/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.iotdb.db.schemaengine.schemaregion.mtree.impl.pbtree;

import org.apache.iotdb.commons.conf.IoTDBConstant;
import org.apache.iotdb.commons.exception.IllegalPathException;
import org.apache.iotdb.commons.exception.MetadataException;
import org.apache.iotdb.commons.path.MeasurementPath;
import org.apache.iotdb.commons.path.PartialPath;
import org.apache.iotdb.commons.path.PathPatternTree;
import org.apache.iotdb.commons.schema.SchemaConstant;
import org.apache.iotdb.commons.schema.node.role.IDeviceMNode;
import org.apache.iotdb.commons.schema.node.role.IMeasurementMNode;
import org.apache.iotdb.commons.schema.node.utils.IMNodeFactory;
import org.apache.iotdb.commons.schema.node.utils.IMNodeIterator;
import org.apache.iotdb.commons.schema.view.LogicalViewSchema;
import org.apache.iotdb.commons.schema.view.viewExpression.ViewExpression;
import org.apache.iotdb.db.exception.metadata.AliasAlreadyExistException;
import org.apache.iotdb.db.exception.metadata.MNodeTypeMismatchException;
import org.apache.iotdb.db.exception.metadata.MeasurementAlreadyExistException;
import org.apache.iotdb.db.exception.metadata.MeasurementInBlackListException;
import org.apache.iotdb.db.exception.metadata.PathAlreadyExistException;
import org.apache.iotdb.db.exception.metadata.PathNotExistException;
import org.apache.iotdb.db.exception.metadata.template.DifferentTemplateException;
import org.apache.iotdb.db.exception.metadata.template.TemplateIsInUseException;
import org.apache.iotdb.db.queryengine.common.schematree.ClusterSchemaTree;
import org.apache.iotdb.db.schemaengine.metric.SchemaRegionCachedMetric;
import org.apache.iotdb.db.schemaengine.rescon.CachedSchemaRegionStatistics;
import org.apache.iotdb.db.schemaengine.schemaregion.mtree.impl.pbtree.mnode.ICachedMNode;
import org.apache.iotdb.db.schemaengine.schemaregion.mtree.loader.MNodeFactoryLoader;
import org.apache.iotdb.db.schemaengine.schemaregion.mtree.traverser.collector.EntityCollector;
import org.apache.iotdb.db.schemaengine.schemaregion.mtree.traverser.collector.MNodeCollector;
import org.apache.iotdb.db.schemaengine.schemaregion.mtree.traverser.collector.MeasurementCollector;
import org.apache.iotdb.db.schemaengine.schemaregion.mtree.traverser.counter.EntityCounter;
import org.apache.iotdb.db.schemaengine.schemaregion.mtree.traverser.updater.EntityUpdater;
import org.apache.iotdb.db.schemaengine.schemaregion.mtree.traverser.updater.MeasurementUpdater;
import org.apache.iotdb.db.schemaengine.schemaregion.read.req.IShowDevicesPlan;
import org.apache.iotdb.db.schemaengine.schemaregion.read.req.IShowNodesPlan;
import org.apache.iotdb.db.schemaengine.schemaregion.read.req.IShowTimeSeriesPlan;
import org.apache.iotdb.db.schemaengine.schemaregion.read.resp.info.IDeviceSchemaInfo;
import org.apache.iotdb.db.schemaengine.schemaregion.read.resp.info.INodeSchemaInfo;
import org.apache.iotdb.db.schemaengine.schemaregion.read.resp.info.ITimeSeriesSchemaInfo;
import org.apache.iotdb.db.schemaengine.schemaregion.read.resp.info.impl.ShowDevicesResult;
import org.apache.iotdb.db.schemaengine.schemaregion.read.resp.info.impl.ShowNodesResult;
import org.apache.iotdb.db.schemaengine.schemaregion.read.resp.info.impl.TimeseriesSchemaInfo;
import org.apache.iotdb.db.schemaengine.schemaregion.read.resp.reader.ISchemaReader;
import org.apache.iotdb.db.schemaengine.schemaregion.read.resp.reader.impl.SchemaReaderLimitOffsetWrapper;
import org.apache.iotdb.db.schemaengine.schemaregion.read.resp.reader.impl.TimeseriesReaderWithViewFetch;
import org.apache.iotdb.db.schemaengine.schemaregion.utils.MetaFormatUtils;
import org.apache.iotdb.db.schemaengine.schemaregion.utils.filter.DeviceFilterVisitor;
import org.apache.iotdb.db.schemaengine.template.Template;

import com.google.common.util.concurrent.ListenableFuture;
import org.apache.tsfile.enums.TSDataType;
import org.apache.tsfile.file.metadata.enums.CompressionType;
import org.apache.tsfile.file.metadata.enums.TSEncoding;
import org.apache.tsfile.utils.Pair;
import org.apache.tsfile.write.schema.IMeasurementSchema;
import org.apache.tsfile.write.schema.MeasurementSchema;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.File;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.function.Consumer;
import java.util.function.Function;

/**
 * The hierarchical struct of the Metadata Tree is implemented in this class.
 *
 * <p>Since there are too many interfaces and methods in this class, we use code region to help
 * manage code. The code region starts with //region and ends with //endregion. When using Intellij
 * Idea to develop, it's easy to fold the code region and see code region overview by collapsing
 * all.
 *
 * <p>The codes are divided into the following code regions:
 *
 * <ol>
 *   <li>MTree initialization, clear and serialization
 *   <li>Timeseries operation, including create and delete
 *   <li>Entity/Device operation
 *   <li>Interfaces and Implementation for metadata info Query
 *   <li>Interfaces and Implementation for MNode Query
 *   <li>Interfaces and Implementation for Template check
 * </ol>
 */
public class MTreeBelowSGCachedImpl {

  private static final Logger logger = LoggerFactory.getLogger(MTreeBelowSGCachedImpl.class);

  private final CachedMTreeStore store;

  @SuppressWarnings("java:S3077")
  private volatile ICachedMNode storageGroupMNode;

  private final ICachedMNode rootNode;
  private final Function<IMeasurementMNode<ICachedMNode>, Map<String, String>> tagGetter;
  private final Function<IMeasurementMNode<ICachedMNode>, Map<String, String>> attributeGetter;
  private final IMNodeFactory<ICachedMNode> nodeFactory =
      MNodeFactoryLoader.getInstance().getCachedMNodeIMNodeFactory();
  private final int levelOfSG;
  private final CachedSchemaRegionStatistics regionStatistics;

  // region MTree initialization, clear and serialization
  public MTreeBelowSGCachedImpl(
      PartialPath storageGroupPath,
      Function<IMeasurementMNode<ICachedMNode>, Map<String, String>> tagGetter,
      Function<IMeasurementMNode<ICachedMNode>, Map<String, String>> attributeGetter,
      Runnable flushCallback,
      Consumer<IMeasurementMNode<ICachedMNode>> measurementProcess,
      Consumer<IDeviceMNode<ICachedMNode>> deviceProcess,
      int schemaRegionId,
      CachedSchemaRegionStatistics regionStatistics,
      SchemaRegionCachedMetric metric)
      throws MetadataException, IOException {
    this.tagGetter = tagGetter;
    this.attributeGetter = attributeGetter;
    this.regionStatistics = regionStatistics;
    store =
        PBTreeFactory.getInstance()
            .createNewCachedMTreeStore(
                storageGroupPath, schemaRegionId, regionStatistics, metric, flushCallback);
    this.storageGroupMNode = store.getRoot();
    this.storageGroupMNode.setParent(storageGroupMNode.getParent());
    this.rootNode = store.generatePrefix(storageGroupPath);
    levelOfSG = storageGroupPath.getNodeLength() - 1;

    // recover MNode
    try (MNodeCollector<Void, ICachedMNode> collector =
        new MNodeCollector<Void, ICachedMNode>(
            this.rootNode,
            new PartialPath(storageGroupMNode.getFullPath()),
            this.store,
            true,
            SchemaConstant.ALL_MATCH_SCOPE) {
          @Override
          protected Void collectMNode(ICachedMNode node) {
            if (node.isMeasurement()) {
              measurementProcess.accept(node.getAsMeasurementMNode());
            } else if (node.isDevice()) {
              deviceProcess.accept(node.getAsDeviceMNode());
            }
            return null;
          }
        }) {
      collector.traverse();
    }
  }

  /** Only used for load snapshot */
  private MTreeBelowSGCachedImpl(
      PartialPath storageGroupPath,
      CachedMTreeStore store,
      Consumer<IMeasurementMNode<ICachedMNode>> measurementProcess,
      Consumer<IDeviceMNode<ICachedMNode>> deviceProcess,
      Function<IMeasurementMNode<ICachedMNode>, Map<String, String>> tagGetter,
      Function<IMeasurementMNode<ICachedMNode>, Map<String, String>> attributeGetter,
      CachedSchemaRegionStatistics regionStatistics)
      throws MetadataException {
    this.store = store;
    this.regionStatistics = regionStatistics;
    this.storageGroupMNode = store.getRoot();
    this.rootNode = store.generatePrefix(storageGroupPath);
    levelOfSG = storageGroupMNode.getPartialPath().getNodeLength() - 1;
    this.tagGetter = tagGetter;
    this.attributeGetter = attributeGetter;

    // recover MNode
    try (MNodeCollector<Void, ICachedMNode> collector =
        new MNodeCollector<Void, ICachedMNode>(
            this.rootNode,
            new PartialPath(storageGroupMNode.getFullPath()),
            this.store,
            true,
            SchemaConstant.ALL_MATCH_SCOPE) {
          @Override
          protected Void collectMNode(ICachedMNode node) {
            if (node.isMeasurement()) {
              measurementProcess.accept(node.getAsMeasurementMNode());
            } else if (node.isDevice()) {
              deviceProcess.accept(node.getAsDeviceMNode());
            }
            return null;
          }
        }) {
      collector.traverse();
    }
  }

  public void clear() {
    store.clear();
    storageGroupMNode = null;
  }

  public boolean createSnapshot(File snapshotDir) {
    return store.createSnapshot(snapshotDir);
  }

  public static MTreeBelowSGCachedImpl loadFromSnapshot(
      File snapshotDir,
      String storageGroupFullPath,
      int schemaRegionId,
      CachedSchemaRegionStatistics regionStatistics,
      SchemaRegionCachedMetric metric,
      Consumer<IMeasurementMNode<ICachedMNode>> measurementProcess,
      Consumer<IDeviceMNode<ICachedMNode>> deviceProcess,
      Function<IMeasurementMNode<ICachedMNode>, Map<String, String>> tagGetter,
      Function<IMeasurementMNode<ICachedMNode>, Map<String, String>> attributeGetter,
      Runnable flushCallback)
      throws IOException, MetadataException {
    return new MTreeBelowSGCachedImpl(
        new PartialPath(storageGroupFullPath),
        PBTreeFactory.getInstance()
            .createCachedMTreeStoreFromSnapshot(
                snapshotDir,
                storageGroupFullPath,
                schemaRegionId,
                regionStatistics,
                metric,
                flushCallback),
        measurementProcess,
        deviceProcess,
        tagGetter,
        attributeGetter,
        regionStatistics);
  }

  // endregion

  // region Timeseries operation, including create and delete

  public IMeasurementMNode<ICachedMNode> createTimeSeries(
      PartialPath path,
      TSDataType dataType,
      TSEncoding encoding,
      CompressionType compressor,
      Map<String, String> props,
      String alias)
      throws MetadataException {
    IMeasurementMNode<ICachedMNode> measurementMNode =
        createTimeSeriesWithPinnedReturn(
            path, dataType, encoding, compressor, props, alias, false, null);
    unPinMNode(measurementMNode.getAsMNode());
    return measurementMNode;
  }

  /**
   * Create a time series with a full path from root to leaf node. Before creating a time series,
   * the database should be set first, throw exception otherwise
   *
   * @param path time series path
   * @param dataType data type
   * @param encoding encoding
   * @param compressor compressor
   * @param props props
   * @param alias alias of measurement
   */
  public IMeasurementMNode<ICachedMNode> createTimeSeriesWithPinnedReturn(
      final PartialPath path,
      final TSDataType dataType,
      final TSEncoding encoding,
      final CompressionType compressor,
      final Map<String, String> props,
      final String alias,
      final boolean withMerge,
      final AtomicBoolean isAligned)
      throws MetadataException {
    final String[] nodeNames = path.getNodes();
    if (nodeNames.length <= 2) {
      throw new IllegalPathException(path.getFullPath());
    }
    MetaFormatUtils.checkTimeseries(path);
    final PartialPath devicePath = path.getDevicePath();
    final ICachedMNode deviceParent = checkAndAutoCreateInternalPath(devicePath);

    try {
      // synchronize check and add, we need addChild and add Alias become atomic operation
      // only write on mTree will be synchronized
      synchronized (this) {
        ICachedMNode device = checkAndAutoCreateDeviceNode(devicePath.getTailNode(), deviceParent);

        if (device.isDevice()
            && device.getAsDeviceMNode().isAlignedNullable() != null
            && isAligned != null) {
          isAligned.set(device.getAsDeviceMNode().isAligned());
        }

        try {
          MetaFormatUtils.checkTimeseriesProps(path.getFullPath(), props);

          final String leafName = path.getMeasurement();

          if (!withMerge && alias != null && store.hasChild(device, alias)) {
            throw new AliasAlreadyExistException(path.getFullPath(), alias);
          }

          if (store.hasChild(device, leafName)) {
            final ICachedMNode node = device.getChild(leafName);
            if (node.isMeasurement()) {
              final IMeasurementMNode<ICachedMNode> measurementNode = node.getAsMeasurementMNode();
              if (measurementNode.isPreDeleted()) {
                throw new MeasurementInBlackListException(path);
              } else if (!withMerge || measurementNode.getDataType() != dataType) {
                // Report conflict if the types are different
                throw new MeasurementAlreadyExistException(
                    path.getFullPath(), node.getAsMeasurementMNode().getMeasurementPath());
              } else {
                // Return null iff we should merge the time series with the existing one
                return null;
              }
            } else {
              throw new PathAlreadyExistException(path.getFullPath());
            }
          }

          final IDeviceMNode<ICachedMNode> entityMNode;
          if (device.isDevice()) {
            entityMNode = device.getAsDeviceMNode();
          } else {
            entityMNode = store.setToEntity(device);
            device = entityMNode.getAsMNode();
          }

          // create a non-aligned time series
          if (entityMNode.isAlignedNullable() == null) {
            entityMNode.setAligned(false);
          }

          final IMeasurementMNode<ICachedMNode> measurementMNode =
              nodeFactory.createMeasurementMNode(
                  entityMNode,
                  leafName,
                  new MeasurementSchema(leafName, dataType, encoding, compressor, props),
                  alias);
          store.addChild(entityMNode.getAsMNode(), leafName, measurementMNode.getAsMNode());
          // link alias to LeafMNode
          if (alias != null) {
            entityMNode.addAlias(alias, measurementMNode);
          }
          return measurementMNode;
        } finally {
          unPinMNode(device);
        }
      }
    } finally {
      if (deviceParent != null) {
        unPinMNode(deviceParent);
      }
    }
  }

  /**
   * Create aligned timeseries with full paths from root to one leaf node. Before creating
   * timeseries, the * database should be set first, throw exception otherwise
   *
   * @param devicePath device path
   * @param measurements measurements list
   * @param dataTypes data types list
   * @param encodings encodings list
   * @param compressors compressor
   */
  public List<IMeasurementMNode<ICachedMNode>> createAlignedTimeSeries(
      final PartialPath devicePath,
      final List<String> measurements,
      final List<TSDataType> dataTypes,
      final List<TSEncoding> encodings,
      final List<CompressionType> compressors,
      final List<String> aliasList,
      final boolean withMerge,
      final Set<Integer> existingMeasurementIndexes,
      final AtomicBoolean isAligned)
      throws MetadataException {
    final List<IMeasurementMNode<ICachedMNode>> measurementMNodeList = new ArrayList<>();
    MetaFormatUtils.checkSchemaMeasurementNames(measurements);
    final ICachedMNode deviceParent = checkAndAutoCreateInternalPath(devicePath);

    try {
      // synchronize check and add, we need addChild operation be atomic.
      // only write operations on mTree will be synchronized
      synchronized (this) {
        ICachedMNode device = checkAndAutoCreateDeviceNode(devicePath.getTailNode(), deviceParent);

        if (device.isDevice()
            && device.getAsDeviceMNode().isAlignedNullable() != null
            && isAligned != null) {
          isAligned.set(device.getAsDeviceMNode().isAligned());
        }

        try {
          for (int i = 0; i < measurements.size(); i++) {
            if (store.hasChild(device, measurements.get(i))) {
              final ICachedMNode node = device.getChild(measurements.get(i));
              if (node.isMeasurement()) {
                final IMeasurementMNode<ICachedMNode> measurementNode =
                    node.getAsMeasurementMNode();
                if (node.getAsMeasurementMNode().isPreDeleted()) {
                  throw new MeasurementInBlackListException(
                      devicePath.concatNode(measurements.get(i)));
                } else if (!withMerge || measurementNode.getDataType() != dataTypes.get(i)) {
                  throw new MeasurementAlreadyExistException(
                      devicePath.getFullPath() + "." + measurements.get(i),
                      node.getAsMeasurementMNode().getMeasurementPath());
                } else {
                  existingMeasurementIndexes.add(i);
                  continue;
                }
              } else {
                throw new PathAlreadyExistException(
                    devicePath.getFullPath() + "." + measurements.get(i));
              }
            }

            if (aliasList != null
                && aliasList.get(i) != null
                && store.hasChild(device, aliasList.get(i))) {
              throw new AliasAlreadyExistException(
                  devicePath.getFullPath() + "." + measurements.get(i), aliasList.get(i));
            }
          }

          final IDeviceMNode<ICachedMNode> entityMNode;
          if (device.isDevice()) {
            entityMNode = device.getAsDeviceMNode();
          } else {
            entityMNode = store.setToEntity(device);
            entityMNode.setAligned(true);
            device = entityMNode.getAsMNode();
          }

          // create an aligned time series
          if (entityMNode.isAlignedNullable() == null) {
            entityMNode.setAligned(true);
          }

          for (int i = 0; i < measurements.size(); i++) {
            if (existingMeasurementIndexes.contains(i)) {
              continue;
            }

            final IMeasurementMNode<ICachedMNode> measurementMNode =
                nodeFactory.createMeasurementMNode(
                    entityMNode,
                    measurements.get(i),
                    new MeasurementSchema(
                        measurements.get(i),
                        dataTypes.get(i),
                        encodings.get(i),
                        compressors.get(i)),
                    aliasList == null ? null : aliasList.get(i));
            store.addChild(
                entityMNode.getAsMNode(), measurements.get(i), measurementMNode.getAsMNode());
            if (aliasList != null && aliasList.get(i) != null) {
              entityMNode.addAlias(aliasList.get(i), measurementMNode);
            }
            measurementMNodeList.add(measurementMNode);
          }
          return measurementMNodeList;
        } finally {
          unPinMNode(device);
        }
      }
    } finally {
      if (deviceParent != null) {
        unPinMNode(deviceParent);
      }
    }
  }

  public boolean changeAlias(String alias, PartialPath fullPath) throws MetadataException {
    IMeasurementMNode<ICachedMNode> measurementMNode = getMeasurementMNode(fullPath);
    try {
      // upsert alias
      if (alias != null && !alias.equals(measurementMNode.getAlias())) {
        synchronized (this) {
          IDeviceMNode<ICachedMNode> device = measurementMNode.getParent().getAsDeviceMNode();
          ICachedMNode cachedMNode = store.getChild(device.getAsMNode(), alias);
          if (cachedMNode != null) {
            unPinMNode(cachedMNode);
            throw new MetadataException(
                "The alias is duplicated with the name or alias of other measurement.");
          }
          if (measurementMNode.getAlias() != null) {
            device.deleteAliasChild(measurementMNode.getAlias());
          }
          device.addAlias(alias, measurementMNode);
          setAlias(measurementMNode, alias);
        }
        return true;
      }
      return false;
    } finally {
      unPinMNode(measurementMNode.getAsMNode());
    }
  }

  public Map<Integer, MetadataException> checkMeasurementExistence(
      PartialPath devicePath, List<String> measurementList, List<String> aliasList) {
    ICachedMNode device;
    try {
      device = getNodeByPath(devicePath);
    } catch (MetadataException e) {
      return Collections.emptyMap();
    }
    try {
      if (!device.isDevice()) {
        return Collections.emptyMap();
      }
      Map<Integer, MetadataException> failingMeasurementMap = new HashMap<>();
      for (int i = 0; i < measurementList.size(); i++) {
        ICachedMNode node = null;
        try {
          node = store.getChild(device, measurementList.get(i));
          if (node != null) {
            if (node.isMeasurement()) {
              if (node.getAsMeasurementMNode().isPreDeleted()) {
                failingMeasurementMap.put(
                    i,
                    new MeasurementInBlackListException(
                        devicePath.concatNode(measurementList.get(i))));
              } else {
                failingMeasurementMap.put(
                    i,
                    new MeasurementAlreadyExistException(
                        devicePath.getFullPath() + "." + measurementList.get(i),
                        node.getAsMeasurementMNode().getMeasurementPath()));
              }
            } else {
              failingMeasurementMap.put(
                  i,
                  new PathAlreadyExistException(
                      devicePath.getFullPath() + "." + measurementList.get(i)));
            }
          }
          if (aliasList != null
              && aliasList.get(i) != null
              && store.hasChild(device, aliasList.get(i))) {
            failingMeasurementMap.put(
                i,
                new AliasAlreadyExistException(
                    devicePath.getFullPath() + "." + measurementList.get(i), aliasList.get(i)));
          }
        } catch (MetadataException e) {
          failingMeasurementMap.put(i, e);
        } finally {
          if (node != null) {
            unPinMNode(node);
          }
        }
      }
      return failingMeasurementMap;
    } finally {
      unPinMNode(device);
    }
  }

  private ICachedMNode checkAndAutoCreateInternalPath(PartialPath devicePath)
      throws MetadataException {
    String[] nodeNames = devicePath.getNodes();
    MetaFormatUtils.checkTimeseries(devicePath);
    if (nodeNames.length == levelOfSG + 1) {
      return null;
    }
    ICachedMNode cur = storageGroupMNode;
    ICachedMNode child;
    String childName;
    try {
      // e.g, path = root.sg.d1.s1,  create internal nodes and set cur to sg node, parent of d1
      for (int i = levelOfSG + 1; i < nodeNames.length - 1; i++) {
        childName = nodeNames[i];
        child = store.getChild(cur, childName);
        if (child == null) {
          child = store.addChild(cur, childName, nodeFactory.createInternalMNode(cur, childName));
        }
        cur = child;

        if (cur.isMeasurement()) {
          throw new PathAlreadyExistException(cur.getFullPath());
        }
      }
      pinMNode(cur);
      return cur;
    } finally {
      unPinPath(cur);
    }
  }

  private ICachedMNode checkAndAutoCreateDeviceNode(String deviceName, ICachedMNode deviceParent)
      throws MetadataException {
    if (deviceParent == null) {
      // device is sg
      pinMNode(storageGroupMNode);
      return storageGroupMNode;
    }
    ICachedMNode device = store.getChild(deviceParent, deviceName);
    if (device == null) {
      device =
          store.addChild(
              deviceParent, deviceName, nodeFactory.createInternalMNode(deviceParent, deviceName));
    }

    if (device.isMeasurement()) {
      throw new PathAlreadyExistException(device.getFullPath());
    }
    return device;
  }

  /**
   * Delete path. The path should be a full path from root to leaf node
   *
   * @param path Format: root.node(.node)+
   */
  public IMeasurementMNode<ICachedMNode> deleteTimeseries(PartialPath path)
      throws MetadataException {
    String[] nodes = path.getNodes();
    if (nodes.length == 0) {
      throw new IllegalPathException(path.getFullPath());
    }

    IMeasurementMNode<ICachedMNode> deletedNode = getMeasurementMNode(path);
    ICachedMNode parent = deletedNode.getParent();
    // delete the last node of path
    synchronized (this) {
      store.deleteChild(parent, path.getMeasurement());
      if (deletedNode.getAlias() != null) {
        parent.getAsDeviceMNode().deleteAliasChild(deletedNode.getAlias());
      }
    }
    deleteAndUnpinEmptyInternalMNode(parent.getAsDeviceMNode());
    return deletedNode;
  }

  /**
   * Used when delete timeseries or deactivate template. The last survived ancestor will be
   * unpinned.
   *
   * @param entityMNode delete empty InternalMNode from entityMNode to storageGroupMNode
   */
  private void deleteAndUnpinEmptyInternalMNode(IDeviceMNode<ICachedMNode> entityMNode)
      throws MetadataException {
    ICachedMNode curNode = entityMNode.getAsMNode();
    if (!entityMNode.isUseTemplate()) {
      synchronized (this) {
        boolean hasMeasurement = false;
        boolean hasNonViewMeasurement = false;
        ICachedMNode child;
        IMNodeIterator<ICachedMNode> iterator = store.getChildrenIterator(curNode);
        try {
          while (iterator.hasNext()) {
            child = iterator.next();
            unPinMNode(child);
            if (child.isMeasurement()) {
              hasMeasurement = true;
              if (!child.getAsMeasurementMNode().isLogicalView()) {
                hasNonViewMeasurement = true;
                break;
              }
            }
          }
        } finally {
          iterator.close();
        }

        if (!hasMeasurement) {
          curNode = store.setToInternal(entityMNode);
        } else if (!hasNonViewMeasurement) {
          // has some measurement but they are all logical view
          store.updateMNode(entityMNode.getAsMNode(), o -> o.getAsDeviceMNode().setAligned(null));
        }
      }
    }

    // delete all empty ancestors except database and MeasurementMNode
    while (true) {
      // if current database has no time series, return the database name
      if (curNode.isDatabase()) {
        return;
      }

      synchronized (this) {
        if (!isEmptyInternalMNode(curNode)) {
          break;
        }
        store.deleteChild(curNode.getParent(), curNode.getName());
        curNode = curNode.getParent();
      }
    }
    unPinMNode(curNode);
  }

  private boolean isEmptyInternalMNode(ICachedMNode node) throws MetadataException {
    IMNodeIterator<ICachedMNode> iterator = store.getChildrenIterator(node);
    try {
      return !IoTDBConstant.PATH_ROOT.equals(node.getName())
          && !node.isMeasurement()
          && !(node.isDevice() && node.getAsDeviceMNode().isUseTemplate())
          && !iterator.hasNext();
    } finally {
      iterator.close();
    }
  }

  public List<PartialPath> constructSchemaBlackList(
      final PartialPath pathPattern, final AtomicBoolean isAllLogicalView)
      throws MetadataException {
    final List<PartialPath> result = new ArrayList<>();
    try (final MeasurementUpdater<ICachedMNode> updater =
        new MeasurementUpdater<ICachedMNode>(
            rootNode, pathPattern, store, false, SchemaConstant.ALL_MATCH_SCOPE) {

          protected void updateMeasurement(final IMeasurementMNode<ICachedMNode> node)
              throws MetadataException {
            if (!node.isLogicalView()) {
              isAllLogicalView.set(false);
            }
            store.updateMNode(
                node.getAsMNode(), o -> o.getAsMeasurementMNode().setPreDeleted(true));
            result.add(getPartialPathFromRootToNode(node.getAsMNode()));
          }
        }) {
      updater.update();
    }
    return result;
  }

  public List<PartialPath> rollbackSchemaBlackList(PartialPath pathPattern)
      throws MetadataException {
    List<PartialPath> result = new ArrayList<>();
    try (MeasurementUpdater<ICachedMNode> updater =
        new MeasurementUpdater<ICachedMNode>(
            rootNode, pathPattern, store, false, SchemaConstant.ALL_MATCH_SCOPE) {

          protected void updateMeasurement(IMeasurementMNode<ICachedMNode> node)
              throws MetadataException {
            store.updateMNode(
                node.getAsMNode(), o -> o.getAsMeasurementMNode().setPreDeleted(false));
            result.add(getPartialPathFromRootToNode(node.getAsMNode()));
          }
        }) {
      updater.update();
    }
    return result;
  }

  public List<PartialPath> getPreDeletedTimeseries(PartialPath pathPattern)
      throws MetadataException {
    List<PartialPath> result = new LinkedList<>();
    try (MeasurementCollector<Void, ICachedMNode> collector =
        new MeasurementCollector<Void, ICachedMNode>(
            rootNode, pathPattern, store, false, SchemaConstant.ALL_MATCH_SCOPE) {

          protected Void collectMeasurement(IMeasurementMNode<ICachedMNode> node) {
            if (node.isPreDeleted()) {
              result.add(getPartialPathFromRootToNode(node.getAsMNode()));
            }
            return null;
          }
        }) {
      collector.traverse();
    }
    return result;
  }

  public Set<PartialPath> getDevicesOfPreDeletedTimeseries(PartialPath pathPattern)
      throws MetadataException {
    Set<PartialPath> result = new HashSet<>();
    try (MeasurementCollector<Void, ICachedMNode> collector =
        new MeasurementCollector<Void, ICachedMNode>(
            rootNode, pathPattern, store, false, SchemaConstant.ALL_MATCH_SCOPE) {

          protected Void collectMeasurement(IMeasurementMNode<ICachedMNode> node) {
            if (node.isPreDeleted()) {
              result.add(getPartialPathFromRootToNode(node.getAsMNode()).getDevicePath());
            }
            return null;
          }
        }) {
      collector.traverse();
    }

    return result;
  }

  public void setAlias(IMeasurementMNode<ICachedMNode> measurementMNode, String alias)
      throws MetadataException {
    store.setAlias(measurementMNode, alias);
  }

  // endregion

  // region Entity/Device operation
  // including device auto creation and transform from InternalMNode to EntityMNode
  /**
   * Add an interval path to MTree. This is only used for automatically creating schema
   *
   * <p>e.g., get root.sg.d1, get or create all internal nodes and return the node of d1
   */
  public ICachedMNode getDeviceNodeWithAutoCreating(PartialPath deviceId) throws MetadataException {
    String[] nodeNames = deviceId.getNodes();
    MetaFormatUtils.checkTimeseries(deviceId);
    ICachedMNode cur = storageGroupMNode;
    ICachedMNode child;
    try {
      for (int i = levelOfSG + 1; i < nodeNames.length; i++) {
        child = store.getChild(cur, nodeNames[i]);
        if (child == null) {
          child =
              store.addChild(cur, nodeNames[i], nodeFactory.createInternalMNode(cur, nodeNames[i]));
        }
        cur = child;
      }
      pinMNode(cur);
      return cur;
    } finally {
      unPinPath(cur);
    }
  }

  /**
   * Check if the device node exists
   *
   * @param deviceId full path of device
   * @return true if the device node exists
   */
  public boolean checkDeviceNodeExists(PartialPath deviceId) {
    ICachedMNode deviceMNode = null;
    try {
      deviceMNode = getNodeByPath(deviceId);
      return deviceMNode.isDevice();
    } catch (MetadataException e) {
      return false;
    } finally {
      if (deviceMNode != null) {
        unPinMNode(deviceMNode);
      }
    }
  }

  // endregion

  // region Interfaces and Implementation for metadata info Query
  public ClusterSchemaTree fetchSchema(
      PartialPath pathPattern,
      Map<Integer, Template> templateMap,
      boolean withTags,
      boolean withAttributes,
      boolean withTemplate,
      boolean withAliasForce)
      throws MetadataException {
    ClusterSchemaTree schemaTree = new ClusterSchemaTree();
    try (MeasurementCollector<Void, ICachedMNode> collector =
        new MeasurementCollector<Void, ICachedMNode>(
            rootNode, pathPattern, store, false, SchemaConstant.ALL_MATCH_SCOPE) {
          protected Void collectMeasurement(IMeasurementMNode<ICachedMNode> node) {
            IDeviceMNode<ICachedMNode> deviceMNode =
                getParentOfNextMatchedNode().getAsDeviceMNode();
            int templateId = deviceMNode.getSchemaTemplateIdWithState();
            if (withTemplate && templateId >= 0) {
              schemaTree.appendTemplateDevice(
                  deviceMNode.getPartialPath(), deviceMNode.isAligned(), templateId, null);
              skipTemplateChildren(deviceMNode);
            } else {
              MeasurementPath path = getCurrentMeasurementPathInTraverse(node);
              schemaTree.appendSingleMeasurement(
                  path,
                  path.getMeasurementSchema(),
                  withTags ? tagGetter.apply(node) : null,
                  withAttributes ? attributeGetter.apply(node) : null,
                  withAliasForce || nodes[nodes.length - 1].equals(node.getAlias())
                      ? node.getAlias()
                      : null,
                  deviceMNode.isAligned());
            }
            return null;
          }
        }) {
      collector.setTemplateMap(templateMap, nodeFactory);
      collector.setSkipPreDeletedSchema(true);
      collector.traverse();
    }
    return schemaTree;
  }

  public ClusterSchemaTree fetchSchemaWithoutWildcard(
      PathPatternTree patternTree,
      Map<Integer, Template> templateMap,
      boolean withTags,
      boolean withAttributes,
      boolean withTemplate)
      throws MetadataException {
    ClusterSchemaTree schemaTree = new ClusterSchemaTree();
    try (MeasurementCollector<Void, ICachedMNode> collector =
        new MeasurementCollector<Void, ICachedMNode>(
            rootNode, patternTree, store, SchemaConstant.ALL_MATCH_SCOPE) {
          protected Void collectMeasurement(IMeasurementMNode<ICachedMNode> node) {
            IDeviceMNode<ICachedMNode> deviceMNode =
                getParentOfNextMatchedNode().getAsDeviceMNode();
            int templateId = deviceMNode.getSchemaTemplateIdWithState();
            if (withTemplate && templateId >= 0) {
              schemaTree.appendTemplateDevice(
                  deviceMNode.getPartialPath(), deviceMNode.isAligned(), templateId, null);
              skipTemplateChildren(deviceMNode);
            } else {
              MeasurementPath path = getCurrentMeasurementPathInTraverse(node);
              schemaTree.appendSingleMeasurement(
                  path,
                  path.getMeasurementSchema(),
                  withTags ? tagGetter.apply(node) : null,
                  withAttributes ? attributeGetter.apply(node) : null,
                  node.getAlias(),
                  deviceMNode.isAligned());
            }
            return null;
          }
        }) {
      collector.setTemplateMap(templateMap, nodeFactory);
      collector.setSkipPreDeletedSchema(true);
      collector.traverse();
    }
    return schemaTree;
  }

  public ClusterSchemaTree fetchDeviceSchema(
      PathPatternTree patternTree, PathPatternTree authorityScope) throws MetadataException {
    ClusterSchemaTree schemaTree = new ClusterSchemaTree();
    for (PartialPath pattern : patternTree.getAllPathPatterns()) {
      try (EntityCollector<Void, ICachedMNode> collector =
          new EntityCollector<Void, ICachedMNode>(rootNode, pattern, store, false, authorityScope) {
            @Override
            protected Void collectEntity(IDeviceMNode<ICachedMNode> node) {
              if (node.isAlignedNullable() != null) {
                schemaTree.appendTemplateDevice(
                    node.getPartialPath(), node.isAligned(), node.getSchemaTemplateId(), null);
              }
              return null;
            }
          }) {
        collector.traverse();
      }
    }
    return schemaTree;
  }

  // endregion

  // region Interfaces and Implementation for MNode Query
  /**
   * Get node by the path
   *
   * @return last node in given seriesPath
   */
  public ICachedMNode getNodeByPath(PartialPath path) throws MetadataException {
    String[] nodes = path.getNodes();
    ICachedMNode cur = storageGroupMNode;
    ICachedMNode next;
    try {
      for (int i = levelOfSG + 1; i < nodes.length; i++) {
        next = store.getChild(cur, nodes[i]);
        if (next == null) {
          throw new PathNotExistException(path.getFullPath(), true);
        } else if (next.isMeasurement()) {
          if (i == nodes.length - 1) {
            return next;
          } else {
            throw new PathNotExistException(path.getFullPath(), true);
          }
        }
        cur = next;
      }
      pinMNode(cur);
      return cur;
    } finally {
      unPinPath(cur);
    }
  }

  public IMeasurementMNode<ICachedMNode> getMeasurementMNode(PartialPath path)
      throws MetadataException {
    ICachedMNode node = getNodeByPath(path);
    if (node.isMeasurement()) {
      return node.getAsMeasurementMNode();
    } else {
      unPinMNode(node);
      throw new MNodeTypeMismatchException(
          path.getFullPath(), SchemaConstant.MEASUREMENT_MNODE_TYPE);
    }
  }

  // endregion

  // region Interfaces and Implementation for Logical View

  public void createLogicalView(PartialPath path, ViewExpression viewExpression)
      throws MetadataException {
    String[] nodeNames = path.getNodes();
    if (nodeNames.length <= 2) {
      throw new IllegalPathException(path.getFullPath());
    }
    MetaFormatUtils.checkTimeseries(path);
    PartialPath devicePath = path.getDevicePath();
    ICachedMNode deviceParent = checkAndAutoCreateInternalPath(devicePath);

    try {
      // synchronize check and add, we need addChild and add Alias become atomic operation
      // only write on mtree will be synchronized
      synchronized (this) {
        ICachedMNode device = checkAndAutoCreateDeviceNode(devicePath.getTailNode(), deviceParent);
        try {
          String leafName = path.getMeasurement();
          if (store.hasChild(device, leafName)) {
            ICachedMNode node = device.getChild(leafName);
            if (node.isMeasurement()) {
              if (node.getAsMeasurementMNode().isPreDeleted()) {
                throw new MeasurementInBlackListException(path);
              } else {
                throw new MeasurementAlreadyExistException(
                    path.getFullPath(), node.getAsMeasurementMNode().getMeasurementPath());
              }
            } else {
              throw new PathAlreadyExistException(path.getFullPath());
            }
          }

          IDeviceMNode<ICachedMNode> entityMNode;
          if (device.isDevice()) {
            entityMNode = device.getAsDeviceMNode();
          } else {
            entityMNode = store.setToEntity(device);
            // this parent has no measurement before. The leafName is his first child who is a
            // logical
            // view.
            entityMNode.setAligned(null);
            device = entityMNode.getAsMNode();
          }

          IMeasurementMNode<ICachedMNode> viewMNode =
              nodeFactory.createLogicalViewMNode(
                  entityMNode, leafName, new LogicalViewSchema(leafName, viewExpression));
          store.addChild(entityMNode.getAsMNode(), leafName, viewMNode.getAsMNode());
          unPinMNode(viewMNode.getAsMNode());
        } finally {
          unPinMNode(device);
        }
      }
    } finally {
      if (deviceParent != null) {
        unPinMNode(deviceParent);
      }
    }
  }

  public List<PartialPath> constructLogicalViewBlackList(PartialPath pathPattern)
      throws MetadataException {
    List<PartialPath> result = new ArrayList<>();
    try (MeasurementUpdater<ICachedMNode> updater =
        new MeasurementUpdater<ICachedMNode>(
            rootNode, pathPattern, store, false, SchemaConstant.ALL_MATCH_SCOPE) {
          protected void updateMeasurement(IMeasurementMNode<ICachedMNode> node)
              throws MetadataException {
            if (node.isLogicalView()) {
              store.updateMNode(
                  node.getAsMNode(), o -> o.getAsMeasurementMNode().setPreDeleted(true));
              result.add(getPartialPathFromRootToNode(node.getAsMNode()));
            }
          }
        }) {
      updater.update();
    }
    return result;
  }

  public List<PartialPath> rollbackLogicalViewBlackList(PartialPath pathPattern)
      throws MetadataException {
    List<PartialPath> result = new ArrayList<>();
    try (MeasurementUpdater<ICachedMNode> updater =
        new MeasurementUpdater<ICachedMNode>(
            rootNode, pathPattern, store, false, SchemaConstant.ALL_MATCH_SCOPE) {
          protected void updateMeasurement(IMeasurementMNode<ICachedMNode> node)
              throws MetadataException {
            if (node.isLogicalView()) {
              store.updateMNode(
                  node.getAsMNode(), o -> o.getAsMeasurementMNode().setPreDeleted(false));
              result.add(getPartialPathFromRootToNode(node.getAsMNode()));
            }
          }
        }) {
      updater.update();
    }
    return result;
  }

  public List<PartialPath> getPreDeletedLogicalView(PartialPath pathPattern)
      throws MetadataException {
    List<PartialPath> result = new LinkedList<>();
    try (MeasurementCollector<Void, ICachedMNode> collector =
        new MeasurementCollector<Void, ICachedMNode>(
            rootNode, pathPattern, store, false, SchemaConstant.ALL_MATCH_SCOPE) {
          protected Void collectMeasurement(IMeasurementMNode<ICachedMNode> node) {
            if (node.isLogicalView() && node.isPreDeleted()) {
              result.add(getPartialPathFromRootToNode(node.getAsMNode()));
            }
            return null;
          }
        }) {
      collector.traverse();
    }
    return result;
  }

  public void alterLogicalView(PartialPath path, ViewExpression expression)
      throws MetadataException {
    IMeasurementMNode<ICachedMNode> leafMNode = getMeasurementMNode(path);
    try {
      if (!leafMNode.isLogicalView()) {
        throw new MetadataException(String.format("[%s] is no view.", path));
      }
      store.updateMNode(
          leafMNode.getAsMNode(),
          o ->
              o.getAsMeasurementMNode()
                  .setSchema(new LogicalViewSchema(leafMNode.getName(), expression)));
    } finally {
      unPinMNode(leafMNode.getAsMNode());
    }
  }

  // endregion

  // region Interfaces and Implementation for Template check and query

  public void activateTemplate(PartialPath activatePath, Template template)
      throws MetadataException {
    String[] nodes = activatePath.getNodes();
    ICachedMNode cur = storageGroupMNode;
    ICachedMNode child;
    IDeviceMNode<ICachedMNode> entityMNode;

    try {
      for (int i = levelOfSG + 1; i < nodes.length; i++) {
        child = store.getChild(cur, nodes[i]);
        if (child == null) {
          throw new PathNotExistException(activatePath.getFullPath());
        }
        cur = child;
      }
      synchronized (this) {
        if (cur.isDevice()) {
          entityMNode = cur.getAsDeviceMNode();
        } else {
          entityMNode = store.setToEntity(cur);
        }

        if (entityMNode.isUseTemplate()) {
          if (template.getId() == entityMNode.getSchemaTemplateId()) {
            throw new TemplateIsInUseException(cur.getFullPath());
          } else {
            throw new DifferentTemplateException(activatePath.getFullPath(), template.getName());
          }
        }
      }

      store.updateMNode(
          entityMNode.getAsMNode(),
          o -> {
            if (!entityMNode.isAligned()) {
              entityMNode.setAligned(template.isDirectAligned());
            }
            entityMNode.setUseTemplate(true);
            entityMNode.setSchemaTemplateId(template.getId());
          });

      regionStatistics.activateTemplate(template.getId());
    } finally {
      unPinPath(cur);
    }
  }

  public void activateTemplateWithoutCheck(
      PartialPath activatePath, int templateId, boolean isAligned) throws MetadataException {
    String[] nodes = activatePath.getNodes();
    ICachedMNode cur = storageGroupMNode;
    ICachedMNode child;
    IDeviceMNode<ICachedMNode> entityMNode;

    try {
      for (int i = levelOfSG + 1; i < nodes.length; i++) {
        child = store.getChild(cur, nodes[i]);
        if (child == null) {
          throw new PathNotExistException(activatePath.getFullPath());
        }
        cur = child;
      }
      if (cur.isDevice()) {
        entityMNode = cur.getAsDeviceMNode();
      } else {
        entityMNode = store.setToEntity(cur);
      }

      store.updateMNode(
          entityMNode.getAsMNode(),
          o -> {
            if (!entityMNode.isAligned()) {
              entityMNode.setAligned(isAligned);
            }
            entityMNode.setUseTemplate(true);
            entityMNode.setSchemaTemplateId(templateId);
          });

      regionStatistics.activateTemplate(templateId);
    } finally {
      unPinPath(cur);
    }
  }

  public Map<PartialPath, List<Integer>> constructSchemaBlackListWithTemplate(
      Map<PartialPath, List<Integer>> templateSetInfo) throws MetadataException {
    Map<PartialPath, List<Integer>> resultTemplateSetInfo = new HashMap<>();
    for (Map.Entry<PartialPath, List<Integer>> entry : templateSetInfo.entrySet()) {
      try (EntityUpdater<ICachedMNode> updater =
          new EntityUpdater<ICachedMNode>(
              rootNode, entry.getKey(), store, false, SchemaConstant.ALL_MATCH_SCOPE) {

            protected void updateEntity(IDeviceMNode<ICachedMNode> node) throws MetadataException {
              if (entry.getValue().contains(node.getSchemaTemplateId())) {
                resultTemplateSetInfo.put(
                    node.getPartialPath(), Collections.singletonList(node.getSchemaTemplateId()));
                store.updateMNode(
                    node.getAsMNode(), o -> o.getAsDeviceMNode().preDeactivateTemplate());
              }
            }
          }) {
        updater.update();
      }
    }
    return resultTemplateSetInfo;
  }

  public Map<PartialPath, List<Integer>> rollbackSchemaBlackListWithTemplate(
      Map<PartialPath, List<Integer>> templateSetInfo) throws MetadataException {
    Map<PartialPath, List<Integer>> resultTemplateSetInfo = new HashMap<>();
    for (Map.Entry<PartialPath, List<Integer>> entry : templateSetInfo.entrySet()) {
      try (EntityUpdater<ICachedMNode> updater =
          new EntityUpdater<ICachedMNode>(
              rootNode, entry.getKey(), store, false, SchemaConstant.ALL_MATCH_SCOPE) {

            protected void updateEntity(IDeviceMNode<ICachedMNode> node) throws MetadataException {
              if (entry.getValue().contains(node.getSchemaTemplateId())
                  && node.isPreDeactivateTemplate()) {
                resultTemplateSetInfo.put(
                    node.getPartialPath(), Collections.singletonList(node.getSchemaTemplateId()));
                store.updateMNode(
                    node.getAsMNode(), o -> o.getAsDeviceMNode().rollbackPreDeactivateTemplate());
              }
            }
          }) {
        updater.update();
      }
    }
    return resultTemplateSetInfo;
  }

  public Map<PartialPath, List<Integer>> deactivateTemplateInBlackList(
      Map<PartialPath, List<Integer>> templateSetInfo) throws MetadataException {
    Map<PartialPath, List<Integer>> resultTemplateSetInfo = new HashMap<>();
    for (Map.Entry<PartialPath, List<Integer>> entry : templateSetInfo.entrySet()) {
      try (EntityUpdater<ICachedMNode> collector =
          new EntityUpdater<ICachedMNode>(
              rootNode, entry.getKey(), store, false, SchemaConstant.ALL_MATCH_SCOPE) {

            protected void updateEntity(IDeviceMNode<ICachedMNode> node) throws MetadataException {
              if (entry.getValue().contains(node.getSchemaTemplateId())
                  && node.isPreDeactivateTemplate()) {
                resultTemplateSetInfo.put(
                    node.getPartialPath(), Collections.singletonList(node.getSchemaTemplateId()));
                regionStatistics.deactivateTemplate(node.getSchemaTemplateId());
                store.updateMNode(
                    node.getAsMNode(), o -> o.getAsDeviceMNode().deactivateTemplate());
              }
            }
          }) {
        collector.traverse();
      }
    }
    for (PartialPath path : resultTemplateSetInfo.keySet()) {
      deleteAndUnpinEmptyInternalMNode(getNodeByPath(path).getAsDeviceMNode());
    }
    return resultTemplateSetInfo;
  }

  public long countPathsUsingTemplate(PartialPath pathPattern, int templateId)
      throws MetadataException {
    try (EntityCounter<ICachedMNode> counter =
        new EntityCounter<>(rootNode, pathPattern, store, false, SchemaConstant.ALL_MATCH_SCOPE)) {
      counter.setSchemaTemplateFilter(templateId);
      return counter.count();
    }
  }

  // endregion

  // region Interfaces and Implementation for Pin/UnPin MNode or Path

  /**
   * Currently, this method is only used for pin node get from mNodeCache
   *
   * @param node
   */
  // TODO: This interface should not be exposed to SchemaRegion
  public void pinMNode(ICachedMNode node) throws MetadataException {
    store.pin(node);
  }

  // TODO: This interface should not be exposed to SchemaRegion
  public void unPinMNode(ICachedMNode node) {
    store.unPin(node);
  }

  private void unPinPath(ICachedMNode node) {
    store.unPinPath(node);
  }

  // TODO: This interface should not be exposed to SchemaRegion
  public void updateMNode(ICachedMNode node, Consumer<ICachedMNode> operation) {
    store.updateMNode(node, operation);
  }

  // endregion

  // region Interfaces for schema reader
  @SuppressWarnings("java:S2095")
  public ISchemaReader<IDeviceSchemaInfo> getDeviceReader(IShowDevicesPlan showDevicesPlan)
      throws MetadataException {
    EntityCollector<IDeviceSchemaInfo, ICachedMNode> collector =
        new EntityCollector<IDeviceSchemaInfo, ICachedMNode>(
            rootNode,
            showDevicesPlan.getPath(),
            store,
            showDevicesPlan.isPrefixMatch(),
            showDevicesPlan.getScope()) {

          protected IDeviceSchemaInfo collectEntity(IDeviceMNode<ICachedMNode> node) {
            PartialPath device = getPartialPathFromRootToNode(node.getAsMNode());
            return new ShowDevicesResult(
                device.getFullPath(), node.isAlignedNullable(), node.getSchemaTemplateId());
          }
        };
    if (showDevicesPlan.usingSchemaTemplate()) {
      collector.setSchemaTemplateFilter(showDevicesPlan.getSchemaTemplateId());
    }
    ISchemaReader<IDeviceSchemaInfo> reader =
        new ISchemaReader<IDeviceSchemaInfo>() {

          private final DeviceFilterVisitor filterVisitor = new DeviceFilterVisitor();
          private IDeviceSchemaInfo next;

          public boolean isSuccess() {
            return collector.isSuccess();
          }

          public Throwable getFailure() {
            return collector.getFailure();
          }

          public void close() {
            collector.close();
          }

          public ListenableFuture<?> isBlocked() {
            return NOT_BLOCKED;
          }

          public boolean hasNext() {
            while (next == null && collector.hasNext()) {
              IDeviceSchemaInfo temp = collector.next();
              if (filterVisitor.process(showDevicesPlan.getSchemaFilter(), temp)) {
                next = temp;
              }
            }
            return next != null;
          }

          public IDeviceSchemaInfo next() {
            if (!hasNext()) {
              throw new NoSuchElementException();
            }
            IDeviceSchemaInfo result = next;
            next = null;
            return result;
          }
        };
    if (showDevicesPlan.getLimit() > 0 || showDevicesPlan.getOffset() > 0) {
      return new SchemaReaderLimitOffsetWrapper<>(
          reader, showDevicesPlan.getLimit(), showDevicesPlan.getOffset());
    } else {
      return reader;
    }
  }

  public ISchemaReader<ITimeSeriesSchemaInfo> getTimeSeriesReader(
      IShowTimeSeriesPlan showTimeSeriesPlan,
      Function<Long, Pair<Map<String, String>, Map<String, String>>> tagAndAttributeProvider)
      throws MetadataException {
    MeasurementCollector<ITimeSeriesSchemaInfo, ICachedMNode> collector =
        new MeasurementCollector<ITimeSeriesSchemaInfo, ICachedMNode>(
            rootNode,
            showTimeSeriesPlan.getPath(),
            store,
            showTimeSeriesPlan.isPrefixMatch(),
            showTimeSeriesPlan.getScope()) {

          protected ITimeSeriesSchemaInfo collectMeasurement(IMeasurementMNode<ICachedMNode> node) {
            return new ITimeSeriesSchemaInfo() {

              private Pair<Map<String, String>, Map<String, String>> tagAndAttribute = null;

              public String getAlias() {
                return node.getAlias();
              }

              public IMeasurementSchema getSchema() {
                return node.getSchema();
              }

              public Map<String, String> getTags() {
                if (tagAndAttribute == null) {
                  tagAndAttribute = tagAndAttributeProvider.apply(node.getOffset());
                }
                return tagAndAttribute.left;
              }

              public Map<String, String> getAttributes() {
                if (tagAndAttribute == null) {
                  tagAndAttribute = tagAndAttributeProvider.apply(node.getOffset());
                }
                return tagAndAttribute.right;
              }

              public boolean isUnderAlignedDevice() {
                return getParentOfNextMatchedNode().getAsDeviceMNode().isAligned();
              }

              @Override
              public boolean isLogicalView() {
                return node.isLogicalView();
              }

              public String getFullPath() {
                return getPartialPathFromRootToNode(node.getAsMNode()).getFullPath();
              }

              public PartialPath getPartialPath() {
                return getPartialPathFromRootToNode(node.getAsMNode());
              }

              @Override
              public ITimeSeriesSchemaInfo snapshot() {
                return new TimeseriesSchemaInfo(
                    node, getPartialPath(), getTags(), getAttributes(), isUnderAlignedDevice());
              }
            };
          }
        };

    collector.setTemplateMap(showTimeSeriesPlan.getRelatedTemplate(), nodeFactory);
    ISchemaReader<ITimeSeriesSchemaInfo> reader =
        new TimeseriesReaderWithViewFetch(
            collector, showTimeSeriesPlan.getSchemaFilter(), showTimeSeriesPlan.needViewDetail());
    if (showTimeSeriesPlan.getLimit() > 0 || showTimeSeriesPlan.getOffset() > 0) {
      return new SchemaReaderLimitOffsetWrapper<>(
          reader, showTimeSeriesPlan.getLimit(), showTimeSeriesPlan.getOffset());
    } else {
      return reader;
    }
  }

  @SuppressWarnings("java:S2095")
  public ISchemaReader<INodeSchemaInfo> getNodeReader(IShowNodesPlan showNodesPlan)
      throws MetadataException {
    MNodeCollector<INodeSchemaInfo, ICachedMNode> collector =
        new MNodeCollector<INodeSchemaInfo, ICachedMNode>(
            rootNode,
            showNodesPlan.getPath(),
            store,
            showNodesPlan.isPrefixMatch(),
            showNodesPlan.getScope()) {

          protected INodeSchemaInfo collectMNode(ICachedMNode node) {
            return new ShowNodesResult(
                getPartialPathFromRootToNode(node).getFullPath(), node.getMNodeType());
          }
        };
    collector.setTargetLevel(showNodesPlan.getLevel());
    return new ISchemaReader<INodeSchemaInfo>() {

      public boolean isSuccess() {
        return collector.isSuccess();
      }

      public Throwable getFailure() {
        return collector.getFailure();
      }

      public void close() {
        collector.close();
      }

      public ListenableFuture<?> isBlocked() {
        return NOT_BLOCKED;
      }

      public boolean hasNext() {
        return collector.hasNext();
      }

      public INodeSchemaInfo next() {
        if (!hasNext()) {
          throw new NoSuchElementException();
        }
        return collector.next();
      }
    };
  }
  // endregion
}
