var Class = {
  create: function() {
    return function() {
      this.initialize.apply(this, arguments);
    }
  }
}

Object.extend = function(destination, source) {
  for (var property in source) {
    destination[property] = source[property];
  }
  return destination;
}

Object.extend(Object, {
  inspect: function(object) {
    try {
      if (object === undefined) return 'undefined';
      if (object === null) return 'null';
      return object.inspect ? object.inspect() : object.toString();
    } catch (e) {
      if (e instanceof RangeError) return '...';
      throw e;
    }
  },

  keys: function(object) {
    var keys = [];
    for (var property in object)
      keys.push(property);
    return keys;
  },

  values: function(object) {
    var values = [];
    for (var property in object)
      values.push(object[property]);
    return values;
  },

  clone: function(object) {
    return Object.extend({}, object);
  }
});

// original class:

Ajax.Autocompleter = Class.create();
Object.extend(Object.extend(Ajax.Autocompleter.prototype, Autocompleter.Base.prototype), {
  initialize: function(element, update, url, options) {
    this.baseInitialize(element, update, options);
    this.options.asynchronous  = true;
    this.options.onComplete    = this.onComplete.bind(this);
    this.options.defaultParams = this.options.parameters || null;
    this.url                   = url;
  },

  getUpdatedChoices: function() {
    entry = encodeURIComponent(this.options.paramName) + '=' + 
      encodeURIComponent(this.getToken());

    this.options.parameters = this.options.callback ?
      this.options.callback(this.element, entry) : entry;

    if(this.options.defaultParams) 
      this.options.parameters += '&' + this.options.defaultParams;

    new Ajax.Request(this.url, this.options);
  },

  onComplete: function(request) {
    this.updateChoices(request.responseText);
  }

});

var Autocompleter = {}
Autocompleter.Base = function() {};
Autocompleter.Base.prototype = {
  baseInitialize: function(element, update, options) {
    this.element     = $(element); 
    this.update      = $(update);  
    this.hasFocus    = false; 
    this.changed     = false; 
    this.active      = false; 
    this.index       = 0;     
    this.entryCount  = 0;

    if(this.setOptions)
      this.setOptions(options);
    else
      this.options = options || {};

    this.options.paramName    = this.options.paramName || this.element.name;
    this.options.tokens       = this.options.tokens || [];
    this.options.frequency    = this.options.frequency || 0.4;
    this.options.minChars     = this.options.minChars || 1;
    this.options.onShow       = this.options.onShow || 
      function(element, update){ 
        if(!update.style.position || update.style.position=='absolute') {
          update.style.position = 'absolute';
          Position.clone(element, update, {
            setHeight: false, 
            offsetTop: element.offsetHeight
          });
        }
        Effect.Appear(update,{duration:0.15});
      };
    this.options.onHide = this.options.onHide || 
      function(element, update){ new Effect.Fade(update,{duration:0.15}) };

    if(typeof(this.options.tokens) == 'string') 
      this.options.tokens = new Array(this.options.tokens);

    this.observer = null;
    
    this.element.setAttribute('autocomplete','off');

    Element.hide(this.update);

    Event.observe(this.element, "blur", this.onBlur.bindAsEventListener(this));
    Event.observe(this.element, "keypress", this.onKeyPress.bindAsEventListener(this));
  },

  show: function() {
    if(Element.getStyle(this.update, 'display')=='none') this.options.onShow(this.element, this.update);
    if(!this.iefix && 
      (navigator.appVersion.indexOf('MSIE')>0) &&
      (navigator.userAgent.indexOf('Opera')<0) &&
      (Element.getStyle(this.update, 'position')=='absolute')) {
      new Insertion.After(this.update, 
       '<iframe id="' + this.update.id + '_iefix" '+
       'style="display:none;position:absolute;filter:progid:DXImageTransform.Microsoft.Alpha(opacity=0);" ' +
       'src="javascript:false;" frameborder="0" scrolling="no"></iframe>');
      this.iefix = $(this.update.id+'_iefix');
    }
    if(this.iefix) setTimeout(this.fixIEOverlapping.bind(this), 50);
  },
  
  fixIEOverlapping: function() {
    Position.clone(this.update, this.iefix, {setTop:(!this.update.style.height)});
    this.iefix.style.zIndex = 1;
    this.update.style.zIndex = 2;
    Element.show(this.iefix);
  },

  hide: function() {
    this.stopIndicator();
    if(Element.getStyle(this.update, 'display')!='none') this.options.onHide(this.element, this.update);
    if(this.iefix) Element.hide(this.iefix);
  },

  startIndicator: function() {
    if(this.options.indicator) Element.show(this.options.indicator);
  },

  stopIndicator: function() {
    if(this.options.indicator) Element.hide(this.options.indicator);
  },

  onKeyPress: function(event) {
    if(this.active)
      switch(event.keyCode) {
       case Event.KEY_TAB:
       case Event.KEY_RETURN:
         this.selectEntry();
         Event.stop(event);
       case Event.KEY_ESC:
         this.hide();
         this.active = false;
         Event.stop(event);
         return;
       case Event.KEY_LEFT:
       case Event.KEY_RIGHT:
         return;
       case Event.KEY_UP:
         this.markPrevious();
         this.render();
         if(navigator.appVersion.indexOf('AppleWebKit')>0) Event.stop(event);
         return;
       case Event.KEY_DOWN:
         this.markNext();
         this.render();
         if(navigator.appVersion.indexOf('AppleWebKit')>0) Event.stop(event);
         return;
      }
     else 
       if(event.keyCode==Event.KEY_TAB || event.keyCode==Event.KEY_RETURN || 
         (navigator.appVersion.indexOf('AppleWebKit') > 0 && event.keyCode == 0)) return;

    this.changed = true;
    this.hasFocus = true;

    if(this.observer) clearTimeout(this.observer);
      this.observer = 
        setTimeout(this.onObserverEvent.bind(this), this.options.frequency*1000);
  },

  activate: function() {
    this.changed = false;
    this.hasFocus = true;
    this.getUpdatedChoices();
  },

  onHover: function(event) {
    var element = Event.findElement(event, 'LI');
    if(this.index != element.autocompleteIndex) 
    {
        this.index = element.autocompleteIndex;
        this.render();
    }
    Event.stop(event);
  },
  
  onClick: function(event) {
    var element = Event.findElement(event, 'LI');
    this.index = element.autocompleteIndex;
    this.selectEntry();
    this.hide();
  },
  
  onBlur: function(event) {
    // needed to make click events working
    setTimeout(this.hide.bind(this), 250);
    this.hasFocus = false;
    this.active = false;     
  }, 
  
  render: function() {
    if(this.entryCount > 0) {
      for (var i = 0; i < this.entryCount; i++)
        this.index==i ? 
          Element.addClassName(this.getEntry(i),"selected") : 
          Element.removeClassName(this.getEntry(i),"selected");
        
      if(this.hasFocus) { 
        this.show();
        this.active = true;
      }
    } else {
      this.active = false;
      this.hide();
    }
  },
  
  markPrevious: function() {
    if(this.index > 0) this.index--
      else this.index = this.entryCount-1;
    this.getEntry(this.index).scrollIntoView(true);
  },
  
  markNext: function() {
    if(this.index < this.entryCount-1) this.index++
      else this.index = 0;
    this.getEntry(this.index).scrollIntoView(false);
  },
  
  getEntry: function(index) {
    return this.update.firstChild.childNodes[index];
  },
  
  getCurrentEntry: function() {
    return this.getEntry(this.index);
  },
  
  selectEntry: function() {
    this.active = false;
    this.updateElement(this.getCurrentEntry());
  },

  updateElement: function(selectedElement) {
    if (this.options.updateElement) {
      this.options.updateElement(selectedElement);
      return;
    }
    var value = '';
    if (this.options.select) {
      var nodes = document.getElementsByClassName(this.options.select, selectedElement) || [];
      if(nodes.length>0) value = Element.collectTextNodes(nodes[0], this.options.select);
    } else
      value = Element.collectTextNodesIgnoreClass(selectedElement, 'informal');
    
    var lastTokenPos = this.findLastToken();
    if (lastTokenPos != -1) {
      var newValue = this.element.value.substr(0, lastTokenPos + 1);
      var whitespace = this.element.value.substr(lastTokenPos + 1).match(/^\s+/);
      if (whitespace)
        newValue += whitespace[0];
      this.element.value = newValue + value;
    } else {
      this.element.value = value;
    }
    this.element.focus();
    
    if (this.options.afterUpdateElement)
      this.options.afterUpdateElement(this.element, selectedElement);
  },

  updateChoices: function(choices) {
    if(!this.changed && this.hasFocus) {
      this.update.innerHTML = choices;
      Element.cleanWhitespace(this.update);
      Element.cleanWhitespace(this.update.down());

      if(this.update.firstChild && this.update.down().childNodes) {
        this.entryCount = 
          this.update.down().childNodes.length;
        for (var i = 0; i < this.entryCount; i++) {
          var entry = this.getEntry(i);
          entry.autocompleteIndex = i;
          this.addObservers(entry);
        }
      } else { 
        this.entryCount = 0;
      }

      this.stopIndicator();
      this.index = 0;
      
      if(this.entryCount==1 && this.options.autoSelect) {
        this.selectEntry();
        this.hide();
      } else {
        this.render();
      }
    }
  },

  addObservers: function(element) {
    Event.observe(element, "mouseover", this.onHover.bindAsEventListener(this));
    Event.observe(element, "click", this.onClick.bindAsEventListener(this));
  },

  onObserverEvent: function() {
    this.changed = false;   
    if(this.getToken().length>=this.options.minChars) {
      this.startIndicator();
      this.getUpdatedChoices();
    } else {
      this.active = false;
      this.hide();
    }
  },

  getToken: function() {
    var tokenPos = this.findLastToken();
    if (tokenPos != -1)
      var ret = this.element.value.substr(tokenPos + 1).replace(/^\s+/,'').replace(/\s+$/,'');
    else
      var ret = this.element.value;

    return /\n/.test(ret) ? '' : ret;
  },

  findLastToken: function() {
    var lastTokenPos = -1;

    for (var i=0; i<this.options.tokens.length; i++) {
      var thisTokenPos = this.element.value.lastIndexOf(this.options.tokens[i]);
      if (thisTokenPos > lastTokenPos)
        lastTokenPos = thisTokenPos;
    }
    return lastTokenPos;
  }
}