function drawNestedSetsTree(data, node) {

  if (data.length === 0) {
    return;
  }

  let sortItems = (a, b) => {
    if (a.left > b.left) {
      return 1;
    }
    if (a.left < b.left) {
      return -1;
    }
  };

  data.sort(sortItems);

  let firstItem = data[0];

  const ul = document.createElement('ul');
  node.appendChild(ul);

  let findItem = (items, value, side='left') => {
    let result = null;
    items.forEach((item, index) => {
      if (item[side] === value) {
         result = item;
         return;
      }
    });
    return result;
  }

  let getSiblings = (data) => {
    let siblings = [data[0]];
    let foundSibling = data[0];

    while (foundSibling != null) {
     foundSibling = findItem(data, (foundSibling.right+1), 'left');
      if (foundSibling != null) {
        siblings.push(foundSibling);
      }
    }

    siblings.sort(sortItems);
    return siblings;
  };

  let getChildren = (data, parent) => {
    let children = [];
    data.forEach((item, index) => {
      if  (item.left === parent.left + 1) {
        children.unshift(item);
      } else if (item.left > parent.left && item.right < parent.right) {
        children.push(item);
      }
    });
    return children;
  }

  let siblings = getSiblings(data, firstItem);

  siblings.forEach((sibling, index) => {
    let li = document.createElement('li');
    ul.appendChild(li);
    li.textContent = sibling.title;

    let siblingChildren = getChildren(data, sibling);

    drawNestedSetsTree(siblingChildren, li);
  });
}



if (typeof module !== 'undefined') {
  module.exports = drawNestedSetsTree;
}