/**
 * 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 static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertTrue;

import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import org.apache.hadoop.hbase.HBaseClassTestRule;
import org.apache.hadoop.hbase.HBaseTestingUtility;
import org.apache.hadoop.hbase.HColumnDescriptor;
import org.apache.hadoop.hbase.HRegionInfo;
import org.apache.hadoop.hbase.HTableDescriptor;
import org.apache.hadoop.hbase.MiniHBaseCluster;
import org.apache.hadoop.hbase.TableName;
import org.apache.hadoop.hbase.client.Admin;
import org.apache.hadoop.hbase.client.Put;
import org.apache.hadoop.hbase.client.RegionLocator;
import org.apache.hadoop.hbase.client.Result;
import org.apache.hadoop.hbase.client.ResultScanner;
import org.apache.hadoop.hbase.client.Scan;
import org.apache.hadoop.hbase.client.Table;
import org.apache.hadoop.hbase.master.HMaster;
import org.apache.hadoop.hbase.testclassification.MediumTests;
import org.apache.hadoop.hbase.testclassification.RegionServerTests;
import org.apache.hadoop.hbase.util.Bytes;
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;

/**
 * Tests that need to spin up a cluster testing an {@link HRegion}.  Use
 * {@link TestHRegion} if you don't need a cluster, if you can test w/ a
 * standalone {@link HRegion}.
 */
@Category({RegionServerTests.class, MediumTests.class})
public class TestHRegionOnCluster {

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

  private static final Logger LOG = LoggerFactory.getLogger(TestHRegionOnCluster.class);
  private static final HBaseTestingUtility TEST_UTIL = new HBaseTestingUtility();

  @Rule
  public TestName name = new TestName();

  @Test
  public void testDataCorrectnessReplayingRecoveredEdits() throws Exception {
    final int NUM_RS = 3;
    Admin hbaseAdmin = null;
    TEST_UTIL.startMiniCluster(NUM_RS);

    try {
      final TableName tableName = TableName.valueOf(name.getMethodName());
      final byte[] FAMILY = Bytes.toBytes("family");
      MiniHBaseCluster cluster = TEST_UTIL.getHBaseCluster();
      HMaster master = cluster.getMaster();

      // Create table
      HTableDescriptor desc = new HTableDescriptor(tableName);
      desc.addFamily(new HColumnDescriptor(FAMILY));
      hbaseAdmin = master.getConnection().getAdmin();
      hbaseAdmin.createTable(desc);

      assertTrue(hbaseAdmin.isTableAvailable(tableName));

      // Put data: r1->v1
      LOG.info("Loading r1 to v1 into " + tableName);
      Table table = TEST_UTIL.getConnection().getTable(tableName);
      putDataAndVerify(table, "r1", FAMILY, "v1", 1);

      TEST_UTIL.waitUntilAllRegionsAssigned(table.getName());
      // Move region to target server

      HRegionInfo regionInfo;
      try (RegionLocator locator = TEST_UTIL.getConnection().getRegionLocator(tableName)) {
        regionInfo = locator.getRegionLocation(Bytes.toBytes("r1")).getRegionInfo();
      }

      int originServerNum = cluster.getServerWith(regionInfo.getRegionName());
      HRegionServer originServer = cluster.getRegionServer(originServerNum);
      int targetServerNum = (originServerNum + 1) % NUM_RS;
      HRegionServer targetServer = cluster.getRegionServer(targetServerNum);
      assertFalse(originServer.equals(targetServer));

      TEST_UTIL.waitUntilAllRegionsAssigned(table.getName());
      LOG.info("Moving " + regionInfo.getEncodedName() + " to " + targetServer.getServerName());
      hbaseAdmin.move(regionInfo.getEncodedNameAsBytes(), targetServer.getServerName());
      do {
        Thread.sleep(1);
      } while (cluster.getServerWith(regionInfo.getRegionName()) == originServerNum);

      // Put data: r2->v2
      LOG.info("Loading r2 to v2 into " + tableName);
      putDataAndVerify(table, "r2", FAMILY, "v2", 2);

      TEST_UTIL.waitUntilAllRegionsAssigned(table.getName());
      // Move region to origin server
      LOG.info("Moving " + regionInfo.getEncodedName() + " to " + originServer.getServerName());
      hbaseAdmin.move(regionInfo.getEncodedNameAsBytes(), originServer.getServerName());
      do {
        Thread.sleep(1);
      } while (cluster.getServerWith(regionInfo.getRegionName()) == targetServerNum);

      // Put data: r3->v3
      LOG.info("Loading r3 to v3 into " + tableName);
      putDataAndVerify(table, "r3", FAMILY, "v3", 3);

      // Kill target server
      LOG.info("Killing target server " + targetServer.getServerName());
      targetServer.kill();
      cluster.getRegionServerThreads().get(targetServerNum).join();
      // Wait until finish processing of shutdown
      while (master.getServerManager().areDeadServersInProgress()) {
        Thread.sleep(5);
      }
      // Kill origin server
      LOG.info("Killing origin server " + targetServer.getServerName());
      originServer.kill();
      cluster.getRegionServerThreads().get(originServerNum).join();

      // Put data: r4->v4
      LOG.info("Loading r4 to v4 into " + tableName);
      putDataAndVerify(table, "r4", FAMILY, "v4", 4);

    } finally {
      if (hbaseAdmin != null) hbaseAdmin.close();
      TEST_UTIL.shutdownMiniCluster();
    }
  }

  private void putDataAndVerify(Table table, String row, byte[] family,
      String value, int verifyNum) throws IOException {
    System.out.println("=========Putting data :" + row);
    Put put = new Put(Bytes.toBytes(row));
    put.addColumn(family, Bytes.toBytes("q1"), Bytes.toBytes(value));
    table.put(put);
    ResultScanner resultScanner = table.getScanner(new Scan());
    List<Result> results = new ArrayList<>();
    while (true) {
      Result r = resultScanner.next();
      if (r == null)
        break;
      results.add(r);
    }
    resultScanner.close();
    if (results.size() != verifyNum) {
      System.out.println(results);
    }
    assertEquals(verifyNum, results.size());
  }

}
