(function($) {

	PPTimeline = function( settings, $scope ) {
		this.node         = $scope;
		this.timeline     = this.node.find('.pp-timeline');
		this.items        = this.node.find('.pp-timeline-vertical .pp-timeline-item');
		this.connector    = this.node.find('.pp-timeline-vertical .pp-timeline-connector');
		this.progressBar  = this.node.find('.pp-timeline-vertical .pp-timeline-connector-inner');
		this.markerClass  = this.node.find('.pp-timeline-vertical .pp-timeline-marker-wrapper');

		if ( 'undefined' !== typeof settings.window ) {
			this.window	= settings.window;
		}

		this.init();
	};

	PPTimeline.prototype = {
		node: '',
		items: '',
		connector: '',
		progressBar: '',
		window: $(window),
		winHeight: 0,
		scrollTop: 0,
		lastWinHeight: -1,
		lastScrollTop: -1,
		isScrolling: false,
		isResizing: false,
		isAnimating: false,
		animationClass: 'bounce-in',

		init: function()
		{
            var timeline_layout = this.timeline.data('timeline-layout');

            if ( timeline_layout == 'vertical' ) {
                this.winHeight	= $(window).height();
                this.scrollTop	= this.window.scrollTop();

                this.bindEvents();
                this.requestAnimation();
                this.revealItems();
            }
		},

		bindEvents: function()
		{
			this.window.on( 'scroll', $.proxy( function() {
				this.scrollTop = this.window.scrollTop();
				
				this.requestAnimation();
				this.revealItems();
			}, this ) );

			$(window).on( 'resize', $.proxy( function() {
				this.scrollTop 	= this.window.scrollTop();
				this.winHeight	= $(window).height();
	
				this.requestAnimation();
			}, this ) );
		},

		requestAnimation: function()
		{
			if ( ! this.isAnimating ) {
				var frameId = requestAnimationFrame( this.reboot.bind(this) );
			}

			this.isAnimating = true;
		},

		revealItems: function()
		{
			var self = this;

			this.items.each( function() {
				if ( ( $(this).offset().top <= ( self.window.scrollTop() + $(window).outerHeight() * 0.95 ) ) && $(this).hasClass('pp-timeline-item-hidden') ) {
					$(this).removeClass('pp-timeline-item-hidden').addClass( self.animationClass );
				}
			} );
		},

		setup: function()
		{
			var self = this,
				lastMarkerHeight = this.items.last().find( this.markerClass ).outerHeight();

			this.connector.css({
				'top': self.items.first().find( self.markerClass ).offset().top - self.items.first().offset().top,
				'bottom': ( self.node.offset().top + self.node.outerHeight() ) - self.items.last().find( self.markerClass ).offset().top - ( lastMarkerHeight / 2 )
			});
		},

		reboot: function()
		{
			this.isAnimating = false;

			if ( this.winHeight !== this.lastWinHeight ) {
				this.setup();
			}

			this.start.bind( this )();
		},

		start: function()
		{
			if ( this.scrollTop !== this.lastScrollTop || this.winHeight !== this.lastWinHeight ) {
				this.lastScrollTop = this.scrollTop;
				this.lastWinHeight = this.winHeight;

				this.progress();
			}
		},

		progress: function()
		{
			var self = this,
				win	= $(window);

			this.items.each( function() {
				if ( $(this).find( self.markerClass ).offset().top < ( self.window.scrollTop() + win.outerHeight() / 2 ) ) {
					$(this).addClass('pp-timeline-item-active');
				} else {
					$(this).removeClass('pp-timeline-item-active');
				}
			} );

			var lastMarkerPos = this.items.last().find( this.markerClass ).offset().top,
				lastMarkerHeight = this.items.last().find( this.markerClass ).outerHeight(),
				progressPos	= ( this.window.scrollTop() - this.progressBar.offset().top ) + ( win.outerHeight() / 2 );

			if ( lastMarkerPos <= ( this.window.scrollTop() + win.outerHeight() / 2 ) ) {
				progressPos = lastMarkerPos - this.progressBar.offset().top;
			}
			
			progressPos = progressPos + ( lastMarkerHeight / 2 );

			this.progressBar.css( 'height', progressPos + 'px' );
		}
	};

})(jQuery);