mirotalk/server.js

/*
http://patorjk.com/software/taag/#p=display&f=ANSI%20Regular&t=Server

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dependencies: {
    compression : https://www.npmjs.com/package/compression
    dotenv      : https://www.npmjs.com/package/dotenv
    express     : https://www.npmjs.com/package/express
    ngrok       : https://www.npmjs.com/package/ngrok
    socket.io   : https://www.npmjs.com/package/socket.io
    swagger     : https://www.npmjs.com/package/swagger-ui-express
    yamljs      : https://www.npmjs.com/package/yamljs
}

MiroTalk Signaling Server
Copyright (C) 2021 Miroslav Pejic <miroslav.pejic.85@gmail.com>

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU Affero General Public License as published
by the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU Affero General Public License for more details.

You should have received a copy of the GNU Affero General Public License
along with this program.  If not, see <https://www.gnu.org/licenses/>.

*/

'use strict'; // https://www.w3schools.com/js/js_strict.asp

require('dotenv').config();

const compression = require('compression');
const express = require('express');
const path = require('path');
const app = express();
app.use(compression()); // Compress all HTTP responses GZip
const http = require('http');
const server = http.createServer(app);
const { Server } = require('socket.io');
const io = new Server().listen(server);
const ngrok = require('ngrok');
const yamlJS = require('yamljs');
const swaggerUi = require('swagger-ui-express');
const swaggerDocument = yamlJS.load(__dirname + '/api/swagger.yaml');
const apiBasePath = '/api/v1';

let API_KEY_SECRET = process.env.API_KEY_SECRET || 'mirotalk_default_secret';
let PORT = process.env.PORT || 3000; // signalingServerPort
let localHost = 'http://localhost:' + PORT; // http
let api_docs = localHost + apiBasePath + '/docs'; // api docs
let channels = {}; // collect channels
let sockets = {}; // collect sockets
let peers = {}; // collect peers info grp by channels

let ngrokEnabled = process.env.NGROK_ENABLED;
let ngrokAuthToken = process.env.NGROK_AUTH_TOKEN;
let turnEnabled = process.env.TURN_ENABLED;
let turnUrls = process.env.TURN_URLS;
let turnUsername = process.env.TURN_USERNAME;
let turnCredential = process.env.TURN_PASSWORD;

// Use all static files from the www folder
app.use(express.static(path.join(__dirname, 'www')));

// Api parse body data as json
app.use(express.json());

// Remove trailing slashes in url handle bad requests
app.use((err, req, res, next) => {
    if (err instanceof SyntaxError && err.status === 400 && 'body' in err) {
        logme('Request Error', {
            header: req.headers,
            body: req.body,
            error: err.message,
        });
        return res.status(400).send({ status: 404, message: err.message }); // Bad request
    }
    if (req.path.substr(-1) === '/' && req.path.length > 1) {
        let query = req.url.slice(req.path.length);
        res.redirect(301, req.path.slice(0, -1) + query);
    } else {
        next();
    }
});

/*
app.get(["/"], (req, res) => {
    res.sendFile(path.join(__dirname, "www/client.html"))
}); */

// all start from here
app.get(['/'], (req, res) => {
    res.sendFile(path.join(__dirname, 'www/landing.html'));
});

// set new room name and join
app.get(['/newcall'], (req, res) => {
    res.sendFile(path.join(__dirname, 'www/newcall.html'));
});

// if not allow video/audio
app.get(['/permission'], (req, res) => {
    res.sendFile(path.join(__dirname, 'www/permission.html'));
});

// privacy policy
app.get(['/privacy'], (req, res) => {
    res.sendFile(path.join(__dirname, 'www/privacy.html'));
});

// no room name specified to join
app.get('/join/', (req, res) => {
    res.redirect('/');
});

// join to room
app.get('/join/*', (req, res) => {
    if (Object.keys(req.query).length > 0) {
        logme('redirect:' + req.url + ' to ' + url.parse(req.url).pathname);
        res.redirect(url.parse(req.url).pathname);
    } else {
        res.sendFile(path.join(__dirname, 'www/client.html'));
    }
});

/**
    MiroTalk API v1
    The response will give you a entrypoint / Room URL for your meeting.
    For api docs we use: https://swagger.io/
*/

// api docs
app.use(apiBasePath + '/docs', swaggerUi.serve, swaggerUi.setup(swaggerDocument));

// request meeting room endpoint
app.post([apiBasePath + '/meeting'], (req, res) => {
    // check if user was authorized for the api call
    let authorization = req.headers.authorization;
    if (authorization != API_KEY_SECRET) {
        logme('MiroTalk get meeting - Unauthorized', {
            header: req.headers,
            body: req.body,
        });
        return res.status(403).json({ error: 'Unauthorized!' });
    }
    // setup meeting URL
    let host = req.headers.host;
    let meetingURL = getMeetingURL(host) + '/join/' + makeId(15);
    res.setHeader('Content-Type', 'application/json');
    res.end(JSON.stringify({ meeting: meetingURL }));

    // logme the output if all done
    logme('MiroTalk get meeting - Authorized', {
        header: req.headers,
        body: req.body,
        meeting: meetingURL,
    });
});

/**
 * Get get Meeting Room URL
 * @param {*} host string
 * @returns meeting Room URL
 */
function getMeetingURL(host) {
    return 'http' + (host.includes('localhost') ? '' : 's') + '://' + host;
}

/**
 * Generate random Id
 * @param {*} length int
 * @returns random id
 */
function makeId(length) {
    let result = '';
    let characters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789';
    let charactersLength = characters.length;
    for (let i = 0; i < length; i++) {
        result += characters.charAt(Math.floor(Math.random() * charactersLength));
    }
    return result;
}
// end of MiroTalk API v1

/**
 * You should probably use a different stun-turn server
 * doing commercial stuff, also see:
 *
 * https://gist.github.com/zziuni/3741933
 * https://www.twilio.com/docs/stun-turn
 * https://github.com/coturn/coturn
 *
 * Check the functionality of STUN/TURN servers:
 * https://webrtc.github.io/samples/src/content/peerconnection/trickle-ice/
 */
let iceServers = [{ urls: 'stun:stun.l.google.com:19302' }];

if (turnEnabled == 'true') {
    iceServers.push({
        urls: turnUrls,
        username: turnUsername,
        credential: turnCredential,
    });
}

/**
 * Expose server to external with https tunnel using ngrok
 * https://ngrok.com
 */
async function ngrokStart() {
    try {
        await ngrok.authtoken(ngrokAuthToken);
        await ngrok.connect(PORT);
        let api = ngrok.getApi();
        let data = await api.listTunnels();
        let pu0 = data.tunnels[0].public_url;
        let pu1 = data.tunnels[1].public_url;
        let tunnelHttps = pu0.startsWith('https') ? pu0 : pu1;
        // server settings
        logme('settings', {
            http: localHost,
            https: tunnelHttps,
            api_docs: api_docs,
            api_key_secret: API_KEY_SECRET,
            iceServers: iceServers,
            ngrok: {
                ngrok_enabled: ngrokEnabled,
                ngrok_token: ngrokAuthToken,
            },
        });
    } catch (err) {
        console.error('[Error] ngrokStart', err);
    }
}

/**
 * Start Local Server with ngrok https tunnel (optional)
 */
server.listen(PORT, null, () => {
    logme(
        `%c

	███████╗██╗ ██████╗ ███╗   ██╗      ███████╗███████╗██████╗ ██╗   ██╗███████╗██████╗ 
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	███████╗██║██║  ███╗██╔██╗ ██║█████╗███████╗█████╗  ██████╔╝██║   ██║█████╗  ██████╔╝
	╚════██║██║██║   ██║██║╚██╗██║╚════╝╚════██║██╔══╝  ██╔══██╗╚██╗ ██╔╝██╔══╝  ██╔══██╗
	███████║██║╚██████╔╝██║ ╚████║      ███████║███████╗██║  ██║ ╚████╔╝ ███████╗██║  ██║
	╚══════╝╚═╝ ╚═════╝ ╚═╝  ╚═══╝      ╚══════╝╚══════╝╚═╝  ╚═╝  ╚═══╝  ╚══════╝╚═╝  ╚═╝ started...

	`,
        'font-family:monospace',
    );

    // https tunnel
    if (ngrokEnabled == 'true') {
        ngrokStart();
    } else {
        // server settings
        logme('settings', {
            http: localHost,
            api_docs: api_docs,
            api_key_secret: API_KEY_SECRET,
            iceServers: iceServers,
        });
    }
});

/**
 * Users will connect to the signaling server, after which they'll issue a "join"
 * to join a particular channel. The signaling server keeps track of all sockets
 * who are in a channel, and on join will send out 'addPeer' events to each pair
 * of users in a channel. When clients receive the 'addPeer' even they'll begin
 * setting up an RTCPeerConnection with one another. During this process they'll
 * need to relay ICECandidate information to one another, as well as SessionDescription
 * information. After all of that happens, they'll finally be able to complete
 * the peer connection and will be in streaming audio/video between eachother.
 * On peer connected
 */
io.sockets.on('connect', (socket) => {
    logme('[' + socket.id + '] --> connection accepted');

    socket.channels = {};
    sockets[socket.id] = socket;

    /**
     * On peer diconnected
     */
    socket.on('disconnect', () => {
        for (let channel in socket.channels) {
            removePeerFrom(channel);
        }
        logme('[' + socket.id + '] <--> disconnected');
        delete sockets[socket.id];
    });

    /**
     * On peer join
     */
    socket.on('join', (config) => {
        logme('[' + socket.id + '] --> join ', config);

        let channel = config.channel;
        let peer_name = config.peerName;
        let peer_video = config.peerVideo;
        let peer_audio = config.peerAudio;
        let peer_hand = config.peerHand;

        if (channel in socket.channels) {
            logme('[' + socket.id + '] [Warning] already joined', channel);
            return;
        }
        // no channel aka room in channels init
        if (!(channel in channels)) {
            channels[channel] = {};
        }

        // no channel aka room in peers init
        if (!(channel in peers)) {
            peers[channel] = {};
        }

        // room locked by the participants can't join
        if (peers[channel]['Locked'] === true) {
            logme('[' + socket.id + '] [Warning] Room Is Locked', channel);
            socket.emit('roomIsLocked');
            return;
        }

        // collect peers info grp by channels
        peers[channel][socket.id] = {
            peer_name: peer_name,
            peer_video: peer_video,
            peer_audio: peer_audio,
            peer_hand: peer_hand,
        };
        logme('connected peers grp by roomId', peers);

        for (let id in channels[channel]) {
            // offer false
            channels[channel][id].emit('addPeer', {
                peer_id: socket.id,
                peers: peers[channel],
                should_create_offer: false,
                iceServers: iceServers,
            });
            // offer true
            socket.emit('addPeer', {
                peer_id: id,
                peers: peers[channel],
                should_create_offer: true,
                iceServers: iceServers,
            });
            logme('[' + socket.id + '] emit addPeer [' + id + ']');
        }

        channels[channel][socket.id] = socket;
        socket.channels[channel] = channel;
    });

    /**
     * Remove peers from channel aka room
     * @param {*} channel
     */
    async function removePeerFrom(channel) {
        if (!(channel in socket.channels)) {
            logme('[' + socket.id + '] [Warning] not in ', channel);
            return;
        }

        delete socket.channels[channel];
        delete channels[channel][socket.id];
        delete peers[channel][socket.id];

        switch (Object.keys(peers[channel]).length) {
            case 0:
                // last peer disconnected from the room without room status set, delete room data
                delete peers[channel];
                break;
            case 1:
                // last peer disconnected from the room having room status set, delete room data
                if ('Locked' in peers[channel]) delete peers[channel];
                break;
        }

        for (let id in channels[channel]) {
            await channels[channel][id].emit('removePeer', { peer_id: socket.id });
            await socket.emit('removePeer', { peer_id: id });
            logme('[' + socket.id + '] emit removePeer [' + id + ']');
        }
    }

    /**
     * Relay ICE to peers
     */
    socket.on('relayICE', (config) => {
        let peer_id = config.peer_id;
        let ice_candidate = config.ice_candidate;

        // logme('[' + socket.id + '] relay ICE-candidate to [' + peer_id + '] ', {
        //     address: config.ice_candidate.address,
        // });

        if (peer_id in sockets) {
            sockets[peer_id].emit('iceCandidate', {
                peer_id: socket.id,
                ice_candidate: ice_candidate,
            });
        }
    });

    /**
     * Relay SDP to peers
     */
    socket.on('relaySDP', (config) => {
        let peer_id = config.peer_id;
        let session_description = config.session_description;

        logme('[' + socket.id + '] relay SessionDescription to [' + peer_id + '] ', { type: session_description.type });

        if (peer_id in sockets) {
            sockets[peer_id].emit('sessionDescription', {
                peer_id: socket.id,
                session_description: session_description,
            });
        }
    });

    /**
     * Refresh Room Status (Locked/Unlocked)
     */
    socket.on('roomStatus', (config) => {
        let peerConnections = config.peerConnections;
        let room_id = config.room_id;
        let room_locked = config.room_locked;
        let peer_name = config.peer_name;

        peers[room_id]['Locked'] = room_locked;

        if (Object.keys(peerConnections).length != 0) {
            logme('[' + socket.id + '] emit roomStatus' + ' to [room_id: ' + room_id + ' locked: ' + room_locked + ']');
            for (let peer_id in peerConnections) {
                if (sockets[peer_id]) {
                    sockets[peer_id].emit('roomStatus', {
                        peer_name: peer_name,
                        room_locked: room_locked,
                    });
                }
            }
        }
    });

    /**
     * Relay NAME to peers
     */
    socket.on('peerName', (config) => {
        let peerConnections = config.peerConnections;
        let room_id = config.room_id;
        let peer_name_old = config.peer_name_old;
        let peer_name_new = config.peer_name_new;
        let peer_id_to_update = null;

        // update peers new name in the specified room
        for (let peer_id in peers[room_id]) {
            if (peers[room_id][peer_id]['peer_name'] == peer_name_old) {
                peers[room_id][peer_id]['peer_name'] = peer_name_new;
                peer_id_to_update = peer_id;

                // logme('[' + socket.id + '] change peer name', {
                //     room_id: room_id,
                //     peer_id: peer_id,
                //     peer_name_old: peer_name_old,
                //     peer_name_new: peer_name_new,
                // });
            }
        }

        // refresh if found
        if (peer_id_to_update && Object.keys(peerConnections).length != 0) {
            logme('[' + socket.id + '] emit peerName to [room_id: ' + room_id + ']', {
                peer_id: peer_id_to_update,
                peer_name: peer_name_new,
            });
            for (let peer_id in peerConnections) {
                if (sockets[peer_id]) {
                    sockets[peer_id].emit('peerName', {
                        peer_id: peer_id_to_update,
                        peer_name: peer_name_new,
                    });
                }
            }
        }
    });

    /**
     * Relay Audio Video Hand ... Status to peers
     */
    socket.on('peerStatus', (config) => {
        let peerConnections = config.peerConnections;
        let room_id = config.room_id;
        let peer_name = config.peer_name;
        let element = config.element;
        let status = config.status;

        // update peers video-audio status in the specified room
        for (let peer_id in peers[room_id]) {
            if (peers[room_id][peer_id]['peer_name'] == peer_name) {
                switch (element) {
                    case 'video':
                        peers[room_id][peer_id]['peer_video'] = status;
                        break;
                    case 'audio':
                        peers[room_id][peer_id]['peer_audio'] = status;
                        break;
                    case 'hand':
                        peers[room_id][peer_id]['peer_hand'] = status;
                        break;
                }

                // logme('[' + socket.id + '] change ' + element + ' status', {
                //     room_id: room_id,
                //     peer_name: peer_name,
                //     element: element,
                //     status: status,
                // });
            }
        }

        // socket.id aka peer that send this status
        if (Object.keys(peerConnections).length != 0) {
            logme('[' + socket.id + '] emit peerStatus to [room_id: ' + room_id + ']', {
                peer_id: socket.id,
                element: element,
                status: status,
            });
            for (let peer_id in peerConnections) {
                if (sockets[peer_id]) {
                    sockets[peer_id].emit('peerStatus', {
                        peer_id: socket.id,
                        peer_name: peer_name,
                        element: element,
                        status: status,
                    });
                }
            }
        }
    });

    /**
     * Relay actions to peers in the same room
     */
    socket.on('peerAction', (config) => {
        let peerConnections = config.peerConnections;
        let room_id = config.room_id;
        let peer_name = config.peer_name;
        let peer_action = config.peer_action;

        // socket.id aka peer that send this status
        if (Object.keys(peerConnections).length != 0) {
            logme('[' + socket.id + '] emit peerAction to [room_id: ' + room_id + ']', {
                peer_id: socket.id,
                peer_name: peer_name,
                peer_action: peer_action,
            });
            for (let peer_id in peerConnections) {
                if (sockets[peer_id]) {
                    sockets[peer_id].emit('peerAction', {
                        peer_name: peer_name,
                        peer_action: peer_action,
                    });
                }
            }
        }
    });

    /**
     * Relay Kick out peer from room
     */
    socket.on('kickOut', (config) => {
        let room_id = config.room_id;
        let peer_id = config.peer_id;
        let peer_name = config.peer_name;

        logme('[' + socket.id + '] kick out peer [' + peer_id + '] from room_id [' + room_id + ']');

        if (peer_id in sockets) {
            sockets[peer_id].emit('kickOut', {
                peer_name: peer_name,
            });
        }
    });

    /**
     * Relay File info
     */
    socket.on('fileInfo', (config) => {
        let peerConnections = config.peerConnections;
        let room_id = config.room_id;
        let peer_name = config.peer_name;
        let file = config.file;

        logme('[' + socket.id + '] Peer [' + peer_name + '] send file to room_id [' + room_id + ']', {
            fileName: file.fileName,
            fileSize: bytesToSize(file.fileSize),
            fileType: file.fileType,
        });

        function bytesToSize(bytes) {
            let sizes = ['Bytes', 'KB', 'MB', 'GB', 'TB'];
            if (bytes == 0) return '0 Byte';
            let i = parseInt(Math.floor(Math.log(bytes) / Math.log(1024)));
            return Math.round(bytes / Math.pow(1024, i), 2) + ' ' + sizes[i];
        }

        if (Object.keys(peerConnections).length != 0) {
            for (let peer_id in peerConnections) {
                if (sockets[peer_id]) {
                    sockets[peer_id].emit('fileInfo', file);
                }
            }
        }
    });

    /**
     * Whiteboard actions for all user in the same room
     */
    socket.on('wb', (config) => {
        let peerConnections = config.peerConnections;
        delete config.peerConnections;
        if (Object.keys(peerConnections).length != 0) {
            // logme("[" + socket.id + "] whiteboard config", config);
            for (let peer_id in peerConnections) {
                if (sockets[peer_id]) {
                    sockets[peer_id].emit('wb', config);
                }
            }
        }
    });
}); // end [sockets.on-connect]

/**
 * log with UTC data time
 * @param {*} msg message any
 * @param {*} op optional params
 */
function logme(msg, op = '') {
    let dataTime = new Date().toISOString().replace(/T/, ' ').replace(/Z/, '');
    console.log('[' + dataTime + '] ' + msg, op);
}