/**
 * Autotab - jQuery plugin 1.1b
 * http://www.lousyllama.com/sandbox/jquery-autotab
 * 
 * Copyright (c) 2008 Matthew Miller
 * 
 * Dual licensed under the MIT and GPL licenses:
 *   http://www.opensource.org/licenses/mit-license.php
 *   http://www.gnu.org/licenses/gpl.html
 * 
 * Revised: 2008-09-10 16:55:08
 */

(function($) {
// Look for an element based on ID or name
var check_element = function(name) {
  var obj = null;
  var check_id = $('#' + name);
  var check_name = $('input[name=' + name + ']');

  if(check_id.length)
    obj = check_id;
  else if(check_name != undefined)
    obj = check_name;

  return obj;
};

/**
 * autotab_magic automatically establishes autotabbing with the
 * next and previous elements as provided by :input.
 * 
 * autotab_magic should called after applying filters, if used.
 * If any filters are applied after calling autotab_magic, then
 * Autotab may not protect against brute force typing.
 * 
 * @name  autotab_magic
 * @param focus Applies focus on the specified element
 * @example $(':input').autotab_magic();
 */
$.fn.autotab_magic = function(focus) {
  for(var i = 0; i < this.length; i++)
  {
    var n = i + 1;
    var p = i - 1;

    if(i > 0 && n < this.length)
      $(this[i]).autotab({ target: $(this[n]), previous: $(this[p]) });
    else if(i > 0)
      $(this[i]).autotab({ previous: $(this[p]) });
    else
      $(this[i]).autotab({ target: $(this[n]) });

    // Set the focus on the specified element
    if(focus != null && (isNaN(focus) && focus == $(this[i]).attr('id')) || (!isNaN(focus) && focus == i))
      $(this[i]).focus();
  }
  return this;
};

/**
 * This will take any of the text that is typed and
 * format it according to the options specified.
 * 
 * Option values:
 *  format    text|number|alphanumeric|all|custom
 *  - Text      Allows all characters except numbers
 *  - Number    Allows only numbers
 *  - Alphanumeric  Allows only letters and numbers
 *  - All     Allows any and all characters
 *  - Custom    Allows developer to provide their own filter
 *
 *  uppercase true|false
 *  - Converts a string to UPPERCASE
 * 
 *  lowercase true|false
 *  - Converts a string to lowecase
 * 
 *  nospace   true|false
 *  - Remove spaces in the user input
 * 
 *  pattern   null|(regular expression)
 *  - Custom regular expression for the filter
 * 
 * @name  autotab_filter
 * @param options   Can be a string, function or a list of options. If a string or
 *            function is passed, it will be assumed to be a format option.
 * @example $('#number1, #number2, #number3').autotab_filter('number');
 * @example $('#product_key').autotab_filter({ format: 'alphanumeric', nospace: true });
 * @example $('#unique_id').autotab_filter({ format: 'custom', pattern: '[^0-9\.]' });
 */
$.fn.autotab_filter = function(options) {
  var defaults = {
    format: 'all',
    uppercase: false,
    lowercase: false,
    nospace: false,
    pattern: null
  };

  if(typeof options == 'string' || typeof options == 'function')
    defaults.format = options;
  else
    $.extend(defaults, options);

  for(var i = 0; i < this.length; i++)
  {
    $(this[i]).bind('keyup', function(e) {
      var val = this.value;

      switch(defaults.format)
      {
        case 'text':
          var pattern = new RegExp('[0-9]+', 'g');
          val = val.replace(pattern, '');
          break;

        case 'alpha':
          var pattern = new RegExp('[^a-zA-Z]+', 'g');
          val = val.replace(pattern, '');
          break;

        case 'number':
        case 'numeric':
          var pattern = new RegExp('[^0-9]+', 'g');
          val = val.replace(pattern, '');
          break;

        case 'alphanumeric':
          var pattern = new RegExp('[^0-9a-zA-Z]+', 'g');
          val = val.replace(pattern, '');
          break;

        case 'custom':
          var pattern = new RegExp(defaults.pattern, 'g');
          val = val.replace(pattern, '');
          break;

        case 'all':
        default:
          if(typeof defaults.format == 'function')
            var val = defaults.format(val);

          break;
      }

      if(defaults.nospace)
      {
        var pattern = new RegExp('[ ]+', 'g');
        val = val.replace(pattern, '');
      }

      if(defaults.uppercase)
        val = val.toUpperCase();

      if(defaults.lowercase)
        val = val.toLowerCase();

      if(val != this.value)
        this.value = val;
    });
  }
};

/**
 * Provides the autotabbing mechanism for the supplied element and passes
 * any formatting options to autotab_filter.
 * 
 * Refer to autotab_filter's description for a detailed explanation of
 * the options available.
 * 
 * @name  autotab
 * @param options
 * @example $('#phone').autotab({ format: 'number' });
 * @example $('#username').autotab({ format: 'alphanumeric', target: 'password' });
 * @example $('#password').autotab({ previous: 'username', target: 'confirm' });
 */
$.fn.autotab = function(options) {
  var defaults = {
    format: 'all',
    maxlength: 2147483647,
    uppercase: false,
    lowercase: false,
    nospace: false,
    target: null,
    previous: null,
    pattern: null
  };

  $.extend(defaults, options);

  // Sets targets to element based on the name or ID
  // passed if they are not currently objects
  if(typeof defaults.target == 'string')
    defaults.target = check_element(defaults.target);

  if(typeof defaults.previous == 'string')
    defaults.previous = check_element(defaults.previous);

  var maxlength = $(this).attr('maxlength');

  // defaults.maxlength has not changed and maxlength was specified
  if(defaults.maxlength == 2147483647 && maxlength != 2147483647)
    defaults.maxlength = maxlength;
  // defaults.maxlength overrides maxlength
  else if(defaults.maxlength > 0)
    $(this).attr('maxlength', defaults.maxlength)
  // defaults.maxlength and maxlength have not been specified
  // A target cannot be used since there is no defined maxlength
  else
    defaults.target = null;

  if(defaults.format != 'all')
    $(this).autotab_filter(defaults);

  // Go to the previous element when backspace
  // is pressed in an empty input field
  return $(this).bind('keydown', function(e) {
    if(e.which == 8 && this.value.length == 0 && defaults.previous)
      defaults.previous.focus().val(defaults.previous.val());
  }).bind('keyup', function(e) {
    /**
     * Do not auto tab when the following keys are pressed
     * 8: Backspace
     * 9: Tab
     * 16:  Shift
     * 17:  Ctrl
     * 18:  Alt
     * 19:  Pause Break
     * 20:  Caps Lock
     * 27:  Esc
     * 33:  Page Up
     * 34:  Page Down
     * 35:  End
     * 36:  Home
     * 37:  Left Arrow
     * 38:  Up Arrow
     * 39:  Right Arrow
     * 40:  Down Arrow
     * 45:  Insert
     * 46:  Delete
     * 144: Num Lock
     * 145: Scroll Lock
     */
    var keys = [8, 9, 16, 17, 18, 19, 20, 27, 33, 34, 35, 36, 37, 38, 39, 40, 45, 46, 144, 145];

    if(e.which != 8)
    {
      var val = $(this).val();

      if($.inArray(e.which, keys) == -1 && val.length == defaults.maxlength && defaults.target)
        defaults.target.focus();
    }
  });
};

})(jQuery);