Initial commit

servers/websocket/actions/template.js

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+/*
+    ! /servers/websocket/actions/template.js – A simple websocket action template
+    ? This module is just a template for the websocket actions
+*/
+
+module.exports = (connectionManager, data, id) => {
+    
+};

servers/websocket/connections.js

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+/*
+    ! /servers/websocket/connections.js – Central WebSocket Connection Manager
+    ? This module handles all websocket connections as a pool and automatically sends heartbeats
+*/
+
+// % import nodejs dependencies
+const path = require('path');
+
+// % import external dependencies
+const rootDir = path.resolve(__dirname, '..', '..');
+const { generatePrefixed } = require(path.resolve(rootDir, 'services', 'idgen.js'));
+
+// % create a new connection mapping
+let connections = new Map();
+let registry = new Map();
+
+// % set heartbeat settings
+let heartbeatInterval = null;
+const heartbeatTime = 5000; // 5 seconds
+
+// $ add a connection
+function add(socket, codename = null) {
+    // % generate a unique id for websocket connections
+    const id = generatePrefixed('ws');
+
+    // ~ add connection to connection pool
+    const conn = { socket, codename, lastHeartbeat: Date.now() };
+    connections.set(id, conn);
+
+    // ~ add registry keys if codename is provided
+    if (codename) registry.set(codename, id);
+
+    // ~ listen for 'pong' events from client to update heartbeat timestamp
+    socket.on('pong', () => conn.lastHeartbeat = Date.now());
+
+    // ~ error handling
+    socket.on('error', (err) => remove(id));
+
+    // ~ close connection
+    socket.on('close', () => remove(id));
+
+    // ~ return client id
+    return id;
+}
+
+// $ remove a connection by id
+function remove(id) {
+    // % find id in connection map
+    const conn = connections.get(id);
+
+    // ~ close and remove connection
+    if (conn) {
+        // ~ cleanup registry if codename exists
+        if (conn.codename) registry.delete(conn.codename);
+
+        // ~ close connection
+        if (conn.socket.readyState === conn.socket.OPEN) conn.socket.close();
+
+        // ~ remove connection from pool
+        connections.delete(id);
+    }
+}
+
+// $ remove all connections
+function removeAll() {
+    // ~ loop through connection mapping
+    for (const id of connections.keys()) {
+        remove(id);
+    }
+}
+
+// $ get a connection by id
+function get(id) {
+    return connections.get(id);
+}
+
+// $ get a connection by codename
+function getByCodename(codename) {
+    // % get id from codename
+    const id = registry.get(codename);
+
+    // ~ return connection
+    return id ? connections.get(id) : null;
+}
+
+// $ get all connections
+function getAll() {
+    // % create a reference for all connections
+    const all = {};
+
+    // ~ loop through connections and fill "all" reference
+    for (const [id, data] of connections.entries()) {
+        all[id] = {
+            codename: data.codename,
+            lastHeartbeat: data.lastHeartbeat
+        };
+    }
+
+    // ~ return the connection reference
+    return all;
+}
+
+// $ send a message to a specific connection by id
+function send(id, message) {
+    // % get id
+    const conn = connections.get(id);
+
+    // ~ check if connection exists and is open
+    if (conn && conn.socket.readyState === conn.socket.OPEN) {
+        conn.socket.send(JSON.stringify(message));
+        return true;
+    }
+
+    // ~ return immediately after a failure
+    return false;
+}
+
+// $ send a message to a specific connection by codename
+function sendTo(codename, message) {
+    // % get id
+    const id = registry.get(codename);
+
+    // ~ send a message if id exists
+    if (id) return send(id, message);
+
+    // ~ immediately return if id not exists
+    return false;
+}
+
+// $ broadcast to all connections
+function broadcast(message) {
+    // % serialize payload
+    const payload = JSON.stringify(message);
+
+    // ~ loop through all established connections
+    for (const conn of connections.values()) {
+        if (conn.socket.readyState === conn.socket.OPEN) {
+            conn.socket.send(payload);
+        }
+    }
+}
+
+// $ start the heartbeat system
+function startBeat() {
+    if (heartbeatInterval) return;
+
+    heartbeatInterval = setInterval(() => {
+        const now = Date.now();
+
+        for (const [id, conn] of connections.entries()) {
+            // ~ send ping to active connections
+            if (conn.socket.readyState === conn.socket.OPEN) {
+                conn.socket.ping();
+            }
+
+            // ~ remove stale connections (no pong in 2 heartbeat intervals)
+            if (now - conn.lastHeartbeat > heartbeatTime * 2) {
+                remove(id);
+            }
+        }
+    }, heartbeatTime);
+}
+
+// $ stop the heartbeat system
+function stopBeat() {
+    if (heartbeatInterval) {
+        clearInterval(heartbeatInterval);
+        heartbeatInterval = null;
+    }
+}
+
+// § export the websocket connection module
+module.exports = { 
+    add,
+    remove,
+    removeAll,
+    get,
+    getByCodename,
+    getAll,
+    send,
+    sendTo,
+    broadcast,
+    startBeat,
+    stopBeat
+};

servers/websocket/server.js

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+/*
+    ! /servers/websocket/server.js – Central Websocket Server Manager
+    ? This module orchestrates the websocket lifecycle, handles connections, heartbeats and actions
+*/
+
+// % import nodejs packages
+const path = require('path');
+const fs = require('fs');
+const http = require('http');
+const WebSocket = require('ws');
+
+// % import external dependencies
+const rootDir = path.resolve(__dirname, '..', '..');
+const { dirs } = require(path.resolve(rootDir, 'configuration', 'mapping.js'));
+const connectionManager = require(path.resolve(dirs.websocketDir, 'connections.js'));
+
+// % declare action directories
+const wsActionsDir = path.resolve(dirs.websocketDir, 'actions');
+
+// % declare reference for actions
+const actions = {};
+
+// % declare references for the websocket server
+const ip = process.env.INTERNAL_HOST_IP;
+const port = process.env.INTERNAL_WEBSOCKET_PORT;
+let server = null;
+
+// $ load all websocket actions recursively
+// ? The loader is loading all actions with a dot notation
+// ?? Usage: actionName || folder.actionName || folder.folder2.actionName ....
+async function loadActions(dir = wsActionsDir, prefix = '') {
+    // ~ reset the action container to ensure a clean state during reloads
+    for (const key in actions) delete actions[key];
+
+    // % read all content synchronously
+    const files = fs.readdirSync(dir);
+
+    // ~ loop through each file or folder found in the directory
+    for (const file of files) {
+        // % construct the absolute path to the current item
+        const fullPath = path.resolve(dir, file);
+
+        // ~ retrieve file system metadata
+        const stat = fs.statSync(fullPath);
+
+        // ~ check if item is a folder
+        if (stat.isDirectory()) {
+            // ~ recurse into subdirs and append the folder name to the prefix
+            loadActions(fullPath, prefix + file + '.');
+        } else if (file.endsWith('.js')) {
+            // ~ generate a unique action name by stripping the file extension and include the prefix
+            const actionName = prefix + file.replace('.js', '');
+
+            // ~ invalidate the require cache to allow loading the updated code
+            delete require.cache[require.resolve(fullPath)];
+
+            // ~ load the fresh module version into the actions registry
+            actions[actionName] = require(fullPath);
+        }
+    }
+}
+
+// $ function to start the websocket server
+async function start() {
+    // ~ initially load all websocket actions
+    await loadActions();
+
+    try {
+        // ~ set up a new websocket server
+        const wss = new WebSocket.Server({
+            host: ip,
+            port: port
+        });
+
+        wss.on('connection', async (socket, req) => {
+            // ~ authorize connection
+            const url = new URL(req.url, `http://${req.headers.host}`);
+            const key = url.searchParams.get('key');
+            const codename = url.searchParams.get('codename');
+            if (key !== process.env.INTERNAL_SECRET) {
+                socket.close(1008, 'Unauthorized');
+                return;
+            }
+
+            // ~ get connection id and establish connection
+            const id = await connectionManager.add(socket, codename);
+            connectionManager.sendTo(codename, id);
+
+            // ~ register websocket messages
+            socket.on('message', async (data) => {
+                // ~ parse json data
+                const msg = JSON.parse(data);
+
+                // % get user id and validate
+                const valid = connectionManager.get(id);
+                if (valid.socket.readyState !== valid.socket.OPEN) {
+                    connectionManager.remove(id);
+                    return;
+                };
+
+                // % declare action type (e.g. folder.actionName)
+                const type = msg.type;
+                if (!type) {
+                    connectionManager.send(id, 'Action value is empty. Please declare an action value.');
+                    return;
+                };
+
+                // ~ set action handler
+                const actionHandler = actions[msg.type];
+                if (!actionHandler) {
+                    connectionManager.send(id, `Action ${actionHandler} not found.`);
+                    return;
+                }
+
+                // ~ send action to handler
+                try {
+                    await actionHandler(connectionManager, msg.data, id);
+                } catch(e) {
+                    console.error('Error while trying to execute the websocket action!', e);
+                    return;
+                }
+            });
+        });
+
+        // ~ start the heartbeat system with the connection manager
+        connectionManager.startBeat();
+    } catch(e) {
+        console.error('Error while trying to start the websocket server', e);
+        connectionManager.stopBeat();
+    }
+}
+
+// § export websocket server and functions
+module.exports = { start, loadActions };