feat(client): add confirmedCOVNotification() for pushing changes to subscribers

Author: adam-nielsen

README.md

@@ -43,6 +43,7 @@ following services are already supported at this point in time:
 | Create Object                  | yes¹                                                                                   | yes¹                                                                          |
 | Delete Object                  | yes¹                                                                                   | yes¹                                                                          |
 | Subscribe COV                  | yes¹                                                                                   | yes¹                                                                          |
+| Confirmed COV Notification     | yes¹                                                                                   | yes¹                                                                          |
 | Subscribe Property             | yes¹                                                                                   | yes¹                                                                          |
 | Atomic Read File               | yes¹                                                                                   | yes¹                                                                          |
 | Atomic Write File              | yes¹                                                                                   | yes¹                                                                          |

lib/client.js

@@ -653,6 +653,71 @@ class Client extends EventEmitter {
     });
   }
 
+  /**
+   * The confirmedCOVNotification command is used to push notifications to other
+   * systems that have registered with us via a subscribeCOV message.
+   * @function bacstack.confirmedCOVNotification
+   * @param {string} address - IP address of the target device.
+   * @param {object} monitoredObject - The object being monitored, from subscribeCOV.
+   * @param {number} monitoredObject.type - Object type.
+   * @param {number} monitoredObject.instance - Object instance.
+   * @param {number} subscribeId - Subscriber ID from subscribeCOV,
+   * @param {number} initiatingDeviceId - Our BACnet device ID.
+   * @param {number} lifetime - Number of seconds left until the subscription expires.
+   * @param {array} values - values for the monitored object.  See example.
+   * @param {object=} options
+   * @param {MaxSegmentsAccepted=} options.maxSegments - The maximimal allowed number of segments.
+   * @param {MaxApduLengthAccepted=} options.maxApdu - The maximal allowed APDU size.
+   * @param {number=} options.invokeId - The invoke ID of the confirmed service telegram.
+   * @param {function} next - The callback containing an error, in case of a failure and value object in case of success.
+   * @example
+   * const bacnet = require('bacstack');
+   * const client = new bacnet();
+   *
+   * const settings = {deviceId: 123}; // our BACnet device
+   *
+   * // Items saved from subscribeCOV message
+   * const monitoredObject = {type: 1, instance: 1};
+   * const subscriberProcessId = 123;
+   *
+   * client.confirmedCOVNotification(
+   *   '192.168.1.43',
+   *   monitoredObject,
+   *   subscriberProcessId,
+   *   settings.deviceId,
+   *   30, // should be lifetime of subscription really
+   *   [
+   *     {
+   *       property: { id: bacnet.enum.PropertyIdentifier.PRESENT_VALUE },
+   *       value: [
+   *         {value: 123, type: bacnet.enum.ApplicationTags.REAL},
+   *       ],
+   *     },
+   *   ],
+   *   (err) => {
+   *     console.log('error: ', err);
+   *   }
+   * );
+   */
+  confirmedCOVNotification(address, monitoredObject, subscribeId, initiatingDeviceId, lifetime, values, options, next) {
+    next = next || options;
+    const settings = {
+      maxSegments: options.maxSegments || baEnum.MaxSegmentsAccepted.SEGMENTS_65,
+      maxApdu: options.maxApdu || baEnum.MaxApduLengthAccepted.OCTETS_1476,
+      invokeId: options.invokeId || this._getInvokeId()
+    };
+    const buffer = this._getBuffer();
+    baNpdu.encode(buffer, baEnum.NpduControlPriority.NORMAL_MESSAGE | baEnum.NpduControlBits.EXPECTING_REPLY, address);
+    baApdu.encodeConfirmedServiceRequest(buffer, baEnum.PduTypes.CONFIRMED_REQUEST, baEnum.ConfirmedServiceChoice.CONFIRMED_COV_NOTIFICATION, settings.maxSegments, settings.maxApdu, settings.invokeId, 0, 0);
+    baServices.covNotify.encode(buffer, subscribeId, initiatingDeviceId, monitoredObject, lifetime, values);
+    baBvlc.encode(buffer.buffer, baEnum.BvlcResultPurpose.ORIGINAL_UNICAST_NPDU, buffer.offset);
+    this._transport.send(buffer.buffer, buffer.offset, address);
+    this._addCallback(settings.invokeId, (err, data) => {
+      if (err) return next(err);
+      next();
+    });
+  }
+
   /**
    * The deviceCommunicationControl command enables or disables network communication of the target device.
    * @function bacstack.deviceCommunicationControl