<?php
/** \file include\i18n.php
 *  \brief DI webinterface internationalization functions
 *  \author Rob Schalken, Core|Vision
 *  \version $Revision: 26247 $
 *  \date $Date: 2016-02-29 10:40:22 +0100 (Mon, 29 Feb 2016) $
 *
 * This file contains the internationalization. This to support multiple languages.
 * This file is always included.
 */

/*
 * Definitions
 */
define("DOMAIN"  , "zkl-module-1");
define("LANG_DIR", $_PAGE_INFO['base_path'] . "locale/");
  
/**
 *  Determine prefered language (db or browser)
 *
 *  Return:                 language
 */ 
function i18n_determine_language() {   
  global $_PAGE_INFO; 
  
  // Already logged on?
  if (isset($_SESSION[$_PAGE_INFO['id']]['logged_on'])) {    
    // Retreive user i18n
    $i18n_locale = db_fetch_i18n($_PAGE_INFO['login']['user']['id']);
  }
  else {
    $i18n_locale = i18n_browser_preferred_language(); 
  }

  /*
   * charset
   */
  $_PAGE_INFO['charset'] = db_fetch_system_lang_charset($i18n_locale); 
    
  /*
   * settext
   */
  i18n_settext_language($i18n_locale); 

  return $i18n_locale;
}


/**
 *  Determine browser preffered language
 *
 *  Return:                 preffered language
 */
function i18n_browser_preferred_language() { 
  if (isset($_SERVER['HTTP_ACCEPT_LANGUAGE'])) {
    // Default values
    $locale = "en";
    $q = 0.0;
    $language_no_q = FALSE;
    
    // Parse Accept languages
    $user_languages = preg_split("/,\s*/", $_SERVER['HTTP_ACCEPT_LANGUAGE']);
  
    if (is_array($user_languages)) {
      foreach($user_languages as $language) {
        $lang_code = preg_split("/;|=/", $language);
        $lang_code[0] = substr($lang_code[0], 0, 2);        
        
        // Double index without 'q' (mostly on telephone) => choose first
        if (!$language_no_q) {        
          if (file_exists(LANG_DIR . $lang_code[0]) && ($lang_code[1] != 'q' || $q < $lang_code[2])) {
              $locale = $lang_code[0];
            if( $lang_code[1] != 'q') {
              $q = 1.0;  
              $language_no_q = TRUE;
            }
            else {
                $q = $lang_code[1];
            }
          }
        }
      }
    }
  }
  else {
    $locale = "en";
  }
  
  return $locale;
}


/**
 *  Write language to environment
 */
function i18n_settext_language($i18n, $language_dir = LANG_DIR) { 
  global $_PAGE_INFO;
  
  if (strlen($i18n)) {
    putenv("LANGUAGE=" . $i18n);
    putenv("LANG=" .     $i18n);
    putenv("LC_ALL=" .   $i18n);
    
    // Restore time and numeric, this to prevent javascript/mysql errors
    setlocale(LC_ALL,     $i18n);
    setlocale(LC_TIME,    'C');
    setlocale(LC_NUMERIC, 'C'); 
    
    // Define charset
    header("Content-Type: text/html; charset=" . $_PAGE_INFO['charset']);
  }

  if (strlen($language_dir)) {
    $textdomain = DOMAIN;
    if(
      preg_match("|^.*/release/([^/]+)/.+$|", $language_dir, $release) ||
      preg_match("|^/home/([^/]+)/.*$|", $language_dir, $release)
    ) {
      $textdomain .= "-" . $release[1];
    }
    bindtextdomain($textdomain, $language_dir);   
    textdomain($textdomain);      
  }
}

/**
 *  Double underscore: Interface to 'ngettext()', using 'sprintf()'
 */
function __($msgid1, $msgid2, $n)
{
  $args = func_get_args();
  // delete 'msgid1' and 'msgid2'
  array_splice($args, 0, 2);
  // format the string
  return vsprintf(ngettext($msgid1, $msgid2, $n), $args);
}

/**
 *  Triple underscore: Format a string in the style of Microsoft's String::Format
 *
 *  NB: Using the Microsoft style is somewhat more convenient than 'sprintf'
 *  as PHP does not implement positional parameters.
 */
function ___($fmt)
{
  // Build argument list
  $args = array_slice(func_get_args(), 1);
  
//  if( PHP_VERSION_ID >= 50300 ) {
//    return preg_replace_callback(
//      "/({[0-9]+})/",
//      function($match) use ($args) { return $args[$match[0]]; },
//      _($fmt)
//    );
//  }
//  else {
    return preg_replace(
      "/\{([0-9]+)\}/e",
      '$args[\1]',
      _($fmt)
    );
//  }
}

/**
 *  Read translation from the database table 'vertaling'
 *
 *  Inputs:
 *  - id                    Database id _or_ array of strings (all translations)
 *                          _or_ string to translate via 'gettext()'
 *                          when 'field' is not set (for symmetry with, erm, well
 *                          the function name :-)
 *  - field                 Table and field in the table 'vertaling'
 *  - i18n                  Target language (auto-detect if not set)
 *
 *  Returns:
 *  - Translation from the table 'vertaling' or via 'gettext()' when 'field' is
 *    not set.
 *  - FALSE on error
 */
function i18n_translate($id, $field = NULL, $i18n = NULL)
{
  // Determine language to use if not passed as a parameter
  if( !$i18n ) {
    $i18n = $_SESSION[$_PAGE_INFO['id']]['i18n'];
    if( !$i18n ) $i18n = i18n_browser_preferred_language();
  }

  // default return value to indicate that we cannot translate 'id'
  $str = FALSE;
  
  if( is_array($id) ) {
    // prefetched array with all translations
    // try the specified target language
    if( $i18n ) $str = $id[$i18n];
    
    // search other languages
    if( !$str && function_exists("db_fetch_system_lang") ) {
      // Get all languages, in the user's preference
      $i18n_languages = db_fetch_system_lang();
      
      foreach ($i18n_languages as $i18n => $lang) {
        $str = $id[$i18n];
        
        if( $str ) return $str;
      }
    }
    else if( $str ) return $str;
  }
  else if( !$field ) {
    // database field is not set: simply translate via 'gettext()'
    $str = _($id);
  }
  else if( $i18n && function_exists("db_fetch_item") ) {
    // try the specified target language
    $str = db_fetch_item("SELECT tekst FROM vertaling WHERE id=" . $id . " AND field='" . $field . "' AND i18n='" . $i18n . "'");
  }
    
  // search the database for other languages when not found above
  if( !$str && is_numeric($id) && $field && function_exists("db_fetch_system_lang") && function_exists("db_fetch_item") ) {
    // Get all languages, in the user's preference
    $i18n_languages = db_fetch_system_lang();
      
    foreach ($i18n_languages as $i18n => $lang) {
      $str = db_fetch_item("SELECT tekst FROM vertaling WHERE id=" . $id . " AND field='" . $field . "' AND i18n='" . $i18n . "'");
        
      if( $str ) return $str;
    }
  }

  // return translated string, or FALSE on error
  return $str;
}

?>