server.js

const http = require('http');
const path = require('path');
const express = require('express');
const ShareDB = require('sharedb');
const WS = require('ws');
const WebSocketJSONStream = require('@teamwork/websocket-json-stream');
const shortid = require('shortid');
const OT = require('./ot.js');

const backend = new ShareDB({
  presence: true,
});
const connection = backend.connect();

const app = express();

// static
const static = express.static('static');
app.use(static);

// client
app.post("/client", (req, res) => {
  const id = shortid.generate();
  res.redirect(`/client/${id}`);
});

const clientPage = path.resolve(__dirname, "static/client.html");
app.use("/client/:id", (req, res) => {
  const id = req.params.id;
  const doc = connection.get("codemirror", id);
  // console.log(id, doc.type);
  if (doc.type === null) {
    doc.create("// hello world", OT.type.name, (err) => {
      if (err) {
        console.error(`error while creating doc "${id}"`, err);
      } else {
        console.log(`doc "${id}" created`);
      }
    });
  }
  res.sendFile(clientPage);
  // res.redirect(`/client.html?id=${id}`);
});

const server = http.createServer(app);

const wss = new WS.Server({
  server: server,
  path: "/client"
});
wss.on('connection', (ws) => {
  const stream = new WebSocketJSONStream(ws);
  backend.listen(stream);
});

const port = 8080;
server.listen(port);
console.debug(`Listening on ${port}`);

process.on('SIGINT', function () {
  console.log("SIGINT received, exiting...");
  process.exit();
});