jQuery.autocomplete = function(input, options) {
  // Create a link to self
  var me = this;

  // Create jQuery object for input element
  var $input = $(input).attr("autocomplete", "off");

  // Apply inputClass if necessary
  if (options.inputClass) $input.addClass(options.inputClass);

  // Create results
  var results = document.createElement("div");
  // Create jQuery object for results
  var $results = $(results);
  $results.hide().addClass(options.resultsClass).css("position", "absolute");
  if( options.width > 0 ) $results.css("width", options.width);

  // Add to body element
  $("body").append(results);

  input.autocompleter = me;

  var timeout = null;
  var prev = "";
  var active = -1;
  var cache = {};
  var keyb = false;
  var hasFocus = false;
  var lastKeyPressCode = null;

  $input
  .keydown(function(e) {
    // track last key pressed
    lastKeyPressCode = e.keyCode;
    switch(e.keyCode) {
      case 38: // up
        e.preventDefault();
        moveSelect(-1);
        break;
      case 40: // down
        e.preventDefault();
        moveSelect(1);
        break;
      case 9:  // tab
      case 13: // return
        if( selectCurrent() ){
          // make sure to blur off the current field
          $input.get(0).blur();
          e.preventDefault();
        }
        break;
      default:
        active = -1;
        if (timeout) clearTimeout(timeout);
        timeout = setTimeout(function(){onChange();}, options.delay);
        break;
    }
  })
  .focus(function(){
    // track whether the field has focus, we shouldn't process any results if the field no longer has focus
    hasFocus = true;
  })
  .blur(function() {
    // track whether the field has focus
    hasFocus = false;
    hideResults();
  });

  hideResultsNow();

  function onChange() {
    // ignore if the following keys are pressed: [del] [shift] [capslock]
    if( lastKeyPressCode == 46 || (lastKeyPressCode > 8 && lastKeyPressCode < 32) ) return $results.hide();
    var v = $input.val();
    if (v == prev) return;
    prev = v;
    if (v.length >= options.minChars) {
      $input.addClass(options.loadingClass);
      requestData(v);
    } else {
      $input.removeClass(options.loadingClass);
      $results.hide();
    }
  };

   function moveSelect(step) {

    var lis = $("li", results);
    if (!lis) return;

    active += step;

    if (active < 0) {
      active = 0;
    } else if (active >= lis.size()) {
      active = lis.size() - 1;
    }

    lis.removeClass("ac_over");

    $(lis[active]).addClass("ac_over");

    // Weird behaviour in IE
    // if (lis[active] && lis[active].scrollIntoView) {
    //   lis[active].scrollIntoView(false);
    // }

  };

  function selectCurrent() {
    var li = $("li.ac_over", results)[0];
    if (!li) {
      var $li = $("li", results);
      if (options.selectOnly) {
        if ($li.length == 1) li = $li[0];
      } else if (options.selectFirst) {
        li = $li[0];
      }
    }
    if (li) {
      selectItem(li);
      return true;
    } else {
      return false;
    }
  };

  function selectItem(li) {
    if (!li) {
      li = document.createElement("li");
      li.extra = [];
      li.selectValue = "";
    }
    var v = $(li).text();
    input.lastSelected = v;
    $results.html("");
    $input.val(v);
    hideResultsNow();
    if (options.onItemSelect) setTimeout(function() { options.onItemSelect(li) }, 1);
  };

  // selects a portion of the input string
  function createSelection(start, end){
    // get a reference to the input element
    var field = $input.get(0);
    if( field.createTextRange ){
      var selRange = field.createTextRange();
      selRange.collapse(true);
      selRange.moveStart("character", start);
      selRange.moveEnd("character", end);
      selRange.select();
    } else if( field.setSelectionRange ){
      field.setSelectionRange(start, end);
    } else {
      if( field.selectionStart ){
        field.selectionStart = start;
        field.selectionEnd = end;
      }
    }
    field.focus();
  };


  function showResults() {
    // get the position of the input field right now (in case the DOM is shifted)
    var pos = findPos(input);
    // either use the specified width, or autocalculate based on form element
    var iWidth = (options.width > 0) ? options.width : $input.width();
    // reposition
    $results.css({
      width: parseInt(iWidth) + "px",
      top: (pos.y + input.offsetHeight) + "px",
      left: pos.x + "px"
    }).show();
  };

  function hideResults() {
    if (timeout) clearTimeout(timeout);
    timeout = setTimeout(hideResultsNow, 200);
  };

  function hideResultsNow() {
    if (timeout) clearTimeout(timeout);
    $input.removeClass(options.loadingClass);
    if ($results.is(":visible")) {
      $results.hide();
    }
    if (options.mustMatch) {
      var v = $input.val();
      if (v != input.lastSelected) {
        selectItem(null);
      }
    }
  };

  function receiveData(q, data) {
    if (data) {
      $input.removeClass(options.loadingClass);
      results.innerHTML = "";

      // if the field no longer has focus or if there are no matches, do not display the drop down
      if( !hasFocus || data.length == 0 ) return hideResultsNow();

      if ($.browser.msie) {
        // we put a styled iframe behind the calendar so HTML SELECT elements don't show through
        $results.append(document.createElement('iframe'));
      }
      results.appendChild(dataToDom(data));

      showResults();
    } else {
      hideResultsNow();
    }
  };

  function dataToDom(data) {
    var ul = document.createElement("ul");
    var num = data.length;

    for (var i=0; i < num; i++) {
      var row = data[i];
      if (!row) continue;
      var li = document.createElement("li");
      
      li.innerHTML = options.convertText(row, i, num);
      li.selectValue = options.convertValue(row, i, num);;
      
      ul.appendChild(li);
      $(li).hover(
        function() { $("li", ul).removeClass("ac_over"); $(this).addClass("ac_over"); active = $("li", ul).indexOf($(this).get(0)); },
        function() { $(this).removeClass("ac_over"); }
      ).click(function(e) { e.preventDefault(); e.stopPropagation(); selectItem(this) });
    }
    return ul;
  };

  function requestData(q) {
      params = (typeof options.extraParams == 'function')? options.extraParams() : options.extraParams;
      params.query = q;
      $.json(options.controller, options.action, params,
          function(data) {
              data = options.parseData(data);
              receiveData(q, data);          
          }
      );  
  };

  function findPos(obj) {
    var curleft = obj.offsetLeft || 0;
    var curtop = obj.offsetTop || 0;
    while (obj = obj.offsetParent) {
      curleft += obj.offsetLeft
      curtop += obj.offsetTop
    }
    return {x:curleft,y:curtop};
  }
}

jQuery.fn.autocomplete = function(controller, action, options) {
  // Make sure options exists
  options = options || {};
  // set some bulk local data
  options.data = null;

  // Set default values for required options
  options.controller = controller;
  options.action = action;
  options.parseData = (typeof(options.parseData) == 'function')? options.parseData : function(data) {return data};
  options.convertValue = (typeof(options.convertValue) == 'function')? options.convertValue : function(row, i, sum) {return row};    
  options.convertText = (typeof(options.convertText) == 'function')? options.convertText : function(row, i, sum) {return row};
                
  options.inputClass = options.inputClass || "ac_input";
  options.resultsClass = options.resultsClass || "ac_results";
  options.lineSeparator = options.lineSeparator || "\n";
  options.cellSeparator = options.cellSeparator || "|";
  options.minChars = options.minChars || 1;
  options.delay = options.delay || 400;
  options.extraParams = options.extraParams || {};   
  options.loadingClass = options.loadingClass || "ac_loading";
  options.selectFirst = options.selectFirst || false;
  options.selectOnly = options.selectOnly || false;
  options.width = parseInt(options.width, 10) || 0;

  this.each(function() {
    var input = this;
    new jQuery.autocomplete(input, options);
  });

  // Don't break the chain
  return this;
}


jQuery.fn.indexOf = function(e){
  for( var i=0; i<this.length; i++ ){
    if( this[i] == e ) return i;
  }
  return -1;
};