const User = require('../../models/User');
const config = require('../../config');
const secret = require('../../secret');

const { authenticateEndpoint } = require('./authfunctions');

// TODO: Might want to use something else (https://blog.benpri.me/blog/2019/01/13/why-you-shouldnt-be-using-bcrypt-and-scrypt/)
const bcrypt = require('bcrypt');
const mongoose = require('mongoose');
const { body, query, param, validationResult } = require('express-validator');
const express = require('express');
const jwt = require('jsonwebtoken');

const app = express.Router();
mongoose.connect(config.mongoUrl, {useNewUrlParser: true, useUnifiedTopology: true});

const rateLimit = require("express-rate-limit");

const createAccountLimiter = rateLimit({
    windowMs: 60 * 60 * 1000, // 1 hour window
    max: 10, // start blocking after 5 requests
    message: "You are being rate limited"
});

app.get('/account/create/info', async (req, res) => {
    const restrictions = config.restrictions.signup;
    let requiresCode = false;
    if (restrictions && restrictions.specialCode) {
        requiresCode = true;
    }

    res.json({
        error: false,
        message: 'SUCCESS_ACCOUNT_CREATE_INFO_FETCH',
        requiresSpecialCode: requiresCode
    });
});

app.post('/account/create', [
    createAccountLimiter,
    body('username').not().isEmpty().trim().isLength({ min: 3, max: 32 }).isAlphanumeric(),
    body('email').not().isEmpty().isEmail().normalizeEmail(),
    body('password').not().isEmpty().isLength({ min: 8, max: 128 }),
    body('specialCode').optional().isLength({ min: 12, max: 12 }).isAlphanumeric()
], async (req, res) => {
    try {
        const errors = validationResult(req);
        if (!errors.isEmpty()) {
            res.status(400).json({ error: true, message: 'ERROR_REQUEST_INVALID_DATA', errors: errors.array() });
            return;
        }

        if (config.restrictions) {
            const restrictions = config.restrictions.signup;
            if (restrictions && restrictions.specialCode) {
                const passedSpecialCode = req.body.specialCode;
                const specialCode = restrictions.specialCode;
    
                if (passedSpecialCode && specialCode) {
                    if (specialCode !== passedSpecialCode) {
                        res.status(401).json({ error: true, message: 'ERROR_REQUEST_SPECIAL_CODE_MISSING', errors: [{ msg: 'No specialCode passed', param: 'specialCode', location: 'body' }] });
                        return false;
                    }
                } else {
                    res.status(401).json({ error: true, message: 'ERROR_REQUEST_SPECIAL_CODE_MISSING', errors: [{ msg: 'No specialCode passed', param: 'specialCode', location: 'body' }] });
                    return false;
                }
            }
        }
    
        const username = req.body.username;
    
        const existingUser = await User.findByUsername(username);
        if (existingUser) {
            res.status(400).json({ error: true, message: 'ERROR_REQUEST_USERNAME_EXISTS', errors: [{ value: username, msg: 'Username exists', param: 'username', location: 'body' }] });
            return;
        }
    
        const unhashedPassword = req.body.password;
        const email = req.body.email;
        const startingRole = 'USER';
    
        const hashedPassword = await bcrypt.hash(unhashedPassword, config.bcryptRounds);
    
        const user = await User.create({
            username,
            email,
            password: hashedPassword,
            role: startingRole,
            color: User.generateColorFromUsername(username)
        });

        const userObject = await user.getPublicObject();

        console.log('[*] [logger] [users] [create] User created', userObject);
    
        res.status(200).json({
            error: false,
            message: 'SUCCESS_USER_CREATED',
            user: userObject
        });
    } catch (e) {
        console.error('Internal server error', e);
        res.status(500).json({ error: true, message: 'INTERNAL_SERVER_ERROR' });
        return;
    }
});

app.post('/token/create', [
    createAccountLimiter,
    body('username').not().isEmpty().trim().isAlphanumeric(),
    body('password').not().isEmpty()
], async (req, res) => {
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
        res.status(400).json({ error: true, message: 'ERROR_REQUEST_LOGIN_INVALID' });
        return;
    }

    const username = req.body.username;

    const existingUser = await User.findByUsername(username);
    if (!existingUser) {
        res.status(403).json({ error: true, message: 'ERROR_REQUEST_LOGIN_INVALID' });
        return;
    }

    const password = req.body.password;

    let passwordCheck;
    try {
        passwordCheck = await bcrypt.compare(password, existingUser.password);
    } catch(e) {
        passwordCheck = false;
    }
    if (!passwordCheck) {
        res.status(403).json({ error: true, message: 'ERROR_REQUEST_LOGIN_INVALID' });
        return;
    }

    jwt.sign({ username }, secret.jwtPrivateKey, { expiresIn: '3h' }, async (err, token) => {
        if (err) {
            res.status(500).json({
                error: true,
                message: 'INTERNAL_SERVER_ERROR'
            });
            return;
        }

        // TODO: Ugly fix for setting httponly cookies
        if (req.body.alsoSetCookie) {
            res.cookie('token', token, {
                maxAge: 3 * 60 * 60 * 1000, httpOnly: true, domain: config.address, 
            });
        }

        const userObject = await existingUser.getPublicObject();

        console.log('[*] [logger] [users] [token create] Token created', userObject);
        
        res.status(200).json({
            error: false,
            message: 'SUCCESS_TOKEN_CREATED',
            user: userObject,
            token
        });
    });
});

app.get('/current/info', authenticateEndpoint(async (req, res, user) => {
    const userObject = await user.getPublicObject();

    res.status(200).json({
        error: false,
        message: 'SUCCESS_USER_DATA_FETCHED',
        user: {
            token: req.cookies.token, // TODO: Passing the token like this is *terribly* insecure
            ...userObject
        },
    });
}, undefined, 0));

app.get('/user/:userid/info', [
    param('userid').not().isEmpty().trim().escape().isLength({ min: 24, max: 24 })
], authenticateEndpoint(async (req, res, user) => {
    const errors = validationResult(req);
    if (!errors.isEmpty()) {
        res.status(400).json({ error: true, message: 'ERROR_REQUEST_INVALID_DATA', errors: errors.array() });
        return;
    }

    const userid = req.params.userid;
    if (!userid) {
        res.sendStatus(400).json({
            error: true,
            message: 'ERROR_REQUEST_INVALID_DATA'
        });
        return;
    }
    const otherUser = await User.findById(userid);

    res.status(200).json({
        error: false,
        message: 'SUCCESS_USER_DATA_FETCHED',
        user: await otherUser.getPublicObject(),
    });
}, undefined, config.roleMap.USER));

app.post('/browser/token/clear', authenticateEndpoint((req, res, user) => {
    res.clearCookie('token');
    res.sendStatus(200);
}));

module.exports = app;