git.basschouten.com Git - openhab-addons.git/blob

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