// Generate a table of contents from the headers (with ids)
(function() {
    var headers = [].slice.call(document.querySelectorAll("h1,h2,h3,h4")).filter(function(e) { return !!e.id; });
    if (headers.length <= 0) { return; }
    var html = '';
    var stack = [];
    headers.forEach(function(header) {
        var tag = header.tagName;
        while (stack.length > 0 && stack[0] > tag) {
            html += '</li>\n</ul>\n';
            stack.shift();
        }
        if (stack.length === 0 || stack[0] < tag) {
            stack.unshift(tag);
            html += '\n<ul class="sub-menu">\n';
        } else if (stack[0] === tag) {
            html += '</li>\n';
        }
        var extras = (window.location.hash === ('#' + header.id)) ? ' active' : '';
        html += '<li><a href="#' + header.id + '" class="' + tag + extras + '">' + header.innerHTML + '</a>';
    });
    while (stack.length > 0) {
        html += '</li>\n</ul>\n';
        stack.shift();
    }
    var toc = document.getElementById('toc');
    if (toc) {
        toc.outerHTML = html;
    }
})();


(function(){
    var bottom_nav = document.querySelector('.bottom-nav');
    if (bottom_nav) {
        var links = [].slice.call(document.querySelectorAll('#sidebar a.sidebar-link'));
        var pos = links.indexOf(document.querySelector('#sidebar a.sidebar-link.current'));
        if (pos < 0 || links.length <= 1) {
            bottom_nav.style.display = 'none';
        }
        var prev = document.getElementById('bottom-nav-prev');
        if (pos > 0) {
            prev.href = links[pos - 1].href;
            prev.innerHTML = links[pos - 1].innerHTML;
        } else {
            prev.parentNode.style.display = 'none';
        }
        var next = document.getElementById('bottom-nav-next');
        if ((pos + 1) < links.length) {
            next.href = links[pos + 1].href;
            next.innerHTML = links[pos + 1].innerHTML;
        } else {
            next.parentNode.style.display = 'none';
        }
    }
})();


if (window['FastClick']) {
    FastClick.attach(document.body);
}

var headerScrollOffset = 100;
smoothScroll.init({
    selector: 'a[href^="#"]',
    offset: headerScrollOffset,
    speed: 400,
    callback: function () { /* scroll complete */ }
});

// Sidebar for mobile
document.querySelector('#mobile-header .menu-button').addEventListener('click', function () {
    document.body.classList.toggle('sidebar-open');
});
document.getElementById('mobile-shade').addEventListener('click', function () {
    document.body.classList.remove('sidebar-open');
});
window.onhashchange = function() {
    document.body.classList.remove('sidebar-open');
    if (window.location.hash.startsWith('#')) {
        var e = document.getElementById(window.location.hash.slice(1));
        if (e) {
            var offsetTop = 0;
            do {
                offsetTop += e.offsetTop;
                e = e.offsetParent;
            } while (e);
            setTimeout(function() { window.scrollTo(0, offsetTop - headerScrollOffset); }, 30);
        }
    } else {
        var toc = document.getElementById('toc');
        if (toc == null) {
            var subMenus = document.getElementsByClassName('sub-menu');
            toc = ((subMenus != null) && (subMenus.length > 0)) ? subMenus[0] : null;
        }
        if (toc) {
            var offsetTop = 0;
            do {
                offsetTop += toc.offsetTop;
                toc = toc.offsetParent;
            } while (toc);
            setTimeout(function() { sidebar.scrollTo(0, offsetTop - headerScrollOffset); }, 30);
        }
    }
};

window.onhashchange(); // Force scroll to link

function setActiveMenu(link) {
    if (link && link.id !== '') {
        var previous = document.querySelector('.sub-menu .active');
        var current = document.querySelector('.sub-menu a[href="#' + link.id + '"]');
        if (current && current !== previous) {
            if (previous) {
                previous.classList.remove('active');
            }
            current.classList.add('active');
        }
    }
}

var sidebar = document.querySelector('#sidebar');
if (sidebar) {
    var sidebarHandle = null;
    function updateSidebar() {
        if (!sidebarHandle) {
            sidebarHandle = setTimeout(function() {
                sidebarHandle = null;
                var doc = document.documentElement;
                var top = doc && doc.scrollTop || document.body.scrollTop;
                var content = document.querySelector('#content');
                if (content) {
                    var links = content.querySelectorAll('h2[id],h3[id],h4[id]');
                    var last = null;
                    for (var i = 0; i < links.length; i++) {
                        var link = links[i];
                        if ((link.offsetTop - 120) > top) {
                            last = last || link;
                            break;
                        }
                        last = link;
                    }
                    setActiveMenu(last);
                }
            }, 100);
        }
    }
    window.addEventListener('scroll', updateSidebar);
    window.addEventListener('resize', updateSidebar);
}

// Support zooming of screenshots in a simple lightbox
/*
[].slice.call(document.querySelectorAll('.screenshot')).forEach(function(image) {
    image.addEventListener('click', function (e) {
        var shade = document.createElement('div');
        shade.className = 'slightbox-shade';
        var inner = document.createElement('div');
        inner.className = 'slightbox-inner';
        inner.style.backgroundImage = "url('" + image.src + "')";
        shade.appendChild(inner);

        function dismiss(e) {
            window.removeEventListener('keydown', catchEscape);
            if (shade.parentElement != null) {
                shade.parentElement.removeChild(shade);
            }
            e.preventDefault();
            return false;
        }
        shade.addEventListener('click', function (e) {
            return dismiss(e);
        });
        function catchEscape(e) {
            if (e.key === 'Escape' || e.keyCode === 27) {
                return dismiss(e);
            }
        }
        window.addEventListener('keydown', catchEscape);
        document.body.appendChild(shade);
        e.preventDefault();
        return false;
    });
});
*/