/**
    * 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.regionserver;
  
  import java.io.Closeable;
  import java.io.IOException;
  import java.util.HashMap;
  import java.util.Map;
  import java.util.Set;
  import java.util.concurrent.ConcurrentHashMap;
  import java.util.concurrent.ScheduledExecutorService;
  import java.util.concurrent.ScheduledFuture;
  import java.util.concurrent.TimeUnit;
  
  import org.apache.hadoop.hbase.CompatibilitySingletonFactory;
  import org.apache.hadoop.hbase.HConstants;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.classification.InterfaceAudience;
  import org.apache.hadoop.metrics2.MetricsExecutor;
  
  import com.google.common.collect.Sets;
  
  @InterfaceAudience.Private
  public class MetricsTableWrapperAggregateImpl implements MetricsTableWrapperAggregate, Closeable {
    private final HRegionServer regionServer;
    private ScheduledExecutorService executor;
    private Runnable runnable;
    private long period;
    private ScheduledFuture<?> tableMetricsUpdateTask;
    private ConcurrentHashMap<TableName, MetricsTableValues> metricsTableMap = new ConcurrentHashMap<>();
  
    public MetricsTableWrapperAggregateImpl(final HRegionServer regionServer) {
      this.regionServer = regionServer;
      this.period = regionServer.conf.getLong(HConstants.REGIONSERVER_METRICS_PERIOD,
        HConstants.DEFAULT_REGIONSERVER_METRICS_PERIOD) + 1000;
      this.executor = CompatibilitySingletonFactory.getInstance(MetricsExecutor.class).getExecutor();
      this.runnable = new TableMetricsWrapperRunnable();
      this.tableMetricsUpdateTask = this.executor.scheduleWithFixedDelay(this.runnable, period, this.period,
        TimeUnit.MILLISECONDS);
    }
  
    public class TableMetricsWrapperRunnable implements Runnable {
  
      @Override
      public void run() {
        Map<TableName, MetricsTableValues> localMetricsTableMap = new HashMap<>();
  
        for (Region r : regionServer.getOnlineRegionsLocalContext()) {
          TableName tbl= r.getTableDesc().getTableName();
          MetricsTableValues metricsTable = localMetricsTableMap.get(tbl);
          if (metricsTable == null) {
            metricsTable = new MetricsTableValues();
            localMetricsTableMap.put(tbl, metricsTable);
          }
          long tempStorefilesSize = 0;
          for (Store store : r.getStores()) {
            tempStorefilesSize += store.getStorefilesSize();
          }
          metricsTable.setMemstoresSize(metricsTable.getMemstoresSize() + r.getMemstoreSize());
          metricsTable.setStoreFilesSize(metricsTable.getStoreFilesSize() + tempStorefilesSize);
          metricsTable.setTableSize(metricsTable.getMemstoresSize() + metricsTable.getStoreFilesSize());
          metricsTable.setReadRequestsCount(metricsTable.getReadRequestsCount() + r.getReadRequestsCount());
          metricsTable.setWriteRequestsCount(metricsTable.getWriteRequestsCount() + r.getWriteRequestsCount());
          metricsTable.setTotalRequestsCount(metricsTable.getReadRequestsCount() + metricsTable.getWriteRequestsCount());
        }
  
        for(Map.Entry<TableName, MetricsTableValues> entry : localMetricsTableMap.entrySet()) {
          TableName tbl = entry.getKey();
          if (metricsTableMap.get(tbl) == null) {
            MetricsTableSource tableSource = CompatibilitySingletonFactory
                .getInstance(MetricsRegionServerSourceFactory.class).createTable(tbl.getNameAsString(),
                  MetricsTableWrapperAggregateImpl.this);
            CompatibilitySingletonFactory
            .getInstance(MetricsRegionServerSourceFactory.class).getTableAggregate()
            .register(tbl.getNameAsString(), tableSource);
          }
          metricsTableMap.put(entry.getKey(), entry.getValue());
        }
        Set<TableName> existingTableNames = Sets.newHashSet(metricsTableMap.keySet());
        existingTableNames.removeAll(localMetricsTableMap.keySet());
        MetricsTableAggregateSource agg = CompatibilitySingletonFactory
            .getInstance(MetricsRegionServerSourceFactory.class).getTableAggregate();
        for (TableName table : existingTableNames) {
         agg.deregister(table.getNameAsString());
         if (metricsTableMap.get(table) != null) {
           metricsTableMap.remove(table);
         }
       }
     }
   }
 
   @Override
   public long getReadRequestsCount(String table) {
     MetricsTableValues metricsTable = metricsTableMap.get(TableName.valueOf(table));
     if (metricsTable == null)
       return 0;
     else
       return metricsTable.getReadRequestsCount();
   }
 
   @Override
   public long getWriteRequestsCount(String table) {
     MetricsTableValues metricsTable = metricsTableMap.get(TableName.valueOf(table));
     if (metricsTable == null)
       return 0;
     else
       return metricsTable.getWriteRequestsCount();
   }
 
   @Override
   public long getTotalRequestsCount(String table) {
     MetricsTableValues metricsTable = metricsTableMap.get(TableName.valueOf(table));
     if (metricsTable == null)
       return 0;
     else
       return metricsTable.getTotalRequestsCount();
   }
 
   @Override
   public long getMemstoresSize(String table) {
     MetricsTableValues metricsTable = metricsTableMap.get(TableName.valueOf(table));
     if (metricsTable == null)
       return 0;
     else
       return metricsTable.getMemstoresSize();
   }
 
   @Override
   public long getStoreFilesSize(String table) {
     MetricsTableValues metricsTable = metricsTableMap.get(TableName.valueOf(table));
     if (metricsTable == null)
       return 0;
     else
       return metricsTable.getStoreFilesSize();
   }
 
   @Override
   public long getTableSize(String table) {
     MetricsTableValues metricsTable = metricsTableMap.get(TableName.valueOf(table));
     if (metricsTable == null)
       return 0;
     else
       return metricsTable.getTableSize();
   }
 
   @Override
   public void close() throws IOException {
     tableMetricsUpdateTask.cancel(true);
   }
 
   private static class MetricsTableValues {
 
     private long totalRequestsCount;
     private long readRequestsCount;
     private long writeRequestsCount;
     private long memstoresSize;
     private long storeFilesSize;
     private long tableSize;
 
     public long getTotalRequestsCount() {
       return totalRequestsCount;
     }
 
     public void setTotalRequestsCount(long totalRequestsCount) {
       this.totalRequestsCount = totalRequestsCount;
     }
 
     public long getReadRequestsCount() {
       return readRequestsCount;
     }
 
     public void setReadRequestsCount(long readRequestsCount) {
       this.readRequestsCount = readRequestsCount;
     }
 
     public long getWriteRequestsCount() {
       return writeRequestsCount;
     }
 
     public void setWriteRequestsCount(long writeRequestsCount) {
       this.writeRequestsCount = writeRequestsCount;
     }
 
     public long getMemstoresSize() {
       return memstoresSize;
     }
 
     public void setMemstoresSize(long memstoresSize) {
       this.memstoresSize = memstoresSize;
     }
 
     public long getStoreFilesSize() {
       return storeFilesSize;
     }
 
     public void setStoreFilesSize(long storeFilesSize) {
       this.storeFilesSize = storeFilesSize;
     }
 
     public long getTableSize() {
       return tableSize;
     }
 
     public void setTableSize(long tableSize) {
       this.tableSize = tableSize;
     }
   }
 
 }