<?php
/** DomFramework
  * @package domframework
  * @author Dominique Fournier <dominique@fournier38.fr>
  */

/** Language class : change the messages */
class language
{
  // Language.php

  // Use Gettext, so the locales must be available in the system
  // Check the output of the command 'locale -a' :
  // en_GB.utf8
  // en_US.utf8
  // [...]
  // fr_FR.utf8
  // The directories must be of this format but with a UTF8 in capital !
  // Example : ./locale/en_US.UTF8/LC_MESSAGES/programme.mo
  // The only available codeset is UTF8
  // The languages are always in the format fr_FR (without the codeset)


  /** Language cache directory */
  public $cacheDir = "data/locale";

  /** Choose the best language in the browser list and which is available in
    * locale path
    * @param string|null $repLocale Directory where are stored the translations
    * @param string|null $languageCode The coding langugage of the soft
    * @return string The choosed locale whithout charset (like fr_FR)
    */
  function languageSelection ($repLocale = "./locale", $languageCode = "fr_FR")
  {
    $arrAccept = array ();
    if (isset ($_SERVER["HTTP_ACCEPT_LANGUAGE"]))
    {
      // Analyse de HTTP_ACCEPT_LANGUAGE
      // HTTP_ACCEPT_LANGUAGE est de la forme : fr,en;q=0.7,en-us;q=0.3
      // Recuperation de la liste des languages souhaitees
      $arrAccept = explode(",", strtolower ($_SERVER["HTTP_ACCEPT_LANGUAGE"]));
      // Pre-traitement des choix de l'utilisateur
      foreach ($arrAccept as $key=>$value)
      {
        // Suppression des poids (l'ordre est donne dans la pile)
        if ( ($pos = strpos ($value, ";")) !== FALSE)
        {
          $arrAccept[$key] = substr ($value,0,$pos);
        }

        // Si la language proposee est du style en-us, convertit en en-US
        if ( ($pos = strpos ($value, "-")) !== FALSE)
        {
          $arrAccept[$key] = substr ($arrAccept[$key], 0, $pos).
                           strtoupper (substr ($arrAccept[$key], $pos));
        }

        // Remplacement des tirets par des soulignes
        $arrAccept[$key] = str_replace ("-", "_", $arrAccept[$key]);
      }
    }
    if (isset ($_SERVER["LC_MESSAGES"]))
    {
      // La ligne ci-dessous permet de récupérer la language sans le codeset si
      // il est fourni en_US.UTF8 -> en_US
      @list ($languageCodetmp, $codeset) = explode (".",
                                                    $_SERVER["LC_MESSAGES"]);
      $arrAccept[] = $languageCodetmp;
    }
    if (isset ($_SERVER["LANG"]))
    {
      // La ligne ci-dessous permet de récupérer la language sans le codeset si
      // il est fourni en_US.UTF8 -> en_US
      @list ($languageCodetmp, $codeset) = explode (".", $_SERVER["LANG"]);
      $arrAccept[] = $languageCodetmp;
    }

    // Si l'utilisateur n'a defini aucune language, on met la language par
    // defaut
    if (empty ($arrAccept))
      $arrAccept[] = $languageCode;
    // Le tableau $arrAccept est trié par priorité de language souhaité par
    // l'utilisateur (0=>le plus important)

    // Recherche des languages disponibles dans le repertoire $repLocale
    $arrLanguageAvailable = $this->languageTraductionsList ($repLocale);
    $arrLanguageAvailable[] = $languageCode;

    $languageCode = "";
    // Analyse pour donner la meilleure language possible
    foreach ($arrAccept as $value)
    {
      // Regarde si un repertoire existe avec la language proposee.
      // Recherche insensible à la casse, retourne le nom du fichier avec la
      // casse
      $val2 = strtolower ($value);
      foreach ($arrLanguageAvailable as $val)
      {
        $val3 = strtolower ($val);
        if ($val2 === $val3)
        {
          $languageCode = $val;
          break;
        }
      }

      // Regarde si un repertoire existe avec language en tant que base
      // (l'utilisateur demande fr et on a fr_FR.utf-8)
      foreach ($arrLanguageAvailable as $languageCodeAvailable)
      {
        if ($value === substr ($languageCodeAvailable, 0, strlen ($value)))
        {
          $languageCode = $languageCodeAvailable;
          break;
        }
      }

      // On a trouvé : on arrête de chercher
      if ($languageCode !== "")
        break;
    }

    // Si on n'a toujours pas trouve de language, c'est que la language par
    // defaut proposee en tete de fichier est inconnue : on met la language "C"
    // et le code s'affiche selon la programmation
    if ($languageCode === "")
      $languageCode = "C";

    return ($languageCode);
  }

  /** Return the language recorded in the Cookie. Check if this language is
    * @param string $cookieName The cookie name
    * @param string|null $repLocale The directory use to store the locale files
    * allowed
    * @return string The language allowed or FALSE
    */
  function languageCookie ($cookieName, $repLocale = "./locale")
  {
    if (!isset ($_COOKIE[$cookieName]))
      return FALSE;
    $listeTranslations = $this->languageTraductionsList ($repLocale);
    if ($listeTranslations === FALSE)
      return FALSE;
    if (in_array ($_COOKIE[$cookieName], $listeTranslations))
      return $_COOKIE[$cookieName];
    return FALSE;
  }

  /** Set the cookie with a TTL of one month
    * @param string $cookieName The name of the cookie
    * @param string $languageCode Language to store
    * @param string $sitepath The site path
    */
  function languageCookieSet ($cookieName, $languageCode, $sitepath)
  {
    @setcookie ($cookieName, $languageCode,  time()+60*60*24*30, $sitepath);
  }

  /** Return an array with all the languages available in the $repLocale dir
    * The languages are in the format 'en_US' without the codeset.
    * @param string|null $repLocale The directory use to store the locale files
    * Return FALSE if there is an error
    */
  function languageTraductionsList ($repLocale = "./locale")
  {
    if (! is_dir ($repLocale) || ! is_readable ($repLocale))
      return FALSE;
    $list = glob ("$repLocale/*");
    foreach ($list as $key=>$val)
    {
      $val = basename ($val);
      $pos = strpos ($val, ".");
      if ($pos === FALSE)
        $list[$key] = $val;
      else
        $list[$key] = substr ($val, 0, $pos);
    }
    sort ($list);
    return $list;
  }

  /** Return the full text of the category
    * Return false if it doesn't exists
    * @param string $category The category to analyze
    */
  private function languageCategoryText ($category)
  {
    $categories[LC_ALL] = "LC_ALL";
    $categories[LC_COLLATE] = "LC_COLLATE";
    $categories[LC_CTYPE] = "LC_CTYPE";
    $categories[LC_MONETARY] = "LC_MONETARY";
    $categories[LC_NUMERIC] = "LC_NUMERIC";
    $categories[LC_TIME] = "LC_TIME";
    $categories[LC_MESSAGES] = "LC_MESSAGES";
    if (! isset ($categories[$category]))
      return FALSE;
    return $categories[$category];
  }

  /** This function manage the cache of $package.mo files as Apache cache them
    * It return the directory to use
    * @param string $languageCode Language with format "fr_FR"
    * @param string|null $package The package name of the soft ($package.mo
    *                             file). "messages" by default
    * @param string|null $category The folder name LC_MESSAGES by default
    * @param string|null $repLocale The folder where all the locales are stored
    */
  function languageCache ($languageCode, $package="messages",
                          $category=LC_MESSAGES, $repLocale = "./locale")
  {
    // Apache cache le fichier messages.mo jusqu'au prochain redémarrage. L'idée
    // est de créer un fichier temporaire basé sur le fichier normal. Du coup,
    // si on change le fichier temporaire, Apache recharge le cache et donne les
    // dernières traductions.
    // Cette fonction gère le cache et renvoie le nom du fichier temporaire

    // La ligne ci-dessous permet de récupérer la language sans le codeset si
    // il est fourni en_US.UTF8 -> en_US
    if (($pos = strpos ($languageCode, ".")) !== FALSE)
      list ($languageCode, $codeset) = explode (".", $languageCode);
    $codeset = "UTF8"; // SANS TIRET ET EN MAJSUCULES!!!
                       // -> Le répertoire de données doit être fr_FR.UTF8
    $category    = $this->languageCategoryText ($category);
    $temporaries = glob ("$repLocale/$languageCode.$codeset/$category/*-*.mo");
    $moFile      = "$repLocale/$languageCode.$codeset/$category/$package.mo";
    if (! file_exists ($moFile))
      return "";
    $linkBase    = $this->cacheDir."/".filemtime($moFile)."/";
    $linkEnd     = "$languageCode.$codeset/$category/$package.mo";
    $link        = $linkBase.$linkEnd;
    clearstatcache (false, $moFile);
    // Manage the cache directory
    if (! file_exists (dirname ($link)))
    {
      // Try to create the cache dir. If there is an error, return the official
      // moFile. Apache will need to be restarted
      @mkdir (dirname ($link), 0777, true);
    }
    if (is_dir (dirname ($link)) && is_writeable (dirname ($link)) &&
        is_readable (dirname ($link)))
    {
      // Manage the cache file
      if (! file_exists ($link) || ! is_readable ($link) ||
          filemtime ($moFile) > filemtime ($link))
      {
        // Do not remove immediately the old files : they can be used by Apache
        $files = glob ($this->cacheDir."/*/".$linkEnd);
        foreach ($files as $file)
        {
          unlink ($file);
          // Remove the empty dirs. If not empty, do not display an error
          @rmdir (dirname ($file));
          @rmdir (dirname (dirname ($file)));
          @rmdir (dirname (dirname (dirname ($file))));
        }
        copy ($moFile, $link);
        chmod ($link, 0666);
      }
      if (filemtime ($moFile) <= filemtime ($link))
      {
        return $link;
      }
    }
    return $moFile;
  }

  /** Start the Gettext support with the cached file .mo provided as parameter
    * @param string $moFile The .mo file
    * @param string $languageCode The language code to use
    * @param integer $category the LC_ type to use
    * @param string|null $repLocale The locale directory. Use "./locale" if not
    * provided
    */
  function languageActivation ($moFile, $languageCode, $category = LC_MESSAGES,
                               $repLocale = "./locale")
  {
    // Active le support Gettext pour le fichier de language .mo caché fourni en
    // paramètre.
    // fichierMo : fichier messages-1354015006.mo
    // On ne vérifie pas la language fournie, elle doit correspondre à un
    // fichier de language (qui peut être récupéré par languageSelection ou
    // languageTraductionsList
    // Language doit être fourni sans codeset (fr_FR et PAS fr_FR.UTF8)
    if ($languageCode !== "C" && $moFile !== "")
    {
      $package = substr (basename ($moFile) , 0, -3);
      // La ligne ci-dessous permet de récupérer la language sans le codeset si
      // il est fourni en_US.UTF8 -> en_US
      if (($pos = strpos ($languageCode, ".")) !== FALSE)
        list ($languageCode, $codeset) = explode (".", $languageCode);
      $codeset = "UTF8"; // SANS TIRET ET EN MAJSUCULES!!!
                         // -> Le répertoire de données doit être fr_FR.UTF8
      putenv ('LANG='.$languageCode.'.'.$codeset);
      putenv ('LANGUAGE='.$languageCode.'.'.$codeset);
      $GLOBALS["domframework"]["lang"] = $languageCode;
      bind_textdomain_codeset ($package, "utf-8");
      bindtextdomain ($package, $repLocale);
      textdomain ($package);

      $rc = setlocale (LC_MESSAGES, $languageCode.'.'.$codeset);
      if ($rc === FALSE)
      {
        // Language non disponible sur le système
        // La liste des languages est affichée par 'locale -a'
        return FALSE;
      }
      $rc = setlocale (LC_TIME, $languageCode.'.'.$codeset);

      return TRUE;
    }
    return FALSE;
  }

  /** The complete stack of language selection
      @param string $package The package name (package.(po|mo) files)
      @param string $languageCookie The name of the cookie saved in the browser
      @param string $forcedLanguage The name of a forced language
      @return string The language with format fr_FR to be used */
  public function activeLanguage ($package, $languageCookie,
                                  $forcedLanguage = null)
  {
    // Prefered language in the browser
    $langNav = $this->languageSelection ("./locale", "fr_FR");
    // Language defined in the cookie
    $langCookie = $this->languageCookie ($languageCookie);
    if ($forcedLanguage !== null)
      $languageCode = $forcedLanguage;
    elseif ($langCookie !== FALSE)
    {
      $languageCode = $langCookie;
      // Update the already set cookie
      $this->languageCookieSet ($languageCookie, $languageCode, "/");
    }
    else
      $languageCode = $langNav;
    // Cache the domframework's .mo file too
    $dfFile = $this->languageCache ($languageCode, "domframework", LC_MESSAGES,
                                    dirname (__FILE__)."/locale");
    $dfDir = dirname (dirname (dirname ($dfFile)));
    $this->languageActivation ($dfFile, $languageCode, LC_MESSAGES, $dfDir);
    $languageCodeFichier = $this->languageCache ($languageCode, $package);
    $languageCodeDir = dirname (dirname (dirname ($languageCodeFichier)));
    $this->languageActivation ($languageCodeFichier, $languageCode, LC_MESSAGES,
                               $languageCodeDir);

    return $languageCode;
  }

  /** Return the language name from the language
      Ex. : $languageCode=fr_FR, return France
      @param string $languageCode Language with format "fr_FR"
      @return string Then language name */
  public function languageName ($languageCode)
  {
    switch ($languageCode)
    {
      case "fr_FR": return dgettext ("domframework", "French");
      case "en_US": return dgettext ("domframework", "English (US)");
      case "en_GB": return dgettext ("domframework", "English (GB)");
      default:
        throw new \Exception ("No language available for '$languageCode'", 500);
    }
  }

  /** Return the language subtag for the language
    * http://www.iana.org/assignments/language-subtag-registry/
    * language-subtag-registry
    * @param string $languageCode The language code to convert
    */
  public function languageSubTag ($languageCode)
  {
    return str_replace ("_", "-", $languageCode);
  }
}