/**
 * 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.fail;

import java.io.IOException;
import java.util.Optional;
import java.util.concurrent.CountDownLatch;
import org.apache.hadoop.hbase.HBaseClassTestRule;
import org.apache.hadoop.hbase.HBaseTestingUtility;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HConstants;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.MetaTableAccessor;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.coprocessor.CoprocessorHost;
import org.apache.hadoop.hbase.coprocessor.MasterCoprocessor;
import org.apache.hadoop.hbase.coprocessor.MasterCoprocessorEnvironment;
import org.apache.hadoop.hbase.coprocessor.MasterObserver;
import org.apache.hadoop.hbase.coprocessor.ObserverContext;
import org.apache.hadoop.hbase.testclassification.MasterTests;
import org.apache.hadoop.hbase.testclassification.MediumTests;
import org.apache.hadoop.hbase.util.Bytes;
import org.junit.After;
import org.junit.Before;
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;

@Category({ MasterTests.class, MediumTests.class })
public class TestEnableTable {

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

  private static final HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();
  private static final Logger LOG = LoggerFactory.getLogger(TestEnableTable.class);
  private static final byte[] FAMILYNAME = Bytes.toBytes("fam");

  @Rule
  public TestName name = new TestName();

  @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();
  }

  /**
   * We were only clearing rows that had a hregioninfo column in hbase:meta.  Mangled rows that
   * were missing the hregioninfo because of error were being left behind messing up any
   * subsequent table made with the same name. HBASE-12980
   * @throws IOException
   * @throws InterruptedException
   */
  @Test
  public void testDeleteForSureClearsAllTableRowsFromMeta()
  throws IOException, InterruptedException {
    final TableName tableName = TableName.valueOf(name.getMethodName());
    final Admin admin = TEST_UTIL.getAdmin();
    final HTableDescriptor desc = new HTableDescriptor(tableName);
    desc.addFamily(new HColumnDescriptor(FAMILYNAME));
    try {
      createTable(TEST_UTIL, desc, HBaseTestingUtility.KEYS_FOR_HBA_CREATE_TABLE);
    } catch (Exception e) {
      e.printStackTrace();
      fail("Got an exception while creating " + tableName);
    }
    // Now I have a nice table, mangle it by removing the HConstants.REGIONINFO_QUALIFIER_STR
    // content from a few of the rows.
    try (Table metaTable = TEST_UTIL.getConnection().getTable(TableName.META_TABLE_NAME)) {
      try (ResultScanner scanner = metaTable.getScanner(
        MetaTableAccessor.getScanForTableName(TEST_UTIL.getConnection(), tableName))) {
        for (Result result : scanner) {
          // Just delete one row.
          Delete d = new Delete(result.getRow());
          d.addColumn(HConstants.CATALOG_FAMILY, HConstants.REGIONINFO_QUALIFIER);
          LOG.info("Mangled: " + d);
          metaTable.delete(d);
          break;
        }
      }
      admin.disableTable(tableName);
      TEST_UTIL.waitTableDisabled(tableName.getName());
      // Rely on the coprocessor based latch to make the operation synchronous.
      try {
        deleteTable(TEST_UTIL, tableName);
      } catch (Exception e) {
        e.printStackTrace();
        fail("Got an exception while deleting " + tableName);
      }
      int rowCount = 0;
      try (ResultScanner scanner = metaTable
        .getScanner(MetaTableAccessor.getScanForTableName(TEST_UTIL.getConnection(), tableName))) {
        for (Result result : scanner) {
          LOG.info("Found when none expected: " + result);
          rowCount++;
        }
      }
      assertEquals(0, rowCount);
    }
  }

  public  static class MasterSyncObserver implements MasterCoprocessor, MasterObserver {
    volatile CountDownLatch tableCreationLatch = null;
    volatile CountDownLatch tableDeletionLatch = null;

    @Override
    public Optional<MasterObserver> getMasterObserver() {
      return Optional.of(this);
    }

    @Override
    public void postCompletedCreateTableAction(
        final ObserverContext<MasterCoprocessorEnvironment> ctx,
        final TableDescriptor desc,
        final RegionInfo[] regions) throws IOException {
      // the AccessController test, some times calls only and directly the
      // postCompletedCreateTableAction()
      if (tableCreationLatch != null) {
        tableCreationLatch.countDown();
      }
    }

    @Override
    public void postCompletedDeleteTableAction(
        final ObserverContext<MasterCoprocessorEnvironment> ctx,
        final TableName tableName)
    throws IOException {
      // the AccessController test, some times calls only and directly the postDeleteTableHandler()
      if (tableDeletionLatch != null) {
        tableDeletionLatch.countDown();
      }
    }
  }

  public static void createTable(HBaseTestingUtility testUtil,
    HTableDescriptor htd, byte [][] splitKeys)
  throws Exception {
    // NOTE: We need a latch because admin is not sync,
    // so the postOp coprocessor method may be called after the admin operation returned.
    MasterSyncObserver observer = testUtil.getHBaseCluster().getMaster()
      .getMasterCoprocessorHost().findCoprocessor(MasterSyncObserver.class);
    observer.tableCreationLatch = new CountDownLatch(1);
    Admin admin = testUtil.getAdmin();
    if (splitKeys != null) {
      admin.createTable(htd, splitKeys);
    } else {
      admin.createTable(htd);
    }
    observer.tableCreationLatch.await();
    observer.tableCreationLatch = null;
    testUtil.waitUntilAllRegionsAssigned(htd.getTableName());
  }

  public static void deleteTable(HBaseTestingUtility testUtil, TableName tableName)
  throws Exception {
    // NOTE: We need a latch because admin is not sync,
    // so the postOp coprocessor method may be called after the admin operation returned.
    MasterSyncObserver observer = testUtil.getHBaseCluster().getMaster()
      .getMasterCoprocessorHost().findCoprocessor(MasterSyncObserver.class);
    observer.tableDeletionLatch = new CountDownLatch(1);
    Admin admin = testUtil.getAdmin();
    try {
      admin.disableTable(tableName);
    } catch (Exception e) {
      LOG.debug("Table: " + tableName + " already disabled, so just deleting it.");
    }
    admin.deleteTable(tableName);
    observer.tableDeletionLatch.await();
    observer.tableDeletionLatch = null;
  }
}
