exports.example = (req, res) => {
  if (!req.query.key || !mongoose.Types.ObjectId.isValid(req.params.id)) return res.status(404).send();

  db.UsersModel.findOne({
    apiKey: req.query.key
  }).exec().then((user, err) => {
    if (err || user === null) return res.status(404).send();

    return db.FormsModel.findOne({
      owner: user._id,
      _id: req.params.id
    }).lean().select('fields name').exec();
  }).then((form, err) => {
    if (err || form === null) return res.status(400).send();

    let fields = {};
    let fieldName = null;
    let regexp, count;

    for (let field of form.fields) {
      fieldName = field.label || field.placeholder || field._id;

      regexp = new RegExp(`(${fieldName})_?`, 'g');
      count = (Object.keys(fields).join(',').match(regexp) || []).length;

      if (count > 0) {
        fieldName = `${fieldName}_${count + 1}`;
      }

      fields[fieldName] = fieldName;
    }

    res.status(200).send([{
      formId: 'formId',
      formName: 'formName',
      fields
    }]).end();
  });
};