/**
    *
    * 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.IOException;
  import org.apache.commons.lang.StringUtils;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.hbase.HBaseTestingUtility;
  import org.apache.hadoop.hbase.HRegionInfo;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.client.Table;
  import org.apache.hadoop.hbase.testclassification.MediumTests;
  import org.apache.hadoop.hbase.testclassification.RegionServerTests;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.apache.hadoop.hbase.util.FSUtils;
  import org.apache.hadoop.hdfs.DFSClient;
  import org.junit.After;
  import org.junit.Assert;
  import org.junit.Before;
  import org.junit.Test;
  import org.junit.experimental.categories.Category;
  
  @Category({RegionServerTests.class, MediumTests.class})
  public class TestHdfsSnapshotHRegion {
  
    private static final HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
    private static final String SNAPSHOT_NAME = "foo_snapshot";
    private Table table;
    public static final TableName TABLE_NAME = TableName.valueOf("foo");
    public static final byte[] FAMILY = Bytes.toBytes("f1");
    private DFSClient client;
    private String baseDir;
  
  
    @Before
    public void setUp() throws Exception {
      Configuration c = TEST_UTIL.getConfiguration();
      c.setBoolean("dfs.support.append", true);
      TEST_UTIL.startMiniCluster(1);
      table = TEST_UTIL.createMultiRegionTable(TABLE_NAME, FAMILY);
      TEST_UTIL.loadTable(table, FAMILY);
  
      // setup the hdfssnapshots
      client = new DFSClient(TEST_UTIL.getDFSCluster().getURI(), TEST_UTIL.getConfiguration());
      String fullUrIPath = TEST_UTIL.getDefaultRootDirPath().toString();
      String uriString = TEST_UTIL.getTestFileSystem().getUri().toString();
      baseDir = StringUtils.removeStart(fullUrIPath, uriString);
      client.allowSnapshot(baseDir);
    }
  
    @After
    public void tearDown() throws Exception {
      client.deleteSnapshot(baseDir, SNAPSHOT_NAME);
      TEST_UTIL.shutdownMiniCluster();
    }
  
    @Test
    public void testOpeningReadOnlyRegionBasic() throws Exception {
      String snapshotDir = client.createSnapshot(baseDir, SNAPSHOT_NAME);
      HRegionInfo firstRegion = TEST_UTIL.getHBaseAdmin().getTableRegions(table.getName()).get(0);
      Path tableDir = FSUtils.getTableDir(new Path(snapshotDir), TABLE_NAME);
      HRegion snapshottedRegion = openSnapshotRegion(firstRegion, tableDir);
      Assert.assertNotNull(snapshottedRegion);
      snapshottedRegion.close();
    }
  
    @Test
    public void testSnapshottingWithTmpSplitsAndMergeDirectoriesPresent() throws Exception {
      // lets get a region and create those directories and make sure we ignore them
      HRegionInfo firstRegion = TEST_UTIL.getHBaseAdmin().getTableRegions(table.getName()).get(0);
      String encodedName = firstRegion.getEncodedName();
      Path tableDir = FSUtils.getTableDir(TEST_UTIL.getDefaultRootDirPath(), TABLE_NAME);
      Path regionDirectoryPath = new Path(tableDir, encodedName);
      TEST_UTIL.getTestFileSystem().create(
          new Path(regionDirectoryPath, HRegionFileSystem.REGION_TEMP_DIR));
      TEST_UTIL.getTestFileSystem().create(
          new Path(regionDirectoryPath, HRegionFileSystem.REGION_SPLITS_DIR));
      TEST_UTIL.getTestFileSystem().create(
          new Path(regionDirectoryPath, HRegionFileSystem.REGION_MERGES_DIR));
      // now snapshot
      String snapshotDir = client.createSnapshot(baseDir, "foo_snapshot");
      // everything should still open just fine
     HRegion snapshottedRegion = openSnapshotRegion(firstRegion,
         FSUtils.getTableDir(new Path(snapshotDir), TABLE_NAME));
     Assert.assertNotNull(snapshottedRegion); // no errors and the region should open
     snapshottedRegion.close();
   }
 
   private HRegion openSnapshotRegion(HRegionInfo firstRegion, Path tableDir) throws IOException {
     return HRegion.openReadOnlyFileSystemHRegion(
         TEST_UTIL.getConfiguration(),
         TEST_UTIL.getTestFileSystem(),
         tableDir,
         firstRegion,
         table.getTableDescriptor()
     );
   }
 }