$(document).ready(function() {
	
	redrawDotNav();
	
	/* Scroll event handler */
    $(window).bind('scroll',function(e){
    	parallaxScroll();
		redrawDotNav();
    });
    
	/* Next/prev and primary nav btn click handlers */
	$('a.home').click(function(){
    	$('html, body').animate({
    		scrollTop:0
    	}, 3500, function() {
	    	parallaxScroll(); // Callback is required for iOS
		});
    	return false;
	});
    $('a.about').click(function(){
    	$('html, body').animate({
    		scrollTop:$('#about').offset().top
    	}, 3500, function() {
	    	parallaxScroll(); // Callback is required for iOS
		});
    	return false;
    });
    $('a.speakers').click(function(){
    	$('html, body').animate({
    		scrollTop:$('#speakers').offset().top
    	}, 3500, function() {
	    	parallaxScroll(); // Callback is required for iOS
		});
    	return false;
    });
	$('a.original-gives').click(function(){
    	$('html, body').animate({
    		scrollTop:$('#original-gives').offset().top
    	}, 3500, function() {
	    	parallaxScroll(); // Callback is required for iOS
		});
    	return false;
    });
    
	$('a.at-a-glance').click(function(){
    	$('html, body').animate({
    		scrollTop:$('#at-a-glance').offset().top
    	}, 3500, function() {
	    	parallaxScroll(); // Callback is required for iOS
		});
    	return false;
    });
    
	$('a.details').click(function(){
    	$('html, body').animate({
    		scrollTop:$('#details').offset().top
    	}, 3500, function() {
	    	parallaxScroll(); // Callback is required for iOS
		});
    	return false;
    });
    
	$('a.contact').click(function(){
    	$('html, body').animate({
    		scrollTop:$('#contact').offset().top
    	}, 3500, function() {
	    	parallaxScroll(); // Callback is required for iOS
		});
    	return false;
    });
    
	$('a.register').click(function(){
    	$('html, body').animate({
    		scrollTop:$('#register').offset().top
    	}, 3500, function() {
	    	parallaxScroll(); // Callback is required for iOS
		});
    	return false;
    });
    
    /* Show/hide dot lav labels on hover */
    $('nav#primary a').hover(
    	function () {
			$(this).prev('h1').show();
		},
		function () {
			$(this).prev('h1').hide();
		}
    );
    
});

/* Scroll the background layers */
function parallaxScroll(){
	var scrolled = $(window).scrollTop();
	$('#parallax3').css('top',(0-(scrolled*.15))+'px');
	$('#parallax2').css('top',(0-(scrolled*.35))+'px');
	$('#parallax1').css('top',(0-(scrolled*.75))+'px');
}

/* Set navigation dots to an active state as the user scrolls */
function redrawDotNav(){
	var section1Top =  0;
	// The top of each section is offset by half the distance to the previous section.
	var section2Top =  $('#about').offset().top - (($('#about').offset().top - $('#home').offset().top) / 2);
	var section3Top =  $('#speakers').offset().top - (($('#speakers').offset().top - $('#about').offset().top) / 2);
	var section4Top =  $('#original-gives').offset().top - (($('#original-gives').offset().top - $('#speakers').offset().top) / 2);
	var section5Top =  $('#details').offset().top - (($('#details').offset().top - $('#original-gives').offset().top) / 2);
	var section6Top =  $('#at-a-glance').offset().top - (($('#at-a-glance').offset().top - $('#details').offset().top) / 2);
	var section7Top =  $('#contact').offset().top - (($('#contact').offset().top - $('#at-a-glance').offset().top) / 2);
	var section8Top =  $('#register').offset().top - (($(document).height() - $('#contact').offset().top) / 2);;
	$('nav#primary a').removeClass('active');
	if($(document).scrollTop() >= section1Top && $(document).scrollTop() < section2Top){
		$('nav#primary a.home').addClass('active');
		$('nav#primary a.logo').removeClass('active');
	} else if ($(document).scrollTop() >= section2Top && $(document).scrollTop() < section3Top){
		$('nav#primary a.about').addClass('active');
	} else if ($(document).scrollTop() >= section3Top && $(document).scrollTop() < section4Top){
		$('nav#primary a.speakers').addClass('active');
	} else if ($(document).scrollTop() >= section4Top && $(document).scrollTop() < section5Top){
		$('nav#primary a.original-gives').addClass('active');
	} else if ($(document).scrollTop() >= section5Top && $(document).scrollTop() < section6Top){
			$('nav#primary a.details').addClass('active');
	} else if ($(document).scrollTop() >= section6Top && $(document).scrollTop() < section7Top){
			$('nav#primary a.at-a-glance').addClass('active');
	} else if ($(document).scrollTop() >= section7Top && $(document).scrollTop() < section8Top){
			$('nav#primary a.contact').addClass('active');
	} else if ($(document).scrollTop() >= section8Top){
		$('nav#primary a.register').addClass('active');
	}
	
}