<?php defined('SYSPATH') or die('No direct script access.');
/**
 * Internationalization (i18n) class. Provides language loading and translation
 * methods without dependancies on [gettext](http://php.net/gettext).
 *
 * Typically this class would never be used directly, but used via the __()
 * function, which loads the message and replaces parameters:
 *
 *     // Display a translated message
 *     echo __('Hello, world');
 *
 *     // With parameter replacement
 *     echo __('Hello, :user', array(':user' => $username));
 *
 * [!!] The __() function is declared in `SYSPATH/base.php`.
 *
 * @package    Kohana
 * @category   Base
 * @author     Kohana Team
 * @copyright  (c) 2008-2009 Kohana Team
 * @license    http://kohanaphp.com/license
 */
class Kohana_I18n {

	/**
	 * @var  string   target language: en-us, es-es, zh-cn, etc
	 */
	public static $lang = 'en-us';

	// Cache of loaded languages
	protected static $_cache = array();

	/**
	 * Get and set the target language.
	 *
	 *     // Get the current language
	 *     $lang = I18n::lang();
	 *
	 *     // Change the current language to Spanish
	 *     I18n::lang('es-es');
	 *
	 * @param   string   new language setting
	 * @return  string
	 * @since   3.0.2
	 */
	public static function lang($lang = NULL)
	{
		if ($lang)
		{
			// Normalize the language
			I18n::$lang = strtolower(str_replace(array(' ', '_'), '-', $lang));
		}

		return I18n::$lang;
	}

	/**
	 * Returns translation of a string. If no translation exists, the original
	 * string will be returned. No parameters are replaced.
	 *
	 *     $hello = I18n::get('Hello friends, my name is :name');
	 *
	 * @param   string   text to translate
	 * @return  string
	 */
	public static function get($string)
	{
		if ( ! isset(I18n::$_cache[I18n::$lang]))
		{
			// Load the translation table
			I18n::load(I18n::$lang);
		}

		// Return the translated string if it exists
		return isset(I18n::$_cache[I18n::$lang][$string]) ? I18n::$_cache[I18n::$lang][$string] : $string;
	}

	/**
	 * Returns the translation table for a given language.
	 *
	 *     // Get all defined Spanish messages
	 *     $messages = I18n::load('es-es');
	 *
	 * @param   string   language to load
	 * @return  array
	 */
	public static function load($lang)
	{
		if (isset(I18n::$_cache[$lang]))
		{
			return I18n::$_cache[$lang];
		}

		// New translation table
		$table = array();

		// Split the language: language, region, locale, etc
		$parts = explode('-', $lang);

		do
		{
			// Create a path for this set of parts
			$path = implode(DIRECTORY_SEPARATOR, $parts);

			if ($files = Kohana::find_file('i18n', $path, NULL, TRUE))
			{
				$t = array();
				foreach ($files as $file)
				{
					// Merge the language strings into the sub table
					$t = array_merge($t, Kohana::load($file));
				}

				// Append the sub table, preventing less specific language
				// files from overloading more specific files
				$table += $t;
			}

			// Remove the last part
			array_pop($parts);
		}
		while ($parts);

		// Cache the translation table locally
		return I18n::$_cache[$lang] = $table;
	}

	final private function __construct()
	{
		// This is a static class
	}

} // End I18n