/**
 * 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.master.procedure;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;

import java.io.IOException;
import java.util.Arrays;
import java.util.stream.Collectors;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileSystem;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.hbase.HBaseClassTestRule;
import org.apache.hadoop.hbase.HBaseIOException;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.TableNotDisabledException;
import org.apache.hadoop.hbase.TableNotFoundException;
import org.apache.hadoop.hbase.client.ColumnFamilyDescriptorBuilder;
import org.apache.hadoop.hbase.client.RegionInfo;
import org.apache.hadoop.hbase.client.TableDescriptor;
import org.apache.hadoop.hbase.client.TableDescriptorBuilder;
import org.apache.hadoop.hbase.master.MasterFileSystem;
import org.apache.hadoop.hbase.procedure2.Procedure;
import org.apache.hadoop.hbase.procedure2.ProcedureExecutor;
import org.apache.hadoop.hbase.procedure2.ProcedureTestingUtility;
import org.apache.hadoop.hbase.testclassification.MasterTests;
import org.apache.hadoop.hbase.testclassification.MediumTests;
import org.apache.hadoop.hbase.util.Bytes;
import org.apache.hadoop.hbase.util.FSUtils;
import org.apache.hadoop.hbase.util.ModifyRegionUtils;
import org.junit.ClassRule;
import org.junit.Rule;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.junit.rules.TestName;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.apache.hadoop.hbase.shaded.protobuf.generated.MasterProcedureProtos;

@Category({ MasterTests.class, MediumTests.class })
public class TestTruncateTableProcedure extends TestTableDDLProcedureBase {

  @ClassRule
  public static final HBaseClassTestRule CLASS_RULE =
    HBaseClassTestRule.forClass(TestTruncateTableProcedure.class);

  private static final Logger LOG = LoggerFactory.getLogger(TestTruncateTableProcedure.class);

  @Rule
  public TestName name = new TestName();

  @Test
  public void testTruncateNotExistentTable() throws Exception {
    final TableName tableName = TableName.valueOf(name.getMethodName());

    final ProcedureExecutor<MasterProcedureEnv> procExec = getMasterProcedureExecutor();
    // HBASE-20178 has us fail-fast, in the constructor, so add try/catch for this case.
    // Keep old way of looking at procedure too.
    Throwable cause = null;
    try {
      long procId = ProcedureTestingUtility.submitAndWait(procExec,
          new TruncateTableProcedure(procExec.getEnvironment(), tableName, true));

      // Second delete should fail with TableNotFound
      Procedure<?> result = procExec.getResult(procId);
      assertTrue(result.isFailed());
      cause = ProcedureTestingUtility.getExceptionCause(result);
    } catch (Throwable t) {
      cause = t;
    }
    LOG.debug("Truncate failed with exception: " + cause);
    assertTrue(cause instanceof TableNotFoundException);
  }

  @Test
  public void testTruncateNotDisabledTable() throws Exception {
    final TableName tableName = TableName.valueOf(name.getMethodName());

    final ProcedureExecutor<MasterProcedureEnv> procExec = getMasterProcedureExecutor();
    MasterProcedureTestingUtility.createTable(procExec, tableName, null, "f");

    // HBASE-20178 has us fail-fast, in the constructor, so add try/catch for this case.
    // Keep old way of looking at procedure too.
    Throwable cause = null;
    try {
      long procId = ProcedureTestingUtility.submitAndWait(procExec,
          new TruncateTableProcedure(procExec.getEnvironment(), tableName, false));

      // Second delete should fail with TableNotDisabled
      Procedure<?> result = procExec.getResult(procId);
      assertTrue(result.isFailed());
      cause = ProcedureTestingUtility.getExceptionCause(result);
    } catch (Throwable t) {
      cause = t;
    }
    LOG.debug("Truncate failed with exception: " + cause);
    assertTrue(cause instanceof TableNotDisabledException);
  }

  @Test
  public void testSimpleTruncatePreserveSplits() throws Exception {
    final TableName tableName = TableName.valueOf(name.getMethodName());
    testSimpleTruncate(tableName, true);
  }

  @Test
  public void testSimpleTruncateNoPreserveSplits() throws Exception {
    final TableName tableName = TableName.valueOf(name.getMethodName());
    testSimpleTruncate(tableName, false);
  }

  private void testSimpleTruncate(final TableName tableName, final boolean preserveSplits)
      throws Exception {
    final String[] families = new String[] { "f1", "f2" };
    final byte[][] splitKeys = new byte[][] {
      Bytes.toBytes("a"), Bytes.toBytes("b"), Bytes.toBytes("c")
    };

    RegionInfo[] regions = MasterProcedureTestingUtility.createTable(
      getMasterProcedureExecutor(), tableName, splitKeys, families);
    // load and verify that there are rows in the table
    MasterProcedureTestingUtility.loadData(
      UTIL.getConnection(), tableName, 100, splitKeys, families);
    assertEquals(100, UTIL.countRows(tableName));
    // disable the table
    UTIL.getAdmin().disableTable(tableName);

    // truncate the table
    final ProcedureExecutor<MasterProcedureEnv> procExec = getMasterProcedureExecutor();
    long procId = ProcedureTestingUtility.submitAndWait(procExec,
      new TruncateTableProcedure(procExec.getEnvironment(), tableName, preserveSplits));
    ProcedureTestingUtility.assertProcNotFailed(procExec, procId);

    // If truncate procedure completed successfully, it means all regions were assigned correctly
    // and table is enabled now.
    UTIL.waitUntilAllRegionsAssigned(tableName);

    // validate the table regions and layout
    regions = UTIL.getAdmin().getRegions(tableName).toArray(new RegionInfo[0]);
    if (preserveSplits) {
      assertEquals(1 + splitKeys.length, regions.length);
    } else {
      assertEquals(1, regions.length);
    }
    MasterProcedureTestingUtility.validateTableCreation(
      UTIL.getHBaseCluster().getMaster(), tableName, regions, families);

    // verify that there are no rows in the table
    assertEquals(0, UTIL.countRows(tableName));

    // verify that the table is read/writable
    MasterProcedureTestingUtility.loadData(
      UTIL.getConnection(), tableName, 50, splitKeys, families);
    assertEquals(50, UTIL.countRows(tableName));
  }

  @Test
  public void testRecoveryAndDoubleExecutionPreserveSplits() throws Exception {
    final TableName tableName = TableName.valueOf(name.getMethodName());
    testRecoveryAndDoubleExecution(tableName, true);
  }

  @Test
  public void testRecoveryAndDoubleExecutionNoPreserveSplits() throws Exception {
    final TableName tableName = TableName.valueOf(name.getMethodName());
    testRecoveryAndDoubleExecution(tableName, false);
  }

  private void testRecoveryAndDoubleExecution(final TableName tableName,
      final boolean preserveSplits) throws Exception {
    final String[] families = new String[] { "f1", "f2" };

    // create the table
    final byte[][] splitKeys = new byte[][] {
      Bytes.toBytes("a"), Bytes.toBytes("b"), Bytes.toBytes("c")
    };
    RegionInfo[] regions = MasterProcedureTestingUtility.createTable(
      getMasterProcedureExecutor(), tableName, splitKeys, families);
    // load and verify that there are rows in the table
    MasterProcedureTestingUtility.loadData(
      UTIL.getConnection(), tableName, 100, splitKeys, families);
    assertEquals(100, UTIL.countRows(tableName));
    // disable the table
    UTIL.getAdmin().disableTable(tableName);

    final ProcedureExecutor<MasterProcedureEnv> procExec = getMasterProcedureExecutor();
    ProcedureTestingUtility.waitNoProcedureRunning(procExec);
    ProcedureTestingUtility.setKillIfHasParent(procExec, false);
    ProcedureTestingUtility.setKillAndToggleBeforeStoreUpdate(procExec, true);

    // Start the Truncate procedure && kill the executor
    long procId = procExec.submitProcedure(
      new TruncateTableProcedure(procExec.getEnvironment(), tableName, preserveSplits));

    // Restart the executor and execute the step twice
    MasterProcedureTestingUtility.testRecoveryAndDoubleExecution(procExec, procId);

    ProcedureTestingUtility.setKillAndToggleBeforeStoreUpdate(procExec, false);
    UTIL.waitUntilAllRegionsAssigned(tableName);

    // validate the table regions and layout
    regions = UTIL.getAdmin().getRegions(tableName).toArray(new RegionInfo[0]);
    if (preserveSplits) {
      assertEquals(1 + splitKeys.length, regions.length);
    } else {
      assertEquals(1, regions.length);
    }
    MasterProcedureTestingUtility.validateTableCreation(
      UTIL.getHBaseCluster().getMaster(), tableName, regions, families);

    // verify that there are no rows in the table
    assertEquals(0, UTIL.countRows(tableName));

    // verify that the table is read/writable
    MasterProcedureTestingUtility.loadData(
      UTIL.getConnection(), tableName, 50, splitKeys, families);
    assertEquals(50, UTIL.countRows(tableName));
  }

  @Test
  public void testOnHDFSFailurePreserveSplits() throws Exception {
    final TableName tableName = TableName.valueOf(name.getMethodName());
    testOnHDFSFailure(tableName, true);
  }

  @Test
  public void testOnHDFSFailureNoPreserveSplits() throws Exception {
    final TableName tableName = TableName.valueOf(name.getMethodName());
    testOnHDFSFailure(tableName, false);
  }

  public static class TruncateTableProcedureOnHDFSFailure extends TruncateTableProcedure {

    private boolean failOnce = false;

    public TruncateTableProcedureOnHDFSFailure() {
      // Required by the Procedure framework to create the procedure on replay
      super();
    }

    public TruncateTableProcedureOnHDFSFailure(final MasterProcedureEnv env, TableName tableName,
      boolean preserveSplits)
      throws HBaseIOException {
      super(env, tableName, preserveSplits);
    }

    @Override
    protected Flow executeFromState(MasterProcedureEnv env,
      MasterProcedureProtos.TruncateTableState state) throws InterruptedException {

      if (!failOnce &&
        state == MasterProcedureProtos.TruncateTableState.TRUNCATE_TABLE_CREATE_FS_LAYOUT) {
        try {
          // To emulate an HDFS failure, create only the first region directory
          RegionInfo regionInfo = getFirstRegionInfo();
          Configuration conf = env.getMasterConfiguration();
          MasterFileSystem mfs = env.getMasterServices().getMasterFileSystem();
          Path tempdir = mfs.getTempDir();
          Path tableDir = FSUtils.getTableDir(tempdir, regionInfo.getTable());
          Path regionDir = FSUtils.getRegionDirFromTableDir(tableDir, regionInfo);
          FileSystem fs = FileSystem.get(conf);
          fs.mkdirs(regionDir);

          failOnce = true;
          return Flow.HAS_MORE_STATE;
        } catch (IOException e) {
          fail("failed to create a region directory: " + e);
        }
      }

      return super.executeFromState(env, state);
    }
  }

  private void testOnHDFSFailure(TableName tableName, boolean preserveSplits) throws Exception {
    String[] families = new String[] { "f1", "f2" };
    byte[][] splitKeys = new byte[][] {
      Bytes.toBytes("a"), Bytes.toBytes("b"), Bytes.toBytes("c")
    };

    // create a table
    MasterProcedureTestingUtility.createTable(
      getMasterProcedureExecutor(), tableName, splitKeys, families);

    // load and verify that there are rows in the table
    MasterProcedureTestingUtility.loadData(
      UTIL.getConnection(), tableName, 100, splitKeys, families);
    assertEquals(100, UTIL.countRows(tableName));

    // disable the table
    UTIL.getAdmin().disableTable(tableName);

    // truncate the table
    final ProcedureExecutor<MasterProcedureEnv> procExec = getMasterProcedureExecutor();
    long procId = ProcedureTestingUtility.submitAndWait(procExec,
      new TruncateTableProcedureOnHDFSFailure(procExec.getEnvironment(), tableName,
        preserveSplits));
    ProcedureTestingUtility.assertProcNotFailed(procExec, procId);
  }

  @Test
  public void testTruncateWithPreserveAfterSplit() throws Exception {
    String[] families = new String[] { "f1", "f2" };
    byte[][] splitKeys =
      new byte[][] { Bytes.toBytes("a"), Bytes.toBytes("b"), Bytes.toBytes("c") };
    TableName tableName = TableName.valueOf(name.getMethodName());
    RegionInfo[] regions = MasterProcedureTestingUtility.createTable(getMasterProcedureExecutor(),
      tableName, splitKeys, families);
    splitAndTruncate(tableName, regions, 1);
  }

  @Test
  public void testTruncatePreserveWithReplicaRegionAfterSplit() throws Exception {
    String[] families = new String[] { "f1", "f2" };
    byte[][] splitKeys =
      new byte[][] { Bytes.toBytes("a"), Bytes.toBytes("b"), Bytes.toBytes("c") };
    TableName tableName = TableName.valueOf(name.getMethodName());

    // create a table with region replications
    TableDescriptor htd = TableDescriptorBuilder.newBuilder(tableName).setRegionReplication(3)
      .setColumnFamilies(Arrays.stream(families)
        .map(fam -> ColumnFamilyDescriptorBuilder.newBuilder(Bytes.toBytes(fam)).build())
        .collect(Collectors.toList()))
      .build();
    RegionInfo[] regions = ModifyRegionUtils.createRegionInfos(htd, splitKeys);
    ProcedureExecutor<MasterProcedureEnv> procExec = getMasterProcedureExecutor();
    long procId = ProcedureTestingUtility.submitAndWait(procExec,
      new CreateTableProcedure(procExec.getEnvironment(), htd, regions));
    ProcedureTestingUtility.assertProcNotFailed(procExec.getResult(procId));

    splitAndTruncate(tableName, regions, 3);
  }

  private void splitAndTruncate(TableName tableName, RegionInfo[] regions, int regionReplication)
      throws IOException, InterruptedException {
    // split a region
    UTIL.getAdmin().split(tableName, new byte[] { '0' });

    // wait until split really happens
    UTIL.waitFor(60000,
      () -> UTIL.getAdmin().getRegions(tableName).size() > regions.length * regionReplication);

    // disable the table
    UTIL.getAdmin().disableTable(tableName);

    // truncate the table
    ProcedureExecutor<MasterProcedureEnv> procExec = getMasterProcedureExecutor();
    long procId = ProcedureTestingUtility.submitAndWait(procExec,
      new TruncateTableProcedure(procExec.getEnvironment(), tableName, true));
    ProcedureTestingUtility.assertProcNotFailed(procExec, procId);

    UTIL.waitUntilAllRegionsAssigned(tableName);
    // confirm that we have the correct number of regions
    assertEquals((regions.length + 1) * regionReplication,
      UTIL.getAdmin().getRegions(tableName).size());
  }
}
