// Copyright 2014 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.


document.addEventListener("DOMContentLoaded", function(event) {

  document.getElementById("toggle-nav").onclick = toggleNav;

  function toggleNav() {
    var toc = document.getElementById("toc");
    var pagewrapper = document.getElementById("page-wrapper");
    toggleClass(toc, "mobile-hidden");
    toggleClass(pagewrapper, "mobile-hidden");
  }

  function toggleClass(el, className) {
     // from http://youmightnotneedjquery.com/
     if (el.classList) {
       el.classList.toggle(className);
     } else {
       var classes = el.className.split(' ');
       var existingIndex = classes.indexOf(className);

       if (existingIndex >= 0) {
         classes.splice(existingIndex, 1);
       } else {
         classes.push(className);
       }

       el.className = classes.join(' ');
     }
  }

  // The below code is used to add prev and next navigation links to the bottom
  // of each of the sections.
  // It works by extracting the current page based on the url and iterates over
  // the menu links until it finds the menu item for the current page. We then
  // create a copy of the preceding and following menu links and add the
  // correct css class and insert them into the bottom of the page.
  var toc = document.getElementById('toc').getElementsByTagName('a');
  var href = document.location.pathname.split('/').pop();
  if (href === 'index.html' || href === '') {
    href = 'README.html';
  }

  for (var i = 0; i < toc.length; i++) {
    if (toc[i].attributes.href.value.split('/').pop() === href) {
      var nav = document.createElement('p');
      if (i > 0) {
        var prevNode = toc[i-1].cloneNode(true);
        prevNode.className = 'left';
        prevNode.setAttribute('rel', 'prev');
        nav.appendChild(prevNode);
      }
      if (i < toc.length - 1) {
        var nextNode = toc[i+1].cloneNode(true);
        nextNode.className = 'right';
        nextNode.setAttribute('rel', 'next');
        nav.appendChild(nextNode);
      }
      document.getElementById('page').appendChild(nav);
      break;
    }
  }

});