const mymongodb = require('../../mongoIndex')


const ExamResultControllerInterface = require('../../controllers/interfaces/examresult.controller.interface');
const { ObjectId } = require('mongodb');

class ExamResultController extends ExamResultControllerInterface {
    async createExamResult(req, res) {
        // const {title, result, abitur_id} = req.body
        // const newExamResult = await db.query('INSERT INTO exam_result (title, result, abitur_id) VALUES ($1, $2, $3) RETURNING *', [title, result, abitur_id])
        // res.json(newExamResult.rows[0])

        const {title, result, abitur_id} = req.body
        const collection = mymongodb.collection('abiturs')
        await collection.updateOne({_id: new ObjectId(abitur_id)}, 
            {
                $push: { exam_results: {
                    _id: new ObjectId(),
                    title: title,
                    result: result
                } }
            }
        )
    }
    async createExamResultWithId(req, res) {
        // const {id, title, result, abitur_id} = req.body
        // const newExamResult = await db.query('INSERT INTO exam_result (id, title, result, abitur_id) VALUES ($1, $2, $3, $4) RETURNING *', [id, title, result, abitur_id])
        // res.json(newExamResult.rows[0])

        const {id, title, result, abitur_id} = req.body
        const collection = mymongodb.collection('abiturs')
        await collection.updateOne({_id: new ObjectId(abitur_id)}, 
            {
                $push: { exam_results: {
                    _id: new ObjectId(id),
                    title: title,
                    result: result
                } }
            }
        )
    }
    async getExamResults(req, res) {
        // const results = await db.query('SELECT * FROM exam_result')
        // res.json(results.rows)
    }
    async getOneExamResult(req, res) {
        // const id = req.params.id
        // const results = await db.query('SELECT * FROM exam_result WHERE id=$1', [id])
        // res.json(results.rows[0])
    }
    async updateExamResult(req, res) {
        // const {id, title, result} = req.body
        // const newExamResult = await db.query('UPDATE exam_result SET title=$1, result=$2 WHERE id=$3 RETURNING *', [title, result, id])
        // res.json(newExamResult.rows[0])
    }
    async deleteExamResult(req, res) {
        // const id = req.params.id
        // const results = await db.query('DELETE FROM exam_result WHERE id=$1', [id])
        // res.json(results.rows[0])

        const {abitur_id, result_id} = req.body
        const collection = mymongodb.collection('abiturs')

        await collection.updateOne({_id: new ObjectId(abitur_id)}, 
            {$pull: {
                exam_results: {_id: new ObjectId(result_id)}
            }}
        )
    }
    async getAbiturExamResults(req, res) {
        // const id = req.params.id
        // const results = await db.query('SELECT * FROM exam_result WHERE abitur_id=$1', [id])
        // res.json(results.rows)
        const collection = mymongodb.collection('abiturs')
        const id = req.params.id
        const abitur = await collection.findOne({_id: new ObjectId(id)})
        res.json(abitur['exam_results'])
    }
    async getAverageResultBySpecialization(req, res) {
        // const id = req.params.id
        // const result = await db.query('select avg(result) from exam_result where id in (select exam_result_id from request_exam_result where request_id in (select id from request where specialization_id = $1))', [id])
        // res.json(result.rows[0])

        const title = req.params.id
        const collection = mymongodb.collection('abiturs')
        const answer = await collection.aggregate([
            { $match: { "requests.specialization": title } },
            { $unwind: "$requests" },
            { $unwind: "$requests.exam_results" },
            {
              $group: {
                _id: {
                  specialization: "$requests.specialization"
                },
                avg_result: { $avg: "$requests.exam_results.result" }
              }
            }
          ]).toArray()
        res.json(answer[0])
    }
}

module.exports = new ExamResultController()