validate.js

const express = require('express');
const bodyParser = require('body-parser');
const mysql = require('mysql');
const msg91 = require('msg91')('YOUR_API_KEY', 'YOUR_SENDER_ID', 'ROUTE_NO');

const app = express();

app.use(bodyParser.urlencoded({
    extended: true
}));

const connection = mysql.createConnection({
    host: 'localhost',
    user: 'YOUR_USERNAME',
    password: 'YOUR_PASSWORD',
    database: 'YOUR_DATABASE'
});

app.post('/sendotp', (req, res) => {
    const mobileNumber = req.body.mobileNumber;
    const otp = Math.floor(100000 + Math.random() * 900000);

    const insertQuery = `INSERT INTO otp (mobile_number, otp, created_at) VALUES (${mobileNumber}, ${otp}, NOW())`;

    connection.query(insertQuery, (insertError, insertResults, insertFields) => {
        if (insertError) {
            console.error(insertError);
            res.status(500).send('Internal Server Error');
        } else {
            const message = `Your OTP for verification is ${otp}. Do not share it with anyone. -Your Company Name`;

            msg91.send(mobileNumber, message, (sendError, response) => {
                if (sendError) {
                    console.error(sendError);
                    res.status(500).send('Failed to send OTP');
                } else {
                    console.log(`OTP sent to ${mobileNumber}`);
                    res.status(200).send('OTP sent successfully');
                }
            });
        }
    });
});

app.post('/validateotp', (req, res) => {
    const mobileNumber = req.body.mobileNumber;
    const enteredOtp = req.body.otp;

    const validateOtp = () => {
        const otpQuery = `SELECT otp, created_at FROM otp WHERE mobile_number=${mobileNumber}`;
        connection.query(otpQuery, (otpError, otpResults, otpFields) => {
            if (otpError) {
                console.error(otpError);
                res.status(500).send('Internal Server Error');
                connection.end();
                return;
            }

            const dbOtp = otpResults[0].otp;
            const createdAt = new Date(otpResults[0].created_at);
            const now = new Date();
            const diff = (now.getTime() - createdAt.getTime()) / 1000;

            if (dbOtp != enteredOtp) {
                const retryCountQuery = `SELECT retry_count FROM otp WHERE mobile_number=${mobileNumber}`;
                connection.query(retryCountQuery, (retryCountError, retryCountResults, retryCountFields) => {
                        if (retryCountError) {
                            console.error(retryCountError);
                            res.status(500).send('Internal Server Error');
                            connection.end();
                            return;
                        }

                        res.status(400).send(`Invalid OTP. You have ${3 - retryCountResults[0].retry_count} attempts left`);

                        if (retryCountResults[0].retry_count >= 2) {
                            const blockQuery = `UPDATE otp SET is_blocked=1 WHERE mobile_number=${mobileNumber}`;
                            connection.query(blockQuery, (blockError, blockResults, blockFields) => {
                                if (blockError) {
                                    console.error(blockError);
                                } else {
                                    console.log('OTP blocked');
                                }
                            });
                        } else {
                            const retryCount = retryCountResults[0].retry_count + 1;
                            const updateQuery = `UPDATE otp SET retry_count=${retryCount} WHERE mobile_number=${mobileNumber}`;
                            connection.query(updateQuery, (updateError, updateResults, updateFields) => {
                                if (updateError) {
                                    console.error(updateError);
                                } else {
                                    console.log(`OTP retry count updated to ${retryCount}`);
                                }
                            });
                        }

                        connection.end();
                    }
                });
        });
    }
});
};

const blockQuery = `SELECT is_blocked FROM otp WHERE mobile_number=${mobileNumber}`;
connection.query(blockQuery, (blockError, blockResults, blockFields) => {
if (blockError) {
    console.error(blockError);
    res.status(500).send('Internal Server Error');
    connection.end();
    return;
}

const isBlocked = blockResults[0].is_blocked;

if (isBlocked) {
    res.status(400).send('OTP blocked. Try again in 5 minutes');
    connection.end();
} else {
    validateOtp();
}
});
});