/**
    * 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.client;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertFalse;
  import static org.junit.Assert.fail;
  
  import java.io.IOException;
  import java.io.InterruptedIOException;
  import java.util.HashSet;
  import java.util.List;
  import java.util.Set;
  import java.util.concurrent.TimeUnit;
  
  import org.apache.hadoop.fs.Path;
  import org.apache.hadoop.hbase.CategoryBasedTimeout;
  import org.apache.hadoop.hbase.HBaseTestingUtility;
  import org.apache.hadoop.hbase.HColumnDescriptor;
  import org.apache.hadoop.hbase.HConstants;
  import org.apache.hadoop.hbase.HRegionInfo;
  import org.apache.hadoop.hbase.HTableDescriptor;
  import org.apache.hadoop.hbase.MetaTableAccessor;
  import org.apache.hadoop.hbase.coprocessor.BaseRegionObserver;
  import org.apache.hadoop.hbase.coprocessor.ObserverContext;
  import org.apache.hadoop.hbase.coprocessor.RegionCoprocessorEnvironment;
  import org.apache.hadoop.hbase.master.RegionState;
  import org.apache.hadoop.hbase.regionserver.InternalScanner;
  import org.apache.hadoop.hbase.regionserver.ScanType;
  import org.apache.hadoop.hbase.regionserver.Store;
  import org.apache.hadoop.hbase.testclassification.LargeTests;
  import org.apache.hadoop.hbase.TableName;
  import org.apache.hadoop.hbase.Waiter;
  import org.apache.hadoop.hbase.master.AssignmentManager;
  import org.apache.hadoop.hbase.master.MasterFileSystem;
  import org.apache.hadoop.hbase.master.snapshot.SnapshotManager;
  import org.apache.hadoop.hbase.regionserver.NoSuchColumnFamilyException;
  import org.apache.hadoop.hbase.snapshot.CorruptedSnapshotException;
  import org.apache.hadoop.hbase.snapshot.SnapshotDoesNotExistException;
  import org.apache.hadoop.hbase.snapshot.SnapshotTestingUtils;
  import org.apache.hadoop.hbase.util.Bytes;
  import org.apache.hadoop.hbase.util.FSUtils;
  import org.junit.After;
  import org.junit.AfterClass;
  import org.junit.Before;
  import org.junit.BeforeClass;
  import org.junit.Rule;
  import org.junit.Test;
  import org.junit.experimental.categories.Category;
  import org.junit.rules.TestRule;
  
  /**
   * Test restore snapshots from the client
   */
  @Category(LargeTests.class)
  public class TestRestoreSnapshotFromClient {
    @Rule public final TestRule timeout = CategoryBasedTimeout.builder()
        .withTimeout(this.getClass())
        .withLookingForStuckThread(true)
        .build();
  
    protected final static HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
  
    protected final byte[] FAMILY = Bytes.toBytes("cf");
  
    protected byte[] emptySnapshot;
    protected byte[] snapshotName0;
    protected byte[] snapshotName1;
    protected byte[] snapshotName2;
    protected int snapshot0Rows;
    protected int snapshot1Rows;
    protected TableName tableName;
    protected Admin admin;
  
    @BeforeClass
    public static void setUpBeforeClass() throws Exception {
      TEST_UTIL.getConfiguration().setBoolean(SnapshotManager.HBASE_SNAPSHOT_ENABLED, true);
      TEST_UTIL.getConfiguration().setBoolean("hbase.online.schema.update.enable", true);
      TEST_UTIL.getConfiguration().setInt("hbase.hstore.compactionThreshold", 10);
      TEST_UTIL.getConfiguration().setInt("hbase.regionserver.msginterval", 100);
      TEST_UTIL.getConfiguration().setInt("hbase.client.pause", 250);
      TEST_UTIL.getConfiguration().setInt(HConstants.HBASE_CLIENT_RETRIES_NUMBER, 6);
      TEST_UTIL.getConfiguration().setBoolean("hbase.master.enabletable.roundrobin", true);
      // Setting bigger value to avoid catalog janitor execution (parent region cleanup)
     TEST_UTIL.getConfiguration().setLong("hbase.catalogjanitor.interval", 1800000);
     TEST_UTIL.startMiniCluster(3);
   }
 
   @AfterClass
   public static void tearDownAfterClass() throws Exception {
     TEST_UTIL.shutdownMiniCluster();
   }
 
   /**
    * Initialize the tests with a table filled with some data
    * and two snapshots (snapshotName0, snapshotName1) of different states.
    * The tableName, snapshotNames and the number of rows in the snapshot are initialized.
    */
   @Before
   public void setup() throws Exception {
     this.admin = TEST_UTIL.getHBaseAdmin();
 
     long tid = System.currentTimeMillis();
     tableName =
         TableName.valueOf("testtb-" + tid);
     emptySnapshot = Bytes.toBytes("emptySnaptb-" + tid);
     snapshotName0 = Bytes.toBytes("snaptb0-" + tid);
     snapshotName1 = Bytes.toBytes("snaptb1-" + tid);
     snapshotName2 = Bytes.toBytes("snaptb2-" + tid);
 
     // create Table and disable it
     SnapshotTestingUtils.createTable(TEST_UTIL, tableName, getNumReplicas(), FAMILY);
     admin.disableTable(tableName);
 
     // take an empty snapshot
     admin.snapshot(emptySnapshot, tableName);
 
     // enable table and insert data
     admin.enableTable(tableName);
     SnapshotTestingUtils.loadData(TEST_UTIL, tableName, 500, FAMILY);
     try (Table table = TEST_UTIL.getConnection().getTable(tableName)) {
       snapshot0Rows = TEST_UTIL.countRows(table);
     }
     admin.disableTable(tableName);
 
     // take a snapshot
     admin.snapshot(snapshotName0, tableName);
 
     // enable table and insert more data
     admin.enableTable(tableName);
     SnapshotTestingUtils.loadData(TEST_UTIL, tableName, 500, FAMILY);
     try (Table table = TEST_UTIL.getConnection().getTable(tableName)) {
       snapshot1Rows = TEST_UTIL.countRows(table);
     }
   }
 
   @After
   public void tearDown() throws Exception {
     TEST_UTIL.deleteTable(tableName);
     SnapshotTestingUtils.deleteAllSnapshots(TEST_UTIL.getHBaseAdmin());
     SnapshotTestingUtils.deleteArchiveDirectory(TEST_UTIL);
   }
 
   @Test
   public void testRestoreSnapshot() throws IOException {
     SnapshotTestingUtils.verifyRowCount(TEST_UTIL, tableName, snapshot1Rows);
     admin.disableTable(tableName);
     admin.snapshot(snapshotName1, tableName);
     // Restore from snapshot-0
     admin.restoreSnapshot(snapshotName0);
     admin.enableTable(tableName);
     SnapshotTestingUtils.verifyRowCount(TEST_UTIL, tableName, snapshot0Rows);
     SnapshotTestingUtils.verifyReplicasCameOnline(tableName, admin, getNumReplicas());
 
     // Restore from emptySnapshot
     admin.disableTable(tableName);
     admin.restoreSnapshot(emptySnapshot);
     admin.enableTable(tableName);
     SnapshotTestingUtils.verifyRowCount(TEST_UTIL, tableName, 0);
     SnapshotTestingUtils.verifyReplicasCameOnline(tableName, admin, getNumReplicas());
 
     // Restore from snapshot-1
     admin.disableTable(tableName);
     admin.restoreSnapshot(snapshotName1);
     admin.enableTable(tableName);
     SnapshotTestingUtils.verifyRowCount(TEST_UTIL, tableName, snapshot1Rows);
     SnapshotTestingUtils.verifyReplicasCameOnline(tableName, admin, getNumReplicas());
 
     // Restore from snapshot-1
     TEST_UTIL.deleteTable(tableName);
     admin.restoreSnapshot(snapshotName1);
     SnapshotTestingUtils.verifyRowCount(TEST_UTIL, tableName, snapshot1Rows);
     SnapshotTestingUtils.verifyReplicasCameOnline(tableName, admin, getNumReplicas());
   }
 
   @Test(timeout = 300000)
   public void testRestoreSnapshotAfterSplit() throws Exception {
     Admin admin = null;
     try {
       admin = TEST_UTIL.getHBaseAdmin();
       final int regionReplication = admin.getTableDescriptor(tableName).getRegionReplication();
       // Region count before split
       final int primaryRegionCountBeforeSplit = MetaTableAccessor
           .getTableRegions(TEST_UTIL.getZooKeeperWatcher(), TEST_UTIL.getConnection(), tableName)
           .size() / regionReplication;
 
       admin.split(tableName, "m".getBytes());
       final AssignmentManager am = TEST_UTIL.getHBaseCluster().getMaster().getAssignmentManager();
       // Wait for replica region to become online
       TEST_UTIL.waitFor(60000, 500, new Waiter.Predicate<IOException>() {
         @Override
         public boolean evaluate() throws IOException {
           return am.getRegionStates().getRegionByStateOfTable(tableName).get(RegionState.State.OPEN)
               .size() == ((primaryRegionCountBeforeSplit + 1) * regionReplication);
         }
       });
 
       int regionCountAfterSplit = MetaTableAccessor
           .getTableRegions(TEST_UTIL.getZooKeeperWatcher(), TEST_UTIL.getConnection(), tableName)
           .size() / regionReplication;
       // regionCountAfterSplit will contain parent region, so primaryregionCountBeforeSplit + 2
       assertEquals(primaryRegionCountBeforeSplit + 2, regionCountAfterSplit);
 
       String snapshotName = "testRestoreSnapshotAfterSplit-snap";
       // Create snapshot after table split
       admin.snapshot(snapshotName, tableName);
       assertEquals(1,
         admin.listTableSnapshots("testtb-.*", "testRestoreSnapshotAfterSplit-snap*").size());
       // Restore snapshot
       admin.disableTable(tableName);
       admin.restoreSnapshot(snapshotName);
 
       int regionCountAfterRestoreSnapshot = MetaTableAccessor
           .getTableRegions(TEST_UTIL.getZooKeeperWatcher(), TEST_UTIL.getConnection(), tableName)
           .size();
       assertEquals(primaryRegionCountBeforeSplit + 2, regionCountAfterRestoreSnapshot);
 
       // Enable the table
       admin.enableTable(tableName);
       assertEquals((primaryRegionCountBeforeSplit + 1) * regionReplication,
         am.getRegionStates().getRegionByStateOfTable(tableName).get(RegionState.State.OPEN).size());
 
     } finally {
       if (admin != null) {
         try {
           admin.deleteTableSnapshots("testtb-.*", "testRestoreSnapshotAfterSplit-snap*");
         } catch (SnapshotDoesNotExistException ignore) {
         }
         admin.close();
       }
     }
   }
 
   protected int getNumReplicas() {
     return 1;
   }
 
   @Test
   public void testRestoreSchemaChange() throws Exception {
     byte[] TEST_FAMILY2 = Bytes.toBytes("cf2");
 
     HTable table = new HTable(TEST_UTIL.getConfiguration(), tableName);
 
     // Add one column family and put some data in it
     admin.disableTable(tableName);
     admin.addColumn(tableName, new HColumnDescriptor(TEST_FAMILY2));
     admin.enableTable(tableName);
     assertEquals(2, table.getTableDescriptor().getFamilies().size());
     HTableDescriptor htd = admin.getTableDescriptor(tableName);
     assertEquals(2, htd.getFamilies().size());
     SnapshotTestingUtils.loadData(TEST_UTIL, tableName, 500, TEST_FAMILY2);
     long snapshot2Rows = snapshot1Rows + 500;
     assertEquals(snapshot2Rows, TEST_UTIL.countRows(table));
     assertEquals(500, TEST_UTIL.countRows(table, TEST_FAMILY2));
     Set<String> fsFamilies = getFamiliesFromFS(tableName);
     assertEquals(2, fsFamilies.size());
 
     // Take a snapshot
     admin.disableTable(tableName);
     admin.snapshot(snapshotName2, tableName);
 
     // Restore the snapshot (without the cf)
     admin.restoreSnapshot(snapshotName0);
     admin.enableTable(tableName);
     assertEquals(1, table.getTableDescriptor().getFamilies().size());
     try {
       TEST_UTIL.countRows(table, TEST_FAMILY2);
       fail("family '" + Bytes.toString(TEST_FAMILY2) + "' should not exists");
     } catch (NoSuchColumnFamilyException e) {
       // expected
     }
     assertEquals(snapshot0Rows, TEST_UTIL.countRows(table));
     htd = admin.getTableDescriptor(tableName);
     assertEquals(1, htd.getFamilies().size());
     fsFamilies = getFamiliesFromFS(tableName);
     assertEquals(1, fsFamilies.size());
 
     // Restore back the snapshot (with the cf)
     admin.disableTable(tableName);
     admin.restoreSnapshot(snapshotName2);
     admin.enableTable(tableName);
     htd = admin.getTableDescriptor(tableName);
     assertEquals(2, htd.getFamilies().size());
     assertEquals(2, table.getTableDescriptor().getFamilies().size());
     assertEquals(500, TEST_UTIL.countRows(table, TEST_FAMILY2));
     assertEquals(snapshot2Rows, TEST_UTIL.countRows(table));
     fsFamilies = getFamiliesFromFS(tableName);
     assertEquals(2, fsFamilies.size());
     table.close();
   }
 
   @Test
   public void testCloneSnapshotOfCloned() throws IOException, InterruptedException {
     TableName clonedTableName =
         TableName.valueOf("clonedtb-" + System.currentTimeMillis());
     admin.cloneSnapshot(snapshotName0, clonedTableName);
     SnapshotTestingUtils.verifyRowCount(TEST_UTIL, clonedTableName, snapshot0Rows);
     SnapshotTestingUtils.verifyReplicasCameOnline(clonedTableName, admin, getNumReplicas());
     admin.disableTable(clonedTableName);
     admin.snapshot(snapshotName2, clonedTableName);
     TEST_UTIL.deleteTable(clonedTableName);
     waitCleanerRun();
 
     admin.cloneSnapshot(snapshotName2, clonedTableName);
     SnapshotTestingUtils.verifyRowCount(TEST_UTIL, clonedTableName, snapshot0Rows);
     SnapshotTestingUtils.verifyReplicasCameOnline(clonedTableName, admin, getNumReplicas());
     TEST_UTIL.deleteTable(clonedTableName);
   }
 
   @Test
   public void testCloneAndRestoreSnapshot() throws IOException, InterruptedException {
     TEST_UTIL.deleteTable(tableName);
     waitCleanerRun();
 
     admin.cloneSnapshot(snapshotName0, tableName);
     SnapshotTestingUtils.verifyRowCount(TEST_UTIL, tableName, snapshot0Rows);
     SnapshotTestingUtils.verifyReplicasCameOnline(tableName, admin, getNumReplicas());
     waitCleanerRun();
 
     admin.disableTable(tableName);
     admin.restoreSnapshot(snapshotName0);
     admin.enableTable(tableName);
     SnapshotTestingUtils.verifyRowCount(TEST_UTIL, tableName, snapshot0Rows);
     SnapshotTestingUtils.verifyReplicasCameOnline(tableName, admin, getNumReplicas());
   }
 
   @Test
   public void testCorruptedSnapshot() throws IOException, InterruptedException {
     SnapshotTestingUtils.corruptSnapshot(TEST_UTIL, Bytes.toString(snapshotName0));
     TableName cloneName = TableName.valueOf("corruptedClone-" + System.currentTimeMillis());
     try {
       admin.cloneSnapshot(snapshotName0, cloneName);
       fail("Expected CorruptedSnapshotException, got succeeded cloneSnapshot()");
     } catch (CorruptedSnapshotException e) {
       // Got the expected corruption exception.
       // check for no references of the cloned table.
       assertFalse(admin.tableExists(cloneName));
     } catch (Exception e) {
       fail("Expected CorruptedSnapshotException got: " + e);
     }
   }
 
   @Test
   public void testRestoreSnapshotAfterSplittingRegions() throws IOException, InterruptedException {
     // HBASE-20008: Add a coprocessor to delay compactions of the daughter regions. To reproduce
     // the NullPointerException, we need to delay compactions of the daughter regions after
     // splitting region.
     HTableDescriptor tableDescriptor = admin.getTableDescriptor(tableName);
     tableDescriptor.addCoprocessor(DelayCompactionObserver.class.getName());
     admin.disableTable(tableName);
     admin.modifyTable(tableName, tableDescriptor);
     admin.enableTable(tableName);
 
     List<HRegionInfo> regionInfos = admin.getTableRegions(tableName);
     RegionReplicaUtil.removeNonDefaultRegions(regionInfos);
 
     // Split the first region
     splitRegion(regionInfos.get(0));
 
     // Take a snapshot
     admin.snapshot(snapshotName1, tableName);
 
     // Restore the snapshot
     admin.disableTable(tableName);
     admin.restoreSnapshot(snapshotName1);
     admin.enableTable(tableName);
 
     SnapshotTestingUtils.verifyRowCount(TEST_UTIL, tableName, snapshot1Rows);
   }
 
   public static class DelayCompactionObserver extends BaseRegionObserver {
     @Override public InternalScanner preCompact(ObserverContext<RegionCoprocessorEnvironment> e,
         final Store store, final InternalScanner scanner, final ScanType scanType)
         throws IOException {
 
       try {
         // Delay 5 seconds.
         TimeUnit.SECONDS.sleep(5);
       } catch (InterruptedException ex) {
         throw new InterruptedIOException(ex.getMessage());
       }
 
       return scanner;
     }
   }
 
   @Test
   public void testOfflineRegionsShouldBeZeroAfterRestoreSnapshot() throws IOException,
       InterruptedException {
     // Load more data to split regions
     SnapshotTestingUtils.loadData(TEST_UTIL, tableName, 2000, FAMILY);
 
     // Split regions
     List<HRegionInfo> regions = admin.getTableRegions(tableName);
     RegionReplicaUtil.removeNonDefaultRegions(regions);
     splitRegion(regions.get(0));
 
     // Restore the snapshot
     admin.disableTable(tableName);
     admin.restoreSnapshot(snapshotName0);
     admin.enableTable(tableName);
 
     int offlineRegions = TEST_UTIL.getHBaseCluster().getMaster().getAssignmentManager()
       .getRegionStates().getRegionByStateOfTable(tableName).get(RegionState.State.OFFLINE).size();
 
     assertEquals(0, offlineRegions);
   }
 
   // ==========================================================================
   //  Helpers
   // ==========================================================================
   private void waitCleanerRun() throws InterruptedException {
     TEST_UTIL.getMiniHBaseCluster().getMaster().getHFileCleaner().choreForTesting();
   }
 
   private Set<String> getFamiliesFromFS(final TableName tableName) throws IOException {
     MasterFileSystem mfs = TEST_UTIL.getMiniHBaseCluster().getMaster().getMasterFileSystem();
     Set<String> families = new HashSet<String>();
     Path tableDir = FSUtils.getTableDir(mfs.getRootDir(), tableName);
     for (Path regionDir: FSUtils.getRegionDirs(mfs.getFileSystem(), tableDir)) {
       for (Path familyDir: FSUtils.getFamilyDirs(mfs.getFileSystem(), regionDir)) {
         families.add(familyDir.getName());
       }
     }
     return families;
   }
 
   protected void splitRegion(final HRegionInfo regionInfo) throws IOException {
     byte[][] splitPoints = Bytes.split(regionInfo.getStartKey(), regionInfo.getEndKey(), 1);
     admin.split(regionInfo.getTable(), splitPoints[1]);
   }
 }