text: /* ***** BEGIN LICENSE BLOCK *****
   *   Version: MPL 1.1/GPL 2.0/LGPL 2.1
   *
   * The contents of this file are subject to the Mozilla Public License Version
   * 1.1 (the "License"); you may not use this file except in compliance with
   * the License. You may obtain a copy of the License at
   * http://www.mozilla.org/MPL/
   *
   * Software distributed under the License is distributed on an "AS IS" basis,
   * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
   * for the specific language governing rights and limitations under the
   * License.
   *
   * The Original Code is Plural Form l10n Code.
   *
   * The Initial Developer of the Original Code is
   * Edward Lee <edward.lee@engineering.uiuc.edu>.
   * Portions created by the Initial Developer are Copyright (C) 2008
   * the Initial Developer. All Rights Reserved.
   *
   * Contributor(s):
   *
   * Alternatively, the contents of this file may be used under the terms of
   * either the GNU General Public License Version 2 or later (the "GPL"), or
   * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
   * in which case the provisions of the GPL or the LGPL are applicable instead
   * of those above. If you wish to allow use of your version of this file only
   * under the terms of either the GPL or the LGPL, and not to allow others to
   * use your version of this file under the terms of the MPL, indicate your
   * decision by deleting the provisions above and replace them with the notice
   * and other provisions required by the GPL or the LGPL. If you do not delete
   * the provisions above, a recipient may use your version of this file under
   * the terms of any one of the MPL, the GPL or the LGPL.
   *
   * ***** END LICENSE BLOCK ***** */
  
  var EXPORTED_SYMBOLS = [ "PluralForm" ];
  
  /**
   * This module provides the PluralForm object which contains a method to figure
   * out which plural form of a word to use for a given number based on the
   * current localization. There is also a makeGetter method that creates a get
   * function for the desired plural rule. This is useful for extensions that
   * specify their own plural rule instead of relying on the browser default.
   * (I.e., the extension hasn't been localized to the browser's locale.)
   *
   * See: http://developer.mozilla.org/en/docs/Localization_and_Plurals
   *
   * List of methods:
   *
   * string pluralForm
   * get(int aNum, string aWords)
   *
   * int numForms
   * numForms()
   *
   * [string pluralForm get(int aNum, string aWords), int numForms numForms()]
   * makeGetter(int aRuleNum)
   * Note: Basically, makeGetter returns 2 functions that do "get" and "numForm"
   */
  
  const Cc = Components.classes;
  const Ci = Components.interfaces;
  
  const kIntlProperties = "chrome://global/locale/intl.properties";
  
  // These are the available plural functions that give the appropriate index
  // based on the plural rule number specified. The first element is the number
  // of plural forms and the second is the function to figure out the index.
  let gFunctions = [
    // 0: Chinese
    [1, function(n) 0],
    // 1: English
    [2, function(n) n!=1?1:0],
    // 2: French
    [2, function(n) n>1?1:0],
    // 3: Latvian
    [3, function(n) n%10==1&&n%100!=11?1:n!=0?2:0],
    // 4: Scottish Gaelic
    [3, function(n) n==1?0:n==2?1:2],
    // 5: Romanian
    [3, function(n) n==1?0:n==0||n%100>0&&n%100<20?1:2],
    // 6: Lithuanian
    [3, function(n) n%10==1&&n%100!=11?0:n%10>=2&&(n%100<10||n%100>=20)?2:1],
    // 7: Russian
    [3, function(n) n%10==1&&n%100!=11?0:n%10>=2&&n%10<=4&&(n%100<10||n%100>=20)?1:2],
    // 8: Slovak
    [3, function(n) n==1?0:n>=2&&n<=4?1:2],
    // 9: Polish
    [3, function(n) n==1?0:n%10>=2&&n%10<=4&&(n%100<10||n%100>=20)?1:2],
    // 10: Slovenian
    [4, function(n) n%100==1?0:n%100==2?1:n%100==3||n%100==4?2:3],
    // 11: Irish Gaeilge
    [5, function(n) n==1?0:n==2?1:n>=3&&n<=6?2:n>=7&&n<=10?3:4],
    // 12: Arabic
    [6, function(n) n==0?5:n==1?0:n==2?1:n%100>=3&&n%100<=10?2:n%100>=11&&n%100<=99?3:4],
    // 13: Maltese
    [4, function(n) n==1?0:n==0||n%100>0&&n%100<=10?1:n%100>10&&n%100<20?2:3],
    // 14: Macedonian
    [3, function(n) n%10==1?0:n%10==2?1:2],
    // 15: Icelandic
    [2, function(n) n%10==1&&n%100!=11?0:1],
  ];
  
  let PluralForm = {
    /**
     * Get the correct plural form of a word based on the number
     *
     * @param aNum
     *        The number to decide which plural form to use
     * @param aWords
     *        A semi-colon (;) separated string of words to pick the plural form
     * @return The appropriate plural form of the word
     */
    get get()
    {
      // This method will lazily load to avoid perf when it is first needed and
      // creates getPluralForm function. The function it creates is based on the
      // value of pluralRule specified in the intl stringbundle.
      // See: http://developer.mozilla.org/en/docs/Localization_and_Plurals
  
      // Delete the getters to be overwritten
      delete PluralForm.numForms;
      delete PluralForm.get;
  
      // Get the plural rule number from the intl stringbundle
      let ruleNum = Number(Cc["@mozilla.org/intl/stringbundle;1"].
        getService(Ci.nsIStringBundleService).createBundle(kIntlProperties).
        GetStringFromName("pluralRule"));
  
      // Make the plural form get function and set it as the default get
      [PluralForm.get, PluralForm.numForms] = PluralForm.makeGetter(ruleNum);
      return PluralForm.get;
    },
  
    /**
     * Create a pair of plural form functions for the given plural rule number.
     *
     * @param aRuleNum
     *        The plural rule number to create functions
     * @return A pair: [function that gets the right plural form,
     *                  function that returns the number of plural forms]
     */
    makeGetter: function(aRuleNum)
    {
      // Default to "all plural" if the value is out of bounds or invalid
      if (aRuleNum < 0 || aRuleNum >= gFunctions.length || isNaN(aRuleNum)) {
        log(["Invalid rule number: ", aRuleNum, " -- defaulting to 0"]);
        aRuleNum = 0;
      }
  
      // Get the desired pluralRule function
      let [numForms, pluralFunc] = gFunctions[aRuleNum];
  
      // Return functions that give 1) the number of forms and 2) gets the right
      // plural form
      return [function(aNum, aWords) {
        // Figure out which index to use for the semi-colon separated words
        let index = pluralFunc(aNum ? Number(aNum) : 0);
        let words = aWords ? aWords.split(/;/) : [""];
  
        // Explicitly check bounds to avoid strict warnings
        let ret = index < words.length ? words[index] : undefined;
  
        // Check for array out of bounds or empty strings
        if ((ret == undefined) || (ret == "")) {
          // Report the caller to help figure out who is causing badness
          let caller = PluralForm.get.caller ? PluralForm.get.caller.name : "top";
  
          // Display a message in the error console
          log(["Index #", index, " of '", aWords, "' for value ", aNum,
              " is invalid -- plural rule #", aRuleNum, "; called by ", caller]);
  
          // Default to the first entry (which might be empty, but not undefined)
          ret = words[0];
        }
  
        return ret;
      }, function() numForms];
    },
  
    /**
     * Get the number of forms for the current plural rule
     *
     * @return The number of forms
     */
    get numForms()
    {
      // We lazily load numForms, so trigger the init logic with get()
      PluralForm.get();
      return PluralForm.numForms;
    },
  };
  
  /**
   * Private helper function to log errors to the error console and command line
   *
   * @param aMsg
   *        Error message to log or an array of strings to concat
   */
  function log(aMsg)
  {
    let msg = "PluralForm.jsm: " + (aMsg.join ? aMsg.join("") : aMsg);
    Cc["@mozilla.org/consoleservice;1"].getService(Ci.nsIConsoleService).
      logStringMessage(msg);
    dump(msg + "\n");
  }
  