/** InfiniteScroller
 *	
 *	Developped for Alfi
 *	@author : Michel-Ange K. partikule, 2010
 *
 */



InfiniteScroller = new Class({

	Extends: Scroller,

	options: {
		mode: 'horizontal',
		nbElements: 4,
		fps: 50
	},

	initialize: function(element, options){
		this.setOptions(options);
		this.element = document.id(element);
		this.docBody = document.id(this.element.getDocument().body);
		this.listener = ($type(this.element) != 'element') ?  this.docBody : this.element;
		this.timer = null;
		this.bound = {
			attach: this.attach.bind(this),
			detach: this.detach.bind(this),
			getCoords: this.getCoords.bind(this)
		};
		this.buildArea();
	},


	buildArea:function()
	{
		this.scroller = this.element.getFirst('div');

		// Dupliquate content to scroll infinitely
		this.scroller.getChildren().clone().inject(this.scroller);

		this.scroller.getChildren().each(function(item, idx){
			item.setProperty('id', 'el' + idx);
		})

		var p = this.scroller.getFirst();
		var size = p.getSize();
	
		// Set the container size
		var X = size.x * this.options.nbElements;
		var Y = size.y * this.options.nbElements;
		
		this.element.setStyles({
			'overflow': 'hidden',
			'height': (this.options.mode == 'horizontal') ? size.y : Y,
			'width': (this.options.mode == 'horizontal') ? X : size.x
		});
		
		// Set the child size
		var n = this.scroller.getChildren().length;
		
		this.scroller.setStyles({
			'height': (this.options.mode == 'horizontal') ? size.y : n * size.y,
			'width': (this.options.mode == 'horizontal') ? n * size.x : size.x
		});
		
		// Set the sensitive area size
		this.options.area = (this.options.mode == 'horizontal') ? X/2 : Y/2;
		
	},

	start: function(){
		this.listener.addEvents({
			mouseenter: this.bound.attach,
			mouseleave: this.bound.detach
		});
	},

	stop: function(){
		this.listener.removeEvents({
			mouseenter: this.bound.attach,
			mouseleave: this.bound.detach
		});
		this.detach();
		this.timer = $clear(this.timer);
	},

	attach: function()
	{
		this.listener.addEvent('mousemove', this.bound.getCoords);
		this.timerOut = $clear(this.timerOut);
	},

	detach: function(ev)
	{
//		this.log('ev',this.timer);	
		this.listener.removeEvent('mousemove', this.bound.getCoords);
		this.timer = $clear(this.timer);
		
		this.smoothOut();
	},

	smoothOut: function(event){
		if (!this.timerOut && this.change) this.timerOut = this.smoothOutCalculate.periodical(Math.round(1000 / this.options.fps), this);
	},

	smoothOutCalculate: function()
	{
		var	size = this.element.getSize(), 
			pos = this.element.getOffsets(),
			d = 0,
			v = 0,
			direction= 1;
	
		var speed = {x:this.change.x * this.options.fps, y:this.change.y * this.options.fps};
		
		var dir = (this.options.mode == 'horizontal') ? 'x' : 'y' ;

		if (speed[dir] > 0)
		{
			// distance = page position - origin
			d = this.page[dir] - pos[dir] - (size[dir] / 2);
			direction = -1;
		}
		else if (speed[dir] < 0)
			d = (pos[dir] + (size[dir] / 2)) - this.page[dir];
			
		v = d / 15;
		this.page[dir] += v * direction;

		if (v < 0.5)
			this.timerOut = $clear(this.timerOut);

		// this.log('x', v);
				
		this.scroll();
	},

	scroll: function()
	{
		var size = this.element.getSize(), 
			scroll = this.element.getScroll(), 
			pos = this.element != this.docBody ? this.element.getOffsets() : {x: 0, y:0}, 
			scrollSize = this.element.getScrollSize(), 
			change = {x: 0, y: 0};

		
		for (var z in this.page) 
		{		
			if (this.page[z] < (this.options.area + pos[z]) && scroll[z] != 0)
				change[z] = (this.page[z] - this.options.area - pos[z]) * this.options.velocity;
			else if (this.page[z] + this.options.area > (size[z] + pos[z]) && scroll[z] + size[z] != scrollSize[z])
				change[z] = (this.page[z] - size[z] + this.options.area - pos[z]) * this.options.velocity;
			else
			{
				if (this.options.mode == 'horizontal') 
				{
					// Swith when arriving max right
					if (scroll.x == 0) {
						this.element.scrollTo(scrollSize.x/2, 0);
						break;
					}
					if (scroll.x == scrollSize.x - size.x)
					{
						this.element.scrollTo(scroll.x - scrollSize.x/2, 0);
						break;
					}
				}
	
				if (this.options.mode == 'vertical') {
					
					if (scroll.y == 0) {
						this.element.scrollTo(0, scrollSize.y/2);
						break;
					}
	
					if (scroll.y == scrollSize.y - size.y) {
						this.element.scrollTo(0, scroll.y - scrollSize.y/2);
						break;
					}
				}
			}
		}
//		log.log('change', change.x + '::' + change.y);		

		this.change = {x: change.x, y: change.y};
		if (change.y || change.x) 
			this.fireEvent('change', [scroll.x + change.x, scroll.y + change.y]);
	},
	
	
	log: function(key, value, clean) {
		
		if (clean== true)
		{
			$('debug').set('html', key + ':' + '<b>' + value + '</b><br/>');
		}
		else
		{
			$('debug').set('html', $('debug').get('html') + key + ':' + '<b>' + value + '</b><br/>');
		}
	},
	log2: function(key, value, clean) {
		
		$('debug2').setStyles({
			// 'font-size' : parseInt(Math.random()/4 * 10) * 30 + 'px'
		});
		
		if (clean== true)
		{
			$('debug2').set('html', key + ':' + '<b>' + value + '</b><br/>');
		}
		else
		{
			$('debug2').set('html', $('debug2').get('html') + key + ':' + '<b>' + value + '</b><br/>');
		}
	}

});