// This file contains the routes for the the account linking process on the parent side.

let express = require('express');
let router = express.Router();
let passport = require('passport');
let directory = require('../directory.js');
let database = require('../config/database.js');

// Consume the pairing code
// Return the student's UPN then delete the pairing code
async function consumePairingCode(pairing_code) {
    return new Promise((resolve, reject) => {
        let sql = 'SELECT upn FROM ps_pairing_codes WHERE pairing_code = ?';
        database.query(sql, pairing_code, function (err, result) {
            if (err) {
                console.log('Error:', err);
                reject(err);
            } else {
                if (result.length === 0) {
                    resolve(null);
                } else {
                    let upn = result[0].upn;
                    let deleteSql = 'DELETE FROM ps_pairing_codes WHERE pairing_code = ?';
                    database.query(deleteSql, pairing_code, function (err, result) {
                        if (err) {
                            console.log('Error:', err);
                        } else {
                            console.log('Pairing code consumed');
                        }
                    });
                    resolve(upn);
                }
            }
        });
    });
}

router.get('/parent/:parent_upn/add-student', async function (req, res) {
    if(!req.isAuthenticated()) {
        return res.status(401).send('Unauthorized');
    }
    let parent_upn = req.params.parent_upn;
    // Is the logged in user a parent with the same UPN as the one in the URL?
    // If not, return a 403 Forbidden response
    if (req.user.username !== parent_upn) {
        return res.status(403).send('Forbidden, UPN mismatch');
    }
    // Consume the pairing code, if it return null, return a 404 Not Found response
    // Don't update the parent's student list yet
    // Note that we won't return the student's details in this route
    // Just a success message
    let pairing_code = req.query.pairing_code;
    // Is the pairing code in the query string?
    if (!pairing_code) {
        return res.status(400).send('Bad Request, pairing_code missing');
    }
    let student_upn = '';
    let student = await consumePairingCode(pairing_code);
    if (!student) {
        return res.status(404).send('Not Found, pairing_code not found');
    }
    await directory.setPrimaryParent(student, parent_upn);
    res.send('Student added');
});

router.get('/parent/:parent_upn', function (req, res) {
    if(!req.isAuthenticated()) {
        return res.status(401).send('Unauthorized');
    }
    let parent_upn = req.params.parent_upn;
    // Is the logged in user a parent with the same UPN as the one in the URL?
    // If not, return a 403 Forbidden response
    if (req.user.username !== parent_upn) {
        return res.status(403).send('Forbidden, UPN mismatch');
    }
    // Return the parent's details in the session in JSON format
    allowedAttributes = ['username', 'first_name', 'last_name'];
    let parent = {};
    allowedAttributes.forEach(function (attribute) {
        parent[attribute] = req.user[attribute];
    });
    res.json(parent);
});

module.exports = router;