var TabElement = Class.create({
initialize: function(params) {
	this.ID_=params.id;
	this.TabBar=params.tabbar;
	this.root = $(params.id);
	this.menuitem = $(params.id + '_tabitem');
	this.root.JSControl=this;
	this.label = this.root.readAttribute('label');
	this.width = this.root.offsetWidth;

	if(Prototype.Browser.IE) {
		this.root.observe('keydown', this.OnKeyDown.bind(this));
	}
	else {
		this.root.observe('keypress', this.OnKeyDown.bind(this));
	}
	this.root.observe('click', this.OnClick.bind(this));
	this.root.observe('focus', this.Focus.bind(this, true));
	this.root.observe('blur', this.Focus.bind(this, false));
	AControl.AddDefaultHandler('CLICK', this.ID_);

	this.Visible = true;
},
Show: function(show) {
	this.Visible = show;
	if (show) {
		this.root.show();
		this.menuitem.hide();
	}
	else {
		this.root.hide();
		this.menuitem.show();
	}
},
SetLast: function(last) {
	if (last) this.root.addClassName("LastTab");
	else this.root.removeClassName("LastTab");
},
Width: function() {
	return this.width;
},
OnClick: function() {
	this.TabBar.Highlight(this);
	new AEvent('CLICK', {}, this.ID_);
},
Focus: function(focused, evt) {
	if (focused) this.root.addClassName('TabBarFocus');
	else this.root.removeClassName('TabBarFocus');
},
Highlight: function(selected) {
	if (selected) {
		this.root.addClassName('TabBarActive');
		this.menuitem.addClassName('TabMenuActive');
	}
	else {
		this.root.removeClassName('TabBarActive');
		this.menuitem.removeClassName('TabMenuActive');
	}
},
OnKeyDown: function(evt) {
	var key=$(evt).which || evt.keyCode;

	switch(key) {
		case 32: // space
		case 13: // enter
		this.OnClick();
		break;
	}
},

SetTabOrder: function(nTabBase) {
	this.root.writeAttribute('tabindex', nTabBase);
	return ++nTabBase;
},
ID: function() {
	return this.ID_;
}
});

var TabBar = Class.create({
initialize: function(params) {
	this.id=params.id;
	this.htmlid=params.htmlid;
	this.winID=params.winID;
	this.visible = true;
	this.tabs = [];
	this.path = [];

	GWindowManager.GetWindow( this.winID )
		.RegisterResizeableChild(this.htmlid + "_tabbar");

	this.popup = new PopupMenu({htmlid: this.htmlid + "_tabmenu"});
	this.tabcontainer = $(this.htmlid + "_tabbar");
	this.morebutton = $(this.htmlid + "_tabmore");	

	this.tabcontainer.JSControl = this;

	if (this.morebutton) {
		this.morebutton.observe('click', this.OnMoreClick.bind(this));
		this.morewidth = this.morebutton.offsetWidth;
	}

	new AEvent('WM_TABBAR',  { winID: this.winID } , this.htmlid);

	SubscribeOnEvent("WM_TABBAR", this.winID, this.Tabbar, this);
	SubscribeOnEvent("WM_RESTORE", this.winID, this.Restore, this);

	SubscribeOnEvent("WM_PUSH", this.winID, this.MainClicked, this);
	SubscribeOnEvent("WM_BACK", this.winID, this.Back, this);
},
OnMoreClick: function() {
	var b = this.morebutton;
	b.addClassName('TabMoreActive');

	this.popup.Show( function(tab) {
		b.removeClassName('TabMoreActive');
		if (tab) tab.OnClick();
	});
},
OnResize: function() {
	this.UpdateWidth();
},
UpdateWidth: function(evt) {
	if (!this.tabs.length || !this.morebutton) return;
	
	for (var i = 0; i < this.tabs.length; ++i) {
		this.tabs[i].Show(false);
	}
	
	var w = 0;
	var availW = this.tabcontainer.offsetWidth;
	var i = 0;
	for (; i < this.tabs.length; ++i) {
		w += this.tabs[i].Width();

		if (w + this.morewidth > availW) break;
		else {
			this.tabs[i].SetLast(false);
			this.tabs[i].Show(true);
		}
	}
	if (i > 0) this.tabs[i - 1].SetLast(true);

	if (i == this.tabs.length) this.morebutton.hide();
	else this.morebutton.show();

	for (; i < this.tabs.length; ++i) {
		this.tabs[i].Show(false);
	}
},
Tabbar: function(evt) {
	if (this.visible) {
		evt.Data().oldWinID = this.winID;
		this.visible = false;
	}
},
Restore: function(evt) {
	this.visible = true;
	this.tabs[this.selected].OnClick();
	this.path.length=0;
	evt.Stop();
},
Built: function() {
	var selected = 0;
	for (var i = 0; i < this.tabs.length; ++i) {
		var a = $( this.tabs[i].ID() ).readAttribute('selected');
		if (a == 'true' || a == 'yes') {
			selected = i;
			break;
		}
	}

	if (this.tabs.length > 0) this.tabs[selected].OnClick();
	this.UpdateWidth();
},
AddTab: function(id) {
	var tab = new TabElement({'id': id, 'tabbar': this});
	this.tabs.push(tab);

	if (this.morebutton) this.popup.AddItem(id + '_tabitem', tab);
},
Back: function(evt) {
	if (!this.visible) return;

	var data=evt.Data();
	var step=parseInt(data.step);
	if(this.path.length-step<0) return;
	var index=this.path.length-step;
	var winHnd=this.path[index];

	var newParams=winHnd.params;
	if(data.refresh=='yes') {
		var vp=URLRestoreVS(winHnd.params);
		for(var p in vp) {
			data.args[p]=vp[p];
		}
		newParams=URLSerializeVS(data.args);
	}
	// TODO: rename 'refresh' to something more understandable
	if(data.refresh=='override') {
		var vp=URLRestoreVS(winHnd.params);
		for(var p in data.args) {
			vp[p]=data.args[p];
		}
		newParams=URLSerializeVS(vp);
	}
	var win=GWindowManager.RefreshWindow({
		sURL: winHnd.src,
		sParent: winHnd.parent,
		sControlID: winHnd.htmlid,
		sParams: newParams,
		sInstanceID: winHnd.instanceID
	});
	// TODO: kosherize access to internal AWindow variables
	if (data.refresh=='yes' && win) win.sParams_=winHnd.params;
	this.path.length=index;

	if (GPopupContainer) GPopupContainer.RemoveAllPopups()
	evt.Stop();
},
MainClicked: function(evt) {
	if (!this.visible) return;

	var data=evt.Data();
	var sArgs="";
	if(data.args) sArgs=URLSerializeVS(data.args);
	if(data.target!='tabbar') {
		var bCheckChanges=true; // default behaviour

		if(evt.Name()=="WM_PUSH") bCheckChanges=false;
		if(data['track-changes']) { 
			if(data['track-changes']=='no' || data['track-changes']=='false') bCheckChanges=false;
			else bCheckChanges=true;
		}

		// remember an old window
		var win=$(this.htmlid+"_WorkSpace").select('DIV')[0].JSControl;

		GWindowManager.CreateWindow({
			sURL: data.src,
			sParent: this.winID,
			sControlID: this.htmlid+"_WorkSpace",
			'bCheckChanges': bCheckChanges,
			sParams: sArgs});
		// looks very bad (uses AWindow internals, esp. sControlID_. TODO: kosherize
		this.path.push({src: win.XMLSource(), parent: win.Parent(), htmlid: win.sControlID_, params: win.sParams_, instanceID: win.InstanceID()});
		if (GPopupContainer) GPopupContainer.RemoveAllPopups();
		evt.Stop();
	}
	else {
		evt.Data()['CurrentWindow']=this.root;
	}
},
Highlight: function(tab) {
	for (var i = 0; i < this.tabs.length; ++i) {
		var sel = (this.tabs[i] == tab);
		this.tabs[i].Highlight(sel);

		if (sel) this.selected = i;
	}

	this.activeTabHidden = !tab.Visible;
	if (!this.morebutton) return;

	if (this.activeTabHidden) this.morebutton.addClassName('TabMoreActive');
	else this.morebutton.removeClassName('TabMoreActive');
},
SetTabOrder: function(nTabBase) {
	for(var i = 0; i < this.tabs.length; ++i) {
		this.tabs[i].SetTabOrder(nTabBase + i);
	}
	return nTabBase + this.tabs.length;
},

ID: function() { return this.ID_; }
});