/**
* @namespace cam
* @description Events section for Cam class
* @author Andrew D.Laptev <a.d.laptev@gmail.com>
* @licence MIT
*/
/**
* @typedef {object} Cam~CreatePullPointSubscriptionResponse
* @property {object} subscriptionReference
* @property {string|object} subscriptionReference.address
* @property {Date} currentTime
* @property {Date} terminationTime
*/
/**
* Events namespace for the device, stores all information about device events
* @name Cam#events
* @type object
* @property {Cam~EventProperties} properties
* @property {Cam~CreatePullPointSubscriptionResponse} subscription
* @property {Date} terminationTime Time when pull-point subscription is over
* @property {number} messageLimit Pull message count
*/
const Cam = require('./cam').Cam
, cam = require('./cam')
, linerase = require('./utils').linerase
, url = require('url')
;
/**
* Event properties object
* @typedef {object} Cam~EventProperties
* @property {array} topicNamespaceLocation
* @property {object} topicSet
* @property {array} topicExpressionDialect
*/
/**
* @callback Cam~GetEventPropertiesCallback
* @property {?Error} err
* @property {Cam~EventProperties} response
* @property {string} response xml
*/
/**
* Get event properties of the device. Sets `events` property of the device
* @param {Cam~GetEventPropertiesCallback} callback
*/
Cam.prototype.getEventProperties = function(callback) {
this._request({
service: 'events'
, body: this._envelopeHeader() +
'<GetEventProperties xmlns="http://www.onvif.org/ver10/events/wsdl"/>' +
this._envelopeFooter()
}, function(err, res, xml) {
if (!err) {
this.events.properties = linerase(res).getEventPropertiesResponse;
}
callback.call(this, err, err ? null : this.events.properties, xml);
}.bind(this));
};
/**
* Get event service capabilities
* @param {function} callback
*/
Cam.prototype.getEventServiceCapabilities = function(callback) {
this._request({
service: 'events'
, body: this._envelopeHeader() +
'<GetServiceCapabilities xmlns="http://www.onvif.org/ver10/events/wsdl"/>' +
this._envelopeFooter()
}, function(err, res, xml) {
if (!err) {
var data = linerase(res[0].getServiceCapabilitiesResponse[0].capabilities[0].$);
}
callback.call(this, err, data, xml);
}.bind(this));
};
/**
* Create pull-point subscription
* @param {function} callback
*/
Cam.prototype.createPullPointSubscription = function(callback) {
this._request({
service: 'events'
, body: this._envelopeHeader() +
'<CreatePullPointSubscription xmlns="http://www.onvif.org/ver10/events/wsdl"/>' +
this._envelopeFooter()
}, function(err, res, xml) {
if (!err) {
this.events.subscription = linerase(res[0].createPullPointSubscriptionResponse[0]);
this.events.subscription.subscriptionReference.address =
this._parseUrl(this.events.subscription.subscriptionReference.address);
this.events.terminationTime = _terminationTime(this.events.subscription);
}
callback.call(this, err, err ? null : this.events.subscription, xml);
}.bind(this));
};
/**
* @typedef {object} Cam~Event
* @property {Date} currentTime
* @property {Date} terminationTime
* @property {Cam~NotificationMessage|Array.<Cam~NotificationMessage>} [notificationMessage]
*/
/**
* @typedef {object} Cam~NotificationMessage
* @property {string} subscriptionReference.address Pull-point address
* @property {string} topic._ Namespace of message topic
* @property {object} message Message object
*/
/**
* @callback Cam~PullMessagesResponse
* @property {?Error} error
* @property {Cam~Event} response Message
* @property {string} xml Raw SOAP response
*/
/**
* Pull messages from pull-point subscription
* @param options
* @param {number} [options.timeout=30000]
* @param {number} [options.messageLimit=1]
* @param {Cam~PullMessagesResponse} callback
* @throws {Error} {@link Cam#events.subscription} must exists
*/
Cam.prototype.pullMessages = function(options, callback) {
try {
var urlAddress = this.events.subscription.subscriptionReference.address;
} catch (e) {
throw new Error('You should create pull-point subscription first!');
}
this._request({
url: urlAddress
, body: this._envelopeHeader() +
'<PullMessages xmlns="http://www.onvif.org/ver10/events/wsdl">' +
'<Timeout>PT' + ((options.timeout || 30000) / 1000) + 'S</Timeout>' +
'<MessageLimit>' + (options.messageLimit || 1) + '</MessageLimit>' +
'</PullMessages>' +
this._envelopeFooter()
}, function(err, res, xml) {
if (!err) {
var data = linerase(res).pullMessagesResponse;
}
callback.call(this, err, data, xml);
}.bind(this));
};
/**
* Count time before pull-point subscription terminates
* @param {Cam~CreatePullPointSubscriptionResponse} response
* @returns {Date}
* @private
*/
function _terminationTime(response) {
return new Date(Date.now() - response.currentTime.getTime() + response.terminationTime.getTime());
}
/**
* Bind event handling to the `event` event
*/
Cam.prototype.on('newListener', function(name) {
// if there is the first listener, start pulling
if (name === 'event' && this.listeners(name).length === 0) {
this._eventRequest();
}
});
/**
* Event loop for pullMessages request
* @private
*/
Cam.prototype._eventRequest = function() {
this.events.timeout = this.events.timeout || 30000; // setting timeout
this.events.messageLimit = this.events.messageLimit || 1; // setting message limit
if (!this.events.terminationTime || (this.events.terminationTime < Date.now() + this.events.timeout)) {
// if there is no pull-point subscription or it will be dead soon, create new
this.createPullPointSubscription(this._eventPull.bind(this));
} else {
this._eventPull();
}
};
/**
* Event loop for pullMessages request
* @private
*/
Cam.prototype._eventPull = function() {
if (this.listeners('event').length) { // check for event listeners, if zero, stop pulling
this.pullMessages({
timeout: this.events.timeout
, messageLimit: this.events.messageLimit
}, function(err, data) {
if (!err) {
if (data.notificationMessage) {
if (!Array.isArray(data.notificationMessage)) {
data.notificationMessage = [data.notificationMessage];
}
data.notificationMessage.forEach(function(message) {
// pull-point address check
if (message.subscriptionReference.address === this.events.subscription.subscriptionReference.address.href) {
/**
* Indicates message from device.
* @event Cam#event
* @type {Cam~NotificationMessage}
*/
this.emit('event', message);
}
}.bind(this));
}
this.events.terminationTime = _terminationTime(data);
}
this._eventRequest();
}.bind(this));
}
};