Fx.AutoLockedAccordion = new Class({

	Extends: Fx.Elements,

	options: {/*
		onActive: $empty(toggler, section),
		onBackground: $empty(toggler, section),
		fixedHeight: false,
		fixedWidth: false,
		*/
		display: 0,
		show: false,
		height: true,
		width: false,
		opacity: true,
		alwaysHide: false,
		trigger: 'click',
		initialDisplayFx: true,
		returnHeightToAuto: true,
		lockClass: 'locked'
	},

	initialize: function(){
		var defined = function(obj){
			return obj != null;
		};
		var params = Array.link(arguments, {
			'container': Type.isElement, //deprecated
			'options': Type.isObject,
			'togglers': defined,
			'elements': defined
		});
		this.parent(params.elements, params.options);
		this.togglers = $$(params.togglers);
		this.previous = -1;
		this.internalChain = new Chain();
		if (this.options.alwaysHide) this.options.wait = true;
		if (this.options.show || this.options.show === 0){
			this.options.display = false;
			this.previous = this.options.show;
		}
		if (this.options.start){
			this.options.display = false;
			this.options.show = false;
		}
		this.effects = {};
		if (this.options.opacity) this.effects.opacity = 'fullOpacity';
		if (this.options.width) this.effects.width = this.options.fixedWidth ? 'fullWidth' : 'offsetWidth';
		if (this.options.height) this.effects.height = this.options.fixedHeight ? 'fullHeight' : 'scrollHeight';
		for (var i = 0, l = this.togglers.length; i < l; i++) this.addSection(this.togglers[i], this.elements[i]);
		this.elements.each(function(el, i){
//			if (this.options.show === i){
			if ((this.options.show === i) || (this.togglers[i].hasClass(this.options.lockClass))){
				this.fireEvent('active', [this.togglers[i], el]);
			} else {
				for (var fx in this.effects) el.setStyle(fx, 0);
			}
		}, this);
		if (this.options.display || this.options.display === 0 || this.options.initialDisplayFx === false) this.display(this.options.display, this.options.initialDisplayFx);
		if (this.options.fixedHeight !== false) this.options.returnHeightToAuto = false;
		this.addEvent('complete', this.internalChain.callChain.bind(this.internalChain));
	},

	addSection: function(toggler, element){
		toggler = document.id(toggler);
		element = document.id(element);
		var test = this.togglers.contains(toggler);
		this.togglers.include(toggler);
		this.elements.include(element);
		var idx = this.togglers.indexOf(toggler);
		var displayer = this.display.bind(this, idx);
		toggler.store('accordion:display', displayer);
		toggler.addEvent(this.options.trigger, displayer);
		if (this.options.height) element.setStyles({'padding-top': 0, 'border-top': 'none', 'padding-bottom': 0, 'border-bottom': 'none'});
		if (this.options.width) element.setStyles({'padding-left': 0, 'border-left': 'none', 'padding-right': 0, 'border-right': 'none'});
		element.fullOpacity = 1;
		if (this.options.fixedWidth) element.fullWidth = this.options.fixedWidth;
		if (this.options.fixedHeight) element.fullHeight = this.options.fixedHeight;
		element.setStyle('overflow', 'hidden');
		if (!test){
			for (var fx in this.effects) element.setStyle(fx, 0);
		}
//
		if (toggler.hasClass(this.options.lockClass)) {
			this.display(element);
		}
//
		return this;
	},

	removeSection: function(toggler, displayIndex){
		var idx = this.togglers.indexOf(toggler);
		var element = this.elements[idx];
		var remover = function(){
			this.togglers.erase(toggler);
			this.elements.erase(element);
			this.detach(toggler);
		}.bind(this);

		if (this.now == idx || displayIndex != null){
			this.display(displayIndex != null ? displayIndex : (idx - 1 >= 0 ? idx - 1 : 0)).chain(remover);
		} else {
			remover();
		}
		return this;
	},

detach: function(){
		this.togglers.each(function(toggler) {
			toggler.removeEvent(this.options.trigger, toggler.retrieve('accordion:display'));
		}, this);
	},

	display: function(index, useFx){
		if (!this.check(index, useFx)) return this;
		useFx = useFx != null ? useFx : true;
		if (this.options.returnHeightToAuto){
			var prev = this.elements[this.previous];
			if (prev && !this.selfHidden){
				for (var fx in this.effects){
					prev.setStyle(fx, prev[this.effects[fx]]);
				}
			}
		}
		index = (typeOf(index) == 'element') ? this.elements.indexOf(index) : index;
//		if ((this.timer && this.options.wait) || (index === this.previous && !this.options.alwaysHide)) return this;
		if ((this.timer && this.options.wait) || (index === this.previous && !this.options.alwaysHide) || (this.togglers[index].hasClass(this.options.lockClass) && (this.elements[index].offsetHeight > 0))) return this;
		this.previous = index;
		var obj = {};
		this.elements.each(function(el, i){
			obj[i] = {};
			var hide;
			if (i != index){
				if (!this.togglers[i].hasClass(this.options.lockClass)) {
					hide = true;
				}
			} else if (this.options.alwaysHide && ((el.offsetHeight > 0 && this.options.height) || el.offsetWidth > 0 && this.options.width)){
				hide = true;
				this.selfHidden = true;
			}
			this.fireEvent(hide ? 'background' : 'active', [this.togglers[i], el]);
			for (var fx in this.effects) obj[i][fx] = hide ? 0 : el[this.effects[fx]];
		}, this);
		this.internalChain.chain(function(){
			if (this.options.returnHeightToAuto && !this.selfHidden){
				var el = this.elements[index];
				if (el) el.setStyle('height', 'auto');
			};
		}.bind(this));
		return useFx ? this.start(obj) : this.set(obj);
	}

});