_US 0"
+msgstr[1] "Multi admin en_US 1"
+msgstr[2] "Multi admin en_US 2"
+
+msgctxt "context"
+msgid "Original"
+msgstr "Original context admin en_US"
+
+msgctxt "context"
+msgid "single"
+msgid_plural "multi"
+msgstr[0] "Multi context admin en_US 0"
+msgstr[1] "Multi context admin en_US 1"
+msgstr[2] "Multi context admin en_US 2"
diff --git a/4dev/tests/includes/locale/en_US.frontend.UTF-8.po b/4dev/tests/includes/locale/en_US.frontend.UTF-8.po
index f955356b..a2f58edb 100644
--- a/4dev/tests/includes/locale/en_US.frontend.UTF-8.po
+++ b/4dev/tests/includes/locale/en_US.frontend.UTF-8.po
@@ -1,2 +1,34 @@
+
+msgid ""
+msgstr ""
+"Project-Id-Version: en_US.UTF-8 LC_MESSAGES frontend\n"
+"Report-Msgid-Bugs-To: clemens.schwaighofer@egplusww.com\n"
+"POT-Creation-Date: 2018-03-28 10:40+0900\n"
+"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
+"Last-Translator: clemens.schwaighofer@egplusww.co\n"
+"Language-Team: E-GRAPHICS COMMUNICATIONS Japan <info.jp@egplusww.com>\n"
+"Language: en_US\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"Plural-Forms: nplurals=2; plural=n != 1;\n"
+
 msgid "Original"
 msgstr "Translated frontend en_US"
+
+msgid "single"
+msgid_plural "multi"
+msgstr[0] "Multi frontend en_US 0"
+msgstr[1] "Multi frontend en_US 1"
+msgstr[2] "Multi frontend en_US 2"
+
+msgctxt "context"
+msgid "Original"
+msgstr "Original context frontend en_US"
+
+msgctxt "context"
+msgid "single"
+msgid_plural "multi"
+msgstr[0] "Multi context frontend en_US 0"
+msgstr[1] "Multi context frontend en_US 1"
+msgstr[2] "Multi context frontend en_US 2"
diff --git a/4dev/tests/includes/locale/en_US/LC_MESSAGES/admin.mo b/4dev/tests/includes/locale/en_US/LC_MESSAGES/admin.mo
index f52560b8..c681b0c4 100644
Binary files a/4dev/tests/includes/locale/en_US/LC_MESSAGES/admin.mo and b/4dev/tests/includes/locale/en_US/LC_MESSAGES/admin.mo differ
diff --git a/4dev/tests/includes/locale/en_US/LC_MESSAGES/frontend.mo b/4dev/tests/includes/locale/en_US/LC_MESSAGES/frontend.mo
index 1d8fb44f..b63ffe74 100644
Binary files a/4dev/tests/includes/locale/en_US/LC_MESSAGES/frontend.mo and b/4dev/tests/includes/locale/en_US/LC_MESSAGES/frontend.mo differ
diff --git a/4dev/tests/includes/locale/ja_JP.admin.UTF-8.po b/4dev/tests/includes/locale/ja_JP.admin.UTF-8.po
index 3f4dccbe..e2a8795c 100644
--- a/4dev/tests/includes/locale/ja_JP.admin.UTF-8.po
+++ b/4dev/tests/includes/locale/ja_JP.admin.UTF-8.po
@@ -1,2 +1,35 @@
+
+msgid ""
+msgstr ""
+"Project-Id-Version: ja_JP.UTF-8 LC_MESSAGES admin\n"
+"Report-Msgid-Bugs-To: clemens.schwaighofer@egplusww.com\n"
+"POT-Creation-Date: 2018-03-28 10:40+0900\n"
+"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
+"Last-Translator: clemens.schwaighofer@egplusww.co\n"
+"Language-Team: E-GRAPHICS COMMUNICATIONS Japan <info.jp@egplusww.com>\n"
+"Language: ja\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"Plural-Forms: nplurals=3; plural=n%10==1 && n%100!=11 ? 0 : n != 0 ? 1 : 2;\n"
+# 0, 1, 2 plural
+
 msgid "Original"
 msgstr "Translated admin ja_JP"
+
+msgid "single"
+msgid_plural "multi"
+msgstr[0] "Multi admin ja_JP 0"
+msgstr[1] "Multi admin ja_JP 1"
+msgstr[2] "Multi admin ja_JP 2"
+
+msgctxt "context"
+msgid "Original"
+msgstr "Original context admin ja_JP"
+
+msgctxt "context"
+msgid "single"
+msgid_plural "multi"
+msgstr[0] "Multi context admin ja_JP 0"
+msgstr[1] "Multi context admin ja_JP 1"
+msgstr[2] "Multi context admin ja_JP 2"
diff --git a/4dev/tests/includes/locale/ja_JP.frontend.UTF-8.po b/4dev/tests/includes/locale/ja_JP.frontend.UTF-8.po
index 3d7318ff..ccdba7a6 100644
--- a/4dev/tests/includes/locale/ja_JP.frontend.UTF-8.po
+++ b/4dev/tests/includes/locale/ja_JP.frontend.UTF-8.po
@@ -1,2 +1,35 @@
+
+msgid ""
+msgstr ""
+"Project-Id-Version: ja_JP.UTF-8 LC_MESSAGES frontend\n"
+"Report-Msgid-Bugs-To: clemens.schwaighofer@egplusww.com\n"
+"POT-Creation-Date: 2018-03-28 10:40+0900\n"
+"PO-Revision-Date: YEAR-MO-DA HO:MI+ZONE\n"
+"Last-Translator: clemens.schwaighofer@egplusww.co\n"
+"Language-Team: E-GRAPHICS COMMUNICATIONS Japan <info.jp@egplusww.com>\n"
+"Language: ja\n"
+"MIME-Version: 1.0\n"
+"Content-Type: text/plain; charset=UTF-8\n"
+"Content-Transfer-Encoding: 8bit\n"
+"Plural-Forms: nplurals=3; plural=n%10==1 && n%100!=11 ? 0 : n != 0 ? 1 : 2;\n"
+# 0, 1, 2 plural
+
 msgid "Original"
 msgstr "Translated frontend ja_JP"
+
+msgid "single"
+msgid_plural "multi"
+msgstr[0] "Multi frontend ja_JP 0"
+msgstr[1] "Multi frontend ja_JP 1"
+msgstr[2] "Multi frontend ja_JP 2"
+
+msgctxt "context"
+msgid "Original"
+msgstr "Original context frontend ja_JP"
+
+msgctxt "context"
+msgid "single"
+msgid_plural "multi"
+msgstr[0] "Multi context frontend ja_JP 0"
+msgstr[1] "Multi context frontend ja_JP 1"
+msgstr[2] "Multi context frontend ja_JP 2"
diff --git a/4dev/tests/includes/locale/ja_JP/LC_MESSAGES/admin.mo b/4dev/tests/includes/locale/ja_JP/LC_MESSAGES/admin.mo
index f4985b59..df8d579c 100644
Binary files a/4dev/tests/includes/locale/ja_JP/LC_MESSAGES/admin.mo and b/4dev/tests/includes/locale/ja_JP/LC_MESSAGES/admin.mo differ
diff --git a/4dev/tests/includes/locale/ja_JP/LC_MESSAGES/frontend.mo b/4dev/tests/includes/locale/ja_JP/LC_MESSAGES/frontend.mo
index 3e45df2d..c8b84144 100644
Binary files a/4dev/tests/includes/locale/ja_JP/LC_MESSAGES/frontend.mo and b/4dev/tests/includes/locale/ja_JP/LC_MESSAGES/frontend.mo differ
diff --git a/www/admin/class_test.lang.php b/www/admin/class_test.lang.php
index c2b936d2..b672478c 100644
--- a/www/admin/class_test.lang.php
+++ b/www/admin/class_test.lang.php
@@ -40,15 +40,35 @@ use CoreLibs\Language\L10n;
 
 $string = 'INPUT TEST';
 
+echo "<br><b>LEGACY TEST</b><br>";
+
+$lang = 'en_utf8';
 $l = new CoreLibs\Language\L10n($lang);
+echo "*<br>";
 echo "LANGUAGE WANT/SET: " . $lang  . '/' . $l->getLocale() . "<br>";
 echo "LANGUAGE FILE: " . $l->getMoFile() . "<br>";
 echo "LOAD ERROR: " . $l->getLoadError() . "<br>";
 echo "INPUT TEST: " . $string . " => " . $l->__($string) . "<br>";
+$single_string = 'single';
+$multi_string = 'multi';
+for ($n = 0; $n <= 3; $n++) {
+	echo "MULTI TEST $n: " . $single_string . "/" . $multi_string . " => "
+		. $l->__n($single_string, $multi_string, $n) . "<br>";
+}
+$context = "month name";
+$context_string = "May";
+echo "CONTEXT TRANSLATION: " . $context_string . " => " . $l->__p($context, $context_string) . "<br>";
+$single_string = 'single';
+$multi_string = 'multi';
+for ($n = 0; $n <= 3; $n++) {
+	echo "CONTEXT MULTI TEST $n: " . $single_string . "/" . $multi_string . " => "
+		. $l->__pn($context, $single_string, $multi_string, $n) . "<br>";
+}
 
 // switch to other language
 $lang = 'ja_utf8';
 $l->l10nReloadMOfile($lang);
+echo "*<br>";
 echo "LANGUAGE WANT/SET: " . $lang  . '/' . $l->getLocale() . "<br>";
 echo "LANGUAGE FILE: " . $l->getMoFile() . "<br>";
 echo "LOAD ERROR: " . $l->getLoadError() . "<br>";
@@ -56,6 +76,7 @@ echo "INPUT TEST: " . $string . " => " . $l->__($string) . "<br>";
 // switch to non existing language
 $lang = 'tr_utf8';
 $l->l10nReloadMOfile($lang);
+echo "*<br>";
 echo "LANGUAGE WANT/SET: " . $lang  . '/' . $l->getLocale() . "<br>";
 echo "LANGUAGE FILE: " . $l->getMoFile() . "<br>";
 echo "LOAD ERROR: " . $l->getLoadError() . "<br>";
@@ -79,33 +100,64 @@ $encoding = 'UTF-8';
 $path = BASE . INCLUDES . LOCALE;
 $l = new CoreLibs\Language\L10n($lang, $path, $domain, false);
 
+echo "*<br>";
 echo "LANGUAGE WANT/SET: " . $lang  . '/' . $l->getLocale() . "<br>";
 echo "DOMAIN WANT/SET: " . $domain  . '/' . $l->getDomain() . "<br>";
 echo "LANGUAGE FILE: " . $l->getMoFile() . "<br>";
+echo "CONTENT PATH: " . $l->getBaseContentPath() . "<br>";
+echo "DOMAIN PATH: " . $l->getTextDomain($domain) . "<br>";
+echo "BASE PATH: " . $l->getBaseLocalePath() . "<br>";
+echo "LOAD ERROR: " . $l->getLoadError() . "<br>";
+echo "INPUT TEST: " . $string . " => " . $l->__($string) . "<br>";
+echo "TROUGH LOAD: " . $l->getTranslatorClass()->gettext($string) . "<br>";
+$single_string = 'single';
+$multi_string = 'multi';
+for ($n = 0; $n <= 3; $n++) {
+	echo "MULTI TEST $n: " . $single_string . "/" . $multi_string . " => "
+		. $l->__n($single_string, $multi_string, $n) . "<br>";
+}
+
+$domain = 'frontend';
+$l->getTranslator('', $path, $domain);
+echo "*<br>";
+echo "LANGUAGE WANT/SET: " . $lang  . '/' . $l->getLocale() . "<br>";
+echo "DOMAIN WANT/SET: " . $domain  . '/' . $l->getDomain() . "<br>";
+echo "LANGUAGE FILE: " . $l->getMoFile() . "<br>";
+echo "CONTENT PATH: " . $l->getBaseContentPath() . "<br>";
+echo "DOMAIN PATH: " . $l->getTextDomain($domain) . "<br>";
+echo "BASE PATH: " . $l->getBaseLocalePath() . "<br>";
 echo "LOAD ERROR: " . $l->getLoadError() . "<br>";
 echo "INPUT TEST: " . $string . " => " . $l->__($string) . "<br>";
 echo "TROUGH LOAD: " . $l->getTranslatorClass()->gettext($string) . "<br>";
 
-
-echo "<br><b>STATIC TYPE</b><br>";
+$domain = 'admin';
+echo "<br><b>STATIC TYPE TEST</b><br>";
 // static tests from l10n_load
 L10n::getInstance()->setLocale($lang);
 echo "SET LOCALE: " . L10n::getInstance()->getLocale() . "<br>";
 L10n::getInstance()->setDomain($domain);
 echo "SET DOMAIN: " . L10n::getInstance()->getDomain() . "<br>";
 L10n::getInstance()->setTextDomain($domain, $path);
-echo "SET DOMAIN: " . L10n::getInstance()->getTextDomain($domain) . "<br>";
+echo "SET TEXT DOMAIN: " . L10n::getInstance()->getTextDomain($domain) . "<br>";
 // null call __bind_textdomain_codeset
 echo "INPUT TEST: " . $string . " => " . L10n::getInstance()->getTranslator()->gettext($string) . "<br>";
 
 echo "<br><b>FUNCTIONS</b><br>";
 // real statisc test
 L10n::loadFunctions();
-__setlocale(LC_MESSAGES, $lang);
+$locale = 'ja';
+__setlocale(LC_MESSAGES, $locale);
 __textdomain($domain);
 __bindtextdomain($domain, $path);
 __bind_textdomain_codeset($domain, $encoding);
-echo "INPUT TEST: " . $string . " => " . __($string) . "<br>";
+echo "INPUT TEST $locale: " . $string . " => " . __($string) . "<br>";
+
+$locale = 'en_US.UTF-8';
+__setlocale(LC_MESSAGES, $locale);
+__textdomain($domain);
+__bindtextdomain($domain, $path);
+__bind_textdomain_codeset($domain, $encoding);
+echo "INPUT TEST $locale: " . $string . " => " . __($string) . "<br>";
 
 print "</body></html>";
 
diff --git a/www/includes/locale/en_US/LC_MESSAGES/admin.mo b/www/includes/locale/en_US/LC_MESSAGES/admin.mo
index da820bb0..6407f2e0 100644
Binary files a/www/includes/locale/en_US/LC_MESSAGES/admin.mo and b/www/includes/locale/en_US/LC_MESSAGES/admin.mo differ
diff --git a/www/includes/locale/ja/LC_MESSAGES/admin.mo b/www/includes/locale/ja/LC_MESSAGES/admin.mo
index 6d2ebed8..76cd4a38 100644
Binary files a/www/includes/locale/ja/LC_MESSAGES/admin.mo and b/www/includes/locale/ja/LC_MESSAGES/admin.mo differ
diff --git a/www/lib/CoreLibs/Basic.php b/www/lib/CoreLibs/Basic.php
index 20fbe1b7..1ff06b44 100644
--- a/www/lib/CoreLibs/Basic.php
+++ b/www/lib/CoreLibs/Basic.php
@@ -715,20 +715,20 @@ class Basic
 
 	// *** ARRAY HANDLING END
 	// [!!! DEPRECATED !!!]
-	// Moved to \CoreLibs\Language\Encoding
+	// Moved to \CoreLibs\Convert\MimeEncode
 
 	/**
 	 * wrapper function for mb mime convert, for correct conversion with long strings
 	 * @param  string $string   string to encode
 	 * @param  string $encoding target encoding
 	 * @return string           encoded string
-	 * @deprecated Use \CoreLibs\Language\Encoding::__mbMimeEncode() instead
+	 * @deprecated Use \CoreLibs\Convert\MimeEncode::__mbMimeEncode() instead
 	 */
 	public static function __mbMimeEncode(string $string, string $encoding): string
 	{
 
-		trigger_error('Method ' . __METHOD__ . ' is deprecated, use \CoreLibs\Language\Encoding::__mbMimeEncode()', E_USER_DEPRECATED);
-		return \CoreLibs\Language\Encoding::__mbMimeEncode($string, $encoding);
+		trigger_error('Method ' . __METHOD__ . ' is deprecated, use \CoreLibs\Convert\MimeEncode::__mbMimeEncode()', E_USER_DEPRECATED);
+		return \CoreLibs\Convert\MimeEncode::__mbMimeEncode($string, $encoding);
 	}
 
 	// *** HUMAND BYTE READABLE CONVERT
@@ -1009,7 +1009,7 @@ class Basic
 
 	// *** ENCODING FUNCTIONS
 	// [!!! DEPRECATED !!!]
-	// Moved to \CoreLibs\Language\Encoding
+	// Moved to \CoreLibs\Check\Encoding and \CoreLibs\Convert\Encoding
 
 	/**
 	 * test if a string can be safely convert between encodings. mostly utf8 to shift jis
@@ -1026,12 +1026,12 @@ class Basic
 	 * @param  string     $from_encoding encoding of string to test
 	 * @param  string     $to_encoding   target encoding
 	 * @return bool|array<mixed>         false if no error or array with failed characters
-	 * @deprecated use \CoreLibs\Language\Encoding::checkConvertEncoding() instead
+	 * @deprecated use \CoreLibs\Check\Encoding::checkConvertEncoding() instead
 	 */
 	public function checkConvertEncoding(string $string, string $from_encoding, string $to_encoding)
 	{
-		trigger_error('Method ' . __METHOD__ . ' is deprecated, use \CoreLibs\Language\Encoding::checkConvertEncoding()', E_USER_DEPRECATED);
-		return \CoreLibs\Language\Encoding::checkConvertEncoding($string, $from_encoding, $to_encoding);
+		trigger_error('Method ' . __METHOD__ . ' is deprecated, use \CoreLibs\Check\Encoding::checkConvertEncoding()', E_USER_DEPRECATED);
+		return \CoreLibs\Check\Encoding::checkConvertEncoding($string, $from_encoding, $to_encoding);
 	}
 
 	/**
@@ -1047,12 +1047,12 @@ class Basic
 	 *                                 check that the source is actually matching
 	 *                                 to what we sav the source is
 	 * @return string                  encoding converted string
-	 * @deprecated use \CoreLibs\Language\Encoding::convertEncoding() instead
+	 * @deprecated use \CoreLibs\Convert\Encoding::convertEncoding() instead
 	 */
 	public static function convertEncoding(string $string, string $to_encoding, string $source_encoding = '', bool $auto_check = true): string
 	{
-		trigger_error('Method ' . __METHOD__ . ' is deprecated, use \CoreLibs\Language\Encoding::convertEncoding()', E_USER_DEPRECATED);
-		return \CoreLibs\Language\Encoding::convertEncoding($string, $to_encoding, $source_encoding, $auto_check);
+		trigger_error('Method ' . __METHOD__ . ' is deprecated, use \CoreLibs\Convert\Encoding::convertEncoding()', E_USER_DEPRECATED);
+		return \CoreLibs\Convert\Encoding::convertEncoding($string, $to_encoding, $source_encoding, $auto_check);
 	}
 
 	// *** ENCODING FUNCTIONS END
diff --git a/www/lib/CoreLibs/Language/Core/FileReader.php b/www/lib/CoreLibs/Language/Core/FileReader.php
index 17bf0dce..cbee1b04 100644
--- a/www/lib/CoreLibs/Language/Core/FileReader.php
+++ b/www/lib/CoreLibs/Language/Core/FileReader.php
@@ -39,7 +39,7 @@ class FileReader
 	 * file read constructor
 	 * @param string $filename file name to load
 	 */
-	public function __construct($filename)
+	public function __construct(string $filename)
 	{
 		if (file_exists($filename)) {
 			$this->fr_length = filesize($filename) ?: 0;
@@ -58,7 +58,7 @@ class FileReader
 	 * @param  int $bytes how many bytes to read
 	 * @return string     read data as string
 	 */
-	public function read($bytes)
+	public function read(int $bytes): string
 	{
 		if (!$bytes || !is_resource($this->fr_fd)) {
 			return '';
@@ -86,7 +86,7 @@ class FileReader
 	 * @param  int $pos position where to go to
 	 * @return int      file position after seek done
 	 */
-	public function seekto($pos)
+	public function seekto(int $pos): int
 	{
 		if (!is_resource($this->fr_fd)) {
 			return 0;
@@ -100,7 +100,7 @@ class FileReader
 	 * get current position in file
 	 * @return int current position in bytes
 	 */
-	public function currentpos()
+	public function currentpos(): int
 	{
 		return $this->fr_pos;
 	}
@@ -109,7 +109,7 @@ class FileReader
 	 * file length/size
 	 * @return int file size in bytes
 	 */
-	public function length()
+	public function length(): int
 	{
 		return $this->fr_length;
 	}
diff --git a/www/lib/CoreLibs/Language/Core/GetTextReader.php b/www/lib/CoreLibs/Language/Core/GetTextReader.php
index 550a1125..f15576e4 100644
--- a/www/lib/CoreLibs/Language/Core/GetTextReader.php
+++ b/www/lib/CoreLibs/Language/Core/GetTextReader.php
@@ -67,17 +67,15 @@ class GetTextReader
 	/** @var array<mixed> */
 	private $cache_translations = [];  // original -> translation mapping
 
-
 	/* Methods */
 
-
 	/**
 	* Reads a 32bit Integer from the Stream
 	*
 	* @access private
 	* @return int Integer from the Stream
 	*/
-	private function readint()
+	private function readint(): int
 	{
 		if ($this->BYTEORDER == 0) {
 			// low endian
@@ -91,10 +89,11 @@ class GetTextReader
 
 	/**
 	 * read bytes
+	 *
 	 * @param  int    $bytes byte length to read
 	 * @return string        return data, possible string
 	 */
-	public function read($bytes)
+	public function read(int $bytes): string
 	{
 		return $this->STREAM->read($bytes);
 	}
@@ -105,7 +104,7 @@ class GetTextReader
 	* @param  int   $count How many elements should be read
 	* @return array<mixed> Array of Integers
 	*/
-	public function readintarray($count)
+	public function readintarray(int $count): array
 	{
 		if ($this->BYTEORDER == 0) {
 			// low endian
@@ -120,9 +119,10 @@ class GetTextReader
 	* Constructor
 	*
 	* @param FileReader|bool $Reader       the StreamReader object
-	* @param bool            $enable_cache Enable or disable caching of strings (default on)
+	* @param bool            $enable_cache Enable or disable caching
+	*                                      of strings (default on)
 	*/
-	public function __construct($Reader, $enable_cache = true)
+	public function __construct($Reader, bool $enable_cache = true)
 	{
 		// If there isn't a StreamReader, turn on short circuit mode.
 		if ((!is_object($Reader) && !$Reader) || (is_object($Reader) && $Reader->error)) {
@@ -159,6 +159,26 @@ class GetTextReader
 		$this->translations = $this->readint();
 	}
 
+	/**
+	 * Get current short circuit, equals to no translator running
+	 *
+	 * @return bool
+	 */
+	public function getShortCircuit(): bool
+	{
+		return $this->short_circuit;
+	}
+
+	/**
+	 * get the current cache enabled status
+	 *
+	 * @return bool
+	 */
+	public function getEnableCache(): bool
+	{
+		return $this->enable_cache;
+	}
+
 	/**
 	* Loads the translation tables from the MO file into the cache
 	* If caching is enabled, also loads all strings into a cache
@@ -207,7 +227,7 @@ class GetTextReader
 	* @param  int    $num Offset number of original string
 	* @return string      Requested string if found, otherwise ''
 	*/
-	private function getOriginalString($num)
+	private function getOriginalString(int $num): string
 	{
 		$length = $this->table_originals[$num * 2 + 1] ?? 0;
 		$offset = $this->table_originals[$num * 2 + 2] ?? 0;
@@ -226,7 +246,7 @@ class GetTextReader
 	* @param  int    $num Offset number of original string
 	* @return string      Requested string if found, otherwise ''
 	*/
-	private function getTranslationString($num)
+	private function getTranslationString(int $num): string
 	{
 		$length = $this->table_translations[$num * 2 + 1] ?? 0;
 		$offset = $this->table_translations[$num * 2 + 2] ?? 0;
@@ -242,12 +262,12 @@ class GetTextReader
 	* Binary search for string
 	*
 	* @access private
-	* @param  string           $string string to find
-	* @param  int              $start  (internally used in recursive function)
-	* @param  int              $end    (internally used in recursive function)
-	* @return int                      (offset in originals table)
+	* @param  string $string string to find
+	* @param  int    $start  (internally used in recursive function)
+	* @param  int    $end    (internally used in recursive function)
+	* @return int            (offset in originals table)
 	*/
-	private function findString($string, $start = -1, $end = -1)
+	private function findString(string $string, int $start = -1, int $end = -1): int
 	{
 		if (($start == -1) or ($end == -1)) {
 			// findString is called with only one parameter, set start end end
@@ -289,7 +309,7 @@ class GetTextReader
 	* @param  string $string to be translated
 	* @return string         translated string (or original, if not found)
 	*/
-	public function translate($string)
+	public function translate(string $string): string
 	{
 		if ($this->short_circuit) {
 			return $string;
@@ -298,7 +318,10 @@ class GetTextReader
 
 		if ($this->enable_cache) {
 			// Caching enabled, get translated string from cache
-			if (is_array($this->cache_translations) && array_key_exists($string, $this->cache_translations)) {
+			if (
+				is_array($this->cache_translations) &&
+				array_key_exists($string, $this->cache_translations)
+			) {
 				return $this->cache_translations[$string];
 			} else {
 				return $string;
@@ -321,7 +344,7 @@ class GetTextReader
 	* @param  string $expr an expression to match
 	* @return string       sanitized plural form expression
 	*/
-	private function sanitizePluralExpression($expr)
+	private function sanitizePluralExpression(string $expr): string
 	{
 		// Get rid of disallowed characters.
 		$expr = preg_replace('@[^a-zA-Z0-9_:;\(\)\?\|\&=!<>+*/\%-]@', '', $expr);
@@ -358,7 +381,7 @@ class GetTextReader
 	* @param  string $header header search in plurals
 	* @return string         verbatim plural form header field
 	*/
-	private function extractPluralFormsHeaderFromPoHeader($header)
+	private function extractPluralFormsHeaderFromPoHeader(string $header): string
 	{
 		if (preg_match("/(^|\n)plural-forms: ([^\n]*)\n/i", $header, $regs)) {
 			$expr = $regs[2];
@@ -374,14 +397,14 @@ class GetTextReader
 	* @access private
 	* @return string plural form header
 	*/
-	private function getPluralForms()
+	private function getPluralForms(): string
 	{
 		// lets assume message number 0 is header
 		// this is true, right?
 		$this->loadTables();
 
 		// cache header field for plural forms
-		if (! is_string($this->pluralheader)) {
+		if (empty($this->pluralheader) || !is_string($this->pluralheader)) {
 			if ($this->enable_cache) {
 				$header = $this->cache_translations[''];
 			} else {
@@ -397,25 +420,37 @@ class GetTextReader
 	* Detects which plural form to take
 	*
 	* @access private
-	* @param  string $n count
-	* @return int       array index of the right plural form
+	* @param  int $n count
+	* @return int    array index of the right plural form
 	*/
-	private function selectString($n)
+	private function selectString(int $n): int
 	{
 		$string = $this->getPluralForms();
 		$string = str_replace('nplurals', "\$total", $string);
-		$string = str_replace("n", $n, $string);
+		$string = str_replace("n", (string)$n, $string);
 		$string = str_replace('plural', "\$plural", $string);
 
 		$total = 0;
 		$plural = 0;
 
 		eval("$string");
-		/** @phpstan-ignore-next-line */
+		/** @phpstan-ignore-next-line 0 >= 0 is always true*/
 		if ($plural >= $total) {
 			$plural = $total - 1;
 		}
-		return $plural;
+		return (int)$plural;
+	}
+
+	/**
+	 * wrapper for translate() method
+	 *
+	 * @access public
+	 * @param  string $string
+	 * @return string
+	 */
+	public function gettext(string $string): string
+	{
+		return $this->translate($string);
 	}
 
 	/**
@@ -424,10 +459,10 @@ class GetTextReader
 	* @access public
 	* @param  string $single
 	* @param  string $plural
-	* @param  string $number
+	* @param  int    $number
 	* @return string plural form
 	*/
-	public function ngettext($single, $plural, $number)
+	public function ngettext(string $single, string $plural, int $number): string
 	{
 		if ($this->short_circuit) {
 			if ($number != 1) {
@@ -465,11 +500,12 @@ class GetTextReader
 
 	/**
 	 * p get text
+	 *
 	 * @param  string $context [description]
 	 * @param  string $msgid   [description]
 	 * @return string          [description]
 	 */
-	public function pgettext($context, $msgid)
+	public function pgettext(string $context, string $msgid): string
 	{
 		$key = $context . chr(4) . $msgid;
 		$ret = $this->translate($key);
@@ -482,14 +518,19 @@ class GetTextReader
 
 	/**
 	 * np get text
+	 *
 	 * @param  string $context  [description]
 	 * @param  string $singular [description]
 	 * @param  string $plural   [description]
-	 * @param  string $number   [description]
+	 * @param  int    $number   [description]
 	 * @return string           [description]
 	 */
-	public function npgettext($context, $singular, $plural, $number)
-	{
+	public function npgettext(
+		string $context,
+		string $singular,
+		string $plural,
+		int $number
+	): string {
 		$key = $context . chr(4) . $singular;
 		$ret = $this->ngettext($key, $plural, $number);
 		if (strpos($ret, "\004") !== false) {
diff --git a/www/lib/CoreLibs/Language/Core/StreamReader.php b/www/lib/CoreLibs/Language/Core/StreamReader.php
index a02450e6..fdd87f0c 100644
--- a/www/lib/CoreLibs/Language/Core/StreamReader.php
+++ b/www/lib/CoreLibs/Language/Core/StreamReader.php
@@ -41,7 +41,7 @@ class StreamReader
 	 * @param  int $bytes bytes to read
 	 * @return bool       dummy false
 	 */
-	public function read($bytes)
+	public function read(int $bytes): bool
 	{
 		return false;
 	}
@@ -51,7 +51,7 @@ class StreamReader
 	 * @param  int $position seek to position
 	 * @return bool          dummy false
 	 */
-	public function seekto($position)
+	public function seekto(int $position): bool
 	{
 		return false;
 	}
@@ -60,7 +60,7 @@ class StreamReader
 	 * returns current position
 	 * @return bool dummy false
 	 */
-	public function currentpos()
+	public function currentpos(): bool
 	{
 		return false;
 	}
@@ -69,7 +69,7 @@ class StreamReader
 	 * returns length of entire stream (limit for seekto()s)
 	 * @return bool dummy false
 	 */
-	public function length()
+	public function length(): bool
 	{
 		return false;
 	}
diff --git a/www/lib/CoreLibs/Language/Core/StringReader.php b/www/lib/CoreLibs/Language/Core/StringReader.php
index 4bf0a7d3..243795ea 100644
--- a/www/lib/CoreLibs/Language/Core/StringReader.php
+++ b/www/lib/CoreLibs/Language/Core/StringReader.php
@@ -35,7 +35,7 @@ class StringReader
 	 * constructor for string reader
 	 * @param string $str basic string
 	 */
-	public function __construct($str = '')
+	public function __construct(string $str = '')
 	{
 		$this->sr_str = $str;
 		$this->sr_pos = 0;
@@ -46,7 +46,7 @@ class StringReader
 	 * @param  int $bytes bytes to read in string
 	 * @return string     data read in length of bytes as string
 	 */
-	public function read($bytes)
+	public function read(int $bytes): string
 	{
 		$data = substr($this->sr_str, $this->sr_pos, $bytes);
 		$this->sr_pos += $bytes;
@@ -62,7 +62,7 @@ class StringReader
 	 * @param  int $pos position in string
 	 * @return int      new position in string after seek
 	 */
-	public function seekto($pos)
+	public function seekto(int $pos): int
 	{
 		$this->sr_pos = $pos;
 		if (strlen($this->sr_str) < $this->sr_pos) {
@@ -75,7 +75,7 @@ class StringReader
 	 * get current position in string
 	 * @return int position in string
 	 */
-	public function currentpos()
+	public function currentpos(): int
 	{
 		return $this->sr_pos;
 	}
@@ -84,7 +84,7 @@ class StringReader
 	 * get length of string
 	 * @return int return length of assigned string
 	 */
-	public function length()
+	public function length(): int
 	{
 		return strlen($this->sr_str);
 	}
diff --git a/www/lib/CoreLibs/Language/L10n.php b/www/lib/CoreLibs/Language/L10n.php
index 81667a27..6b37ab86 100644
--- a/www/lib/CoreLibs/Language/L10n.php
+++ b/www/lib/CoreLibs/Language/L10n.php
@@ -40,104 +40,530 @@ use CoreLibs\Language\Core\GetTextReader;
 
 class L10n
 {
-	/** @var string */
-	private $lang = '';
-	/** @var string */
+	/** @var string the current locale */
+	private $locale = '';
+	/** @var string the default selected/active domain */
+	private $domain = '';
+	/** @var array<string,array<string,GetTextReader>> locale > domain = translator */
+	private $domains = [];
+	/** @var array<string,string> bound paths for domains */
+	private $paths = ['' => './'];
+	/** @var string the full path to the mo file to loaded */
 	private $mofile = '';
-	/** @var FileReader|bool */
-	private $input;
-	/** @var GetTextReader */
+	/** @var string base path to search level */
+	private $base_locale_path = '';
+	/** @var string dynamic set path to where the mo file is actually */
+	private $base_content_path = '';
+	/** @var bool if load of mo file was unsuccessful */
+	private $load_failure = false;
+
+	/** @var FileReader|bool reader class for file reading, false for short circuit */
+	private $input = false;
+	/** @var GetTextReader reader class for MO data */
 	private $l10n;
+	/**
+	 * @static
+	 * @var L10n self class
+	 */
+	private static $instance;
 
 	/**
 	 * class constructor call for language getstring
-	 * @param string $lang language name (optional), fallback is en
-	 * @param string $path path, if empty fallback on default internal path
+	 * if locale is not empty will load translation
+	 * else getTranslator needs to be called
+	 *
+	 * @param string $locale language name, default empty string
+	 *                       will return self instance
+	 * @param string $path   path, if empty fallback on default internal path
+	 * @param string $domain override CONTENT_PATH . $encoding name for mo file
+	 * @param bool   $legacy default true, if set to true, will look in the old
+	 *                       folder format lang/ CONTENT_PATH / $lang . mo
 	 */
-	public function __construct(string $lang = '', string $path = '')
-	{
-		if (!$lang) {
-			$this->lang = 'en';
-		} else {
-			$this->lang = $lang;
+	public function __construct(
+		string $locale = '',
+		string $path = '',
+		string $domain = '',
+		bool $legacy = true
+	) {
+		// load the mo file if locale is not empty
+		if (!empty($locale)) {
+			$this->getTranslator($locale, $path, $domain, $legacy);
 		}
-
-		// override path check
-		if (!is_dir($path)) {
-			$path = BASE . INCLUDES . LANG . CONTENT_PATH;
-		}
-
-		$this->mofile = $path . $this->lang . ".mo";
-
-		// check if get a readable mofile
-		if (is_readable($this->mofile)) {
-			$this->input = new FileReader($this->mofile);
-		} else {
-			$this->input = false;
-		}
-		$this->l10n = new GetTextReader($this->input);
 	}
 
 	/**
-	 * reloads the mofile, if the location of the lang file changes
-	 * @param  string $lang language to reload data
-	 * @param  string $path optional path, if not set fallback on internal
-	 * @return bool         successfull reload true/false
+	 * Returns the singleton L10n object.
+	 * For function wrapper use
+	 *
+	 * @return L10n object
 	 */
-	public function l10nReloadMOfile(string $lang, string $path = ''): bool
+	public static function getInstance(): L10n
 	{
-		$success = false;
-		$old_mofile = $this->mofile;
-		$old_lang = $this->lang;
-
-		$this->lang = $lang;
-
-		// override path check
-		if (!is_dir($path)) {
-			$path = BASE . INCLUDES . LANG . CONTENT_PATH;
+		/** @phpstan-ignore-next-line */
+		if (empty(self::$instance)) {
+			self::$instance = new self();
 		}
+		return self::$instance;
+	}
 
-		$this->mofile = $path . $this->lang . ".mo";
+	/**
+	 * Loads global localization functions.
+	 * prefixed with double underscore
+	 * eg: gettext -> __gettext
+	 */
+	public static function loadFunctions(): void
+	{
+		require_once __DIR__ . '/l10n_functions.php';
+	}
+
+	/**
+	 * legacy loader name for getTranslator
+	 * instead of returning the GetTextReader object it returns
+	 * true or false for successful load.
+	 * NOTE: some time down the road this will be deprecated
+	 *
+	 * @param string $locale
+	 * @param string $path
+	 * @param string $domain
+	 * @param bool   $legacy
+	 * @return bool          Returns true for successfull load, false for error
+	 */
+	public function l10nReloadMOfile(
+		string $locale,
+		string $path = '',
+		string $domain = '',
+		bool $legacy = true
+	): bool {
+		$this->getTranslator($locale, $path, $domain, $legacy);
+		return $this->load_failure ? false : true;
+	}
+
+	/**
+	 * loads the mo file base on path, locale and domain set
+	 *
+	 * @param string $locale language name (optional), fallback is en
+	 * @param string $path   path, if empty fallback on default internal path
+	 * @param string $domain override CONTENT_PATH . $encoding name for mo file
+	 * @param bool   $legacy default true, if set to true, will look in the old
+	 *                       folder format lang/ CONTENT_PATH / $lang . mo
+	 * @return GetTextReader the main gettext reader object
+	 */
+	public function getTranslator(
+		string $locale = '',
+		string $path = '',
+		string $domain = '',
+		bool $legacy = false
+	): GetTextReader {
+		// set local if not from parameter
+		if (empty($locale)) {
+			$locale = $this->locale;
+		}
+		// set domain if not given
+		if (empty($domain)) {
+			$domain = $this->domain;
+		}
+		// store old settings
+		$old_mofile = $this->mofile;
+		$old_lang = $this->locale;
+		$old_domain = $this->domain;
+		$old_base_locale_path = $this->base_locale_path;
+		$old_base_content_path = $this->base_content_path;
+
+		// legacy or new type
+		// legacy will use the old lang/content/file.mo type as default
+		// if path is not set, also locale is the file name
+		// for new type it follows the gettext spec and path is just the
+		// base folder where the mo files will be searched
+		if ($legacy === true) {
+			if (!is_dir($path)) {
+				$this->base_locale_path = BASE . INCLUDES . LANG;
+				$this->base_content_path = CONTENT_PATH;
+				$path = $this->base_locale_path . $this->base_content_path;
+			}
+			$this->mofile = $path . $locale . ".mo";
+		} else {
+			// if new path is a dir
+			// 1) from a previous set domain
+			// 2) from method option as is
+			// 3) fallback if BASE/INCLUDES/LOCALE set
+			// 4) current dir
+			if (!empty($this->paths[$domain]) && is_dir($this->paths[$domain])) {
+				$this->base_locale_path = $this->paths[$domain];
+			} elseif (is_dir($path)) {
+				$this->base_locale_path = $path;
+			} elseif (
+				defined('BASE') && defined('INCLUDES') && defined('LOCALE')
+			) {
+				// set fallback base path if constant set
+				$this->base_locale_path = BASE . INCLUDES . LOCALE;
+			} else {
+				$this->base_locale_path = './';
+			}
+			// now we loop over lang compositions to get the base path
+			// then we check
+			$locales = $this->listLocales($locale);
+			foreach ($locales as $_locale) {
+				$this->base_content_path = $_locale . DIRECTORY_SEPARATOR
+					. 'LC_MESSAGES' . DIRECTORY_SEPARATOR;
+				$this->mofile = $this->base_locale_path
+					. $this->base_content_path
+					. $domain . '.mo';
+				if (file_exists($this->mofile)) {
+					break;
+				}
+			}
+		}
 
 		// check if get a readable mofile
 		if (is_readable($this->mofile)) {
+			// locale and domain current wanted
+			$this->locale = $locale;
+			$this->domain = $domain;
+			// set empty domains path with current locale
+			if (empty($this->domains[$locale])) {
+				$this->domains[$locale] = [];
+			}
+			// store current base path (without locale, etc)
+			if (empty($this->paths[$domain])) {
+				$this->paths[$domain] = $this->base_locale_path;
+			}
+			// file reader and mo reader
 			$this->input = new FileReader($this->mofile);
 			$this->l10n = new GetTextReader($this->input);
-			// we successfully loaded
-			$success = true;
-		} else {
+			// if short circuit is true, we failed to have a translator loaded
+			$this->load_failure = $this->l10n->getShortCircuit();
+			// below is not used at the moment, but can be to avoid reloading
+			$this->domains[$this->locale][$domain] = $this->l10n;
+		} elseif (!empty($old_mofile)) {
+			// mo file not readable
+			$this->load_failure = true;
 			// else fall back to the old ones
 			$this->mofile = $old_mofile;
-			$this->lang = $old_lang;
+			$this->locale = $old_lang;
+			$this->domain = $old_domain;
+			$this->base_locale_path = $old_base_locale_path;
+			$this->base_content_path = $old_base_content_path;
+		} else {
+			// mo file not readable, no previous mo file set, set short circuit
+			$this->load_failure = true;
+			// dummy
+			$this->l10n = new GetTextReader($this->input);
 		}
-		return $success;
+		return $this->l10n;
 	}
 
-		/**
+	/**
+	 * return current set GetTextReader or return the one for given
+	 * domain name if set
+	 * This can be used to access all the public methods from the
+	 * GetTextReader
+	 *
+	 * @param  string        $domain optional domain name
+	 * @return GetTextReader
+	 */
+	public function getTranslatorClass(string $domain = ''): GetTextReader
+	{
+		if (!empty($domain) && !empty($this->domains[$this->locale][$domain])) {
+			return $this->domains[$this->locale][$domain];
+		}
+		// if null return short circuit version
+		if ($this->l10n === null) {
+			return new GetTextReader($this->input);
+		}
+		return $this->l10n;
+	}
+
+	/**
+	 * original:
+	 * vendor/phpmyadmin/motranslator/src/Loader.php
+	 *
+	 * Returns array with all possible locale combinations based on the
+	 * given locale name
+	 *
+	 * I.e. for sr_CS.UTF-8@latin, look through all of
+	 * sr_CS.UTF-8@latin, sr_CS@latin, sr@latin, sr_CS.UTF-8, sr_CS, sr.
+	 *
+	 * @param  string $locale Locale string
+	 * @return array<string>  List of locale path parts that can be possible
+	 */
+	public static function listLocales(string $locale): array
+	{
+		$locale_list = [];
+
+		if (empty($locale)) {
+			return $locale_list;
+		}
+		// is matching regex
+		if (
+			!preg_match(
+				// language code
+				'/^(?P<lang>[a-z]{2,3})'
+				// country code
+				. '(?:_(?P<country>[A-Z]{2}))?'
+				// charset
+				. '(?:\\.(?P<charset>[-A-Za-z0-9_]+))?'
+				// @ modifier
+				. '(?:@(?P<modifier>[-A-Za-z0-9_]+))?$/',
+				$locale,
+				$matches
+			)
+		) {
+			// not matching, return as is
+			return [$locale];
+		}
+		// do matching run
+		$lang = $matches['lang'] ?? null;
+		$country = $matches['country'] ?? null;
+		$charset = $matches['charset'] ?? null;
+		$modifier = $matches['modifier'] ?? null;
+		// we need to add all possible cominations from not null set
+		// entries to the list, from longest to shortest
+		// %s_%s.%s@%s　(lang _ country . encoding @ suffix)
+		// %s_%s@%s　(lang _ country @ suffix)
+		// %s@%s　(lang @ suffix)
+		// %s_%s.%s　(lang _ country . encoding)
+		// %s_%s (lang _ country)
+		// %s (lang)
+
+		// if lang is set
+		if ($lang) {
+			// modifier group
+			if ($modifier) {
+				if ($country) {
+					if ($charset) {
+						array_push(
+							$locale_list,
+							sprintf('%s_%s.%s@%s', $lang, $country, $charset, $modifier)
+						);
+					}
+
+					array_push(
+						$locale_list,
+						sprintf('%s_%s@%s', $lang, $country, $modifier)
+					);
+				} elseif ($charset) {
+					array_push(
+						$locale_list,
+						sprintf('%s.%s@%s', $lang, $charset, $modifier)
+					);
+				}
+
+				array_push(
+					$locale_list,
+					sprintf('%s@%s', $lang, $modifier)
+				);
+			}
+			// country group
+			if ($country) {
+				if ($charset) {
+					array_push(
+						$locale_list,
+						sprintf('%s_%s.%s', $lang, $country, $charset)
+					);
+				}
+
+				array_push(
+					$locale_list,
+					sprintf('%s_%s', $lang, $country)
+				);
+			} elseif ($charset) {
+				array_push(
+					$locale_list,
+					sprintf('%s.%s', $lang, $charset)
+				);
+			}
+			// lang only
+			array_push($locale_list, $lang);
+		}
+
+		// If the locale name doesn't match POSIX style, just include it as-is.
+		if (!in_array($locale, $locale_list)) {
+			array_push($locale_list, $locale);
+		}
+
+		return $locale_list;
+	}
+
+	/**
+	 * tries to detect the locale set in the following order:
+	 * - globals: LOCALE
+	 * - globals: LANG
+	 * - env: LC_ALL
+	 * - env: LC_MESSAGES
+	 * - env: LANG
+	 * if nothing set, returns 'en' as default
+	 *
+	 * @return string
+	 */
+	public static function detectLocale(): string
+	{
+		// globals
+		foreach (['LOCALE', 'LANG'] as $global) {
+			if (!empty($GLOBALS[$global])) {
+				return $GLOBALS[$global];
+			}
+		}
+		// enviroment
+		foreach (['LC_ALL', 'LC_MESSAGES', 'LANG'] as $env) {
+			$locale = getenv($env);
+			if ($locale !== false && !empty($locale)) {
+				return $locale;
+			}
+		}
+		return 'en';
+	}
+
+	/************
+	 * INTERNAL VAR SET/GET
+	 */
+
+	/**
+	 * Sets the path for a domain.
+	 * must be set before running l10nReloadMOfile
+	 *
+	 * @param string $domain Domain name
+	 * @param string $path   Path where to find locales
+	 */
+	public function setTextDomain(string $domain, string $path): void
+	{
+		$this->paths[$domain] = $path;
+	}
+
+	/**
+	 * return set path for given domain
+	 * if not found return false
+	 *
+	 * @param  string $domain
+	 * @return string|bool
+	 */
+	public function getTextDomain(string $domain)
+	{
+		return $this->paths[$domain] ?? false;
+	}
+
+	/**
+	 * sets the default domain.
+	 *
+	 * @param string $domain Domain name
+	 */
+	public function setDomain(string $domain): void
+	{
+		$this->domain = $domain;
+	}
+
+	/**
+	 * return current set domain name
+	 *
+	 * @return string
+	 */
+	public function getDomain(): string
+	{
+		return $this->domain;
+	}
+
+	/**
+	 * sets a requested locale.
+	 *
+	 * @param string $locale Locale name
+	 * @return string Set or current locale
+	 */
+	public function setLocale(string $locale): string
+	{
+		if (!empty($locale)) {
+			$this->locale = $locale;
+		}
+		return $this->locale;
+	}
+
+	/**
+	 * get current set locale
+	 *
+	 * @return string
+	 */
+	public function getLocale(): string
+	{
+		return $this->locale;
+	}
+
+	/**
 	 * get current set language
+	 *
 	 * @return string current set language string
+	 * @deprecated Use getLocale()
 	 */
 	public function __getLang(): string
 	{
-		return $this->lang;
+		return $this->getLocale();
 	}
 
 	/**
 	 * get current set mo file
+	 *
 	 * @return string current set mo language file
 	 */
-	public function __getMoFile(): string
+	public function getMoFile(): string
 	{
 		return $this->mofile;
 	}
 
+	/**
+	 * get current set mo file
+	 *
+	 * @return string current set mo language file
+	 * @deprecated  Use getMoFile()
+	 */
+	public function __getMoFile(): string
+	{
+		return $this->getMoFile();
+	}
+
+	/**
+	 * get the current base path in which we search
+	 *
+	 * @return string
+	 */
+	public function getBaseLocalePath(): string
+	{
+		return $this->base_locale_path;
+	}
+
+	/**
+	 * the path below the base path to where the mo file is located
+	 *
+	 * @return string
+	 */
+	public function getBaseContentPath(): string
+	{
+		return $this->base_content_path;
+	}
+
+	/**
+	 * get the current load error status
+	 * if true then the mo file failed to load
+	 *
+	 * @return bool
+	 */
+	public function getLoadError(): bool
+	{
+		return $this->load_failure;
+	}
+
+	/************
+	 * TRANSLATION METHODS
+	 */
+
 	/**
 	 * translates a string and returns translated text
+	 *
 	 * @param  string $text text to translate
 	 * @return string       translated text
 	 */
 	public function __(string $text): string
 	{
+		// fallback passthrough
+		if ($this->l10n === null) {
+			return $text;
+		}
 		return $this->l10n->translate($text);
 	}
 
@@ -145,32 +571,75 @@ class L10n
 	 * prints translated string out to the screen
 	 * @param  string $text text to translate
 	 * @return void         has no return
+	 * @deprecated use echo __() instead
 	 */
 	public function __e(string $text): void
 	{
+		// fallback passthrough
+		if ($this->l10n === null) {
+			echo $text;
+		}
 		echo $this->l10n->translate($text);
 	}
 
-	// Return the plural form.
 	/**
 	 * Return the plural form.
-	 * @param  string    $single string for single word
-	 * @param  string    $plural string for plural word
-	 * @param  int|float $number number value
-	 * @return string            translated plural string
+	 *
+	 * @param  string  $single string for single word
+	 * @param  string  $plural string for plural word
+	 * @param  int     $number number value
+	 * @return string          translated plural string
 	 */
-	public function __n(string $single, string $plural, $number): string
+	public function __n(string $single, string $plural, int $number): string
 	{
+		// in case nothing got set yet, this is fallback
+		if ($this->l10n === null) {
+			return $number > 1 ? $plural : $single;
+		}
 		return $this->l10n->ngettext($single, $plural, $number);
 	}
 
+	/**
+	 * context translation via msgctxt
+	 *
+	 * @param  string $context context string
+	 * @param  string $text    text to translate
+	 * @return string
+	 */
+	public function __p(string $context, string $text): string
+	{
+		if ($this->l10n === null) {
+			return $text;
+		}
+		return $this->l10n->pgettext($context, $text);
+	}
+
+	/**
+	 * context translation via msgctxt
+	 *
+	 * @param  string $context context string
+	 * @param  string $single  string for single word
+	 * @param  string $plural  string for plural word
+	 * @param  int    $number  number value
+	 * @return string
+	 */
+	public function __pn(string $context, string $single, string $plural, int $number): string
+	{
+		if ($this->l10n === null) {
+			return $number > 1 ? $plural : $single;
+		}
+		return $this->l10n->npgettext($context, $single, $plural, $number);
+	}
+
 	// alias functions to mimic gettext calls
 
 	/**
-	 * Undocumented function
+	 * alias for gettext,
+	 * calls __
 	 *
 	 * @param  string $text
 	 * @return string
+	 * @deprecated Use __()
 	 */
 	public function gettext(string $text): string
 	{
@@ -178,22 +647,24 @@ class L10n
 	}
 
 	/**
-	 * Undocumented function
+	 * alias for ngettext
+	 * calls __n
 	 *
 	 * @param  string    $single
 	 * @param  string    $plural
-	 * @param  int|float $number
+	 * @param  int       $number
 	 * @return string
+	 * @deprecated Use __n()
 	 */
-	public function ngettext(string $single, string $plural, $number): string
+	public function ngettext(string $single, string $plural, int $number): string
 	{
 		return $this->__n($single, $plural, $number);
 	}
 
 	// TODO: dgettext(string $domain, string $message): string
 	// TODO: dngettext(string $domain, string $singular, string $plural, int $count): string
-	// TODO: dcgettext(string $domain, string $message, int $category): string
-	// TODO: dcngettext(string $domain, string $singular, string $plural, int $count, int $category): string
+	// TODO: dpgettext(string $domain, string $message, int $category): string
+	// TODO: dpngettext(string $domain, string $singular, string $plural, int $count, int $category): string
 }
 
 // __END__
diff --git a/www/lib/CoreLibs/Language/l10n_functions.php b/www/lib/CoreLibs/Language/l10n_functions.php
new file mode 100644
index 00000000..93a3188c
--- /dev/null
+++ b/www/lib/CoreLibs/Language/l10n_functions.php
@@ -0,0 +1,208 @@
+<?php
+
+declare(strict_types=1);
+
+use CoreLibs\Language\L10n;
+
+/**
+ * Sets a requested locale.
+ *
+ * @param int    $category Locale category, ignored
+ * @param string $locale   Locale name
+ *
+ * @return string Set or current locale
+ */
+function __setlocale(int $category, string $locale): string
+{
+	return L10n::getInstance()->setLocale($locale);
+}
+
+/**
+ * Sets the path for a domain.
+ *
+ * @param string $domain Domain name
+ * @param string $path   Path where to find locales
+ */
+function __bindtextdomain(string $domain, string $path): void
+{
+	L10n::getInstance()->setTextDomain($domain, $path);
+}
+
+/**
+ * Dummy compatibility function, MoTranslator assumes
+ * everything is using same character set on input and
+ * output.
+ *
+ * Generally it is wise to output in UTF-8 and have
+ * mo files in UTF-8.
+ *
+ * @param string $domain  Domain where to set character set
+ * @param string $codeset Character set to set
+ */
+function __bind_textdomain_codeset(string $domain, string $codeset): void
+{
+}
+
+/**
+ * Sets the default domain.
+ *
+ * @param string $domain Domain name
+ */
+function __textdomain(string $domain): void
+{
+	L10n::getInstance()->setDomain($domain);
+}
+
+/**
+ * Translates a string.
+ *
+ * @param string $msgid String to be translated
+ *
+ * @return string translated string (or original, if not found)
+ */
+function __gettext(string $msgid): string
+{
+	return L10n::getInstance()->getTranslator()->gettext(
+		$msgid
+	);
+}
+
+/**
+ * Translates a string, alias for _gettext.
+ *
+ * @param string $msgid String to be translated
+ *
+ * @return string translated string (or original, if not found)
+ */
+function __(string $msgid): string
+{
+	return L10n::getInstance()->getTranslator()->gettext(
+		$msgid
+	);
+}
+
+/**
+ * Plural version of gettext.
+ *
+ * @param string $msgid       Single form
+ * @param string $msgidPlural Plural form
+ * @param int    $number      Number of objects
+ *
+ * @return string translated plural form
+ */
+function __ngettext(string $msgid, string $msgidPlural, int $number): string
+{
+	return L10n::getInstance()->getTranslator()->ngettext(
+		$msgid,
+		$msgidPlural,
+		$number
+	);
+}
+
+/**
+ * Translate with context.
+ *
+ * @param string $msgctxt Context
+ * @param string $msgid   String to be translated
+ *
+ * @return string translated plural form
+ */
+function __pgettext(string $msgctxt, string $msgid): string
+{
+	return L10n::getInstance()->getTranslator()->pgettext(
+		$msgctxt,
+		$msgid
+	);
+}
+
+/**
+ * Plural version of pgettext.
+ *
+ * @param string $msgctxt     Context
+ * @param string $msgid       Single form
+ * @param string $msgidPlural Plural form
+ * @param int    $number      Number of objects
+ *
+ * @return string translated plural form
+ */
+function __npgettext(string $msgctxt, string $msgid, string $msgidPlural, int $number): string
+{
+	return L10n::getInstance()->getTranslator()->npgettext(
+		$msgctxt,
+		$msgid,
+		$msgidPlural,
+		$number
+	);
+}
+
+/**
+ * Translates a string.
+ *
+ * @param string $domain Domain to use
+ * @param string $msgid  String to be translated
+ *
+ * @return string translated string (or original, if not found)
+ */
+function __dgettext(string $domain, string $msgid): string
+{
+	return L10n::getInstance()->getTranslator('', '', $domain)->gettext(
+		$msgid
+	);
+}
+
+/**
+ * Plural version of gettext.
+ *
+ * @param string $domain      Domain to use
+ * @param string $msgid       Single form
+ * @param string $msgidPlural Plural form
+ * @param int    $number      Number of objects
+ *
+ * @return string translated plural form
+ */
+function __dngettext(string $domain, string $msgid, string $msgidPlural, int $number): string
+{
+	return L10n::getInstance()->getTranslator('', '', $domain)->ngettext(
+		$msgid,
+		$msgidPlural,
+		$number
+	);
+}
+
+/**
+ * Translate with context.
+ *
+ * @param string $domain  Domain to use
+ * @param string $msgctxt Context
+ * @param string $msgid   String to be translated
+ *
+ * @return string translated plural form
+ */
+function __dpgettext(string $domain, string $msgctxt, string $msgid): string
+{
+	return L10n::getInstance()->getTranslator('', '', $domain)->pgettext(
+		$msgctxt,
+		$msgid
+	);
+}
+
+/**
+ * Plural version of pgettext.
+ *
+ * @param string $domain      Domain to use
+ * @param string $msgctxt     Context
+ * @param string $msgid       Single form
+ * @param string $msgidPlural Plural form
+ * @param int    $number      Number of objects
+ *
+ * @return string translated plural form
+ */
+function __dnpgettext(string $domain, string $msgctxt, string $msgid, string $msgidPlural, int $number): string
+{
+	return L10n::getInstance()->getTranslator('', '', $domain)->npgettext(
+		$msgctxt,
+		$msgid,
+		$msgidPlural,
+		$number
+	);
+}