domotz-remote-pawn/src/discovery/ip_network/engine_report_strategy.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/>.
 *
 *
 * This module has the responsibility to send the discovered IP devices to the engine, choosing between a full or
 * a delta report following an internal logic
 *
 * Created by Iacopo Papalini <iacopo@domotz.com> on 19/05/16.
 */


var engineIpDiscoveryReportStrategyFactory = function (q, engineRequest, interfacesBindingStorage, configuration) {
    "use strict";

    var discovery = configuration.discovery;

    var fullDiscoveryPeriod = (discovery && discovery.refresh) ? discovery.refresh : 30;

    return function () {
        var counter = 0;

        var ret = {

            reportDiscovery: function () {
                var seq = getNextSequenceNumber();
                var payload = (seq !== 0) ? ret.createDeltaPayload() :
                    ret.createFullPayload();
                console.debug("Sending IP Network device discovery report " +
                    "to engine. Sequence number: " + seq);
                console.verbose(JSON.stringify(payload, null, 2));

                var deferred = q.defer();
                if (isToSend(payload, seq)) {
                    engineRequest.send('/device/ip?seq=' + seq, 'PUT', payload,
                        function () {
                            console.verbose("Report successfully sent to " +
                                "engine. Sequence number: " + seq);
                            return deferred.resolve();
                        },
                        function (err) {
                            console.warn("Error reporting IP network devices " +
                                "to engine. Sequence number: " + seq +
                            " - Rolling back sequence number");
                            counter --;
                            return deferred.reject(err);
                        });
                } else {
                    console.debug("No changes in IP network - no report will " +
                        "be sent to the agent");
                    deferred.resolve();
                }

                function isToSend(payload, seq){
                    return seq === 0  || isNotEmpty(payload) ;
                }

                function isNotEmpty(payload){
                    // http://stackoverflow.com/questions/679915/how-do-i-test-for-an-empty-javascript-object
                    return (!( Object.keys(payload).length === 0 &&
                                        payload.constructor === Object ));
                }

                return deferred.promise;
            },
            createFullPayload: function () {
                return bindingListToDictionary(interfacesBindingStorage.listFresh());
            },
            createDeltaPayload: function () {
                var payload = {};
                var fresh = bindingListToDictionary(interfacesBindingStorage.listFresh());

                var add_stale_info = function (stale) {
                    var mac = stale.mac;
                    if (fresh[mac]) {
                        if (payload[mac] === undefined) {
                            payload[mac] = [];
                        }
                        payload[mac] = payload[mac].concat(fresh[mac]);
                    }
                    if (payload[mac] !== undefined) {
                        return;
                    }
                    payload[mac] = null;
                };
                var add_new_info = function (new_one) {
                    var mac = new_one.mac;
                    // new device is always fresh - add it with all the fresh IP addresses
                    payload[mac] = fresh[mac];
                };

                interfacesBindingStorage.listStale().forEach(add_stale_info);
                interfacesBindingStorage.listNew().forEach(add_new_info);

                return payload;


            }
        };

        function getNextSequenceNumber() {
            var ret = (counter % fullDiscoveryPeriod) ? counter : 0;
            counter++;
            return ret;
        }

        function bindingListToDictionary(list) {
            var ret = {};
            list.forEach(function (binding) {
                if (ret[binding.mac] === undefined) {
                    ret[binding.mac] = [];
                }
                ret[binding.mac].push({ip: binding.ip, host_name: binding.hostname});
            });
            return ret;
        }
        return ret;
    }();


};

module.exports.engineIpDiscoveryReportStrategyFactory = engineIpDiscoveryReportStrategyFactory;