// page init
jQuery(function(){
	initBackgroundResize();
});
jQuery(window).load(function(){
	initSlideBlock();
});

// image stretch init
function initBackgroundResize() {
	var holder = document.getElementById('bg');
	var images = holder.getElementsByTagName('img');
	for(var i = 0; i < images.length; i++) {
		backgroundStretcher.stretchImage(images[i]);
	}
	backgroundStretcher.setBgHolder(holder);
};

// slide block init
function initSlideBlock(){
	var animSpeed = 1500; //ms
	jQuery('div.slide').animate({marginLeft:0},{duration: animSpeed, queue: false})
	
};

// image stretch module
backgroundStretcher = {
	images: [],
	holders: [],
	viewWidth: 0,
	viewHeight: 0,
	stretchByWindow: true,
	init: function(){
		this.addHandlers();
		this.resizeAll();
		return this;
	},
	stretchImage: function(obj) {
		var img = new Image();
		img.onload = this.bind(function(){
			obj.iRatio = img.width / img.height;
			obj.iWidth = img.width;
			obj.iHeight = img.height;
			obj.style.msInterpolationMode = 'bicubic'; // IE7 fix
			this.resizeImage(obj);
		});
		img.src = obj.src;
		this.images.push(obj);
	},
	setBgHolder: function(obj) {
		this.holders.push(obj);
		this.resizeAll();
	},
	resizeImage: function(obj) {
		if(obj.iRatio) {
			var slideWidth = this.viewWidth;
			var slideHeight = slideWidth / obj.iRatio;
			if(slideHeight < this.viewHeight) {
				slideHeight = this.viewHeight;
				slideWidth = slideHeight * obj.iRatio;
			}
			obj.style.width = slideWidth+'px';
			obj.style.height = slideHeight+'px';
			obj.style.top = (this.viewHeight - slideHeight)/2+'px';
			obj.style.left = (this.viewWidth - slideWidth)/2+'px';
		}
	},
	resizeHolder: function(obj) {
		obj.style.width = this.viewWidth+'px';
		obj.style.height = this.viewHeight+'px';
	},
	getWindowWidth: function() {
		return typeof window.innerWidth === 'number' ? window.innerWidth : document.documentElement.clientWidth;
	},
	getWindowHeight: function() {
		return typeof window.innerHeight === 'number' ? window.innerHeight : document.documentElement.clientHeight;
	},
	getPageWidth: function() {
		if(!document.body) return 0;
		return Math.max(
			Math.max(document.body.clientWidth, document.documentElement.clientWidth),
			Math.max(document.body.offsetWidth, document.body.scrollWidth)
		);
	},
	getPageHeight: function() {
		if(!document.body) return 0;
		return Math.max(
			Math.max(document.body.clientHeight, document.documentElement.clientHeight),
			Math.max(document.body.offsetHeight, document.body.scrollHeight)
		);
	},
	resizeAll: function() {
		for(var i = 0; i < this.holders.length; i++) {
			this.holders[i].style.width = '100%'; 
		}
		clearTimeout(this.resizeTimer);
		this.resizeTimer = setTimeout(this.bind(function(){
			// hide background holders
			for(var i = 0; i < this.holders.length; i++) {
				this.holders[i].style.display = 'none';
			}
			this.viewWidth = this[this.stretchByWindow ? 'getWindowWidth' : 'getPageWidth']();
			this.viewHeight = this[this.stretchByWindow ? 'getWindowHeight' : 'getPageHeight']();
			for(i = 0; i < this.holders.length; i++) {
				this.holders[i].style.display = 'block';
				this.resizeHolder(this.holders[i]);
			}
			for(i = 0; i < this.images.length; i++) {
				this.resizeImage(this.images[i]);
			}
		}),10);
	},
	addHandlers: function() {
		if (window.addEventListener) window.addEventListener('resize', this.bind(this.resizeAll), false);
		else if (window.attachEvent) window.attachEvent('onresize', this.bind(this.resizeAll));
	},
	bind: function(fn, scope, args) {
		var newScope = scope || this;
		return function() {
			return fn.apply(newScope, args || arguments);
		}
	} 
}.init();