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   1 /**
   2  * Copyright (c) 2010-2022 Contributors to the openHAB project
   3  *
   4  * See the NOTICE file(s) distributed with this work for additional
   5  * information.
   6  *
   7  * This program and the accompanying materials are made available under the
   8  * terms of the Eclipse Public License 2.0 which is available at
   9  * http://www.eclipse.org/legal/epl-2.0
  10  *
  11  * SPDX-License-Identifier: EPL-2.0
  12  */
  13 package org.openhab.binding.mqtt.homie.internal.discovery;
  14
  15 import java.nio.charset.StandardCharsets;
  16 import java.util.Collections;
  17 import java.util.HashMap;
  18 import java.util.Map;
  19
  20 import org.eclipse.jdt.annotation.NonNullByDefault;
  21 import org.eclipse.jdt.annotation.Nullable;
  22 import org.openhab.binding.mqtt.discovery.AbstractMQTTDiscovery;
  23 import org.openhab.binding.mqtt.discovery.MQTTTopicDiscoveryService;
  24 import org.openhab.binding.mqtt.homie.generic.internal.MqttBindingConstants;
  25 import org.openhab.core.config.discovery.DiscoveryResultBuilder;
  26 import org.openhab.core.config.discovery.DiscoveryService;
  27 import org.openhab.core.io.transport.mqtt.MqttBrokerConnection;
  28 import org.openhab.core.thing.ThingUID;
  29 import org.osgi.service.component.annotations.Activate;
  30 import org.osgi.service.component.annotations.Component;
  31 import org.osgi.service.component.annotations.Reference;
  32 import org.slf4j.Logger;
  33 import org.slf4j.LoggerFactory;
  34
  35 /**
  36  * The {@link Homie300Discovery} is responsible for discovering device nodes that follow the
  37  * Homie 3.x convention (https://github.com/homieiot/convention).
  38  *
  39  * @author David Graeff - Initial contribution
  40  */
  41 @Component(service = DiscoveryService.class, configurationPid = "discovery.mqtthomie")
  42 @NonNullByDefault
  43 public class Homie300Discovery extends AbstractMQTTDiscovery {
  44     private final Logger logger = LoggerFactory.getLogger(Homie300Discovery.class);
  45
  46     protected final MQTTTopicDiscoveryService discoveryService;
  47
  48     @Activate
  49     public Homie300Discovery(@Reference MQTTTopicDiscoveryService discoveryService) {
  50         super(Collections.singleton(MqttBindingConstants.HOMIE300_MQTT_THING), 3, true, "+/+/$homie");
  51         this.discoveryService = discoveryService;
  52     }
  53
  54     @Override
  55     protected MQTTTopicDiscoveryService getDiscoveryService() {
  56         return discoveryService;
  57     }
  58
  59     /**
  60      * @param topic A topic like "homie/mydevice/$homie"
  61      * @return Returns the "mydevice" part of the example
  62      */
  63     public static @Nullable String extractDeviceID(String topic) {
  64         String[] strings = topic.split("/");
  65         if (strings.length > 2) {
  66             return strings[1];
  67         }
  68         return null;
  69     }
  70
  71     /**
  72      * Returns true if the version is something like "3.x" or "4.x".
  73      */
  74     public static boolean checkVersion(byte[] payload) {
  75         return payload.length > 0 && (payload[0] == '3' || payload[0] == '4');
  76     }
  77
  78     @Override
  79     public void receivedMessage(ThingUID connectionBridge, MqttBrokerConnection connection, String topic,
  80             byte[] payload) {
  81         resetTimeout();
  82
  83         if (!checkVersion(payload)) {
  84             logger.trace("Found homie device. But version {} is out of range.",
  85                     new String(payload, StandardCharsets.UTF_8));
  86             return;
  87         }
  88         final String deviceID = extractDeviceID(topic);
  89         if (deviceID == null) {
  90             logger.trace("Found homie device. But deviceID {} is invalid.", deviceID);
  91             return;
  92         }
  93
  94         publishDevice(connectionBridge, connection, deviceID, topic, deviceID);
  95     }
  96
  97     void publishDevice(ThingUID connectionBridge, MqttBrokerConnection connection, String deviceID, String topic,
  98             String name) {
  99         Map<String, Object> properties = new HashMap<>();
 100         properties.put("deviceid", deviceID);
 101         properties.put("basetopic", topic.substring(0, topic.indexOf("/")));
 102
 103         thingDiscovered(DiscoveryResultBuilder
 104                 .create(new ThingUID(MqttBindingConstants.HOMIE300_MQTT_THING, connectionBridge, deviceID))
 105                 .withBridge(connectionBridge).withProperties(properties).withRepresentationProperty("deviceid")
 106                 .withLabel(name).build());
 107     }
 108
 109     @Override
 110     public void topicVanished(ThingUID connectionBridge, MqttBrokerConnection connection, String topic) {
 111         String deviceID = extractDeviceID(topic);
 112         if (deviceID == null) {
 113             return;
 114         }
 115         thingRemoved(new ThingUID(MqttBindingConstants.HOMIE300_MQTT_THING, connectionBridge, deviceID));
 116     }
 117 }