/**
    * 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.hadoop.hbase.namespace;
  
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Map.Entry;
  import java.util.Set;
  import java.util.concurrent.atomic.AtomicInteger;
  
  import org.apache.hadoop.hbase.TableName;
  
  import com.google.common.base.Joiner;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  
  /**
   * NamespaceTableAndRegionInfo is a helper class that contains information about current state of
   * tables and regions in a namespace.
   */
  @InterfaceAudience.Private
  class NamespaceTableAndRegionInfo {
    private String name;
    private Map<TableName, AtomicInteger> tableAndRegionInfo;
  
    public NamespaceTableAndRegionInfo(String namespace) {
      this.name = namespace;
      this.tableAndRegionInfo = new HashMap<TableName, AtomicInteger>();
    }
  
    /**
     * Gets the name of the namespace.
     * @return name of the namespace.
     */
    String getName() {
      return name;
    }
  
    /**
     * Gets the set of table names belonging to namespace.
     * @return A set of table names.
     */
    synchronized Set<TableName> getTables() {
      return this.tableAndRegionInfo.keySet();
    }
  
    /**
     * Gets the total number of regions in namespace.
     * @return the region count
     */
    synchronized int getRegionCount() {
      int regionCount = 0;
      for (Entry<TableName, AtomicInteger> entry : this.tableAndRegionInfo.entrySet()) {
        regionCount = regionCount + entry.getValue().get();
      }
      return regionCount;
    }
  
    synchronized int getRegionCountOfTable(TableName tableName) {
      if (tableAndRegionInfo.containsKey(tableName)) {
        return this.tableAndRegionInfo.get(tableName).get();
      } else {
        return -1;
      }
    }
  
    synchronized boolean containsTable(TableName tableName) {
      return this.tableAndRegionInfo.containsKey(tableName);
    }
  
    synchronized void addTable(TableName tableName, int regionCount) {
      if (!name.equalsIgnoreCase(tableName.getNamespaceAsString())) {
        throw new IllegalStateException("Table : " + tableName + " does not belong to namespace "
            + name);
      }
      if (!tableAndRegionInfo.containsKey(tableName)) {
        tableAndRegionInfo.put(tableName, new AtomicInteger(regionCount));
      } else {
        throw new IllegalStateException("Table already in the cache " + tableName);
      }
    }
  
    synchronized void removeTable(TableName tableName) {
      tableAndRegionInfo.remove(tableName);
    }
  
    synchronized int incRegionCountForTable(TableName tableName, int count) {
      return tableAndRegionInfo.get(tableName).addAndGet(count);
    }
  
    synchronized int decrementRegionCountForTable(TableName tableName, int count) {
     return tableAndRegionInfo.get(tableName).decrementAndGet();
   }
 
   @Override
   public String toString() {
     Joiner.MapJoiner mapJoiner = Joiner.on(',').withKeyValueSeparator("=");
     return "NamespaceTableAndRegionInfo [name=" + name + ", tableAndRegionInfo="
         + mapJoiner.join(tableAndRegionInfo) + "]";
   }
 }