/**
    *
    * 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.snapshot;
  
  import static org.junit.Assert.assertEquals;
  import java.io.IOException;
  import java.util.concurrent.atomic.AtomicInteger;
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.hbase.HBaseTestingUtility;
  import org.apache.hadoop.hbase.HTableDescriptor;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.TableNameTestRule;
  import org.apache.hadoop.hbase.coprocessor.BaseMasterObserver;
  import org.apache.hadoop.hbase.coprocessor.CoprocessorHost;
  import org.apache.hadoop.hbase.coprocessor.MasterCoprocessorEnvironment;
  import org.apache.hadoop.hbase.coprocessor.ObserverContext;
  import org.apache.hadoop.hbase.protobuf.generated.HBaseProtos.SnapshotDescription;
  import org.apache.hadoop.hbase.testclassification.MediumTests;
  import org.junit.After;
  import org.junit.Before;
  import org.junit.Rule;
  import org.junit.Test;
  import org.junit.experimental.categories.Category;
  
  @Category({ MediumTests.class })
  public class TestSnapshotClientRetries {
    private static final HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
    private static final Log LOG = LogFactory.getLog(TestSnapshotClientRetries.class);
  
    @Rule public TableNameTestRule testTable = new TableNameTestRule();
  
    @Before
    public void setUp() throws Exception {
      TEST_UTIL.getConfiguration().set(CoprocessorHost.MASTER_COPROCESSOR_CONF_KEY,
        MasterSyncObserver.class.getName());
      TEST_UTIL.startMiniCluster(1);
    }
  
    @After
    public void tearDown() throws Exception {
      TEST_UTIL.shutdownMiniCluster();
    }
  
    @Test(timeout = 60000, expected=SnapshotExistsException.class)
    public void testSnapshotAlreadyExist() throws Exception {
      final String snapshotName = "testSnapshotAlreadyExist";
      TEST_UTIL.createTable(testTable.getTableName(), "f");
      TEST_UTIL.getHBaseAdmin().snapshot(snapshotName, testTable.getTableName());
      snapshotAndAssertOneRetry(snapshotName, testTable.getTableName());
    }
  
    @Test(timeout = 60000, expected=SnapshotDoesNotExistException.class)
    public void testCloneNonExistentSnapshot() throws Exception {
      final String snapshotName = "testCloneNonExistentSnapshot";
      cloneAndAssertOneRetry(snapshotName, testTable.getTableName());
    }
  
    public static class MasterSyncObserver extends BaseMasterObserver {
      volatile AtomicInteger snapshotCount = null;
      volatile AtomicInteger cloneCount = null;
  
      @Override
      public void preSnapshot(final ObserverContext<MasterCoprocessorEnvironment> ctx,
          final SnapshotDescription snapshot, final HTableDescriptor hTableDescriptor)
          throws IOException {
        if (snapshotCount != null) {
          snapshotCount.incrementAndGet();
        }
      }
  
      @Override
      public void preCloneSnapshot(final ObserverContext<MasterCoprocessorEnvironment> ctx,
          final SnapshotDescription snapshot, final HTableDescriptor hTableDescriptor)
          throws IOException {
        if (cloneCount != null) {
          cloneCount.incrementAndGet();
        }
      }
    }
  
    public void snapshotAndAssertOneRetry(final String snapshotName, final TableName tableName)
        throws Exception {
     MasterSyncObserver observer = getMasterSyncObserver();
     observer.snapshotCount = new AtomicInteger(0);
     TEST_UTIL.getHBaseAdmin().snapshot(snapshotName, tableName);
     assertEquals(1, observer.snapshotCount.get());
   }
 
   public void cloneAndAssertOneRetry(final String snapshotName, final TableName tableName)
       throws Exception {
     MasterSyncObserver observer = getMasterSyncObserver();
     observer.cloneCount = new AtomicInteger(0);
     TEST_UTIL.getHBaseAdmin().cloneSnapshot(snapshotName, tableName);
     assertEquals(1, observer.cloneCount.get());
   }
 
   private MasterSyncObserver getMasterSyncObserver() {
     return (MasterSyncObserver)TEST_UTIL.getHBaseCluster().getMaster()
       .getMasterCoprocessorHost().findCoprocessor(MasterSyncObserver.class.getName());
   }
 }