/*
 * jQuery Caret Range plugin
 * Copyright (c) 2009 Matt Zabriskie
 * Released under the MIT and GPL licenses.
 */
(function($) {
  $.extend($.fn, {
    caret: function ( start, end ) {
      var elem = this[0];
      var val;
      var range;

      if ( elem ) {
        // get caret range
        if (typeof start == "undefined") {
          if (elem.selectionStart) {
            start = elem.selectionStart;
            end = elem.selectionEnd;
          }
          else if (document.selection) {
            val = this.val();
            range = document.selection.createRange().duplicate();
            range.moveEnd("character", val.length);
            start = (range.text == "" ? val.length : val.lastIndexOf(range.text));

            range = document.selection.createRange().duplicate();
            range.moveStart("character", -val.length);
            end = range.text.length;
          }
        }
        // set caret range
        else {
          val = this.val();

          if (typeof start != "number") start = -1;
          if (typeof end != "number") end = -1;
          if (start < 0) start = 0;
          if (end > val.length) end = val.length;
          if (end < start) end = start;
          if (start > end) start = end;

          elem.focus();

          if (elem.selectionStart) {
            elem.selectionStart = start;
            elem.selectionEnd = end;
          }
          else if (document.selection) {
            range = elem.createTextRange();
            range.collapse(true);
            range.moveStart("character", start);
            range.moveEnd("character", end - start);
            range.select();
          }
        }

        return {start:start, end:end};
      }
    },

    insertAtCaret: function(val) {
      this.each( function(i)
      {
        if ( document.selection )
        {
          this.focus();
          var sel = document.selection.createRange();
          sel.text = val;
          this.focus();
        }
        else if ( this.selectionStart || this.selectionStart == '0' )
        {
          var startPos = this.selectionStart;
          var endPos = this.selectionEnd;
          var scrollTop = this.scrollTop;
          this.value = this.value.substring( 0, startPos ) + val + this.value.substring( endPos, this.value.length );
          this.focus();
          this.selectionStart = startPos + val.length;
          this.selectionEnd = startPos + val.length;
          this.scrollTop = scrollTop;
        }
        else
        {
          this.value += val;
          this.focus();
        }
      });
    }
  })
})(jQuery);