/*
---
name: TabSwapper.js
authors: Aaron Newton
description: Handles the scripting for a common UI layout; the tabbed box.
license: MIT-Style License
requires:
 core:1.2.4: [Element.Event, Fx.Tween, Fx.Morph]
 more:1.2.4.2: [Element.Shortcuts, Element.Dimensions, Element.Measure]
provides: [TabSwapper]
...
*/

var TabSwapper = new Class({
	Implements: [Options, Events],
	options: {
		selectedClass: 'tabSelected',
		mouseoverClass: 'tabOver',
		deselectedClass: '',
		rearrangeDOM: true,
		initPanel: 0, 
		smooth: false, 
		smoothSize: false,
		maxSize: null,
		effectOptions: {
			duration: 500
		},
		cookieName: null, 
		cookieDays: 999
//	onActive: $empty,
//	onActiveAfterFx: $empty,
//	onBackground: $empty
	},
	tabs: [],
	sections: [],
	clickers: [],
	sectionFx: [],
	initialize: function(options){
		this.setOptions(options);
		var prev = this.setup();
		if (prev) return prev;
		if (this.options.cookieName && this.recall()) this.show(this.recall().toInt());
		else this.show(this.options.initPanel);
	},
	setup: function(){
		var opt = this.options;
		sections = $$(opt.sections);
		tabs = $$(opt.tabs);
		if (tabs[0] && tabs[0].retrieve('tabSwapper')) return tabs[0].retrieve('tabSwapper');
		clickers = $$(opt.clickers);
		tabs.each(function(tab, index){
			this.addTab(tab, sections[index], clickers[index], index);
		}, this);
	},
	addTab: function(tab, section, clicker, index){
		tab = document.id(tab); clicker = document.id(clicker); section = document.id(section);
		//if the tab is already in the interface, just move it
		if (this.tabs.indexOf(tab) >= 0 && tab.retrieve('tabbered') 
			 && this.tabs.indexOf(tab) != index && this.options.rearrangeDOM) {
			this.moveTab(this.tabs.indexOf(tab), index);
			return this;
		}
		//if the index isn't specified, put the tab at the end
		if (!$defined(index)) index = this.tabs.length;
		//if this isn't the first item, and there's a tab
		//already in the interface at the index 1 less than this
		//insert this after that one
		if (index > 0 && this.tabs[index-1] && this.options.rearrangeDOM) {
			tab.inject(this.tabs[index-1], 'after');
			section.inject(this.tabs[index-1].retrieve('section'), 'after');
		}
		this.tabs.splice(index, 0, tab);
		clicker = clicker || tab;

		tab.addEvents({
			mouseout: function(){
				tab.removeClass(this.options.mouseoverClass);
			}.bind(this),
			mouseover: function(){
				tab.addClass(this.options.mouseoverClass);
			}.bind(this)
		});

		clicker.addEvent('click', function(e){
			e.preventDefault();
			this.show(index);
		}.bind(this));

		tab.store('tabbered', true);
		tab.store('section', section);
		tab.store('clicker', clicker);
		this.hideSection(index);
		return this;
	},
	removeTab: function(index){
		var now = this.tabs[this.now];
		if (this.now == index){
			if (index > 0) this.show(index - 1);
			else if (index < this.tabs.length) this.show(index + 1);
		}
		this.now = this.tabs.indexOf(now);
		return this;
	},
	moveTab: function(from, to){
		var tab = this.tabs[from];
		var clicker = tab.retrieve('clicker');
		var section = tab.retrieve('section');
		
		var toTab = this.tabs[to];
		var toClicker = toTab.retrieve('clicker');
		var toSection = toTab.retrieve('section');
		
		this.tabs.erase(tab).splice(to, 0, tab);

		tab.inject(toTab, 'before');
		clicker.inject(toClicker, 'before');
		section.inject(toSection, 'before');
		return this;
	},
	show: function(i){
		if (!$chk(this.now)) {
			this.tabs.each(function(tab, idx){
				if (i != idx) 
					this.hideSection(idx);
			}, this);
		}
		this.showSection(i).save(i);
		return this;
	},
	save: function(index){
		if (this.options.cookieName) 
			Cookie.write(this.options.cookieName, index, {duration:this.options.cookieDays});
		return this;
	},
	recall: function(){
		return (this.options.cookieName)?$pick(Cookie.read(this.options.cookieName), false): false;
	},
	hideSection: function(idx) {
		var tab = this.tabs[idx];
		if (!tab) return this;
		var sect = tab.retrieve('section');
		if (!sect) return this;
		if (sect.getStyle('display') != 'none') {
			this.lastHeight = sect.getSize().y;
			sect.setStyle('display', 'none');
			tab.swapClass(this.options.selectedClass, this.options.deselectedClass);
			this.fireEvent('onBackground', [idx, sect, tab]);
		}
		return this;
	},
	showSection: function(idx) {
		var tab = this.tabs[idx];
		if (!tab) return this;
		var sect = tab.retrieve('section');
		if (!sect) return this;
		var smoothOk = this.options.smooth && !Browser.Engine.trident4;
		if (this.now != idx) {
			if (!tab.retrieve('tabFx')) 
				tab.store('tabFx', new Fx.Morph(sect, this.options.effectOptions));
			var overflow = sect.getStyle('overflow');
			var start = {
				display:'block',
				overflow: 'hidden'
			};
			if (smoothOk) start.opacity = 0;
			var effect = false;
			if (smoothOk) {
				effect = {opacity: 1};
			} else if (sect.getStyle('opacity').toInt() < 1) {
				sect.setStyle('opacity', 1);
				if (!this.options.smoothSize) this.fireEvent('onActiveAfterFx', [idx, sect, tab]);
			}
			if (this.options.smoothSize) {
				var size = sect.getDimensions().height;
				if ($chk(this.options.maxSize) && this.options.maxSize < size) 
					size = this.options.maxSize;
				if (!effect) effect = {};
				effect.height = size;
			}
			if ($chk(this.now)) this.hideSection(this.now);
			if (this.options.smoothSize && this.lastHeight) start.height = this.lastHeight;
			sect.setStyles(start);
			if (effect) {
				tab.retrieve('tabFx').start(effect).chain(function(){
					this.fireEvent('onActiveAfterFx', [idx, sect, tab]);
					sect.setStyles({
						height: this.options.maxSize == effect.height ? this.options.maxSize : "auto",
						overflow: overflow
					});
					sect.getElements('input, textarea').setStyle('opacity', 1);
				}.bind(this));
			}
			this.now = idx;
			this.fireEvent('onActive', [idx, sect, tab]);
		}
		tab.swapClass(this.options.deselectedClass, this.options.selectedClass);
		return this;
	}
});