server/index.js

'use strict';

/**
 * Load Twilio configuration from .env config file - the following environment
 * variables should be set:
 * process.env.TWILIO_ACCOUNT_SID
 * process.env.TWILIO_API_KEY
 * process.env.TWILIO_API_SECRET
 */
require('dotenv').load();

const express = require('express');
const http = require('http');
const path = require('path');
const axios = require('axios');

// Max. period that a Participant is allowed to be in a Room (currently 14400 seconds or 4 hours)
const MAX_ALLOWED_SESSION_DURATION = 14400;
const dailyAPIURL = `https://api.daily.co/v1`;

// Create Express webapp.
const app = express();

// Set up the paths for the examples.
[
  'bandwidthconstraints',
  'codecpreferences',
  'dominantspeaker',
  'localvideofilter',
  'localvideosnapshot',
  'mediadevices',
  'networkquality',
  'reconnection',
  'screenshare',
  'localmediacontrols',
  'remotereconnection',
  'datatracks',
  'manualrenderhint',
  'autorenderhint'
].forEach(example => {
  const examplePath = path.join(__dirname, `../examples/${example}/public`);
  app.use(`/${example}`, express.static(examplePath));
});

// Set up the path for the quickstart.
const quickstartPath = path.join(__dirname, '../quickstart/public');
app.use('/quickstart', express.static(quickstartPath));

// Set up the path for the examples page.
const examplesPath = path.join(__dirname, '../examples');
app.use('/examples', express.static(examplesPath));

/**
 * Default to the Quick Start application.
 */
app.get('https://github.com/', (request, response) => {
  response.redirect('/quickstart');
});

/**
 * Generate an Access Token for a chat application user.
 * Retrieve an existing room or create one with the given
 * name if it does not already exist.
 */
app.get('/token', async function (request, response) {
  const query = request.query;
  const userName = query.identity;
  const roomName = query.roomName;

  let roomData = await getRoom(roomName);
  if (!roomData) {
    roomData = await createRoom(roomName);
  }
  const token = await getMeetingToken(roomName, userName);
  const res = {
    token: token,
    roomURL: roomData.url,
  };
  response.send(JSON.stringify(res));
});

// Create http server and run it.
const server = http.createServer(app);
const port = process.env.PORT || 3000;
server.listen(port, function() {
  console.log('Express server running on *:' + port);
});

// getRoom() retrieves a room by name, if one exists.
async function getRoom(roomName) {
  const apiKey = process.env.DAILY_API_KEY;
  // Prepare our headers, containing our Daily API key
  const headers = {
    Authorization: `Bearer ${apiKey}`,
    'Content-Type': 'application/json',
  };
  const url = `${dailyAPIURL}/rooms/${roomName}`;
  const errMsg = "Failed to get room information."

  let res;
  try {
    res = await axios
    .get(url, {
      headers: headers,
    })
  } catch(error) {
    if (error.response?.status === 404) {
      return null;
    }
    throw new Error(`${errMsg}: ${error})`);
  }

  if (res.status !== 200 || !res.data) {
    console.error('unexpected room retrieval response:', res);
    throw new Error(errMsg);
  }

  return res.data;
}

async function createRoom(roomName) {
  const apiKey = process.env.DAILY_API_KEY;
  // Prepare our desired room properties. 
  const req = {
    name: roomName,
    privacy: 'private',
    properties: {
      exp: Math.floor(Date.now() / 1000) + MAX_ALLOWED_SESSION_DURATION,
      // Start right away in SFU mode
      sfu_switchover: 0.5,
    },
  };

  // Prepare our headers, containing our Daily API key
  const headers = {
    Authorization: `Bearer ${apiKey}`,
    'Content-Type': 'application/json',
  };

  const url = `${dailyAPIURL}/rooms/`;
  const data = JSON.stringify(req);

  const roomErrMsg = 'failed to create room';

  const res = await axios
    .post(url, data, {
      headers: headers,
    })
    .catch((error) => {
      console.error(roomErrMsg, error);
      throw new Error(`${roomErrMsg}: ${error})`);
    });

  if (res.status !== 200 || !res.data) {
    console.error('unexpected room creation response:', res);
    throw new Error(roomErrMsg);
  }
  return res.data;
}


// getMeetingToken() obtains a meeting token for a room from Daily
async function getMeetingToken(roomName, userName) {
  const req = {
    properties: {
      room_name: roomName,
      user_name: userName,
      exp: Math.floor(Date.now() / 1000) + MAX_ALLOWED_SESSION_DURATION,
    },
  };

  const data = JSON.stringify(req);
  const headers = {
    Authorization: `Bearer ${process.env.DAILY_API_KEY}`,
    'Content-Type': 'application/json',
  };
  const url = `${dailyAPIURL}/meeting-tokens/`;

  const errMsg = 'failed to create meeting token';
  const res = await axios.post(url, data, { headers }).catch((error) => {
    throw new Error(`${errMsg}: ${error})`);
  });
  if (res.status !== 200) {
    throw new Error(`${errMsg}: got status ${res.status})`);
  }
  return res.data?.token;
}