//other math stuff
function rangeFinder(x, min, max, margin) {
    return (x > (min - margin) && x <= (max - margin));
}



//******************************************************************************************************
//finds section by range in heights
function setSection() {
    var freshRun = true;
    var sections = [
        'section#content>section#heim',
        'section#content>section#tilbud',
        'section#content>section#galleri',
        'section#content>section#feedback'
    ];
    var sectionsID = [
        '#heim',
        '#tilbud',
        '#galleri',
        '#feedback'
    ];

    var lastSection = 'body>section#content>section#heim';
    var obj = new Object()

    //desides the section
    function getCurrentSection(o, m, offsets) {
        var section = 0;
        var margin = m;

        if (rangeFinder(o, 0, offsets[1], margin)) { section = 0; }
        else if (rangeFinder(o, offsets[1], offsets[2], margin)) { section = 1; }
        else if (rangeFinder(o, offsets[2], offsets[3], margin)) { section = 2; }
        else { section = 3; }

        return section;
    }

    //set and removes attributes from relevant <li>
    function setAttributes(a) {
        $('nav#main>ul.positionLinks>li#current').removeAttr('id');
        $('nav#main>ul.positionLinks>li[data-gotoSection="' + sectionsID[a] + '"]').attr('id', 'current');
        return false;
    }

    //fade out inactive sections
    function fadeUnseenSections() {

        for (var i = 0; i < sections.length; i++) {
            if (sectionArray[i] != section) $(sectionArray[i]).fadeOut(250);
        }

        return false;
    }

    //desides if the right functions should be called
    function construct(topOffset,offsets) {
        var menuHeight = $('nav#main').height();
        var offset = $('nav#main').offset().top + menuHeight;
        if (topOffset != offset || (topOffset <= menuHeight+2 && freshRun == true) || freshRun == true) {
            freshRun = false;
            var sectionKey = getCurrentSection(offset, 1, offsets);//offset, margin, offsets
            setAttributes(sectionKey);


            $('#tull').html('x: ' + offset + '<br>margin: 3<br>min: ' + 0 + '<br>max: ' + $('section#tilbud').offset().top + '<br>section: ' + sectionsID[sectionKey]);
            lastSection = sectionsID[sectionKey];//sets the last section
        }
    }

    //return object so inner functions can be accessed
    obj.construct = construct;
    return obj;
}


/********************************************************************/
//starter alt

function offsetsFunc(){
return [$('body>section#content>section#heim').offset().top,
    $('body>section#content>section#tilbud').offset().top,
    $('body>section#content>section#galleri').offset().top,
    $('body>section#content>section#feedback').offset().top];
}
var topOffset=$('nav#main').offset().top+$('nav#main').height();
var offsets = offsetsFunc();

var section = new setSection();
window.setInterval(function(){section.construct(topOffset,offsets);},50);