exports.findOneAndCurrent = (req, res) => {
  // First, get which student to base the query on
  const studentId = req.user.studentId
                    ? req.user.studentId
                    : req.query.student
                      ? req.query.student
                      : null;

  if (studentId === null) {
    res.status(404).json({
      success: false,
      msg: "No student_id provided!"
    });
  }

  Task.findOne({
    where: {
      student_id: studentId,
      unit_id: req.params.id,
      is_active: true
    },
    include: [{
      model: Unit,
      where: {
        id: req.params.id,
        is_active: true
      },
      include: [{
        model: Question,
        as: 'questions',
        where: {
          unit_id: req.params.id,
          is_active: true
        },
        order: [['id', 'ASC']],
        required: false
      }]
    }],
    required: true
  })
  .then(task => {
    if (task === null) {
      res.status(400).json({
        success: false,
        msg: "This student is not assigned a task with this unit!"
      });
    }

    const questionIds = task.Unit.questions.map(question => question.id);
    Activity.findAll({
      where: {
        question_id: { [Op.or]: [questionIds] },
        student_id: studentId,
        finish_time: {
          [Op.ne]: null
        }
      },
      order: [['question_id', 'ASC' ]]
    })
    .then(activities => {
      let questionIdsCopy = questionIds;
      activities.forEach(activity => {
        const index = questionIdsCopy.indexOf(activity.question_id);
        if (index > -1) questionIdsCopy.splice(index, 1);
      });

      const current_question = questionIdsCopy.length > 0
                               ? task.Unit.questions[questionIds.indexOf(questionIdsCopy[0])]
                               : null;

      res.json({...task.Unit.dataValues, current_question});
    })
  })
  .catch(err => {
    console.log(err);
    res.status(500).json({
      success: false,
      msg: "Something went wrong: " + err
    });
  });
};