<?php defined("SYSPATH") or die("No direct script access.");
/**
 * Gallery - a web based photo album viewer and editor
 * Copyright (C) 2000-2013 Bharat Mediratta
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or (at
 * your option) any later version.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA  02110-1301, USA.
 */

/**
 * Translates a localizable message.
 * @param $message String The message to be translated. E.g. "Hello world"
 * @param $options array (optional) Options array for key value pairs which are used
 *        for pluralization and interpolation. Special key: "locale" to override the
 *        currently configured locale.
 * @return String The translated message string.
 */
function t($message, $options=array()) {
  return Gallery_I18n::instance()->translate($message, $options);
}

/**
 * Translates a localizable message with plural forms.
 * @param $singular String The message to be translated. E.g. "There is one album."
 * @param $plural String The plural message to be translated. E.g.
 *        "There are %count albums."
 * @param $count Number The number which is inserted for the %count placeholder and
 *        which is used to select the proper plural form ($singular or $plural).
 * @param $options array (optional) Options array for key value pairs which are used
 *        for pluralization and interpolation. Special key: "locale" to override the
 *        currently configured locale.
 * @return String The translated message string.
 */
function t2($singular, $plural, $count, $options=array()) {
  return Gallery_I18n::instance()->translate(array("one" => $singular, "other" => $plural),
                                             array_merge($options, array("count" => $count)));
}

class Gallery_I18n_Core {
  private static $_instance;
  private $_config = array();
  private $_call_log = array();
  private $_cache = array();

  private function __construct($config) {
    $this->_config = $config;
    $this->locale($config['default_locale']);
  }

  public static function instance($config=null) {
    if (self::$_instance == NULL || isset($config)) {
      $config = isset($config) ? $config : Kohana::config('locale');
      if (empty($config['default_locale'])) {
        $config['default_locale'] = module::get_var('gallery', 'default_locale');
      }
      self::$_instance = new Gallery_I18n_Core($config);
    }

    return self::$_instance;
  }

  public function locale($locale=null) {
    if ($locale) {
      $this->_config['default_locale'] = $locale;
      $php_locale = setlocale(LC_ALL, 0);
      list ($php_locale, $unused) = explode('.', $php_locale . '.');
      if ($php_locale != $locale) {
        // Attempt to set PHP's locale as well (for number formatting, collation, etc.)
        $locale_prefs = array($locale);
        // Try appending some character set names; some systems (like FreeBSD) need this.
        // Some systems require a format with hyphen (eg. Gentoo) and others without (eg. FreeBSD).
        $charsets = array('utf8', 'UTF-8', 'UTF8', 'ISO8859-1', 'ISO-8859-1');
        if (substr($locale, 0, 2) != 'en') {
          $charsets = array_merge($charsets, array(
              'EUC', 'Big5', 'euc', 'ISO8859-2', 'ISO8859-5', 'ISO8859-7',
              'ISO8859-9', 'ISO-8859-2', 'ISO-8859-5', 'ISO-8859-7', 'ISO-8859-9'));
        }
        foreach ($charsets as $charset) {
          $locale_prefs[] = $locale . '.' . $charset;
        }
        $locale_prefs[] = 'en_US';
        $php_locale = setlocale(LC_ALL, $locale_prefs);
      }
      if (is_string($php_locale) && substr($php_locale, 0, 2) == 'tr') {
        // Make PHP 5 work with Turkish (the localization results are mixed though).
        // Hack for http://bugs.php.net/18556
        setlocale(LC_CTYPE, 'C');
      }
    }
    return $this->_config['default_locale'];
  }

  public function is_rtl($locale=null) {
    $is_rtl = !empty($this->_config["force_rtl"]);
    if (empty($is_rtl)) {
      $locale or $locale = $this->locale();
      list ($language, $territory) = explode('_', $locale . "_");
      $is_rtl = in_array($language, array("he", "fa", "ar"));
    }
    return $is_rtl;
  }

  /**
   * Translates a localizable message.
   *
   * Security:
   * The returned string is safe for use in HTML (it contains a safe subset of HTML and
   * interpolation parameters are converted to HTML entities).
   * For use in JavaScript, please call ->for_js() on it.
   *
   * @param $message String|array The message to be translated. E.g. "Hello world"
   *                 or array("one" => "One album", "other" => "%count albums")
   * @param $options array (optional) Options array for key value pairs which are used
   *        for pluralization and interpolation. Special keys are "count" and "locale",
   *        the latter to override the currently configured locale.
   * @return String The translated message string.
   */
  public function translate($message, $options=array()) {
    $locale = empty($options['locale']) ? $this->_config['default_locale'] : $options['locale'];
    $count = isset($options['count']) ? $options['count'] : null;
    $values = $options;
    unset($values['locale']);
    $this->log($message, $options);

    $entry = $this->lookup($locale, $message);

    if (null === $entry) {
      // Default to the root locale.
      $entry = $message;
      $locale = $this->_config['root_locale'];
    }

    $entry = $this->pluralize($locale, $entry, $count);

    $entry = $this->interpolate($locale, $entry, $values);

    return SafeString::of_safe_html($entry);
  }

  private function lookup($locale, $message) {
    if (!isset($this->_cache[$locale])) {
      $this->_cache[$locale] = self::load_translations($locale);
    }

    $key = self::get_message_key($message);

    if (isset($this->_cache[$locale][$key])) {
      return $this->_cache[$locale][$key];
    } else {
      return null;
    }
  }

  private static function load_translations($locale) {
    $cache_key = "translation|" . $locale;
    $cache = Cache::instance();
    $translations = $cache->get($cache_key);
    if (!isset($translations) || !is_array($translations)) {
      $translations = array();
      foreach (db::build()
               ->select("key", "translation")
               ->from("incoming_translations")
               ->where("locale", "=", $locale)
               ->execute() as $row) {
        $translations[$row->key] = unserialize($row->translation);
      }

      // Override incoming with outgoing...
      foreach (db::build()
               ->select("key", "translation")
               ->from("outgoing_translations")
               ->where("locale", "=", $locale)
               ->execute() as $row) {
        $translations[$row->key] = unserialize($row->translation);
      }

      $cache->set($cache_key, $translations, array("translation"), 0);
    }
    return $translations;
  }

  public function has_translation($message, $options=null) {
    $locale = empty($options['locale']) ? $this->_config['default_locale'] : $options['locale'];

    $entry = $this->lookup($locale, $message);

    if (null === $entry) {
      return false;
    } else if (!is_array($message)) {
      return $entry !== '';
    } else {
      if (!is_array($entry) || empty($entry)) {
        return false;
      }
      // It would be better to verify that all the locale's plural forms have a non-empty
      // translation, but this is fine for now.
      foreach ($entry as $value) {
        if ($value === '') {
          return false;
        }
      }
      return true;
    }
  }

  static function get_message_key($message) {
    $as_string = is_array($message) ? implode('|', $message) : $message;
    return md5($as_string);
  }

  static function is_plural_message($message) {
    return is_array($message);
  }

  private function interpolate($locale, $string, $key_values) {
    // TODO: Handle locale specific number formatting.

    // Replace x_y before replacing x.
    krsort($key_values, SORT_STRING);

    $keys = array();
    $values = array();
    foreach ($key_values as $key => $value) {
      $keys[] = "%$key";
      $values[] = new SafeString($value);
    }
    return str_replace($keys, $values, $string);
  }

  private function pluralize($locale, $entry, $count) {
    if (!is_array($entry)) {
      return $entry;
    }

    $plural_key = self::get_plural_key($locale, $count);
    if (!isset($entry[$plural_key])) {
      // Fallback to the default plural form.
      $plural_key = 'other';
    }

    if (isset($entry[$plural_key])) {
      return $entry[$plural_key];
    } else {
      // Fallback to just any plural form.
      $plural_key = key($entry);
      $string = current($entry);
      return $string;
    }
  }

  private function log($message, $options) {
    $key = self::get_message_key($message);
    isset($this->_call_log[$key]) or $this->_call_log[$key] = array($message, $options);
  }

  public function call_log() {
    return $this->_call_log;
  }

  public static function clear_cache($locale=null) {
    $cache = Cache::instance();
    if ($locale) {
      $cache->delete("translation|" . $locale);
    } else {
      $cache->delete_tag("translation");
    }
  }

  private static function get_plural_key($locale, $count) {
    $parts = explode('_', $locale);
    $language = $parts[0];

    // Data from CLDR 1.6 (http://unicode.org/cldr/data/common/supplemental/plurals.xml).
    // Docs: http://www.unicode.org/cldr/data/charts/supplemental/language_plural_rules.html
    switch ($language) {
      case 'az':
      case 'fa':
      case 'hu':
      case 'ja':
      case 'ko':
      case 'my':
      case 'to':
      case 'tr':
      case 'vi':
      case 'yo':
      case 'zh':
      case 'bo':
      case 'dz':
      case 'id':
      case 'jv':
      case 'ka':
      case 'km':
      case 'kn':
      case 'ms':
      case 'th':
        return 'other';

      case 'ar':
        if ($count == 0) {
          return 'zero';
        } else if ($count == 1) {
          return 'one';
        } else if ($count == 2) {
          return 'two';
        } else if (is_int($count) && ($i = $count % 100) >= 3 && $i <= 10) {
          return 'few';
        } else if (is_int($count) && ($i = $count % 100) >= 11 && $i <= 99) {
          return 'many';
        } else {
          return 'other';
        }

      case 'pt':
      case 'am':
      case 'bh':
      case 'fil':
      case 'tl':
      case 'guw':
      case 'hi':
      case 'ln':
      case 'mg':
      case 'nso':
      case 'ti':
      case 'wa':
        if ($count == 0 || $count == 1) {
          return 'one';
        } else {
          return 'other';
        }

      case 'fr':
        if ($count >= 0 and $count < 2) {
          return 'one';
        } else {
          return 'other';
        }

      case 'lv':
        if ($count == 0) {
          return 'zero';
        } else if ($count % 10 == 1 && $count % 100 != 11) {
          return 'one';
        } else {
          return 'other';
        }

      case 'ga':
      case 'se':
      case 'sma':
      case 'smi':
      case 'smj':
      case 'smn':
      case 'sms':
        if ($count == 1) {
          return 'one';
        } else if ($count == 2) {
          return 'two';
        } else {
          return 'other';
        }

      case 'ro':
      case 'mo':
        if ($count == 1) {
          return 'one';
        } else if (is_int($count) && $count == 0 && ($i = $count % 100) >= 1 && $i <= 19) {
          return 'few';
        } else {
          return 'other';
        }

      case 'lt':
        if (is_int($count) && $count % 10 == 1 && $count % 100 != 11) {
          return 'one';
        } else if (is_int($count) && ($i = $count % 10) >= 2 && $i <= 9 && ($i = $count % 100) < 11 && $i > 19) {
          return 'few';
        } else {
          return 'other';
        }

      case 'hr':
      case 'ru':
      case 'sr':
      case 'uk':
      case 'be':
      case 'bs':
      case 'sh':
        if (is_int($count) && $count % 10 == 1 && $count % 100 != 11) {
          return 'one';
        } else if (is_int($count) && ($i = $count % 10) >= 2 && $i <= 4 && ($i = $count % 100) < 12 && $i > 14) {
          return 'few';
        } else if (is_int($count) && ($count % 10 == 0 || (($i = $count % 10) >= 5 && $i <= 9) || (($i = $count % 100) >= 11 && $i <= 14))) {
          return 'many';
        } else {
          return 'other';
        }

      case 'cs':
      case 'sk':
        if ($count == 1) {
          return 'one';
        } else if (is_int($count) && $count >= 2 && $count <= 4) {
          return 'few';
        } else {
          return 'other';
        }

      case 'pl':
        if ($count == 1) {
          return 'one';
        } else if (is_int($count) && ($i = $count % 10) >= 2 && $i <= 4 &&
                   ($i = $count % 100) < 12 && $i > 14 && ($i = $count % 100) < 22 && $i > 24) {
          return 'few';
        } else {
          return 'other';
        }

      case 'sl':
        if ($count % 100 == 1) {
          return 'one';
        } else if ($count % 100 == 2) {
          return 'two';
        } else if (is_int($count) && ($i = $count % 100) >= 3 && $i <= 4) {
          return 'few';
        } else {
          return 'other';
        }

      case 'mt':
        if ($count == 1) {
          return 'one';
        } else if ($count == 0 || is_int($count) && ($i = $count % 100) >= 2 && $i <= 10) {
          return 'few';
        } else if (is_int($count) && ($i = $count % 100) >= 11 && $i <= 19) {
          return 'many';
        } else {
          return 'other';
        }

      case 'mk':
        if ($count % 10 == 1) {
          return 'one';
        } else {
          return 'other';
        }

      case 'cy':
        if ($count == 1) {
          return 'one';
        } else if ($count == 2) {
          return 'two';
        } else if ($count == 8 || $count == 11) {
          return 'many';
        } else {
          return 'other';
        }

      default: // en, de, etc.
        return $count == 1 ? 'one' : 'other';
    }
  }
}
