if(typeof window.console === "undefined"){
	window.console = {
		log : function(){
			//do nothing
		}
	};
}
(function($){
	$.fn.extend({
		snapToggle : function(options){
			var _options = {
				initialPosition : 0
			},
			_bar = $('.snap-toggle-bar', this),
			_handle = $('.snap-toggle-handle', this),
			_listElements = $('ul li', this);

			$.extend(_options, options);
			this._snapToggle.setup(_options, _bar, _handle, _listElements);
		},
		
		_snapToggle : {
			options : null,
			bar : null,
			handle : null,
			listElements : null,
			length : null,
			position : 0,
			positionCoord : null,
			handleIsAnimating : false,
			previousPosition : null,
			
			setup : function(options, bar, handle, listElements){
				this.options = options;
				this.bar = bar;
				this.handle = handle;
				this.listElements = listElements;
				this.length = this.listElements.length;
				this.position = this.options.initialPosition;
				
				this.setupPositionCoords();
				this.setupInitialItemVisible();
				this.hookUpHandleListeners();
			},
			
			toString : function(){
				console.log(this.options);
				console.log(this.bar);
				console.log(this.handle);
			},
			
			setupPositionCoords : function(){
				this.positionCoord = new Array(this.length);
				this.positionCoord[0] = parseInt(this.handle.css('margin-left'));
				this.positionCoord[this.length - 1] = this.determineLastPosition();
				this.determineMiddlePositions();
			},
			
			setupInitialItemVisible : function(){
				this.animateHandle(this.position);
				this.animateListElement(this.position);
			},
			
			determineLastPosition : function(){
				var barLength = parseInt(this.bar.css('width'));
				var handleWidth = parseInt(this.handle.css('width'));
				var margin = parseInt(this.handle.css('margin-left'));
				return barLength - handleWidth - margin;
			},
			
			determineMiddlePositions : function(){
				var totalWidth = this.positionCoord[this.length - 1] - this.positionCoord[0];
				var incrementLength = totalWidth / (this.length - 1);
				for(var i = 1 ; i < this.length - 1; i++){
					this.positionCoord[i]= i * incrementLength;
				}
				console.log(this.positionCoord);
			},
			
			hookUpHandleListeners : function(){
				var self = this;
				this.handle.mousedown(function(e){
					self.handleMouseDown(e);
				});
				this.handle.mouseup(function(e){
					self.handleMouseUp(e);
				});
				this.handle.hover(null, function(e){
					self.handleMouseUp(e);
				});
			},
			
			handleMouseDown : function(e){
				var self = this;
				var previousOffsetX = null;
				this.handle.mousemove(function(e){
					previousOffsetX = self.handleMouseMove(e, previousOffsetX);
				});
			},
			
			handleMouseUp : function(e){
				this.handle.unbind('mousemove');
			},
			
			handleMouseMove : function(e, previousOffsetX){
				var self = this;
				if(previousOffsetX === null){
					previousOffsetX = e.pageX;
				}
				var offset = e.pageX - previousOffsetX;
				console.log(e);
				if(offset > 0){
					this.next();
				} else if(offset < 0){
					this.prev();
				}
				
				return e.pageX;
			},
			
			animateListElement : function(position){
				var self = this;
				var current = this.listElements[position];
				
				if(this.previousPosition === null){
					$(current).css({
						'z-index' : 10
					});
					$(current).animate({
						'opacity' : 1
					});
				} else {
					var previous = this.listElements[this.previousPosition];
					$(previous).css({
						'z-index' : 5
					});
					this.bringForward(current, function(){
						$(previous).css({
							'z-index' : 1,
							'opacity' : 0
						});
					});
				}				
			},
			
			bringForward : function(element, callback){
				$(element).css({
					'z-index' : 10
				});
				$(element).animate({
					opacity : 1
				}, 1000, 'swing', callback);
			},
			
			animateHandle : function(position){
				var self = this;
				this.handle.animate({
					'margin-left' : this.positionCoord[position] + 'px'
				}, 1000, 'swing', function(){
					self.handleIsAnimating = false;
				});
			},
			
			updatePosition : function(position){
				if(this.position !== position){
					this.previousPosition = this.position;
					this.position = position;
					this.handleIsAnimating = true;
					this.animateListElement(this.position);
					this.animateHandle(this.position);
				}
			},
			
			next : function(){
				if(this.position + 1 < this.length && 
					!this.handleIsAnimating){
					this.updatePosition(this.position + 1);
				}
			},
			
			prev : function(){
				if(this.position !== 0 && 
					!this.handleIsAnimating){
					this.updatePosition(this.position - 1);
				}
			}
		}
	});
})(jQuery);