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   1 /**
   2  * Copyright (c) 2010-2020 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.io.homekit.internal.accessories;
  14
  15 import static org.openhab.io.homekit.internal.HomekitAccessoryType.*;
  16 import static org.openhab.io.homekit.internal.HomekitCharacteristicType.*;
  17
  18 import java.lang.reflect.InvocationTargetException;
  19 import java.util.AbstractMap.SimpleEntry;
  20 import java.util.ArrayList;
  21 import java.util.Arrays;
  22 import java.util.Collections;
  23 import java.util.HashMap;
  24 import java.util.List;
  25 import java.util.Map;
  26 import java.util.Map.Entry;
  27 import java.util.Optional;
  28 import java.util.stream.Collectors;
  29 import java.util.stream.Stream;
  30
  31 import org.eclipse.jdt.annotation.NonNullByDefault;
  32 import org.eclipse.jdt.annotation.Nullable;
  33 import org.openhab.core.items.GenericItem;
  34 import org.openhab.core.items.GroupItem;
  35 import org.openhab.core.items.Item;
  36 import org.openhab.core.items.ItemRegistry;
  37 import org.openhab.core.items.Metadata;
  38 import org.openhab.core.items.MetadataKey;
  39 import org.openhab.core.items.MetadataRegistry;
  40 import org.openhab.core.library.items.ColorItem;
  41 import org.openhab.core.library.items.DimmerItem;
  42 import org.openhab.io.homekit.internal.HomekitAccessoryType;
  43 import org.openhab.io.homekit.internal.HomekitAccessoryUpdater;
  44 import org.openhab.io.homekit.internal.HomekitCharacteristicType;
  45 import org.openhab.io.homekit.internal.HomekitException;
  46 import org.openhab.io.homekit.internal.HomekitOHItemProxy;
  47 import org.openhab.io.homekit.internal.HomekitSettings;
  48 import org.openhab.io.homekit.internal.HomekitTaggedItem;
  49 import org.slf4j.Logger;
  50 import org.slf4j.LoggerFactory;
  51
  52 import io.github.hapjava.accessories.HomekitAccessory;
  53 import io.github.hapjava.characteristics.Characteristic;
  54 import io.github.hapjava.services.Service;
  55
  56 /**
  57  * Creates a HomekitAccessory for a given HomekitTaggedItem.
  58  *
  59  * @author Andy Lintner - Initial contribution
  60  * @author Eugen Freiter - refactoring for optional characteristics
  61  */
  62 @NonNullByDefault
  63 @SuppressWarnings("deprecation")
  64 public class HomekitAccessoryFactory {
  65     private static final Logger logger = LoggerFactory.getLogger(HomekitAccessoryFactory.class);
  66     public final static String METADATA_KEY = "homekit"; // prefix for HomeKit meta information in items.xml
  67
  68     /** List of mandatory attributes for each accessory type. **/
  69     private final static Map<HomekitAccessoryType, HomekitCharacteristicType[]> MANDATORY_CHARACTERISTICS = new HashMap<HomekitAccessoryType, HomekitCharacteristicType[]>() {
  70         {
  71             put(LEAK_SENSOR, new HomekitCharacteristicType[] { LEAK_DETECTED_STATE });
  72             put(MOTION_SENSOR, new HomekitCharacteristicType[] { MOTION_DETECTED_STATE });
  73             put(OCCUPANCY_SENSOR, new HomekitCharacteristicType[] { OCCUPANCY_DETECTED_STATE });
  74             put(CONTACT_SENSOR, new HomekitCharacteristicType[] { CONTACT_SENSOR_STATE });
  75             put(SMOKE_SENSOR, new HomekitCharacteristicType[] { SMOKE_DETECTED_STATE });
  76             put(HUMIDITY_SENSOR, new HomekitCharacteristicType[] { RELATIVE_HUMIDITY });
  77             put(AIR_QUALITY_SENSOR, new HomekitCharacteristicType[] { AIR_QUALITY });
  78             put(SWITCH, new HomekitCharacteristicType[] { ON_STATE });
  79             put(CARBON_DIOXIDE_SENSOR, new HomekitCharacteristicType[] { CARBON_DIOXIDE_DETECTED_STATE });
  80             put(CARBON_MONOXIDE_SENSOR, new HomekitCharacteristicType[] { CARBON_MONOXIDE_DETECTED_STATE });
  81             put(WINDOW_COVERING, new HomekitCharacteristicType[] { TARGET_POSITION, CURRENT_POSITION, POSITION_STATE });
  82             put(LIGHTBULB, new HomekitCharacteristicType[] { ON_STATE });
  83             put(FAN, new HomekitCharacteristicType[] { ACTIVE_STATUS });
  84             put(LIGHT_SENSOR, new HomekitCharacteristicType[] { LIGHT_LEVEL });
  85             put(TEMPERATURE_SENSOR, new HomekitCharacteristicType[] { CURRENT_TEMPERATURE });
  86             put(THERMOSTAT, new HomekitCharacteristicType[] { CURRENT_HEATING_COOLING_STATE,
  87                     TARGET_HEATING_COOLING_STATE, CURRENT_TEMPERATURE, TARGET_TEMPERATURE });
  88             put(LOCK, new HomekitCharacteristicType[] { LOCK_CURRENT_STATE, LOCK_TARGET_STATE });
  89             put(VALVE, new HomekitCharacteristicType[] { ACTIVE_STATUS, INUSE_STATUS });
  90             put(SECURITY_SYSTEM,
  91                     new HomekitCharacteristicType[] { SECURITY_SYSTEM_CURRENT_STATE, SECURITY_SYSTEM_TARGET_STATE });
  92             put(OUTLET, new HomekitCharacteristicType[] { ON_STATE, INUSE_STATUS });
  93             put(SPEAKER, new HomekitCharacteristicType[] { MUTE });
  94             put(GARAGE_DOOR_OPENER,
  95                     new HomekitCharacteristicType[] { CURRENT_DOOR_STATE, TARGET_DOOR_STATE, OBSTRUCTION_STATUS });
  96             put(HEATER_COOLER, new HomekitCharacteristicType[] { ACTIVE_STATUS, CURRENT_HEATER_COOLER_STATE,
  97                     TARGET_HEATER_COOLER_STATE, CURRENT_TEMPERATURE });
  98             // LEGACY
  99             put(BLINDS, new HomekitCharacteristicType[] { TARGET_POSITION, CURRENT_POSITION, POSITION_STATE });
 100             put(WINDOW, new HomekitCharacteristicType[] { CURRENT_POSITION, TARGET_POSITION, POSITION_STATE });
 101             put(DOOR, new HomekitCharacteristicType[] { CURRENT_POSITION, TARGET_POSITION, POSITION_STATE });
 102
 103             put(OLD_HUMIDITY_SENSOR, new HomekitCharacteristicType[] { RELATIVE_HUMIDITY });
 104             put(OLD_DIMMABLE_LIGHTBULB, new HomekitCharacteristicType[] { ON_STATE });
 105             put(OLD_COLORFUL_LIGHTBULB, new HomekitCharacteristicType[] { ON_STATE });
 106         }
 107     };
 108
 109     /** List of service implementation for each accessory type. **/
 110     private final static Map<HomekitAccessoryType, Class<? extends AbstractHomekitAccessoryImpl>> SERVICE_IMPL_MAP = new HashMap<HomekitAccessoryType, Class<? extends AbstractHomekitAccessoryImpl>>() {
 111         {
 112             put(LEAK_SENSOR, HomekitLeakSensorImpl.class);
 113             put(MOTION_SENSOR, HomekitMotionSensorImpl.class);
 114             put(OCCUPANCY_SENSOR, HomekitOccupancySensorImpl.class);
 115             put(CONTACT_SENSOR, HomekitContactSensorImpl.class);
 116             put(SMOKE_SENSOR, HomekitSmokeSensorImpl.class);
 117             put(HUMIDITY_SENSOR, HomekitHumiditySensorImpl.class);
 118             put(AIR_QUALITY_SENSOR, HomekitAirQualitySensorImpl.class);
 119             put(SWITCH, HomekitSwitchImpl.class);
 120             put(CARBON_DIOXIDE_SENSOR, HomekitCarbonDioxideSensorImpl.class);
 121             put(CARBON_MONOXIDE_SENSOR, HomekitCarbonMonoxideSensorImpl.class);
 122             put(WINDOW_COVERING, HomekitWindowCoveringImpl.class);
 123             put(LIGHTBULB, HomekitLightbulbImpl.class);
 124             put(FAN, HomekitFanImpl.class);
 125             put(LIGHT_SENSOR, HomekitLightSensorImpl.class);
 126             put(TEMPERATURE_SENSOR, HomekitTemperatureSensorImpl.class);
 127             put(THERMOSTAT, HomekitThermostatImpl.class);
 128             put(LOCK, HomekitLockImpl.class);
 129             put(VALVE, HomekitValveImpl.class);
 130             put(SECURITY_SYSTEM, HomekitSecuritySystemImpl.class);
 131             put(OUTLET, HomekitOutletImpl.class);
 132             put(SPEAKER, HomekitSpeakerImpl.class);
 133             put(GARAGE_DOOR_OPENER, HomekitGarageDoorOpenerImpl.class);
 134             put(BLINDS, HomekitWindowCoveringImpl.class);
 135             put(DOOR, HomekitDoorImpl.class);
 136             put(WINDOW, HomekitWindowImpl.class);
 137             put(HEATER_COOLER, HomekitHeaterCoolerImpl.class);
 138             put(OLD_HUMIDITY_SENSOR, HomekitHumiditySensorImpl.class);
 139             put(OLD_DIMMABLE_LIGHTBULB, HomekitLightbulbImpl.class);
 140             put(OLD_COLORFUL_LIGHTBULB, HomekitLightbulbImpl.class);
 141         }
 142     };
 143
 144     /** mapping of legacy attributes to new attributes. **/
 145     private final static Map<HomekitCharacteristicType, HomekitCharacteristicType> LEGACY_CHARACTERISTICS_MAPPING = new HashMap<HomekitCharacteristicType, HomekitCharacteristicType>() {
 146         {
 147             put(OLD_CURRENT_HEATING_COOLING_STATE, CURRENT_HEATING_COOLING_STATE);
 148             put(OLD_TARGET_HEATING_COOLING_MODE, TARGET_HEATING_COOLING_STATE);
 149             put(OLD_TARGET_TEMPERATURE, TARGET_TEMPERATURE);
 150             put(OLD_BATTERY_LOW_STATUS, BATTERY_LOW_STATUS);
 151             put(VERY_OLD_TARGET_HEATING_COOLING_MODE, CURRENT_HEATING_COOLING_STATE);
 152         }
 153     };
 154
 155     /** list of optional implicit optional characteristics. mainly used for legacy accessory type */
 156     private final static Map<HomekitAccessoryType, HomekitCharacteristicType[]> IMPLICIT_OPTIONAL_CHARACTERISTICS = new HashMap<HomekitAccessoryType, HomekitCharacteristicType[]>() {
 157         {
 158             put(OLD_DIMMABLE_LIGHTBULB, new HomekitCharacteristicType[] { BRIGHTNESS });
 159             put(OLD_COLORFUL_LIGHTBULB, new HomekitCharacteristicType[] { HUE, SATURATION, BRIGHTNESS });
 160
 161         }
 162     };
 163
 164     /**
 165      * creates HomeKit accessory for a openhab item.
 166      *
 167      * @param taggedItem openhab item tagged as HomeKit item
 168      * @param metadataRegistry openhab metadata registry required to get item meta information
 169      * @param updater OH HomeKit update class that ensure the status sync between OH item and corresponding HomeKit
 170      *            characteristic.
 171      * @param settings OH settings
 172      * @return HomeKit accessory
 173      * @throws HomekitException exception in case HomeKit accessory could not be created, e.g. due missing mandatory
 174      *             characteristic
 175      */
 176     @SuppressWarnings("null")
 177     public static HomekitAccessory create(HomekitTaggedItem taggedItem, MetadataRegistry metadataRegistry,
 178             HomekitAccessoryUpdater updater, HomekitSettings settings) throws HomekitException {
 179         final HomekitAccessoryType accessoryType = taggedItem.getAccessoryType();
 180         logger.trace("Constructing {} of accessory type {}", taggedItem.getName(), accessoryType.getTag());
 181         final List<HomekitTaggedItem> requiredCharacteristics = getMandatoryCharacteristics(taggedItem,
 182                 metadataRegistry);
 183         final HomekitCharacteristicType[] mandatoryCharacteristics = MANDATORY_CHARACTERISTICS.get(accessoryType);
 184         if ((mandatoryCharacteristics != null) && (requiredCharacteristics.size() < mandatoryCharacteristics.length)) {
 185             logger.warn("Accessory of type {} must have following characteristics {}. Found only {}",
 186                     accessoryType.getTag(), mandatoryCharacteristics, requiredCharacteristics);
 187             throw new HomekitException("Missing mandatory characteristics");
 188         }
 189         AbstractHomekitAccessoryImpl accessoryImpl;
 190         try {
 191             final @Nullable Class<? extends AbstractHomekitAccessoryImpl> accessoryImplClass = SERVICE_IMPL_MAP
 192                     .get(accessoryType);
 193             if (accessoryImplClass != null) {
 194                 accessoryImpl = accessoryImplClass
 195                         .getConstructor(HomekitTaggedItem.class, List.class, HomekitAccessoryUpdater.class,
 196                                 HomekitSettings.class)
 197                         .newInstance(taggedItem, requiredCharacteristics, updater, settings);
 198                 addOptionalCharacteristics(taggedItem, accessoryImpl, metadataRegistry);
 199                 return accessoryImpl;
 200             } else {
 201                 logger.warn("Unsupported HomeKit type: {}", accessoryType.getTag());
 202                 throw new HomekitException("Unsupported HomeKit type: " + accessoryType);
 203             }
 204         } catch (NoSuchMethodException | IllegalAccessException | InstantiationException
 205                 | InvocationTargetException e) {
 206             logger.warn("Cannot instantiate accessory implementation for accessory {}", accessoryType.getTag(), e);
 207             throw new HomekitException("Cannot instantiate accessory implementation for accessory " + accessoryType);
 208         }
 209     }
 210
 211     /**
 212      * return HomeKit accessory types for a OH item based on meta data
 213      *
 214      * @param item OH item
 215      * @param metadataRegistry meta data registry
 216      * @return list of HomeKit accessory types and characteristics.
 217      */
 218     public static List<Entry<HomekitAccessoryType, HomekitCharacteristicType>> getAccessoryTypes(Item item,
 219             MetadataRegistry metadataRegistry) {
 220         final List<Entry<HomekitAccessoryType, HomekitCharacteristicType>> accessories = new ArrayList<>();
 221         final @Nullable Metadata metadata = metadataRegistry.get(new MetadataKey(METADATA_KEY, item.getUID()));
 222         boolean legacyMode = metadata == null;
 223         String[] tags = !legacyMode ? metadata.getValue().split(",") : item.getTags().toArray(new String[0]); // fallback
 224         for (String tag : tags) {
 225             final String[] meta = tag.split("\\.");
 226             Optional<HomekitAccessoryType> accessoryType = HomekitAccessoryType.valueOfTag(meta[0].trim());
 227             if (accessoryType.isPresent()) { // it accessory, check for characteristic
 228                 HomekitAccessoryType type = accessoryType.get();
 229                 if ((legacyMode) && (type.equals(LIGHTBULB))) { // support old smart logic to convert Lighting to
 230                                                                 // DimmableLighting or ColorfulLighting depending on
 231                                                                 // item type
 232                     if (item instanceof ColorItem) {
 233                         type = OLD_COLORFUL_LIGHTBULB;
 234                     } else if (item instanceof DimmerItem) {
 235                         type = OLD_DIMMABLE_LIGHTBULB;
 236                     }
 237                 }
 238                 if (meta.length > 1) {
 239                     // it has characteristic as well
 240                     accessories.add(new SimpleEntry<>(type,
 241                             HomekitCharacteristicType.valueOfTag(meta[1].trim()).orElse(EMPTY)));
 242                 } else {// it has no characteristic
 243                     accessories.add(new SimpleEntry<>(type, EMPTY));
 244                 }
 245             } else { // it is no accessory, so, maybe it is a characteristic
 246                 HomekitCharacteristicType.valueOfTag(meta[0].trim())
 247                         .ifPresent(c -> accessories.add(new SimpleEntry<>(DUMMY, c)));
 248             }
 249         }
 250         return accessories;
 251     }
 252
 253     public static @Nullable Map<String, Object> getItemConfiguration(Item item, MetadataRegistry metadataRegistry) {
 254         final @Nullable Metadata metadata = metadataRegistry.get(new MetadataKey(METADATA_KEY, item.getUID()));
 255         return metadata != null ? metadata.getConfiguration() : null;
 256     }
 257
 258     /**
 259      * return list of HomeKit relevant groups linked to an accessory
 260      *
 261      * @param item OH item
 262      * @param itemRegistry item registry
 263      * @param metadataRegistry metadata registry
 264      * @return list of relevant group items
 265      */
 266     public static List<GroupItem> getAccessoryGroups(Item item, ItemRegistry itemRegistry,
 267             MetadataRegistry metadataRegistry) {
 268         return item.getGroupNames().stream().flatMap(name -> {
 269             final @Nullable Item groupItem = itemRegistry.get(name);
 270             if ((groupItem instanceof GroupItem) && ((GroupItem) groupItem).getBaseItem() == null) {
 271                 return Stream.of((GroupItem) groupItem);
 272             } else {
 273                 return Stream.empty();
 274             }
 275         }).filter(groupItem -> !getAccessoryTypes(groupItem, metadataRegistry).isEmpty()).collect(Collectors.toList());
 276     }
 277
 278     /**
 279      * collect all mandatory characteristics for a given tagged item, e.g. collect all mandatory HomeKit items from a
 280      * GroupItem
 281      *
 282      * @param taggedItem HomeKit tagged item
 283      * @param metadataRegistry meta data registry
 284      * @return list of mandatory
 285      */
 286     private static List<HomekitTaggedItem> getMandatoryCharacteristics(HomekitTaggedItem taggedItem,
 287             MetadataRegistry metadataRegistry) {
 288         List<HomekitTaggedItem> collectedCharacteristics = new ArrayList<>();
 289         if (taggedItem.isGroup()) {
 290             for (Item item : ((GroupItem) taggedItem.getItem()).getAllMembers()) {
 291                 addMandatoryCharacteristics(taggedItem, collectedCharacteristics, item, metadataRegistry);
 292             }
 293         } else {
 294             addMandatoryCharacteristics(taggedItem, collectedCharacteristics, taggedItem.getItem(), metadataRegistry);
 295         }
 296         logger.trace("Mandatory characteristics for item {} characteristics {}", taggedItem.getName(),
 297                 collectedCharacteristics);
 298         return collectedCharacteristics;
 299     }
 300
 301     /**
 302      * add mandatory HomeKit items for a given main item to a list of characteristics.
 303      * Main item is use only to determine, which characteristics are mandatory.
 304      * The characteristics are added to item.
 305      * e.g. mainItem could be a group tagged as "thermostat" and item could be item linked to the group and marked as
 306      * TargetTemperature
 307      *
 308      * @param mainItem main item
 309      * @param characteristics list of characteristics
 310      * @param item current item
 311      * @param metadataRegistry meta date registry
 312      */
 313     private static void addMandatoryCharacteristics(HomekitTaggedItem mainItem, List<HomekitTaggedItem> characteristics,
 314             Item item, MetadataRegistry metadataRegistry) {
 315         // get list of mandatory characteristics
 316         HomekitCharacteristicType[] mandatoryCharacteristics = MANDATORY_CHARACTERISTICS
 317                 .get(mainItem.getAccessoryType());
 318         if ((mandatoryCharacteristics == null) || (mandatoryCharacteristics.length == 0)) {
 319             // no mandatory characteristics linked to accessory type of mainItem. we are done
 320             return;
 321         }
 322         // check whether we adding characteristic to the main item, and if yes, use existing item proxy.
 323         // if we adding no to the main item (typical for groups), create new proxy item.
 324         final HomekitOHItemProxy itemProxy = mainItem.getItem().equals(item) ? mainItem.getProxyItem()
 325                 : new HomekitOHItemProxy(item);
 326         // an item can have several tags, e.g. "ActiveStatus, InUse". we iterate here over all his tags
 327         for (Entry<HomekitAccessoryType, HomekitCharacteristicType> accessory : getAccessoryTypes(item,
 328                 metadataRegistry)) {
 329             // if the item has only accessory tag, e.g. TemperatureSensor,
 330             // the we will link all mandatory characteristic to this item,
 331             // e.g. we will link CurrentTemperature in case of TemperatureSensor.
 332             if (isRootAccessory(accessory)) {
 333                 Arrays.stream(mandatoryCharacteristics)
 334                         .forEach(c -> characteristics.add(new HomekitTaggedItem(itemProxy, accessory.getKey(), c,
 335                                 mainItem.isGroup() ? (GroupItem) mainItem.getItem() : null,
 336                                 HomekitAccessoryFactory.getItemConfiguration(item, metadataRegistry))));
 337             } else {
 338                 // item has characteristic tag on it, so, adding it as that characteristic.
 339
 340                 // check whether it is a legacy characteristic, i.e. old tag was used, and replaced by a new one
 341                 final HomekitCharacteristicType characteristic = legacyCheck(accessory.getValue());
 342
 343                 // check whether it is a mandatory characteristic. optional will be added later by another method.
 344                 if (isMandatoryCharacteristic(mainItem.getAccessoryType(), characteristic)) {
 345                     characteristics.add(new HomekitTaggedItem(itemProxy, accessory.getKey(), characteristic,
 346                             mainItem.isGroup() ? (GroupItem) mainItem.getItem() : null,
 347                             HomekitAccessoryFactory.getItemConfiguration(item, metadataRegistry)));
 348                 }
 349             }
 350         }
 351     }
 352
 353     /**
 354      * add optional characteristic for given accessory.
 355      *
 356      * @param taggedItem main item
 357      * @param accessory accessory
 358      * @param metadataRegistry metadata registry
 359      */
 360     private static void addOptionalCharacteristics(HomekitTaggedItem taggedItem, AbstractHomekitAccessoryImpl accessory,
 361             MetadataRegistry metadataRegistry) {
 362         Map<HomekitCharacteristicType, GenericItem> characteristics = getOptionalCharacteristics(
 363                 accessory.getRootAccessory(), metadataRegistry);
 364         Service service = accessory.getPrimaryService();
 365         HashMap<String, HomekitOHItemProxy> proxyItems = new HashMap<>();
 366         proxyItems.put(taggedItem.getItem().getUID(), taggedItem.getProxyItem());
 367         // an accessory can have multiple optional characteristics. iterate over them.
 368         characteristics.forEach((type, item) -> {
 369             try {
 370                 // check whether a proxyItem already exists, if not create one.
 371                 final HomekitOHItemProxy proxyItem = proxyItems.computeIfAbsent(item.getUID(),
 372                         k -> new HomekitOHItemProxy(item));
 373                 final HomekitTaggedItem optionalItem = new HomekitTaggedItem(proxyItem,
 374                         accessory.getRootAccessory().getAccessoryType(), type,
 375                         accessory.getRootAccessory().getRootDeviceGroupItem(),
 376                         getItemConfiguration(item, metadataRegistry));
 377                 final Characteristic characteristic = HomekitCharacteristicFactory.createCharacteristic(optionalItem,
 378                         accessory.getUpdater());
 379                 // find the corresponding add method at service and call it.
 380                 service.getClass().getMethod("addOptionalCharacteristic", characteristic.getClass()).invoke(service,
 381                         characteristic);
 382                 accessory.addCharacteristic(optionalItem);
 383             } catch (NoSuchMethodException | IllegalAccessException | InvocationTargetException | HomekitException e) {
 384                 logger.warn("Unsupported optional HomeKit characteristic: service type {}, characteristic type {}",
 385                         service.getType(), type.getTag());
 386             }
 387         });
 388     }
 389
 390     /**
 391      * collect optional HomeKit characteristics for a OH item.
 392      *
 393      * @param taggedItem main OH item
 394      * @param metadataRegistry OH metadata registry
 395      * @return a map with characteristics and corresponding OH items
 396      */
 397     private static Map<HomekitCharacteristicType, GenericItem> getOptionalCharacteristics(HomekitTaggedItem taggedItem,
 398             MetadataRegistry metadataRegistry) {
 399         Map<HomekitCharacteristicType, GenericItem> characteristicItems = new HashMap<>();
 400         if (taggedItem.isGroup()) {
 401             GroupItem groupItem = (GroupItem) taggedItem.getItem();
 402             groupItem.getMembers().forEach(item -> getAccessoryTypes(item, metadataRegistry).stream()
 403                     .filter(c -> !isRootAccessory(c))
 404                     .filter(c -> !isMandatoryCharacteristic(taggedItem.getAccessoryType(), legacyCheck(c.getValue())))
 405                     .forEach(characteristic -> characteristicItems.put(legacyCheck(characteristic.getValue()),
 406                             (GenericItem) item)));
 407         } else {
 408             getAccessoryTypes(taggedItem.getItem(), metadataRegistry).stream().filter(c -> !isRootAccessory(c))
 409                     .filter(c -> !isMandatoryCharacteristic(taggedItem.getAccessoryType(), legacyCheck(c.getValue())))
 410                     .forEach(characteristic -> characteristicItems.put(legacyCheck(characteristic.getValue()),
 411                             (GenericItem) taggedItem.getItem()));
 412             final HomekitCharacteristicType[] implicitOptionalCharacteristics = IMPLICIT_OPTIONAL_CHARACTERISTICS
 413                     .get(taggedItem.getAccessoryType());
 414             if (implicitOptionalCharacteristics != null) {
 415                 Arrays.stream(implicitOptionalCharacteristics)
 416                         .filter(c -> !isMandatoryCharacteristic(taggedItem.getAccessoryType(), c))
 417                         .forEach(characteristic -> characteristicItems.put(legacyCheck(characteristic),
 418                                 (GenericItem) taggedItem.getItem()));
 419             }
 420         }
 421         logger.trace("Optional characteristics for item {} characteristics {}", taggedItem.getName(),
 422                 characteristicItems);
 423         return Collections.unmodifiableMap(characteristicItems);
 424     }
 425
 426     /**
 427      * return true is characteristic is a mandatory characteristic for the accessory.
 428      *
 429      * @param accessory accessory
 430      * @param characteristic characteristic
 431      * @return true if characteristic is mandatory, false if not mandatory
 432      */
 433     private static boolean isMandatoryCharacteristic(HomekitAccessoryType accessory,
 434             HomekitCharacteristicType characteristic) {
 435         return MANDATORY_CHARACTERISTICS.containsKey(accessory)
 436                 && Arrays.asList(MANDATORY_CHARACTERISTICS.get(accessory)).contains(characteristic);
 437     }
 438
 439     /**
 440      * check whether accessory is root accessory, i.e. without characteristic tag.
 441      *
 442      * @param accessory accessory
 443      * @return true if accessory has not characteristic.
 444      */
 445     private static boolean isRootAccessory(Entry<HomekitAccessoryType, HomekitCharacteristicType> accessory) {
 446         return ((accessory.getValue() == null) || (accessory.getValue() == EMPTY));
 447     }
 448
 449     /**
 450      * check whether it is legacy characteristic and return new name in such case. otherwise return the input parameter
 451      * unchanged.
 452      *
 453      * @param characteristicType characteristic to check
 454      * @return new characteristic type
 455      */
 456     private static HomekitCharacteristicType legacyCheck(HomekitCharacteristicType characteristicType) {
 457         return LEGACY_CHARACTERISTICS_MAPPING.getOrDefault(characteristicType, characteristicType);
 458     }
 459 }