index.js

const express = require('express')
const { randomBytes } = require('crypto')
const bodyParser = require('body-parser')
const axios = require('axios')
const app = express()
const cors = require('cors')


app.use(bodyParser.json())
app.use(bodyParser.urlencoded({ extended: true }))
app.use(cors())
const commentsByPostId = {};
app.get('/posts/:id/comments', (req, res) => {
    return res.send(commentsByPostId[req.params.id] || []);
});

app.post('/posts/:id/comments', async (req, res) => {
    const commentsId = randomBytes(4).toString('hex');
    const { content } = req.body;


    const comments = commentsByPostId[req.params.id] || [];
    comments.push({ id: commentsId, content: content });
    commentsByPostId[req.params.id] = comments


    await axios.post('http://localhost:4005/events', {
        type: "Created Comment", data: {
            id: commentsId, content, postId: req.params.id, status: 'pending'

        }
    })
    return res.send(comments)

});

app.post('/events', async (req, res) => {
    const { type, data } = req.body;

    // its call to comments server to modared comment
    if (type === 'CommentModerated') {
        const { postId, id, status, content } = data
        const comments = commentsByPostId[postId]
        const comment = comments.find(comment => {
            return comment.id === id
        })
        comment.status = status




        await axios.post('http://localhost:4005/events', {
            type: 'CommentUpdated', data: {
                id: data.id,
                postId,
                status,
                content
            }
        })

    }
})
app.listen(4001, () => {
    console.log('Comment server listening on port 4001!');
});