domotz-remote-pawn/src/upnp/upnpEventHandler.js

Domotz Agent

/** This file is part of Domotz Agent.
  * Copyright (C) 2016  Domotz Ltd
  *
  * Domotz Agent is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
  * the Free Software Foundation, either version 3 of the License, or
  * (at your option) any later version.
  *
  * Domotz Agent 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 General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Domotz Agent.  If not, see <http://www.gnu.org/licenses/>.
  **/
/**
 * Created by Massimiliano Cuzzoli <mcuzzoli@domotz.com> on 21/04/15.
 *
 */


var handleUpnpEvent = function (request, response, resourceLocator) {
    var body = '';
    var xml2js = resourceLocator.xml2js;
    var processors = resourceLocator.xml2jsProcessor;
    var credentials = resourceLocator.configuration.credentials;
    var engineEndpoint = resourceLocator.configuration.engine.api_endpoints.hub;

    function extractFirstValidProperty(jsonBody, subscription) {
        var propertyElement = jsonBody.propertyset.property[0];
        var property;
        var propertyValue;
        for (var i in propertyElement) {
            if (propertyElement.hasOwnProperty(i) && i[0] !== '$') {
                // Skip attributes and namespace declarations
                if (subscription.properties.indexOf(i) >= 0) {
                    property = i;
                    propertyValue = propertyElement[i][0]._;
                    break;
                }
            }
        }
        if (property) {
            return {name: property, value: propertyValue};
        }
        else {
            return null;
        }
    }

    var handleOnEnd = function () {
        var parser = new xml2js.Parser({
            xmlns: true,
            tagNameProcessors: [processors.stripPrefix]
        });
        parser.parseString(body,
            function (error, jsonBody) {
                if (error) {
                    console.warn("Error in XML:" + body + " - " +
                        JSON.stringify(error));
                    response.writeHead(400);
                    response.end();
                    return;
                }

                var subscription = resourceLocator.upnp.registry.getSubscriptionById(request.headers.sid);
                var property = extractFirstValidProperty(jsonBody, subscription);

                if (property) {

                    var sentBody = {
                        'payload': property,
                        'meta_info': {
                            'address': subscription.device_info[0],
                            'port': subscription.device_info[1],
                            'protocol': 'UPNP',
                            'event': request.headers.nts
                        }
                    };

                    var actualUrl = engineEndpoint + subscription.callback_url;
                    console.log(subscription.correlation_id + " - Signaling property `" + property.name + "` change to " + actualUrl);
                    resourceLocator.request({
                        method: 'POST',
                        uri: actualUrl,
                        headers: {'Content-Type': 'application/json'},
                        json: true,
                        body: sentBody,
                        auth: {
                            user: credentials.user,
                            password: credentials.password

                        }
                    }, function (error, response) {
                        if (error) {
                            console.error(subscription.correlation_id + " -Cannot send UPnp event notification to engine: " + error);
                        }
                        if (response.statusCode !== 204) {
                            console.error(subscription.correlation_id + " - Unexpected status code:" + response.statusCode);
                        }

                    });
                }
                else {
                    console.log(subscription.correlation_id + " - No interesting property found");
                }
                response.writeHead(200);
                response.end();

            });
    };

    request.on('data', function (data) {
        body += data;
    });

    request.on('end', handleOnEnd);
};


module.exports.handleUpnpEvent = handleUpnpEvent;