exports.findOneAndCurrent = (req, res) => {
  Unit.findOne({
    where: {
      id: req.params.id,
      is_active: true
    },
    include: [{
      model: Question,
      as: 'questions',
      where: {
        unit_id: req.params.id,
        is_active: true
      },
      required: false,
    }]
  })
  .then(unit => {
    if (unit) {
      const questionIds = unit.questions.map(question => question.id);
      Activity.findAll({
        limit: 1,
        where: {
          question_id: { [Op.or]: [questionIds] },
          finish_time: null
        },
        order: [ [ 'id', 'ASC' ]]
      })
      .then(unfinishedActivity => {
        let current_question = unit.questions.length > 0 ? unit.questions[0] : null;
        if (unfinishedActivity !== null && unfinishedActivity.length > 0) {
          current_question = unit.questions.filter(question => question.id === unfinishedActivity[0].question_id)[0];
        }
        res.json({...unit.dataValues, current_question});
      })
    } else {
      res.status(404).json({
        success: false,
        msg: "No unit with this ID found!"
      });
    }
  })
  .catch(err => {
    console.log(err);
    res.status(500).json({
      success: false,
      msg: "Something went wrong: " + err
    });
  });
};