/**
    * 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.wal;
  
  import org.apache.commons.logging.Log;
  import org.apache.commons.logging.LogFactory;
  import org.apache.hadoop.conf.Configuration;
  import org.apache.hadoop.fs.FileStatus;
  import org.apache.hadoop.fs.FileSystem;
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.hbase.HBaseTestingUtility;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.HTableDescriptor;
  import org.apache.hadoop.hbase.HColumnDescriptor;
  import org.apache.hadoop.hbase.KeyValue;
  import org.apache.hadoop.hbase.HConstants;
  import org.apache.hadoop.hbase.HRegionInfo;
  import org.apache.hadoop.hbase.fs.HFileSystem;
  import org.apache.hadoop.hbase.regionserver.MultiVersionConcurrencyControl;
  import org.apache.hadoop.hbase.regionserver.wal.WALEdit;
  import org.apache.hadoop.hbase.testclassification.MediumTests;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.apache.hadoop.hbase.util.FSUtils;
  import org.junit.AfterClass;
  import org.junit.Before;
  import org.junit.BeforeClass;
  import org.junit.Test;
  import org.junit.experimental.categories.Category;
  
  import java.io.IOException;
  import java.util.ArrayList;
  import java.util.Collections;
  import java.util.List;
  
  import static org.junit.Assert.assertEquals;
  
  @Category(MediumTests.class)
  public class TestWALRootDir {
    private static final Log LOG = LogFactory.getLog(TestWALRootDir.class);
    private final static HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
    private static Configuration conf;
    private static FileSystem fs;
    private static FileSystem walFs;
    static final TableName tableName = TableName.valueOf("TestWALWALDir");
    private static final byte [] rowName = Bytes.toBytes("row");
    private static final byte [] family = Bytes.toBytes("column");
    private static HTableDescriptor htd;
    private static Path walRootDir;
    private static Path rootDir;
    private static WALFactory wals;
  
    @Before
    public void setUp() throws Exception {
      cleanup();
    }
  
    @BeforeClass
    public static void setUpBeforeClass() throws Exception {
      conf = TEST_UTIL.getConfiguration();
      TEST_UTIL.startMiniDFSCluster(1);
      rootDir = TEST_UTIL.createRootDir();
      walRootDir = TEST_UTIL.createWALRootDir();
      fs = FSUtils.getRootDirFileSystem(conf);
      walFs = FSUtils.getWALFileSystem(conf);
      htd = new HTableDescriptor(tableName);
      htd.addFamily(new HColumnDescriptor(family));
    }
  
    @AfterClass
    public static void tearDownAfterClass() throws Exception {
      cleanup();
      TEST_UTIL.shutdownMiniDFSCluster();
    }
  
    @Test
    public void testWALRootDir() throws Exception {
      HRegionInfo regionInfo = new HRegionInfo(tableName);
      wals = new WALFactory(conf, null, "testWALRootDir");
      WAL log = wals.getWAL(regionInfo.getEncodedNameAsBytes(), regionInfo.getTable().getNamespace());
  
      assertEquals(1, getWALFiles(walFs, walRootDir).size());
      byte [] value = Bytes.toBytes("value");
      WALEdit edit = new WALEdit();
      edit.add(new KeyValue(rowName, family, Bytes.toBytes("1"),
         System.currentTimeMillis(), value));
     long txid = log.append(htd,regionInfo, getWalKey(System.currentTimeMillis(), regionInfo, 0), edit, true);
     log.sync(txid);
     assertEquals("Expect 1 log have been created", 1, getWALFiles(walFs, walRootDir).size());
     log.rollWriter();
     //Create 1 more WAL
     assertEquals(2, getWALFiles(walFs, new Path(walRootDir, HConstants.HREGION_LOGDIR_NAME)).size());
     edit.add(new KeyValue(rowName, family, Bytes.toBytes("2"),
         System.currentTimeMillis(), value));
     txid = log.append(htd, regionInfo, getWalKey(System.currentTimeMillis(), regionInfo, 1), edit, true);
     log.sync(txid);
     log.rollWriter();
     log.shutdown();
 
     assertEquals("Expect 3 logs in WALs dir", 3, getWALFiles(walFs, new Path(walRootDir, HConstants.HREGION_LOGDIR_NAME)).size());
   }
 
   protected WALKey getWalKey(final long time, HRegionInfo hri, final long startPoint) {
     return new WALKey(hri.getEncodedNameAsBytes(), tableName, time, new MultiVersionConcurrencyControl(startPoint));
   }
 
   private List<FileStatus> getWALFiles(FileSystem fs, Path dir)
       throws IOException {
     List<FileStatus> result = new ArrayList<FileStatus>();
     LOG.debug("Scanning " + dir.toString() + " for WAL files");
 
     FileStatus[] files = fs.listStatus(dir);
     if (files == null) return Collections.emptyList();
     for (FileStatus file : files) {
       if (file.isDirectory()) {
         // recurse into sub directories
         result.addAll(getWALFiles(fs, file.getPath()));
       } else {
         String name = file.getPath().toString();
         if (!name.startsWith(".")) {
           result.add(file);
         }
       }
     }
     return result;
   }
 
   private static void cleanup() throws Exception{
     walFs.delete(walRootDir, true);
     fs.delete(rootDir, true);
   }
 
 }