var Checklist = Class.create(JSControl, {
	initialize: function($super, element, types, desc){
		$super(element);
		this.setHandlers();
		this.types = types;
		this.desc = desc;
		this.delimiter_ = this.element.getAttribute("delimiter") || ", ";
		this.update_table_ref();
	},

	update_table_ref: function(){
		var table = null;
		for (var child = this.element.firstChild; child; child = child.nextSibling){
			if (child.nodeType == Node.ELEMENT_NODE && Node.localName(child) == "table"){
				table = child;
				break;
			}
		}
		if (table){
			this.col_ = null;
			for (var child = table.firstChild; child; child = child.nextSibling){
				if (child.nodeType == Node.ELEMENT_NODE && Node.localName(child) == "col"){
					this.col_ = child;
					break;
				}
			}
			if (!this.col_ && table.firstChild)
				this.col_ = table.insertBefore(document.createElement("col"), table.firstChild);
			this.tbody_ = table.tBodies[0];
		}else this.tbody_ = this.col_ = null;
	},

	setHandlers: function(){
		$A(this.element.elements).each(function(element){
			Event.observe(element, "change", this.onchange.bind(this)); }, this);
	},

	onchange: function($super){
		delete this.value_;
		$super();
	},

	SetTabOrder: function(tabbase){
		$A(this.element.elements).each(function(element){ element.tabIndex = tabbase++; });
		return tabbase;
	},

	serialize: function(obj){
		while (obj instanceof Optional) obj = obj.Value();
		return URLSerialize(obj);
	},

	getval: function(element){
		if (!element) return null;
		if (this.dynamic_) return URLRestore(element.getAttribute("full-value") || element.name);
		else{
			var str = String(element.name);
			switch (this.element.getAttribute("key-type")){
				case "int": return int(parseInt(str, 10));
				case "int64": return int64(parseInt(str, 10));
				case "string":
				default: return str;
			}
		}
	},

	Value: function(){
		if (this.value_) return this.value_;
		var result = [];
		var checked = $A(this.element.elements).findAll(function(element){ return element.checked; });
		return checked.collect(this.getval, this);
	},

	val2str: function(val){
		if (this.dynamic_) return this.serialize(val);
		else{
			if (val instanceof Optional) val = val.Value();
			return String(val);
		}
	},

	SetValue: function(array){
		if (this.dynamic_ && !this.loaded_){
			this.value_ = array;
			return;
		}
		this.element.reset();
		if (Object.isString(array)) array = [array];
		else if (!Object.isArray(array)) return;
		$A(array).each(function(obj){
			var element = this.element.elements[this.val2str(obj)];
			if (element) element.checked = true;
		}, this);
		if (["vo", "link"].indexOf(this.visibility_) != -1) this.reset_layout(this.get_cols(), this.visibility_);
	},

	init_dynamic: function(apacket){
		var data = apacket.Data(); if (data.length == 0) return;
		var val_colnam = this.element.getAttribute("key-column") || this.element.getAttribute("key") || "";
		var lbl_colnam = this.element.getAttribute("show") || "";
		var header = data.shift();
		var val_col = -1; var lbl_col = -1;
		for (var iii = 0; iii < header.length; ++iii){
			if (header[iii] == val_colnam) val_col = iii;
			if (header[iii] == lbl_colnam) lbl_col = iii;
			if (val_col >= 0 && lbl_col >= 0) break;
		}
		if (val_col < 0 || lbl_col < 0) return;
		this.loaded_ = true;
		var old_value = this.Value();
		var desc = Object.clone(this.desc);
		desc["childNodes"] = $A(data).collect(function(row){
			var val = this.serialize(row[val_col]);
			return {"nodeName": "st:item", "id": val, "value": val, "label": row[lbl_col], "full-value": URLSerialize(row[val_col])};
		}, this);
		var aux = new Element("span");
		aux.innerHTML = JSControl.TransformElementAndUnwrap(desc, this.types);
		Element.clear(this.element);
		for (var child = aux.firstChild; child; child = child.nextSibling)
			if (child.nodeType == Node.ELEMENT_NODE){
				var scripts = String(child.innerHTML).extractScripts();
				this.element.innerHTML = String(child.innerHTML).stripScripts();
				try{ scripts.each(eval); }catch (err){ alert(["Checklist:", err.name, err.message].join("\n")); }
				break;
			}
		this.setHandlers();
		this.SetValue(old_value);
		if (typeof this.value_ != "undefined") delete this.value_;
		this.update_table_ref();
		if (this.visibility_ && ["yes", "no"].indexOf(this.visibility_) == -1)
			this.reset_layout(this.get_cols(), this.visibility_);//!!!!!
	},

	clear: function(elem){
		if (!elem) return;
		while (elem.firstChild) elem.removeChild(elem.firstChild);
	},

	reset_layout: function(ncols, vis){
		if ("no" == vis) return void Element.setStyle(this.element, {"display": "none"});
		var chkbx = $A(this.element.elements);
		var items = chkbx.pluck("parentNode");
		var vo = ["vo", "link"].indexOf(vis) != -1;
		for (var iii = 0; iii < chkbx.length; ++iii){
			if (items[iii].parentNode) items[iii] = items[iii].parentNode.removeChild(items[iii]);
			chkbx[iii].disabled = "ro" == vis;
			Element.setStyle(items[iii], {"display": vo && !chkbx[iii].checked ? "none" : ""});
		}
		if (isNaN(ncols) || ncols < 1){
			this.clear(this.element);
			if (this.tbody_){
				this.tbody_ = null;
				this.col_ = null;
			}
			var lastchecked = -1;
			for (var iii = chkbx.length - 1; iii >= 0; --iii)
				if (chkbx[iii].checked){ lastchecked = iii; break; }
			for (var iii = 0; iii < items.length; ++iii){
				this.element.appendChild(items[iii]);
				if (vo && chkbx[iii].checked && iii < lastchecked)
					this.element.appendChild(document.createTextNode(this.delimiter_));
			}
		}else{
			if (!this.tbody_){
				this.clear(this.element);
				var table = this.element.appendChild(document.createElement("table"));
				this.col_ = table.appendChild(document.createElement("col"));
				this.col_.width = "1*";
				this.tbody_ = table.appendChild(document.createElement("tbody"));
			}else while (this.tbody_.rows.length > 0) this.tbody_.deleteRow(0);
			if (this.col_) this.col_.span = ncols;
			var tr = null;
			var td = null;
			var num = -1;
			for (var iii = 0; iii < items.length; ++iii){
				if (Element.getStyle(items[iii], "display") != "none"){
					++num;
					if (num % ncols == 0) tr = this.tbody_.insertRow(-1);
					td = tr.insertCell(-1)
				}else if (!tr){
					tr = this.tbody_.insertRow(-1);
					Element.setStyle(tr, {"display": "none"});
					td = tr.insertCell(-1);
				}
				if (td) td.appendChild(items[iii]);
				else alert("no parent");
			}
		}
		Element.setStyle(this.element, {"display": ""});
	},

	get_cols: function(){
		var str = this.desc["cols"];
		return str ? parseInt(str, 10) : 0;
	},

	SetAttribute: function($super, nam, val){
		switch (nam){
			case "src":
				if (val == this.src_) break;
				this.src_ = val;
				this.dynamic_ = true;
				this.loaded_ = false;
				new ServerCall(val, null, {
					"onSuccess": this.init_dynamic,
					"thisObject": this
				});
				break;
			case "visibility":
				if (!["yes", "ro", "vo", "link", "no"].include(val)) break;
				if (typeof this.visibility_ == "undefined") this.visibility_ = "yes";
				if (this.visibility_ == val) break;
				this.visibility_ = val;
				Element.setStyle(this.element, {"display": val == "no" ? "none" : ""});
				Element[val == "vo" || val == "link" ? "addClassName" : "removeClassName"](this.element, "VO");
				Element[val == "link" ? "addClassName" : "removeClassName"](this.element, "Link");
				if (val == "link"){
					if (!this.link_click_handler_) this.link_click_handler_ = function(event){ new AEvent("CLICK", {}, this); }.bind(this);
					Event.observe(this.element, "click", this.link_click_handler_);
				}else if(this.link_click_handler_) Event.stopObserving(this.element, "click", this.link_click_handler_);
				this.reset_layout(this.get_cols(), this.visibility_);
				break;
			case "cols":
				if (this.desc[nam] == val) return;
				this.desc[nam] = val;
				this.element.setAttribute(nam, val);
				this.reset_layout(this.get_cols(), this.visibility_);
				break;
			case "delimiter":
				this.delimiter_ = val;
				break;
			default: $super(nam, val);
		}
	}
});