if (typeof Effect == 'undefined')
throw("accordion.js requires including script.aculo.us' effects.js library!");

var Accordion = Class.create();
Accordion.prototype = {

	showAccordion: null,
	currentAccordion: null,
	duration: null,
	effects: [],
	animating: false,

	initialize: function(container, options) {
		if(!$(container)) {
			throw(container+" doesn't exist!");
			return false;
		}
		this.options = Object.extend({
			resizeSpeed: 8,
			classNames: {
				toggle: 'accordion-head',
				toggleActive: 'current',
				content: 'accordion-child'
			},
			defaultSize: {
				height: null,
				width: null
			},
			direction: 'vertical',
			onEvent: 'click'
		}, options || {});
		this.duration = ((11-this.options.resizeSpeed)*0.15);
		var accordions = $$('#'+container+' .'+this.options.classNames.toggle);
		accordions.each(function(accordion) {
			Event.observe(accordion, this.options.onEvent, this.activate.bind(this, accordion), false);
			if (this.options.onEvent == 'click') {
			  accordion.onclick = function() {return false;};
			}
			if(this.options.direction == 'horizontal') {
				var options = $H({width: '0px'});
			}
			else {
				var options = $H({height: '0px'});
			}
			options.merge({display: 'none'});
			this.currentAccordion = $(accordion.next(0)).setStyle(options);
		}.bind(this));
	},

	activate: function(accordion) {
		if(this.animating) {
			return false;
		}
		this.effects = [];
		this.currentAccordion = $(accordion.next(0));
		this.currentAccordion.setStyle({
			display: 'block'
		});
		this.currentAccordion.previous(0).addClassName(this.options.classNames.toggleActive);
		if(this.options.direction == 'horizontal') {
			this.scaling = $H({
				scaleX: true,
				scaleY: false
			});
		}
		else {
			this.scaling = $H({
				scaleX: false,
				scaleY: true
			});
		}

		if(this.currentAccordion == this.showAccordion) {
			this.deactivate();
		}
		else {
			this._handleAccordion();
		}
	},

	deactivate: function() {
		var options = $H({
		  duration: this.duration,
			scaleContent: false,
			transition: Effect.Transitions.sinoidal,
			queue: {
				position: 'end',
				scope: 'accordionAnimation'
			},
			scaleMode: {
				originalHeight: this.options.defaultSize.height ? this.options.defaultSize.height : this.currentAccordion.scrollHeight,
				originalWidth: this.options.defaultSize.width   ? this.options.defaultSize.width  : this.currentAccordion.scrollWidth
			},
			afterFinish: function() {
				this.showAccordion.setStyle({
					height: 'auto',
					display: 'none'
				});
				this.showAccordion = null;
				this.animating = false;
			}.bind(this)
		});
		options.merge(this.scaling);
		this.showAccordion.previous(0).removeClassName(this.options.classNames.toggleActive);
		new Effect.Scale(this.showAccordion, 0, options);
	},

	_handleAccordion: function() {
		var options = $H({
			sync: true,
			scaleFrom: 0,
			scaleContent: false,
			transition: Effect.Transitions.sinoidal,
			scaleMode: {
				originalHeight: this.options.defaultSize.height ? this.options.defaultSize.height : this.currentAccordion.scrollHeight,
				originalWidth: this.options.defaultSize.width   ? this.options.defaultSize.width  : this.currentAccordion.scrollWidth
			}
		});
		options.merge(this.scaling);
		this.effects.push(
			new Effect.Scale(this.currentAccordion, 100, options)
		);
		if (this.showAccordion) {
			this.showAccordion.previous(0).removeClassName(this.options.classNames.toggleActive);
			options = $H({
				sync: true,
				scaleContent: false,
				transition: Effect.Transitions.sinoidal
			});
			options.merge(this.scaling);
			this.effects.push(
				new Effect.Scale(this.showAccordion, 0, options)
			);
		}
		new Effect.Parallel(this.effects, {
			duration: this.duration,
			queue: {
				position: 'end',
				scope: 'accordionAnimation'
			},
			beforeStart: function() {
				this.animating = true;
			}.bind(this),
			afterFinish: function() {
				if(this.showAccordion) {
					this.showAccordion.setStyle({
						display: 'none'
					});
				}
				$(this.currentAccordion).setStyle({
				  height: 'auto'
				});
				this.showAccordion = this.currentAccordion;
				this.animating = false;
			}.bind(this)
		});
	}
}