TestForm = Class.create();
TestForm.prototype = {
    initialize: function(formId, firstFieldFocus){
        this.form       = $(formId);
        if (!this.form) {
            return;
        }
        this.cache      = $A();
        this.currLoader = false;
        this.currDataIndex = false;
        this.validator  = new Validation(this.form);
        this.elementFocus   = this.elementOnFocus.bindAsEventListener(this);
        this.elementBlur    = this.elementOnBlur.bindAsEventListener(this);
        this.childLoader    = this.onChangeChildLoad.bindAsEventListener(this);
        this.highlightClass = 'highlight';
        this.extraChildParams = '';
        this.firstFieldFocus= firstFieldFocus || false;
        this.bindElements();
        if(this.firstFieldFocus){
            try{
                Form.Element.focus(Form.findFirstElement(this.form))
            }
            catch(e){}
        }
    },

    submit : function(url){
        if(this.validator && this.validator.validate()){
             this.form.submit();
        }
        return false;
    },

    bindElements:function (){
        var elements = Form.getElements(this.form);
        for (var row in elements) {
            if (elements[row].id) {
                Event.observe(elements[row],'focus',this.elementFocus);
                Event.observe(elements[row],'blur',this.elementBlur);
            }
        }
    },

    elementOnFocus: function(event){
        var element = Event.findElement(event, 'fieldset');
        if(element.className){
            Element.addClassName(element, this.highlightClass);
        }
    },

    elementOnBlur: function(event){
        var element = Event.findElement(event, 'fieldset');
        if(element.className){
            Element.removeClassName(element, this.highlightClass);
        }
    },

    setElementsRelation: function(parent, child, dataUrl, first){
        if (parent=$(parent)) {
            // TODO: array of relation and caching
            if (!this.cache[parent.id]){
                this.cache[parent.id] = $A();
                this.cache[parent.id]['child']     = child;
                this.cache[parent.id]['dataUrl']   = dataUrl;
                this.cache[parent.id]['data']      = $A();
                this.cache[parent.id]['first']      = first || false;
            }
            Event.observe(parent,'change',this.childLoader);
        }
    },

    onChangeChildLoad: function(event){
        element = Event.element(event);
        this.elementChildLoad(element);
    },

    elementChildLoad: function(element, callback){
        this.callback = callback || false;
        if (element.value) {
            this.currLoader = element.id;
            this.currDataIndex = element.value;
            if (this.cache[element.id]['data'][element.value]) {
                this.setDataToChild(this.cache[element.id]['data'][element.value]);
            }
            else{
                new Ajax.Request(this.cache[this.currLoader]['dataUrl'],{
                        method: 'post',
                        parameters: {"parent":element.value},
                        onComplete: this.reloadChildren.bind(this)
                });
            }
        }
    },

    reloadChildren: function(transport){
        var data = eval('(' + transport.responseText + ')');
        this.cache[this.currLoader]['data'][this.currDataIndex] = data;
        this.setDataToChild(data);
    },

    setDataToChild: function(data){
        if (data.length) {
            var child = $(this.cache[this.currLoader]['child']);
            if (child){
                var html = '<select name="'+child.name+'" id="'+child.id+'" class="'+child.className+'" title="'+child.title+'" '+this.extraChildParams+'>';
                if(this.cache[this.currLoader]['first']){
                    html+= '<option value="">'+this.cache[this.currLoader]['first']+'</option>';
                }
                for (var i in data){
                    if(data[i].value) {
                        html+= '<option value="'+data[i].value+'"';
                        if(child.value && (child.value == data[i].value || child.value == data[i].label)){
                            html+= ' selected';
                        }
                        html+='>'+data[i].label+'</option>';
                    }
                }
                html+= '</select>';
                new Insertion.Before(child,html);
                Element.remove(child);
            }
        }
        else{
            var child = $(this.cache[this.currLoader]['child']);
            if (child){
                var html = '<input type="text" name="'+child.name+'" id="'+child.id+'" class="'+child.className+'" title="'+child.title+'" '+this.extraChildParams+'>';
                new Insertion.Before(child,html);
                Element.remove(child);
            }
        }

        this.bindElements();
        if (this.callback) {
            this.callback();
        }
    }
}