/* created by legendary MooTools developer, Jan Kassens */
Fx.Explode = new Class({
	Extends: Fx.CSS,
	
	options: {
		grow: 2,
		expand: 1,
		transition: "expo:out",
		duration: 500
	},

	initialize: function(elements, options){
		this.elements = this.subject = $$(elements);
		this.parent(options);
		this.addEvent('complete', function(){
			this.clones.dispose();
			if (this.inverted) this.elements.setStyle('opacity', 1);
		}, true);
	},

	compute: function(from, to, delta){
		var now = {};
		for (var i in from){
			var iFrom = from[i], iTo = to[i], iNow = now[i] = {};
			for (var p in iFrom) iNow[p] = this.parent(iFrom[p], iTo[p], delta);
		}
		return now;
	},

	set: function(now){
		for (var i in now){
			var iNow = now[i];
			for (var p in iNow) this.render(this.clones[i], p, iNow[p], this.options.unit);
		}
		return this;
	},

	start: function(fromX, fromY, inverted){
		this.inverted = !!inverted;
		var from = {}, to = {};
		this.clones = $$(this.elements.map(function(el, i){
			var clone = el.clone();
			var coords = el.getCoordinates();
			clone.setStyles(coords).setStyle('position', 'absolute').inject(document.body);
			el.setStyle('visibility', 'hidden');
			
			var center = {
				x: coords.left + coords.width / 2,
				y: coords.top + coords.height / 2
			};
			
			var self = this;
			(function(prop, end){
				var parsed = self.prepare(clone, prop, end);
				if (self.inverted) {
					(from[i] = from[i] || {})[prop] = parsed.to;;
					(to[i] = to[i] || {})[prop] = parsed.from;
				} else {
					(from[i] = from[i] || {})[prop] = parsed.from;;
					(to[i] = to[i] || {})[prop] = parsed.to;
				}
				return arguments.callee;
			})
			('top', coords.top + (center.y - fromY) * this.options.expand - coords.height * this.options.grow / 2)
			('left', coords.left + (center.x - fromX) * this.options.expand - coords.width * this.options.grow / 2)
			('width', coords.width * (1 + this.options.grow))
			('height', coords.height * (1 + this.options.grow))
			('opacity', 0);
			
			return clone;
		}, this));
		return this.parent(from, to);
	}
});