auth.js

const shortid = require('shortid');
const User = require('./user.js').User;
const Token = require('./user.js').Token;

function auth(socket, users, tokens) {
    function checkRegis(name, list) {
        let n = list.length;
        for (let i = 0; i < n; i++) {
            if (list[i]['username'] === name) return false;
        }
        return true;
    }

    function checkLogin(name, pwd, list) {
        let n = list.length;
        for (let i = 0; i < n; i++) {
            if (list[i]['username'] === name && list[i]['password'] === pwd) return list[i]['id'];
        }
        return false;
    }

    function Register(uname, pwd, list) {
        if (checkRegis(uname, list)) {
            let id = shortid.generate();
            let user = new User(id, uname, pwd);
            list.push(user);
            return true;
        } else {
            return false;
        }
    }

    function Login(uname, pwd, list) {
        let temp = checkLogin(uname, pwd, list);
        if (temp) {
            let idToken = shortid.generate();
            let token = new Token(temp, idToken);
            tokens.push(token);
            socket.username = uname;
            socket.join(temp);
            return token;
        } else return false;
    }

    socket.on('signup', (data) => {
        let stat = Register(data['uname'], data['pwd'], users);
        if (stat) socket.emit('signup_success', {
            'msg': 'Register succeed'
        });
        else socket.emit('signup_failed', {
            'msg': 'Register failed'
        });
    });

    socket.on('login', (data) => {
        let temp = Login(data['uname'], data['pwd'], users);
        if (temp) socket.emit('login_succeed', {
            'msg': "Login succeed",
            'data': temp
        });
        else socket.emit('login_failed', {
            'msg': 'Login failed'
        });
    });

}

exports.auth = auth;