server.js

require('dotenv').config();
const express = require('express');
const admin = require('firebase-admin');
const socket = require('socket.io');

//  Express setup
const app = express();
const NODE_ENV = process.env.NODE_ENV || 'development';
const port = process.env.PORT || 5000;
const server = app.listen(port, () =>
  console.log(`Listening at http://localhost:${port}`),
);
app.use(express.static('public'));
app.use(express.json({ limit: '1mb' }));

const io = socket(server);

io.on('connection', (socket) => {
  socket.on('userSession', (userSession) => {
    let userId = userSession.userId;
    socket.join(userId);
    socket.to(userId).emit('userSession', userSession);
  });

  socket.on('collabSession', (currentSession) => {
    let sessionId = currentSession.sessionId;
    if (currentSession.action == 'subscribe') {
      socket.join(sessionId);
      socket.to(sessionId).emit('collabSession', currentSession);
    } else if (currentSession.action == 'unsubscribe') {
      socket.to(sessionId).emit('collabSession', currentSession);
      socket.leave(sessionId);
    }
  });
});

const serviceAccount =
  NODE_ENV == 'production'
    ? require('/etc/secrets/serviceAccountKey.json')
    : JSON.parse(
        Buffer.from(process.env.GOOGLE_FIREBASE_AUTH, 'base64').toString(
          'utf-8',
        ),
      );

//  Firestore setup
admin.initializeApp({
  credential: admin.credential.cert(serviceAccount),
});

const db = admin.firestore();
admin.firestore().settings({
  ignoreUndefinedProperties: true,
});

async function updateNotes(userId, note) {
  let folderRef = db
    .collection('users')
    .doc(userId)
    .collection('folders')
    .doc(note.folderId);
  //  Folder name can be later set from folderMetadata if adding a folder feature
  await folderRef.set({ folderName: 'Default' });

  let notesRef = db
    .collection('users')
    .doc(userId)
    .collection('notes')
    .doc(note.noteId);
  await notesRef.set({
    noteName: note.noteName,
    mdContent: note.mdContent,
    blockContent: note.blockContent,
    noteType: note.noteType,
    folderId: note.folderId,
  });
}

async function updateUserProfile(user) {
  let userRef = db.collection('users').doc(user.userId);
  await userRef.set({
    name: user.name,
    email: user.email,
  });
}

app.post('/notes', (req, res) => {
  updateNotes(req.body.userId, req.body.note)
    .then(() => res.json({ message: 'Database updated' }))
    .catch((err) => console.log(err));
});

app.post('/deleteNote', (req, res) => {
  db.collection('users')
    .doc(req.body.userId)
    .collection('notes')
    .doc(req.body.noteId)
    .delete()
    .then(() => res.json({ message: 'Note deleted' }))
    .catch((err) => console.log(err));
});

app.post('/users', (req, res) => {
  updateUserProfile(req.body)
    .then(() => res.json({ message: 'profile updated' }))
    .catch((err) => console.log(err));
});

app.post('/notesList', (req, res) => {
  let notes = {};
  db.collection('users')
    .doc(req.body.userId)
    .collection('notes')
    .orderBy(req.body.orderBy.sortBy, req.body.orderBy.direction)
    .get()
    .then((snapshot) => {
      snapshot.forEach((note) => {
        notes[note.id] = note.data();
      });
      res.json(notes);
    })
    .catch((err) => console.log(err));
});