FRIDGE-2080 Add gql subscription (#435)

* FRIDGE-2080 test graphql-ws

* FRIDGE-2080 Add GQL Subscriptions

Author: andreasonny83

lib/Worker.js

@@ -3,6 +3,7 @@ import isObject from 'lodash/isObject';
 import isString from 'lodash/isString';
 import Configuration from './util/Configuration';
 import EventBridgeSignaling from './signaling/EventBridgeSignaling';
+import GraphQLSignaling from './signaling/GraphqlSignaling';
 import { EventEmitter } from 'events';
 import Logger from './util/Logger';
 import Request from './util/Request';
@@ -71,7 +72,7 @@ class Worker extends EventEmitter {
      * @param {WorkerOptions} [options]
      * @param {WorkerDeps} [deps]
      */
-    constructor(token, options = {}, deps = { Request, EventBridgeSignaling }) {
+    constructor(token, options = {}, deps = { Request, EventBridgeSignaling, GraphQLSignaling }) {
         super();
 
         // check the jwt token
@@ -88,6 +89,7 @@ class Worker extends EventEmitter {
             wsServer: (val) => isString(val),
             region: (val) => isString(val),
             enableVersionCheck: (val) => isBoolean(val),
+            useGraphQL: (val) => isBoolean(val),
         };
 
         validateOptions(options, types);
@@ -102,6 +104,11 @@ class Worker extends EventEmitter {
          * @type {boolean}
          */
         this._closeExistingSessions = options.closeExistingSessions;
+        /**
+         * @private
+         * @type {boolean}
+         */
+        this._useGraphQL = options.useGraphQL || false;
         /**
          * @private
          * @type {string}
@@ -143,19 +150,34 @@ class Worker extends EventEmitter {
         this._connectRetry = 0;
         /**
          * @private
-         * @type {EventBridgeSignaling}
+         * @type {GraphQLSignaling}
          */
-        this._signaling = new deps.EventBridgeSignaling(this, {
-            closeExistingSessions: options.closeExistingSessions,
-            setWorkerOfflineIfDisconnected: options.setWorkerOfflineIfDisconnected,
-        });
+        if (this._useGraphQL) {
+            this._gqlSignaling = new deps.GraphQLSignaling(this, {
+                closeExistingSessions: options.closeExistingSessions,
+                setWorkerOfflineIfDisconnected: options.setWorkerOfflineIfDisconnected,
+            });
+        } else {
+            /**
+             * @private
+             * @type {EventBridgeSignaling}
+             */
+            this._signaling = new deps.EventBridgeSignaling(this, {
+                closeExistingSessions: options.closeExistingSessions,
+                setWorkerOfflineIfDisconnected: options.setWorkerOfflineIfDisconnected,
+            });
+        }
         /**
          * @private
          * @type {RetryUtil}
          */
         this.retryUtil = new RetryUtil();
 
-        this._subscribeToSignalingEvents();
+        if (this._useGraphQL) {
+            this._subscribeToGQLEvents();
+        } else {
+            this._subscribeToSignalingEvents();
+        }
 
         let eventHandler;
         if (options.eventHandlerClass) {
@@ -362,7 +384,11 @@ class Worker extends EventEmitter {
 
         try {
             this._config.updateToken(newToken);
-            this._signaling.updateToken(newToken);
+            if (this._useGraphQL) {
+                this._gqlSignaling.updateToken(newToken);
+            } else {
+                this._signaling.updateToken(newToken);
+            }
             this.emit('tokenUpdated');
         } catch (err) {
             this.emit('error', err);
@@ -417,13 +443,53 @@ class Worker extends EventEmitter {
         });
     }
 
+    /**
+     * @private
+     */
+    _subscribeToGQLEvents() {
+        this._log.info('[GQL] Subscribing to Signaling events .... ');
+
+        this._gqlSignaling.on('connected', () => {
+            this._log.info('[GQL] Received Event: \'connected\' from Signaling layer. Pending initialization.', this.sid);
+        });
+
+        this._gqlSignaling.on('disconnected', reason  => {
+            this._log.info('[GQL] Received Event: \'disconnected\' from Signaling layer for Worker %s. %s', this.sid, reason);
+            this._unSubscribeFromTaskRouterEvents();
+            this.emit('disconnected', reason);
+        });
+
+        this._gqlSignaling.on('init', evt => {
+            this._log.info('[GQL] Received Event: \'init\' from Signaling layer. Proceeding to initialize Worker %s.', evt.channel_id);
+            this.sid = evt.channel_id;
+            this.accountSid = evt.account_sid;
+            this.workspaceSid = evt.workspace_sid;
+            // Check if we need this: this._gqlSignaling.setLifetime(evt.token_lifetime);
+            this._initialize();
+        });
+
+        this._gqlSignaling.on('error', err => {
+            this._log.info('[GQL] Received Event: \'error\' from Signaling layer for Worker %s.', this.sid);
+            this.emit('error', err);
+        });
+
+        this._gqlSignaling.on('tokenExpired', () => {
+            this._log.info('[GQL] Received Event: \'tokenExpired\' for for Worker %s. Please update the token. Websocket will not reconnect automatically until token is updated.', this.sid);
+            this.emit('tokenExpired');
+        });
+    }
+
     /**
      * @private
      */
     _subscribeToTaskRouterEvents() {
         this._log.info('Subscribing to TaskRouter events ... ');
         for (let [eventName, eventHandler] of Object.entries(this.taskRouterEventHandler.getTREventsToHandlerMapping())) {
-            this._signaling.on(eventName, this.taskRouterEventHandler[eventHandler]);
+            if (this._useGraphQL) {
+                this._gqlSignaling.on(eventName, this.taskRouterEventHandler[eventHandler]);
+            } else {
+                this._signaling.on(eventName, this.taskRouterEventHandler[eventHandler]);
+            }
         }
     }
 
@@ -434,7 +500,11 @@ class Worker extends EventEmitter {
     _unSubscribeFromTaskRouterEvents() {
         this._log.info('Unsubscribing from TaskRouter events ... ');
         for (let [eventName, eventHandler] of Object.entries(this.taskRouterEventHandler.getTREventsToHandlerMapping())) {
-            this._signaling.removeListener(eventName, this.taskRouterEventHandler[eventHandler]);
+            if (this._useGraphQL) {
+                this._gqlSignaling.removeListener(eventName, this.taskRouterEventHandler[eventHandler]);
+            } else {
+                this._signaling.removeListener(eventName, this.taskRouterEventHandler[eventHandler]);
+            }
         }
     }
 
@@ -634,7 +704,11 @@ class Worker extends EventEmitter {
      * @returns {void}
      */
     disconnect() {
-        this._signaling.disconnect();
+        if (this._useGraphQL) {
+            this._gqlSignaling.disconnect();
+        } else {
+            this._signaling.disconnect();
+        }
     }
 
     /**
@@ -723,12 +797,14 @@ export default Worker;
  *   ['error', 'warn', 'info', 'debug', 'trace', 'silent']
  * @property {string} [region] - the realm for connections (ex. "stage-us1")
  * @property {boolean} [enableVersionCheck=false] - To avoid accidentally overwriting objects with outdated data
+ * @property {boolean} [useGraphQL=false] - Subscribe to worker events using GraphQL subscriptions
  */
 
 /**
  * @typedef {Object} WorkerDeps
  * @property {Request} Request
  * @property {EventBridgeSignaling} EventBridgeSignaling
+ * @property {GraphQLSignaling} [GraphQLSignaling=undefined]
  */
 
 /**