baseapp.js

const express = require('express');
const bodyParser = require('body-parser');
const mongoose = require('mongoose');
const jwt = require('jsonwebtoken');
const app= express();

    

app.use(bodyParser.json());
app.use(express.json());

const SECRET= 'secrat';
  

const userSchema = new mongoose.Schema({
  username:{type: String},// above and below same
  password: String,  // above and below same
  purchasedCourses: [{ type: mongoose.Schema.Types.ObjectId, ref: 'Course' }]
  
})

const adminSchema = new mongoose.Schema({
  username: String,
  password: String 
});

const courseSchema = new mongoose.Schema({
  title: String,
  description: String,
  price: Number,
  imageLink: String,
  published: Boolean
});

const USer = mongoose.model('User',userSchema);
const Admin = mongoose.model('Admin',adminSchema);
const Course =mongoose.model('Course',courseSchema);


const authenticateJwt =(req,res,next) =>{
  const authHeader =req.headers.authorization;
  if(authHeader){
    const token =authHeader.split(' ')[1];
    jwt.verify(token,SECRET,(err,user)=>{
      if(err){
        return res.sendStatus(402);
      }
      req.user =user;
      next();
    });
  }else{
    res.sendStatus(401);
  }
};
mongoose.connect('mongodb+srv://plevenansh:PpxhXRfn33nqr9lX@cluster0.fsv3gi4.mongodb.net/')

// Admin route
app.post('/admin/signup', async(req, res) => {
  const {username,password} =req.body;
  const admin =await Admin.findOne({username,password});
  if(admin){
    res.json({
      message:'Admin Exits'
    });
  }
  else{
    const obj ={ username: username, password: password };
    const newAdmin =new Admin(obj);
    newAdmin.save();
    const token =jwt.sign({username,role:'admin'},SECRET,{expiresIn:'1h'});
     res.json({ message: 'Admin created successfully', token });
}
});
app.post('/admin/login',async (req, res) => {
  const {username,password} =req.headers;
  const admin=await Admin.findOne({username,password});
  if (admin) {
    const token = jwt.sign({ username, role: 'admin' }, SECRET, { expiresIn: '1h' });
    res.json({ message: 'Logged in successfully', token });
  } else {
    res.status(403).json({ message: 'Invalid username or password' });
  }
});

app.post('/admin/courses',authenticateJwt, async(req, res) => {
  const course = new Course(req.body);
  await course.save();
  res.json({ message: 'Course created successfully', courseId: course.id });
});

app.put('/admin/courses/:courseId',authenticateJwt, async (req, res) => {
  const course =await Course.findByIdAndUpdate(req.params.courseId,req.body,{new:true});
  if (course) {
    res.json({ message: 'Course updated successfully' });
  } else {
    res.status(404).json({ message: 'Course not found' });
}
});

app.get('/admin/courses', authenticateJwt, async(req, res) => {
  const courses = await Course.find({});
  res.json({ courses });
});

// User routes

app.post('/users/signup', async (req, res) => {
  const { username, password } = req.body;
  const user = await User.findOne({ username });
  if (user) {
    res.status(403).json({ message: 'User already exists' });
  } else {
    const newUser = new User({ username, password });
    await newUser.save();
    const token = jwt.sign({ username, role: 'user' }, SECRET, { expiresIn: '1h' });
    res.json({ message: 'User created successfully', token });
  }
});

app.post('/users/login', async (req, res) => {
  const { username, password } = req.headers;
  const user = await User.findOne({ username, password });
  if (user) {
    const token = jwt.sign({ username, role: 'user' }, SECRET, { expiresIn: '1h' });
    res.json({ message: 'Logged in successfully', token });
  } else {
    res.status(403).json({ message: 'Invalid username or password' });
  }
});

app.get('/users/courses', authenticateJwt, async (req, res) => {
  const courses = await Course.find({published: true});
  res.json({ courses });
});

app.post('/users/courses/:courseId', authenticateJwt, async (req, res) => {
  const course = await Course.findById(req.params.courseId);
  console.log(course);
  if (course) {
    const user = await User.findOne({ username: req.user.username });
    if (user) {
      user.purchasedCourses.push(course);
      await user.save();
      res.json({ message: 'Course purchased successfully' });
    } else {
      res.status(403).json({ message: 'User not found' });
    }
  } else {
    res.status(404).json({ message: 'Course not found' });
  }
});

app.get('/users/purchasedCourses', authenticateJwt, async (req, res) => {
  const user = await User.findOne({ username: req.user.username }).populate('purchasedCourses');
  if (user) {
    res.json({ purchasedCourses: user.purchasedCourses || [] });
  } else {
    res.status(403).json({ message: 'User not found' });
  }
});

app.listen(3000, () => {console.log('Server is listening on port 3000');})