Ajax.CachedAutocompleter = Class.create();

Object.extend(Object.extend(Ajax.CachedAutocompleter.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;
this.cache = {};
},

getUpdatedChoices: function() {
var t = this.getToken();
if (this.cache[t]) {
this.updateChoices(this.cache[t]);
} else {
entry = encodeURIComponent(this.options.paramName) + '=' +
encodeURIComponent(t);

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(this.cache[this.getToken()] = request.responseText);
},

// Page jump fix
markPrevious: function() {
if (this.index > 0) {
this.index--;
} else {
this.index = this.entryCount-1;
this.update.scrollTop = this.update.scrollHeight;
}

selection = this.getEntry(this.index);
selection_top = selection.offsetTop;

if (selection_top < this.update.scrollTop) {
this.update.scrollTop = this.update.scrollTop - selection.offsetHeight;
}
},

markNext: function() {
 if(this.index < this.entryCount-1) {
        this.index++;
    } else {
        this.index = 0;
        this.update.scrollTop = 0;
    }
    selection = this.getEntry(this.index);
    selection_bottom = selection.offsetTop+selection.offsetHeight;
    if(selection_bottom > this.update.scrollTop+this.update.offsetHeight) {
        this.update.scrollTop = this.update.scrollTop + selection.offsetHeight;
    }

},

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.update.scrollTop = 0;
this.index = 0;

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