server.js

require('dotenv').config();
const express = require('express');
const path = require('path');
const app = express();
const bp = require('body-parser');
const bcrypt = require('bcrypt');
const fileupload = require('express-fileupload');
const nodemailer = require('nodemailer');
const otpGenerator = require('otp-generator');
const { response } = require('express');
const { MongoClient, ObjectId } = require('mongodb');
const url = process.env.MONGO_LINK;
const client = new MongoClient(url);
const session = require('express-session');
const cookieparser = require('cookie-parser');
const User = require(path.join(__dirname, "./Models/User.js"));
const qrcode = require('qrcode');
const port = process.env.PORT || 5500;


const publicpath = path.join(__dirname, "./public");
const srcpath = __dirname;
const uploadspath = path.join(__dirname, "./uploads");
const viewspath = path.join(__dirname, "./views");
const Modelspath = path.join(__dirname, "./Models");
const imagepath = path.join(__dirname,"./images"); 
app.set('views', viewspath);


app.use(session({
    secret: process.env.SECRET_KEY,
    resave: false,
    saveUninitialized: false,
    cookie: {
        httpOnly: true,
        maxAge: 3600000
    }
}));

app.use(bp.urlencoded({ extended: true }));
app.use(express.static(path.join(__dirname, "./public")));
app.use(express.static(path.join(__dirname, "./images")));
app.use(fileupload({ createParentPath: true }));
app.use(cookieparser());
app.use((req, res, next) => {
    if (req.cookies.secret_key && !req.session.user) {
        console.log('inside everytime middleware');
        res.clearCookie("secret_key");
    }
    next();
});
app.set('view engine', 'ejs');
const sessioncheck = (req, res, next) => {
    if (req.session.secret_key) {
        res.sendFile(path.join(__dirname, "./public/services.html"));
    }
    else
        next();
}
const gatecheck = async (req, res, next) => {

    let result = await connection();
    let id = JSON.stringify(req.session.secret_key);
    console.log(id);
    id = JSON.parse(id);
    console.log(id);
    let responce = await result.findOne({ _id: new ObjectId(id) });
    console.log(responce);
    if (responce.email == process.env.GAURD_MAIL) {
        next();
    }
    else {
        res.json({ status: 404 });
    }
}
const statuscheck = (req, res, next) => {
    if (req.session.secret_key) {
        next();
    }
    else
        res.redirect("/login");
}
const admincheck = async(req, res, next) => {
    let result = await connection();
    // console.log('admin check:', req.body.email, req.body.password);
    // console.log('saved details:', process.env.ADMIN_MAIL, process.env.ADMIN_PASS);
    // if (req.body.email == process.env.ADMIN_MAIL && req.body.password == process.env.ADMIN_PASS) {
    if (req.body.email == process.env.ADMIN_MAIL ) 
    {
        let responce = await result.findOne({email:req.body.email});
        console.log('admin check ',responce);
        if(responce  && req.body.password ===responce.password)
        {
            req.session.loginmail = process.env.ADMIN_MAIL;
            req.session.loginpassword = process.env.ADMIN_PASS;
            res.sendFile(path.join(__dirname, "./public/admin.html"));
        }
        else
        {
            // next();
            res.send('Incorrect credentials');
        }
    }
    // else if (req.body.email == process.env.GAURD_MAIL && req.body.password == process.env.GAURD_PASS) {
    else if (req.body.email == process.env.GAURD_MAIL ) 
    {
        let responce = await result.findOne({email:req.body.email});
        console.log('gate check:',responce);
        if (responce && req.body.password === responce.password)
        {
            req.session.loginmail = process.env.GAURD_MAIL;
            req.session.loginpassword = process.env.GAURD_PASS;
            res.render("scanner");
        }
        else
        {
            // next();
            res.send('Incorrect Credentials');
        }
    }
    else
        next();
}
const studentdatacheck =(req,res,next)=>
{
    if(req.session.loginmail ==process.env.ADMIN_MAIL && req.session.loginpassword == process.env.ADMIN_PASS)
    {
        next();
    }
    else
    {
        res.redirect("/login");
    }
}


async function connection() {
    let result = await client.connect();
    let database = await result.db('Practicum4');
    return database.collection('collections');
}
async function leave() {
    let result = await client.connect();
    let database = result.db('Practicum4');
    return database.collection('leave');
}
var transporter = nodemailer.createTransport({
    host: 'smtp.gmail.com',
    port: 587,
    secure: false,
    requireTLS: true,
    auth: {
        user: process.env.MAIL_USER,
        pass: process.env.MAIL_PASS,
    }
});
function PinGenerator() {
    pinReturn = otpGenerator.generate(5, { digits: true, upperCase: true, specialChars: false, alphabets: false });
    // req.session.pinReturn = pinReturn;
    console.log(pinReturn);
}
PinGenerator.prototype.getPin = function () {
    return pinReturn;
};

app.get("/", (req, res) => {
    console.log(process.env.MAIL_USER)
    res.sendFile(publicpath + "/home.html");
})
app.get("/login", sessioncheck, (req, res) => {
    res.sendFile(publicpath + "/login.html")
})
app.get("/services", sessioncheck, (req, res) => {
    res.sendFile(publicpath + "/login.html")
})
app.get("/status", statuscheck, async (req, res) => {
    let qr;
    let cresult = await connection();
    let id = JSON.stringify(req.session.secret_key);
    console.log(id);
    id = JSON.parse(id);
    console.log(id);
    let result = await leave();
    let respons = await cresult.findOne({ email: req.session.loginmail });
    // let responce = await result.findOne({ email: loginemail }, { sort: { _id: -1 } });
    let responce = await result.findOne({ email: req.session.loginmail}, { sort: { _id: -1 } });
    if (!responce) {
        res.send(`<center><h1>No leave form found</h1></center>`);
    }
    // console.log('generating qrcode');
    else if (responce.exit == 'null' && responce.status == 'Approved') {
        let data = { btn: '1', id: responce._id };
        qr = await new Promise((resolve, reject) => {
            qrcode.toDataURL(JSON.stringify(data), (err, src) => {
                if (err) {
                    reject(err);
                } else {
                    resolve(src);
                }
            });
        });
        // console.log('qrcode generated', qr);
    }
    else if (responce.exit == 'done' && responce.status == 'Approved' && responce.entry == 'null') {
        let data = { btn: '2', id: responce._id };
        qr = await new Promise((resolve, reject) => {
            qrcode.toDataURL(JSON.stringify(data), (err, src) => {
                if (err) {
                    reject(err);
                } else {
                    resolve(src);
                }
            });
        });
        // console.log('qrcode generated', qr);
    }
    if(responce)
    {
        let data = {
            name: respons.name,
            email: responce.email,
            semester: responce.semester,
            reason: responce.reason,
            leaveStartDate: responce.leaveStartDate,
            leaveEndDate: responce.leaveEndDate,
            Uploadedon: responce.Uploadedon,
            filename: responce.filename,
            status: responce.status,
            exit: responce.exit,
            entry: responce.entry,
            qrcode: qr,
        }
        // console.log('rendering data',data.qrcode);
        res.render(viewspath + "/status.ejs", { data });

    }
})
app.post("/getuser",(req,res)=>
{
    console.log('inside /getuser');
    if(!req.session.secret_key)
    {
        return res.status(300).json({message:'not a user'})
    }
    return res.status(200).json({message:'user exist'})
})
app.get("/about", (req, res) => {
    res.sendFile(publicpath + "/about.html");
})
app.post("/sign", async (req, res) => {
    // signemail = req.body.email;
    // signname = req.body.name;
    // signgender = req.body.gender;
    // signpassword = req.body.password;
    req.session.signmail = req.body.email;
    req.session.signname = req.body.name;
    req.session.signgender = req.body.gender;
    req.session.signpass = req.body.password;
    let signmail1 = req.session.signmail;
    let collegemailcheck = signmail1.includes('iiitu.ac.in');
    let alradyemail = await User.findOne({ email: signmail1 }).exec();
    console.log(alradyemail);
    if (alradyemail != null) {
        res.send('User already exists!');
    }
    else if (!collegemailcheck) {
        res.send('Please use email provided by college');
    }
    else {
        PinGenerator();
        req.session.pinReturn= pinReturn;
        console.log('generated and saved pin is:',req.session.pinReturn);
        var mailoption = {
            from: process.env.MAIL_FROM,
            to: req.body.email,
            subject: "IIITU Leave  sign up otp password ",
            text: "Your Pin is:",
            html: `<h3>Your pin is:</h3><h1>${pinReturn}</h1>`
        };

        transporter.sendMail(mailoption, function (err, info) {
            if (err) {
                console.log('error is sign up'+err);
                res.redirect("/login");
            }
            else {
                console.log('Email has been sent');
                res.redirect("/otppage");
            }
        })
    }
})
app.get("/otppage", async (req, res) => 
{
    res.sendFile(publicpath + "/sign_otp.html");
});
app.post("/login", admincheck, async (req, res) => 
{
    // loginemail = req.body.email;
    // loginpassword = req.body.password;
    req.session.loginmail = req.body.email;
    req.session.loginpassword = req.body.password;
    let user = await User.findOne({ email: req.body.email }).exec();
    let loginsavedpassword;
    if (user == null) {

        res.send(`<script>alert('email not found')</script>`);
    }
    else {
        loginsavedpassword = req.body.password;
        let data2 = await user.comparepassword(req.session.loginpassword, loginsavedpassword);
        if (data2 == null) {
            res.send(`password is incorrect`);
        }
        else {
            // username = data2.name;
            // usernameenable = 1;
            // req.session.user = user;
            // loginname = user.name;
            req.session.loginname = user.name;
            req.session.secret_key = user._id;
            console.log('session id is', req.session.secret_key);
            res.cookie('user', data2._id, { maxAge: 3600000 });
            res.redirect("/services");
        }
    }

})
app.post("/leaveformupload", statuscheck, async (req, res) => {
    // let user = await User.findOne({ email: loginemail }).exec();
    let id = JSON.stringify(req.session.secret_key);
    console.log(id);
    id = JSON.parse(id);
    console.log(id);
    let user = await User.findOne({ _id: new ObjectId(id) }).exec();
    if (!user) {
        res.json({ status: 'User not found' });
    }
    else {
        console.log(req.body);
        let result = await leave();
        let currentdatetime = new Date();
        let month = currentdatetime.getMonth() + 1;
        let rolldata = req.session.loginmail.split('@');
        rollnumber = rolldata[0];
        filename = rollnumber + '@' + currentdatetime.getFullYear() + '@' + month + '@' + currentdatetime.getDate() + '@' + currentdatetime.getHours() + '@' + currentdatetime.getMinutes() + '@' + currentdatetime.getSeconds() + ".pdf";
        let file = req.files.leavefile;
        // file.mv('../uploads/' + file.name, function (err) {
        file.mv('../uploads/' + filename, function (err) {
            if (err) {
                return res.status(500).send(err);
            }
        });
        console.log(filename);
        var mailoption = {
            from: process.env.MAIL_FROM,
            to: process.env.MAIL_FROM,
            subject: "Uploaded leave form successfully",
            // html: `<p>hello ${loginname}! You have successfully uploaded leave form, IIITU administration will send you a confirmation email after approving. <br> -by <h1>IIITU</h1> </p>`
            html: `<p>A new submission recorded, It was filled by ${req.session.loginname} and filename is ${filename}</p>`
        };

        transporter.sendMail(mailoption, function (err, info) {
            if (err) {
                console.log(err);
            }
            else {
                console.log('Email has been sent');
            }
        })
        let user = await User.findOne({ _id: new ObjectId(id) }).exec();
        // let user = await User.findOne({ email: loginemail }).exec();
        let formincrease = user.totalForms + 1;
        console.log(user);
        console.log(formincrease);
        // let updateuser = await User.updateOne({ email: loginemail }, { $set: { totalForms: formincrease } });
        let updateuser = await User.updateOne({ _id: new ObjectId(id) }, { $set: { totalForms: formincrease } });
        // let inserting = await result.insertOne({ email: loginemail, semester: req.body.semester, reason: req.body.reason, leaveStartDate: req.body.leavestart, leaveEndDate: req.body.leaveend, Uploadedon: currentdatetime, filename: filename, status: 'null', exit: 'null', entry: 'null' });
        let inserting = await result.insertOne({ email: req.session.loginmail, semester: req.body.semester, reason: req.body.reason, leaveStartDate: req.body.leavestart, leaveEndDate: req.body.leaveend, Uploadedon: currentdatetime, filename: filename, status: 'null', exit: 'null', entry: 'null' });
        console.log(inserting);
        res.send(`<center><h3>File uploaded successfully</h3><h1><a href="/">Go to Homepage</a></h1></center>`)
    }
})
app.post("/signotp", async (req, res) => {
    let submittedotp = req.body.otp;
    console.log('submitted otp is:',submittedotp," otp sent is: ",req.session.pinReturn)
    let signhashedpass = await bcrypt.hashSync(req.session.signpass, 10);
    console.log(signhashedpass);
    if (submittedotp === req.session.pinReturn) {
        const user = new User(
            {
                name: req.session.signname,
                email: req.session.signmail,
                gender: req.session.signgender,
                password: req.session.signpass,
            }
        );
        let saving = await user.save();
        console.log(saving);
        res.redirect('/login');
    }
    else {
        res.send('otp is not correct');
    }
})
app.post("/studentsdata", async (req, res) => {
    console.log(req.body);
    req.session.studentsmail = req.body.email;
    let result1 = await connection();
    let responce1 = await result1.findOne({ email: req.body.email });
    console.log(responce1);
    if (responce1 != null) {
        let result2 = await leave();
        let responce2 = await result2.findOne({ email: req.session.studentsmail, status: "null" });
        console.log(responce2);
        if (responce2 != null) {
            req.session.studentfilename = responce2.filename;
            let data = { name: responce1.name, email: req.session.studentsmail, reason: responce2.reason, leaveStartDate: responce2.leaveStartDate, leaveEndDate: responce2.leaveEndDate, Uploadedon: responce2.Uploadedon, filename: responce2.filename };
            res.render(viewspath + "/studentdata.ejs", { data });
        }
        else {
            res.send(`<center><h1>No leave Form Found</h1></center>`);
        }
    }
    else {
        res.send('email not found');
    }
});

app.post("/approvel", async (req, res) => {
    console.log(req.body.approval);
    let result = await leave();
    let responce = await result.findOne({ filename: req.session.studentfilename });
    let resps = await result.findOne({ filename: req.session.studentfilename })
    // console.log(response);
    console.log(req.session.studentfilename);
    responce = await result.updateOne({ filename: req.session.studentfilename }, { $set: { status: req.body.approval } });
    console.log(responce);
    var mailoption = {
        from: process.env.MAIL_FROM,
        to: process.env.MAIL_FROM,
        subject: "Status of Your Application",
        // html: `<p>hello ${loginname}! You have successfully uploaded leave form, IIITU administration will send you a confirmation email after approving. <br> -by <h1>IIITU</h1> </p>`
        html: `<p>Your Uploaded Application on date ${resps.Uploadedon} has been ${req.body.approval}</p>`
    };

    transporter.sendMail(mailoption, function (err, info) {
        if (err) {
            console.log(err);
        }
        else {
            console.log('Email has been sent');
        }
    })
    res.redirect('/services')
})
app.get("/allstudentdata", studentdatacheck, async (req, res) => {
    res.sendFile(publicpath + "/allstudentdata.html");
})
app.get('/checkdata', studentdatacheck, async (req, res) => {
    let result = await leave();
    let responce = await result.find({}).toArray();
    res.json(responce);
})
app.get("/scan", gatecheck, (req, res) => {
    res.render("scanner");
});
app.post("/scanneddata", gatecheck, async (req, res) => {
    console.log('getting data from scanner');
    console.log(req.body.content);
    let arr = JSON.parse(req.body.content);
    console.log(arr);
    console.log(arr.btn);
    console.log(arr.id);
    let result = await leave();
    let responce = await result.findOne({ _id: new ObjectId(arr.id) }, { sort: { _id: -1 } });
    if (!responce) {
        res.json('data not found');
    }
    else {
        if (arr.btn == 1) {
            let upd = await result.updateOne({ _id: new ObjectId(arr.id) }, { $set: { exit: 'done', exiton: new Date() } });
            console.log(upd);
        }
        else {
            let upd = await result.updateOne({ _id: new ObjectId(arr.id) }, { $set: { entry: 'done', entryon: new Date() } });
            console.log(upd);
        }
    }
    res.json('data entered successfully');
})

app.get("/logout", async (req, res) => {
    req.session.destroy();
    res.clearCookie();
    res.redirect("/");
})

app.get("*",(req,res)=>
{
    res.sendFile(imagepath+"/404-errors.png");
})

app.listen(port);