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 myConsole = resourceLocator.log.decorateLogs();
    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) {
                myConsole.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;
                myConsole.info(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) {
                            myConsole.error(subscription.correlation_id + ' -Cannot send UPnp event notification to engine: ' + error);
                        }
                        if (response.statusCode !== 204) {
                            myConsole.error(subscription.correlation_id + ' - Unexpected status code:' + response.statusCode);
                        }
                    }
                );
            } else {
                myConsole.info(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;