var router = require('express').Router();
const { Op } = require('sequelize');
const DB = require('../../../database/mysql');
const auth = require('../../../middlewares/auth');
const mailer = require('@sendgrid/mail');
const { UserService } = require('../../../services');

mailer.setApiKey(process.env.SENDGRID_API_KEY);

// Preload application objects on routes with ':application'
router.param('application', function (req, res, next, slug) {
    DB.Application.findOne({ where: { slug } })
        .then(function (application) {
            if (!application) {
                return res.sendStatus(404);
            }
            req.application = application;
            return next();
        }).catch(next);
});

/**
 * return all applications
 */
router.get('/', auth.required, function (req, res, next) {
    const limit = parseInt(req.query.limit) || 25;
    const offset = parseInt(req.query.offset) || 0;
    const where = {};

    if (req.query.apikey) where.apikey = req.query.apikey;
    if (req.query.maskedkey) where.maskedkey = req.query.maskedkey;

    Promise.all([
        req.query.author ? UserService.getUserByUsername(req.query.author) : null,
        req.payload ? UserService.getUserById(req.payload.id) : null
    ]).then(function ([author, user]) {
        if (author) where.authorId = author.id;

        return Promise.all([
            DB.Application.findAll({ where, limit, offset, order: [['createdAt', 'DESC']] }),
            DB.Application.count({ where })
        ]).then(function ([applications, applicationsCount]) {
            return res.json({
                applications: applications.map((a) => a.toJSONFor(user)),
                applicationsCount
            });
        });
    }).catch(next);
});

/**
 * save an application
 */
router.post('/', auth.required, function (req, res, next) {
    Promise.all([
        UserService.getUserById(req.payload.id),
        auth.generateAPIKey()
    ]).then(function ([user, keys]) {
        if (!user) {
            return res.status(401).json({ message: 'Unauthorized - You are not allowed to access this resource.' });
        }

        const application = DB.Application.build(req.body.application);
        application.authorId = user.id;
        application.apikey = keys.encrypted;
        application.maskedkey = keys.masked;

        return application.save().then(function () {
            const msg = {
                to: user.email,
                from: process.env.SENDGRID_FROM_MAIL,
                subject: `Api-Key ${application.title}`,
                text: `Votre Api-Key: ${keys.key}\nAttention, cette Api-Key doit être conservée et ne sera plus affichée.\n\n${application.title}\n${application.description}`,
                html: `<h2>${application.title}</h2>
                <p>
                Votre Api-Key: ${keys.key}<br />
                <strong>Attention, cette Api-Key doit être conservée et ne sera plus affichée.</strong>
                </p>
                <hr />
                <p>${application.description}</p>`
            };
            return mailer.send(msg).then(() => {
                return res.json({ application: application.toJSONFor(user) });
            }).catch(err => {
                return res.status(500).json({ message: 'A SendGrid error occured while sending an email', err });
            });
        });
    }).catch(next);
});

/**
 * return an application
 */
router.get('/:application', auth.required, function (req, res, next) {
    Promise.resolve(req.payload ? UserService.getUserById(req.payload.id) : null)
        .then(function (user) {
            return res.json({ application: req.application.toJSONFor(user) });
        }).catch(next);
});

/**
 * update an application
 */
router.put('/:application', auth.required, function (req, res, next) {
    UserService.getUserById(req.payload.id).then(function (user) {
        if (req.application.authorId !== req.payload.id) {
            return res.status(403).json({ errors: { Forbidden: 'Vous ne disposez pas des autorisations suffisantes' } });
        }

        const fields = ['title', 'description', 'apikey', 'maskedkey'];
        fields.forEach((f) => {
            if (typeof req.body.application[f] !== 'undefined') {
                req.application[f] = req.body.application[f];
            }
        });

        return req.application.save().then(function (application) {
            return res.json({ application: application.toJSONFor(user) });
        }).catch(next);
    });
});

/**
 * delete an application
 */
router.delete('/:application', auth.required, function (req, res, next) {
    UserService.getUserById(req.payload.id).then(function (user) {
        if (!user) {
            return res.status(401).json({ errors: { Unauthorized: 'authentification requise' } });
        }
        if (user.role !== 'Admin' && req.application.authorId !== req.payload.id) {
            return res.status(403).json({ errors: { Forbidden: 'Vous ne disposez pas des autorisations suffisantes' } });
        }
        return req.application.destroy().then(function () {
            return res.json({ deleted: true });
        });
    }).catch(next);
});

module.exports = router;