6 files changed, 1017 insertions, 0 deletions
diff --git a/phpBB/phpbb/language/exception/invalid_plural_rule_exception.php b/phpBB/phpbb/language/exception/invalid_plural_rule_exception.php
new file mode 100644
index 0000000000..94e3466208
--- /dev/null
+++ b/phpBB/phpbb/language/exception/invalid_plural_rule_exception.php
@@ -0,0 +1,22 @@
+<?php
+/**
+ *
+ * This file is part of the phpBB Forum Software package.
+ *
+ * @copyright (c) phpBB Limited <https://www.phpbb.com>
+ * @license GNU General Public License, version 2 (GPL-2.0)
+ *
+ * For full copyright and license information, please see
+ * the docs/CREDITS.txt file.
+ *
+ */
+
+namespace phpbb\language\exception;
+
+/**
+ * Thrown when nonexistent plural rule is specified
+ */
+class invalid_plural_rule_exception extends language_exception
+{
+
+}
diff --git a/phpBB/phpbb/language/exception/language_exception.php b/phpBB/phpbb/language/exception/language_exception.php
new file mode 100644
index 0000000000..b1258414aa
--- /dev/null
+++ b/phpBB/phpbb/language/exception/language_exception.php
@@ -0,0 +1,22 @@
+<?php
+/**
+ *
+ * This file is part of the phpBB Forum Software package.
+ *
+ * @copyright (c) phpBB Limited <https://www.phpbb.com>
+ * @license GNU General Public License, version 2 (GPL-2.0)
+ *
+ * For full copyright and license information, please see
+ * the docs/CREDITS.txt file.
+ *
+ */
+
+namespace phpbb\language\exception;
+
+/**
+ * Base exception class for language exceptions
+ */
+class language_exception extends \phpbb\exception\runtime_exception
+{
+
+}
diff --git a/phpBB/phpbb/language/exception/language_file_not_found.php b/phpBB/phpbb/language/exception/language_file_not_found.php
new file mode 100644
index 0000000000..89364267eb
--- /dev/null
+++ b/phpBB/phpbb/language/exception/language_file_not_found.php
@@ -0,0 +1,22 @@
+<?php
+/**
+ *
+ * This file is part of the phpBB Forum Software package.
+ *
+ * @copyright (c) phpBB Limited <https://www.phpbb.com>
+ * @license GNU General Public License, version 2 (GPL-2.0)
+ *
+ * For full copyright and license information, please see
+ * the docs/CREDITS.txt file.
+ *
+ */
+
+namespace phpbb\language\exception;
+
+/**
+ * This exception is thrown when the language file is not found
+ */
+class language_file_not_found extends language_exception
+{
+
+}
diff --git a/phpBB/phpbb/language/language.php b/phpBB/phpbb/language/language.php
new file mode 100644
index 0000000000..51e6d0b185
--- /dev/null
+++ b/phpBB/phpbb/language/language.php
@@ -0,0 +1,673 @@
+<?php
+/**
+ *
+ * This file is part of the phpBB Forum Software package.
+ *
+ * @copyright (c) phpBB Limited <https://www.phpbb.com>
+ * @license GNU General Public License, version 2 (GPL-2.0)
+ *
+ * For full copyright and license information, please see
+ * the docs/CREDITS.txt file.
+ *
+ */
+
+namespace phpbb\language;
+
+use phpbb\language\exception\invalid_plural_rule_exception;
+
+/**
+ * Wrapper class for loading translations
+ */
+class language
+{
+	/**
+	 * Global fallback language
+	 *
+	 * ISO code of the language to fallback to when the specified language entries
+	 * cannot be found.
+	 *
+	 * @var string
+	 */
+	const FALLBACK_LANGUAGE = 'en';
+
+	/**
+	 * @var array	List of common language files
+	 */
+	protected $common_language_files;
+
+	/**
+	 * @var bool
+	 */
+	protected $common_language_files_loaded;
+
+	/**
+	 * @var string	ISO code of the default board language
+	 */
+	protected $default_language;
+
+	/**
+	 * @var string	ISO code of the User's language
+	 */
+	protected $user_language;
+
+	/**
+	 * @var array	Language fallback array (the order is important)
+	 */
+	protected $language_fallback;
+
+	/**
+	 * @var array	Array of language variables
+	 */
+	protected $lang;
+
+	/**
+	 * @var array	Loaded language sets
+	 */
+	protected $loaded_language_sets;
+
+	/**
+	 * @var \phpbb\language\language_file_loader Language file loader
+	 */
+	protected $loader;
+
+	/**
+	 * Constructor
+	 *
+	 * @param \phpbb\language\language_file_loader	$loader			Language file loader
+	 * @param array|null							$common_modules	Array of common language modules to load (optional)
+	 */
+	public function __construct(language_file_loader $loader, $common_modules = null)
+	{
+		$this->loader = $loader;
+
+		// Set up default information
+		$this->user_language		= false;
+		$this->default_language		= false;
+		$this->lang					= array();
+		$this->loaded_language_sets	= array(
+			'core'	=> array(),
+			'ext'	=> array(),
+		);
+
+		// Common language files
+		if (is_array($common_modules))
+		{
+			$this->common_language_files = $common_modules;
+		}
+		else
+		{
+			$this->common_language_files = array(
+				'common',
+			);
+		}
+
+		$this->common_language_files_loaded = false;
+
+		$this->language_fallback = array(self::FALLBACK_LANGUAGE);
+	}
+
+	/**
+	 * Function to set user's language to display.
+	 *
+	 * @param string	$user_lang_iso		ISO code of the User's language
+	 * @param bool		$reload				Whether or not to reload language files
+	 */
+	public function set_user_language($user_lang_iso, $reload = false)
+	{
+		$this->user_language = $user_lang_iso;
+
+		$this->set_fallback_array($reload);
+	}
+
+	/**
+	 * Function to set the board's default language to display.
+	 *
+	 * @param string	$default_lang_iso	ISO code of the board's default language
+	 * @param bool		$reload				Whether or not to reload language files
+	 */
+	public function set_default_language($default_lang_iso, $reload = false)
+	{
+		$this->default_language = $default_lang_iso;
+
+		$this->set_fallback_array($reload);
+	}
+
+	/**
+	 * Returns language array
+	 *
+	 * Note: This function is needed for the BC purposes, until \phpbb\user::lang[] is
+	 *       not removed.
+	 *
+	 * @return array	Array of loaded language strings
+	 */
+	public function get_lang_array()
+	{
+		// Load common language files if they not loaded yet
+		if (!$this->common_language_files_loaded)
+		{
+			$this->load_common_language_files();
+		}
+
+		return $this->lang;
+	}
+
+	/**
+	 * Add Language Items
+	 *
+	 * Examples:
+	 * <code>
+	 * $component = array('posting');
+	 * $component = array('posting', 'viewtopic')
+	 * $component = 'posting'
+	 * </code>
+	 *
+	 * @param string|array	$component		The name of the language component to load
+	 * @param string|null	$extension_name	Name of the extension to load component from, or null for core file
+	 */
+	public function add_lang($component, $extension_name = null)
+	{
+		// Load common language files if they not loaded yet
+		// This needs to be here to correctly merge language arrays
+		if (!$this->common_language_files_loaded)
+		{
+			$this->load_common_language_files();
+		}
+
+		if (!is_array($component))
+		{
+			if (!is_null($extension_name))
+			{
+				$this->load_extension($extension_name, $component);
+			}
+			else
+			{
+				$this->load_core_file($component);
+			}
+		}
+		else
+		{
+			foreach ($component as $lang_file)
+			{
+				$this->add_lang($lang_file, $extension_name);
+			}
+		}
+	}
+
+	/**
+	 * @param $key array|string		The language key we want to know more about. Can be string or array.
+	 *
+	 * @return bool		Returns whether the language key is set.
+	 */
+	public function is_set($key)
+	{
+		// Load common language files if they not loaded yet
+		if (!$this->common_language_files_loaded)
+		{
+			$this->load_common_language_files();
+		}
+
+		if (is_array($key))
+		{
+			$lang = &$this->lang[array_shift($key)];
+
+			foreach ($key as $_key)
+			{
+				$lang = &$lang[$_key];
+			}
+		}
+		else
+		{
+			$lang = &$this->lang[$key];
+		}
+
+		return isset($lang);
+	}
+
+	/**
+	 * Advanced language substitution
+	 *
+	 * Function to mimic sprintf() with the possibility of using phpBB's language system to substitute nullar/singular/plural forms.
+	 * Params are the language key and the parameters to be substituted.
+	 * This function/functionality is inspired by SHS` and Ashe.
+	 *
+	 * Example call: <samp>$user->lang('NUM_POSTS_IN_QUEUE', 1);</samp>
+	 *
+	 * If the first parameter is an array, the elements are used as keys and subkeys to get the language entry:
+	 * Example: <samp>$user->lang(array('datetime', 'AGO'), 1)</samp> uses $user->lang['datetime']['AGO'] as language entry.
+	 *
+	 * @return string	Return localized string or the language key if the translation is not available
+	 */
+	public function lang()
+	{
+		$args = func_get_args();
+		$key = array_shift($args);
+
+		return $this->lang_array($key, $args);
+	}
+
+	/**
+	 * Returns the raw value associated to a language key or the language key no translation is available.
+	 * No parameter substitution is performed, can be a string or an array.
+	 *
+	 * @param string|array	$key	Language key
+	 *
+	 * @return array|string
+	 */
+	public function lang_raw($key)
+	{
+		// Load common language files if they not loaded yet
+		if (!$this->common_language_files_loaded)
+		{
+			$this->load_common_language_files();
+		}
+
+		if (is_array($key))
+		{
+			$lang = &$this->lang[array_shift($key)];
+
+			foreach ($key as $_key)
+			{
+				$lang = &$lang[$_key];
+			}
+		}
+		else
+		{
+			$lang = &$this->lang[$key];
+		}
+
+		// Return if language string does not exist
+		if (!isset($lang) || (!is_string($lang) && !is_array($lang)))
+		{
+			return $key;
+		}
+
+		return $lang;
+	}
+
+	/**
+	 * Act like lang() but takes a key and an array of parameters instead of using variadic
+	 *
+	 * @param string|array	$key	Language key
+	 * @param array			$args	Parameters
+	 *
+	 * @return string
+	 */
+	public function lang_array($key, $args = array())
+	{
+		$lang = $this->lang_raw($key);
+
+		if ($lang === $key)
+		{
+			return $key;
+		}
+
+		// If the language entry is a string, we simply mimic sprintf() behaviour
+		if (is_string($lang))
+		{
+			if (count($args) === 0)
+			{
+				return $lang;
+			}
+
+			// Replace key with language entry and simply pass along...
+			return vsprintf($lang, $args);
+		}
+		else if (count($lang) == 0)
+		{
+			// If the language entry is an empty array, we just return the language key
+			return $key;
+		}
+
+		// It is an array... now handle different nullar/singular/plural forms
+		$key_found = false;
+
+		// We now get the first number passed and will select the key based upon this number
+		for ($i = 0, $num_args = count($args); $i < $num_args; $i++)
+		{
+			if (is_int($args[$i]) || is_float($args[$i]))
+			{
+				if ($args[$i] == 0 && isset($lang[0]))
+				{
+					// We allow each translation using plural forms to specify a version for the case of 0 things,
+					// so that "0 users" may be displayed as "No users".
+					$key_found = 0;
+					break;
+				}
+				else
+				{
+					$use_plural_form = $this->get_plural_form($args[$i]);
+					if (isset($lang[$use_plural_form]))
+					{
+						// The key we should use exists, so we use it.
+						$key_found = $use_plural_form;
+					}
+					else
+					{
+						// If the key we need to use does not exist, we fall back to the previous one.
+						$numbers = array_keys($lang);
+
+						foreach ($numbers as $num)
+						{
+							if ($num > $use_plural_form)
+							{
+								break;
+							}
+
+							$key_found = $num;
+						}
+					}
+					break;
+				}
+			}
+		}
+
+		// Ok, let's check if the key was found, else use the last entry (because it is mostly the plural form)
+		if ($key_found === false)
+		{
+			$numbers = array_keys($lang);
+			$key_found = end($numbers);
+		}
+
+		// Use the language string we determined and pass it to sprintf()
+		return vsprintf($lang[$key_found], $args);
+	}
+
+	/**
+	 * Loads common language files
+	 */
+	protected function load_common_language_files()
+	{
+		if (!$this->common_language_files_loaded)
+		{
+			foreach ($this->common_language_files as $lang_file)
+			{
+				$this->load_core_file($lang_file);
+			}
+
+			$this->common_language_files_loaded = true;
+		}
+	}
+
+	/**
+	 * Determine which plural form we should use.
+	 *
+	 * For some languages this is not as simple as for English.
+	 *
+	 * @param int|float		$number		The number we want to get the plural case for. Float numbers are floored.
+	 * @param int|bool		$force_rule	False to use the plural rule of the language package
+	 *									or an integer to force a certain plural rule
+	 *
+	 * @return int	The plural-case we need to use for the number plural-rule combination
+	 *
+	 * @throws \phpbb\language\exception\invalid_plural_rule_exception	When $force_rule has an invalid value
+	 */
+	public function get_plural_form($number, $force_rule = false)
+	{
+		$number			= (int) $number;
+		$plural_rule	= ($force_rule !== false) ? $force_rule : ((isset($this->lang['PLURAL_RULE'])) ? $this->lang['PLURAL_RULE'] : 1);
+
+		if ($plural_rule > 15 || $plural_rule < 0)
+		{
+			throw new invalid_plural_rule_exception('INVALID_PLURAL_RULE', array(
+				'plural_rule' => $plural_rule,
+			));
+		}
+
+		/**
+		 * The following plural rules are based on a list published by the Mozilla Developer Network
+		 * https://developer.mozilla.org/en/Localization_and_Plurals
+		 */
+		switch ($plural_rule)
+		{
+			case 0:
+				/**
+				 * Families: Asian (Chinese, Japanese, Korean, Vietnamese), Persian, Turkic/Altaic (Turkish), Thai, Lao
+				 * 1 - everything: 0, 1, 2, ...
+				 */
+				return 1;
+
+			case 1:
+				/**
+				 * Families: Germanic (Danish, Dutch, English, Faroese, Frisian, German, Norwegian, Swedish), Finno-Ugric (Estonian, Finnish, Hungarian), Language isolate (Basque), Latin/Greek (Greek), Semitic (Hebrew), Romanic (Italian, Portuguese, Spanish, Catalan)
+				 * 1 - 1
+				 * 2 - everything else: 0, 2, 3, ...
+				 */
+				return ($number === 1) ? 1 : 2;
+
+			case 2:
+				/**
+				 * Families: Romanic (French, Brazilian Portuguese)
+				 * 1 - 0, 1
+				 * 2 - everything else: 2, 3, ...
+				 */
+				return (($number === 0) || ($number === 1)) ? 1 : 2;
+
+			case 3:
+				/**
+				 * Families: Baltic (Latvian)
+				 * 1 - 0
+				 * 2 - ends in 1, not 11: 1, 21, ... 101, 121, ...
+				 * 3 - everything else: 2, 3, ... 10, 11, 12, ... 20, 22, ...
+				 */
+				return ($number === 0) ? 1 : ((($number % 10 === 1) && ($number % 100 != 11)) ? 2 : 3);
+
+			case 4:
+				/**
+				 * Families: Celtic (Scottish Gaelic)
+				 * 1 - is 1 or 11: 1, 11
+				 * 2 - is 2 or 12: 2, 12
+				 * 3 - others between 3 and 19: 3, 4, ... 10, 13, ... 18, 19
+				 * 4 - everything else: 0, 20, 21, ...
+				 */
+				return ($number === 1 || $number === 11) ? 1 : (($number === 2 || $number === 12) ? 2 : (($number >= 3 && $number <= 19) ? 3 : 4));
+
+			case 5:
+				/**
+				 * Families: Romanic (Romanian)
+				 * 1 - 1
+				 * 2 - is 0 or ends in 01-19: 0, 2, 3, ... 19, 101, 102, ... 119, 201, ...
+				 * 3 - everything else: 20, 21, ...
+				 */
+				return ($number === 1) ? 1 : ((($number === 0) || (($number % 100 > 0) && ($number % 100 < 20))) ? 2 : 3);
+
+			case 6:
+				/**
+				 * Families: Baltic (Lithuanian)
+				 * 1 - ends in 1, not 11: 1, 21, 31, ... 101, 121, ...
+				 * 2 - ends in 0 or ends in 10-20: 0, 10, 11, 12, ... 19, 20, 30, 40, ...
+				 * 3 - everything else: 2, 3, ... 8, 9, 22, 23, ... 29, 32, 33, ...
+				 */
+				return (($number % 10 === 1) && ($number % 100 != 11)) ? 1 : ((($number % 10 < 2) || (($number % 100 >= 10) && ($number % 100 < 20))) ? 2 : 3);
+
+			case 7:
+				/**
+				 * Families: Slavic (Croatian, Serbian, Russian, Ukrainian)
+				 * 1 - ends in 1, not 11: 1, 21, 31, ... 101, 121, ...
+				 * 2 - ends in 2-4, not 12-14: 2, 3, 4, 22, 23, 24, 32, ...
+				 * 3 - everything else: 0, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 25, 26, ...
+				 */
+				return (($number % 10 === 1) && ($number % 100 != 11)) ? 1 : ((($number % 10 >= 2) && ($number % 10 <= 4) && (($number % 100 < 10) || ($number % 100 >= 20))) ? 2 : 3);
+
+			case 8:
+				/**
+				 * Families: Slavic (Slovak, Czech)
+				 * 1 - 1
+				 * 2 - 2, 3, 4
+				 * 3 - everything else: 0, 5, 6, 7, ...
+				 */
+				return ($number === 1) ? 1 : ((($number >= 2) && ($number <= 4)) ? 2 : 3);
+
+			case 9:
+				/**
+				 * Families: Slavic (Polish)
+				 * 1 - 1
+				 * 2 - ends in 2-4, not 12-14: 2, 3, 4, 22, 23, 24, 32, ... 104, 122, ...
+				 * 3 - everything else: 0, 5, 6, ... 11, 12, 13, 14, 15, ... 20, 21, 25, ...
+				 */
+				return ($number === 1) ? 1 : ((($number % 10 >= 2) && ($number % 10 <= 4) && (($number % 100 < 12) || ($number % 100 > 14))) ? 2 : 3);
+
+			case 10:
+				/**
+				 * Families: Slavic (Slovenian, Sorbian)
+				 * 1 - ends in 01: 1, 101, 201, ...
+				 * 2 - ends in 02: 2, 102, 202, ...
+				 * 3 - ends in 03-04: 3, 4, 103, 104, 203, 204, ...
+				 * 4 - everything else: 0, 5, 6, 7, 8, 9, 10, 11, ...
+				 */
+				return ($number % 100 === 1) ? 1 : (($number % 100 === 2) ? 2 : ((($number % 100 === 3) || ($number % 100 === 4)) ? 3 : 4));
+
+			case 11:
+				/**
+				 * Families: Celtic (Irish Gaeilge)
+				 * 1 - 1
+				 * 2 - 2
+				 * 3 - is 3-6: 3, 4, 5, 6
+				 * 4 - is 7-10: 7, 8, 9, 10
+				 * 5 - everything else: 0, 11, 12, ...
+				 */
+				return ($number === 1) ? 1 : (($number === 2) ? 2 : (($number >= 3 && $number <= 6) ? 3 : (($number >= 7 && $number <= 10) ? 4 : 5)));
+
+			case 12:
+				/**
+				 * Families: Semitic (Arabic)
+				 * 1 - 1
+				 * 2 - 2
+				 * 3 - ends in 03-10: 3, 4, ... 10, 103, 104, ... 110, 203, 204, ...
+				 * 4 - ends in 11-99: 11, ... 99, 111, 112, ...
+				 * 5 - everything else: 100, 101, 102, 200, 201, 202, ...
+				 * 6 - 0
+				 */
+				return ($number === 1) ? 1 : (($number === 2) ? 2 : ((($number % 100 >= 3) && ($number % 100 <= 10)) ? 3 : ((($number % 100 >= 11) && ($number % 100 <= 99)) ? 4 : (($number != 0) ? 5 : 6))));
+
+			case 13:
+				/**
+				 * Families: Semitic (Maltese)
+				 * 1 - 1
+				 * 2 - is 0 or ends in 01-10: 0, 2, 3, ... 9, 10, 101, 102, ...
+				 * 3 - ends in 11-19: 11, 12, ... 18, 19, 111, 112, ...
+				 * 4 - everything else: 20, 21, ...
+				 */
+				return ($number === 1) ? 1 : ((($number === 0) || (($number % 100 > 1) && ($number % 100 < 11))) ? 2 : ((($number % 100 > 10) && ($number % 100 < 20)) ? 3 : 4));
+
+			case 14:
+				/**
+				 * Families: Slavic (Macedonian)
+				 * 1 - ends in 1: 1, 11, 21, ...
+				 * 2 - ends in 2: 2, 12, 22, ...
+				 * 3 - everything else: 0, 3, 4, ... 10, 13, 14, ... 20, 23, ...
+				 */
+				return ($number % 10 === 1) ? 1 : (($number % 10 === 2) ? 2 : 3);
+
+			case 15:
+				/**
+				 * Families: Icelandic
+				 * 1 - ends in 1, not 11: 1, 21, 31, ... 101, 121, 131, ...
+				 * 2 - everything else: 0, 2, 3, ... 10, 11, 12, ... 20, 22, ...
+				 */
+				return (($number % 10 === 1) && ($number % 100 != 11)) ? 1 : 2;
+		}
+	}
+
+	/**
+	 * Returns the ISO code of the used language
+	 *
+	 * @return string	The ISO code of the currently used language
+	 */
+	public function get_used_language()
+	{
+		return $this->language_fallback[0];
+	}
+
+	/**
+	 * Returns language fallback data
+	 *
+	 * @param bool	$reload	Whether or not to reload language files
+	 *
+	 * @return array
+	 */
+	protected function set_fallback_array($reload = false)
+	{
+		$fallback_array = array();
+
+		if ($this->user_language)
+		{
+			$fallback_array[] = $this->user_language;
+		}
+
+		if ($this->default_language)
+		{
+			$fallback_array[] = $this->default_language;
+		}
+
+		$fallback_array[] = self::FALLBACK_LANGUAGE;
+
+		$this->language_fallback = $fallback_array;
+
+		if ($reload)
+		{
+			$this->reload_language_files();
+		}
+	}
+
+	/**
+	 * Load core language file
+	 *
+	 * @param string	$component	Name of the component to load
+	 */
+	protected function load_core_file($component)
+	{
+		// Check if the component is already loaded
+		if (isset($this->loaded_language_sets['core'][$component]))
+		{
+			return;
+		}
+
+		$this->loader->load($component, $this->language_fallback, $this->lang);
+		$this->loaded_language_sets['core'][$component] = true;
+	}
+
+	/**
+	 * Load extension language file
+	 *
+	 * @param string	$extension_name	Name of the extension to load language from
+	 * @param string	$component		Name of the component to load
+	 */
+	protected function load_extension($extension_name, $component)
+	{
+		// Check if the component is already loaded
+		if (isset($this->loaded_language_sets['ext'][$extension_name][$component]))
+		{
+			return;
+		}
+
+		$this->loader->load_extension($extension_name, $component, $this->language_fallback, $this->lang);
+		$this->loaded_language_sets['ext'][$extension_name][$component] = true;
+	}
+
+	/**
+	 * Reload language files
+	 */
+	protected function reload_language_files()
+	{
+		$loaded_files = $this->loaded_language_sets;
+		$this->loaded_language_sets	= array(
+			'core'	=> array(),
+			'ext'	=> array(),
+		);
+
+		// Reload core files
+		foreach ($loaded_files['core'] as $component => $value)
+		{
+			$this->load_core_file($component);
+		}
+
+		// Reload extension files
+		foreach ($loaded_files['ext'] as $ext_name => $ext_info)
+		{
+			foreach ($ext_info as $ext_component => $value)
+			{
+				$this->load_extension($ext_name, $ext_component);
+			}
+		}
+	}
+}
diff --git a/phpBB/phpbb/language/language_file_helper.php b/phpBB/phpbb/language/language_file_helper.php
new file mode 100644
index 0000000000..85de034fb8
--- /dev/null
+++ b/phpBB/phpbb/language/language_file_helper.php
@@ -0,0 +1,72 @@
+<?php
+/**
+ *
+ * This file is part of the phpBB Forum Software package.
+ *
+ * @copyright (c) phpBB Limited <https://www.phpbb.com>
+ * @license GNU General Public License, version 2 (GPL-2.0)
+ *
+ * For full copyright and license information, please see
+ * the docs/CREDITS.txt file.
+ *
+ */
+
+namespace phpbb\language;
+
+use Symfony\Component\Finder\Finder;
+
+/**
+ * Helper class for language file related functions
+ */
+class language_file_helper
+{
+	/**
+	 * @var string	Path to phpBB's root
+	 */
+	protected $phpbb_root_path;
+
+	/**
+	 * Constructor
+	 *
+	 * @param string	$phpbb_root_path	Path to phpBB's root
+	 */
+	public function __construct($phpbb_root_path)
+	{
+		$this->phpbb_root_path = $phpbb_root_path;
+	}
+
+	/**
+	 * Returns available languages
+	 *
+	 * @return array
+	 */
+	public function get_available_languages()
+	{
+		// Find available language packages
+		$finder = new Finder();
+		$finder->files()
+			->name('iso.txt')
+			->depth('== 1')
+			->followLinks()
+			->in($this->phpbb_root_path . 'language');
+
+		$available_languages = array();
+		foreach ($finder as $file)
+		{
+			$path = $file->getRelativePath();
+			$info = explode("\n", $file->getContents());
+
+			$available_languages[] = array(
+				// Get the name of the directory containing iso.txt
+				'iso' => $path,
+
+				// Recover data from file
+				'name' => trim($info[0]),
+				'local_name' => trim($info[1]),
+				'author' => trim($info[2])
+			);
+		}
+
+		return $available_languages;
+	}
+}
diff --git a/phpBB/phpbb/language/language_file_loader.php b/phpBB/phpbb/language/language_file_loader.php
new file mode 100644
index 0000000000..b6816afd16
--- /dev/null
+++ b/phpBB/phpbb/language/language_file_loader.php
@@ -0,0 +1,206 @@
+<?php
+/**
+ *
+ * This file is part of the phpBB Forum Software package.
+ *
+ * @copyright (c) phpBB Limited <https://www.phpbb.com>
+ * @license GNU General Public License, version 2 (GPL-2.0)
+ *
+ * For full copyright and license information, please see
+ * the docs/CREDITS.txt file.
+ *
+ */
+
+namespace phpbb\language;
+
+use \phpbb\language\exception\language_file_not_found;
+
+/**
+ * Language file loader
+ */
+class language_file_loader
+{
+	/**
+	 * @var string	Path to phpBB's root
+	 */
+	protected $phpbb_root_path;
+
+	/**
+	 * @var string	Extension of PHP files
+	 */
+	protected $php_ext;
+
+	/**
+	 * @var \phpbb\extension\manager	Extension manager
+	 */
+	protected $extension_manager;
+
+	/**
+	 * Constructor
+	 *
+	 * @param string	$phpbb_root_path	Path to phpBB's root
+	 * @param string	$php_ext			Extension of PHP files
+	 */
+	public function __construct($phpbb_root_path, $php_ext)
+	{
+		$this->phpbb_root_path	= $phpbb_root_path;
+		$this->php_ext			= $php_ext;
+
+		$this->extension_manager = null;
+	}
+
+	/**
+	 * Extension manager setter
+	 *
+	 * @param \phpbb\extension\manager	$extension_manager	Extension manager
+	 */
+	public function set_extension_manager(\phpbb\extension\manager $extension_manager)
+	{
+		$this->extension_manager = $extension_manager;
+	}
+
+	/**
+	 * Loads language array for the given component
+	 *
+	 * @param string		$component	Name of the language component
+	 * @param string|array	$locale		ISO code of the language to load, or array of ISO codes if you want to
+	 * 									specify additional language fallback steps
+	 * @param array			$lang		Array reference containing language strings
+	 */
+	public function load($component, $locale, &$lang)
+	{
+		$locale = (array) $locale;
+
+		// Determine path to language directory
+		$path = $this->phpbb_root_path . 'language/';
+
+		$this->load_file($path, $component, $locale, $lang);
+	}
+
+	/**
+	 * Loads language array for the given extension component
+	 *
+	 * @param string		$extension	Name of the extension
+	 * @param string		$component	Name of the language component
+	 * @param string|array	$locale		ISO code of the language to load, or array of ISO codes if you want to
+	 * 									specify additional language fallback steps
+	 * @param array			$lang		Array reference containing language strings
+	 */
+	public function load_extension($extension, $component, $locale, &$lang)
+	{
+		// Check if extension manager was loaded
+		if ($this->extension_manager === null)
+		{
+			// If not, let's return
+			return;
+		}
+
+		$locale = (array) $locale;
+
+		// Determine path to language directory
+		$path = $this->extension_manager->get_extension_path($extension, true) . 'language/';
+
+		$this->load_file($path, $component, $locale, $lang);
+	}
+
+	/**
+	 * Prepares language file loading
+	 *
+	 * @param string	$path		Path to search for file in
+	 * @param string	$component	Name of the language component
+	 * @param array		$locale		Array containing language fallback options
+	 * @param array		$lang		Array reference of language strings
+	 */
+	protected function load_file($path, $component, $locale, &$lang)
+	{
+		// This is BC stuff and not the best idea as it makes language fallback
+		// implementation quite hard like below.
+		if (strpos($this->phpbb_root_path . $component, $path) === 0)
+		{
+			// Filter out the path
+			$path_diff = str_replace($path, '', dirname($this->phpbb_root_path . $component));
+			$language_file = basename($component, '.' . $this->php_ext);
+			$component = '';
+
+			// This step is needed to resolve language/en/subdir style $component
+			// $path already points to the language base directory so we need to eliminate
+			// the first directory from the path (that should be the language directory)
+			$path_diff_parts = explode('/', $path_diff);
+
+			if (count($path_diff_parts) > 1)
+			{
+				array_shift($path_diff_parts);
+				$component = implode('/', $path_diff_parts) . '/';
+			}
+
+			$component .= $language_file;
+		}
+
+		// Determine filename
+		$filename = $component . '.' . $this->php_ext;
+
+		// Determine path to file
+		$file_path = $this->get_language_file_path($path, $filename, $locale);
+
+		// Load language array
+		$this->load_language_file($file_path, $lang);
+	}
+
+	/**
+	 * This function implements language fallback logic
+	 *
+	 * @param string	$path		Path to language directory
+	 * @param string	$filename	Filename to load language strings from
+	 *
+	 * @return string	Relative path to language file
+	 *
+	 * @throws language_file_not_found	When the path to the file cannot be resolved
+	 */
+	protected function get_language_file_path($path, $filename, $locales)
+	{
+		$language_file_path = $filename;
+
+		// Language fallback logic
+		foreach ($locales as $locale)
+		{
+			$language_file_path = $path . $locale . '/' . $filename;
+
+			// If we are in install, try to use the updated version, when available
+			if (defined('IN_INSTALL'))
+			{
+				$install_language_path = str_replace('language/', 'install/update/new/language/', $language_file_path);
+				if (file_exists($install_language_path))
+				{
+					return $install_language_path;
+				}
+			}
+
+			if (file_exists($language_file_path))
+			{
+				return $language_file_path;
+			}
+		}
+
+		// The language file is not exist
+		throw new language_file_not_found('Language file ' . $language_file_path . ' couldn\'t be opened.');
+	}
+
+	/**
+	 * Loads language file
+	 *
+	 * @param string	$path	Path to language file to load
+	 * @param array		$lang	Reference of the array of language strings
+	 */
+	protected function load_language_file($path, &$lang)
+	{
+		// Do not suppress error if in DEBUG mode
+		if (defined('DEBUG'))
+		{
+			include $path;
+		}
+		else
+		{
+			@include $path;
+		}
+	}
+}