<?php

namespace cyclone;
/**
 * 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    cyclone
 * @category   Base
 * @author     Kohana Team
 * @copyright  (c) 2008-2009 Kohana Team
 * @license    http://kohanaphp.com/license
 */
class 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. Example: @code
     *
     *     $hello = I18n::get('Hello :name !', array(
     *          ':name' => 'World'
     *     )); @endcode
     *
     * <p>Hint: in most cases it is more convenient to use the __() alias function
     * of this method, which is defined in the <code>init.php</code> of the library.</p>
     *
     * @param string $string  text to translate
     * @param array $values key-value pairs to be replaced in the translated text
     * @param string $lang can be used to specify the target language. If it is
     *  null then the method will fall back to <code>I18n::$lang</code>
     * @return string the transtaled text with the parameters replaced
     */
    public static function get($string, $values = array(), $lang = NULL) {
        if (NULL === $lang) {
            $lang = static::$lang;
        }

        if (!isset(I18n::$_cache[$lang])) {
            // Load the translation table
            I18n::load($lang);
        }

        $string = isset(I18n::$_cache[$lang][$string]) ? I18n::$_cache[$lang][$string] : $string;

        $rval = strtr($string, $values);

        // Return the translated string if it exists
        return $rval;
    }

    /**
     * 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);

            $table += FileSystem::get_default()->list_files("i18n/$path.php", TRUE);
            // Remove the last part
            array_pop($parts);
        } while ($parts);

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

} // End I18n