$(()=>{setTimeout(()=>{
  if (!/\/teach\/control\/lesson\/view/gm.test(window.location.href)) return;
  window.lessonId = typeof window.lessonId != "undefined" ? window.lessonId : parseInt(/id=(\d+)/gm.exec(window.location.href)[1]);
  let $nav_left = $('.lesson-navigation td:first-child');
  let $nav_right = $('.lesson-navigation td:last-child');
  let needPrev = ($nav_left.length && $nav_left.text().trim() == "");
  let needNext = ($nav_right.length && $nav_right.text().trim() == "");
  if(needPrev || needNext) {
    getModule((data)=>{
      if(needPrev && typeof data.prev != "undefined") {
        $nav_left.html(`
          <a target="_self" href="${data.prev.link}"><span class="fui fui-arrow-left"></span> Предыдущий модуль</a>
          <div class="hidden-xs" style="font-weight: normal; font-size: 1em; line-height: 16px "> ${data.prev.name}</div>
        `);
      }
      if(needNext && typeof data.next != "undefined") {
        $nav_right.html(`
          <a target="_self" href="${data.next.link}">Следующий модуль <span class="fui fui-arrow-right"></span> </a>
          <div class="hidden-xs" style="font-weight: normal; font-size: 1em; line-height: 16px "> ${data.next.name}</div>
        `);
      }
    });
  }
  function getModule(callback){
    let currentTraining = $('.page-header h1 a').attr('href');
    let parentTraining = $('.breadcrumb li:last-child:not(:first-child) a').attr('href');
    if (typeof parentTraining !== "undefined") $.get(parentTraining, (data)=>{
        let pageDom = $('<xxx/>').append($.parseHTML(data));
        let $currentTraining = pageDom.find('.stream-table tr[data-training-id="'+currentTraining.replace(/\D+/,"")+'"]');
        let $nextTraining = $currentTraining.next('tr');
        let $prevTraining = $currentTraining.prev('tr');
        let result = {};
        if($nextTraining.length) Object.assign(result, {
          "next":{
            "name": $nextTraining.find('.stream-title').text().trim(),
            "link": $nextTraining.find('a').eq(0).attr('href'),
          }
        });
        if($prevTraining.length) Object.assign(result, {
          "prev":{
            "name": $prevTraining.find('.stream-title').text().trim(),
            "link": $prevTraining.find('a').eq(0).attr('href'),
          }
        });
        callback(result);
    });
    else callback({});
  }
 })});