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

const app = express();
app.use(bodyParser.json());
app.use(cors());

const commentsByPostID = {};

app.get('/posts/:id/comments', (req, res) => {
  res.send(commentsByPostID[req.params.id] || []);
});

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

  const comments = commentsByPostID[req.params.id] ||  [];

  comments.push({ id: commentID, content, status: 'pending' })
  
  commentsByPostID[req.params.id] = comments;

  await axios.post('http://localhost:4005/events', {
    type: 'CommentCreated',
    data: {
      id: commentID, content, postId: req.params.id, status: 'pending'
    }
  }).catch(error => console.log(error));

  res.status(201).send(comments);
});

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

  if(type === 'CommentModerated') {
    const { postId, id, status, content } = data;
    const comments = commentsByPostID[postId];
    const comment = comments.find(comment => comment.id === id);
    comment.status = status;

    await axios.post('http://localhost:4005/events', {
      type: 'CommentUpdated',
      data: { id, status, postId, content }
    }).catch(error => console.log(error));
  }

  res.send({});
});

app.listen(4001, () => {
  console.log('Listening on 4001');
});