content: /*
   * 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.bifromq.basekv.store;
  
  import static org.awaitility.Awaitility.await;
  import static org.testng.Assert.assertTrue;
  import static org.testng.Assert.fail;
  
  import org.apache.bifromq.basekv.proto.KVRangeId;
  import org.apache.bifromq.basekv.raft.exception.LeaderTransferException;
  import org.apache.bifromq.basekv.store.exception.KVRangeException;
  import java.util.concurrent.TimeUnit;
  import lombok.extern.slf4j.Slf4j;
  import org.testng.annotations.Test;
  
  @Slf4j
  public class KVRangeStoreTransferLeadershipTest extends KVRangeStoreClusterTestTemplate {
  
      @Test(groups = "integration")
      public void testRequestTransferLeadershipFromLeaderStore() {
          KVRangeId rangeId = cluster.genesisKVRangeId();
          await().until(() -> {
              KVRangeConfig settings = cluster.kvRangeSetting(rangeId);
              return settings != null && settings.ver >= 2;
          });
          KVRangeConfig rangeSettings = cluster.kvRangeSetting(rangeId);
          String oldLeader = rangeSettings.leader;
          String newLeader = nonLeaderStore(rangeSettings);
          await().ignoreExceptions().until(() -> {
              KVRangeConfig setting = cluster.kvRangeSetting(rangeId);
              if (setting.leader.equals(newLeader)) {
                  return true;
              }
              cluster.transferLeader(oldLeader, setting.ver, rangeId, newLeader)
                  .toCompletableFuture()
                  .orTimeout(30, TimeUnit.SECONDS)
                  .join();
              setting = cluster.kvRangeSetting(rangeId);
              return setting.leader.equals(newLeader);
          });
      }
  
      @Test(groups = "integration")
      public void testTransferLeadershipToFakeLeader() {
          KVRangeId rangeId = cluster.genesisKVRangeId();
          KVRangeConfig rangeSetting = cluster.kvRangeSetting(rangeId);
          String oldLeader = rangeSetting.leader;
  
          try {
              cluster.transferLeader(oldLeader, rangeSetting.ver, rangeId, "FakeLeader")
                  .toCompletableFuture()
                  .orTimeout(30, TimeUnit.SECONDS)
                  .join();
              fail();
          } catch (Throwable e) {
              assertTrue(e.getCause() instanceof KVRangeException.BadRequest);
          }
      }
  
      @Test(groups = "integration")
      public void testTransferLeadershipToSelf() {
          KVRangeId rangeId = cluster.genesisKVRangeId();
          await().until(() -> {
              KVRangeConfig settings = cluster.kvRangeSetting(rangeId);
              return settings != null && settings.ver >= 2;
          });
          await().ignoreExceptions().until(() -> {
              KVRangeConfig rangeSettings = cluster.kvRangeSetting(rangeId);
              try {
                  cluster.transferLeader(rangeSettings.leader, rangeSettings.ver, rangeId, rangeSettings.leader)
                      .toCompletableFuture().join();
              } catch (Throwable e) {
                  return e.getCause().getCause() instanceof LeaderTransferException.SelfTransferException;
              }
              KVRangeConfig newRangeSettings = cluster.kvRangeSetting(rangeId);
              return newRangeSettings.leader.equals(rangeSettings.leader);
          });
      }
  
      @Test(groups = "integration")
      public void testTransferLeadershipConcurrently() {
          KVRangeId rangeId = cluster.genesisKVRangeId();
          await().until(() -> {
              KVRangeConfig setting = cluster.kvRangeSetting(rangeId);
              return setting != null && setting.ver >= 2;
          });
          KVRangeConfig rangeSettings = cluster.kvRangeSetting(rangeId);
          String oldLeader = rangeSettings.leader;
          String newLeader = nonLeaderStore(rangeSettings);
  
          await().ignoreExceptions().until(() -> {
              KVRangeConfig setting = cluster.kvRangeSetting(rangeId);
              if (setting.leader.equals(newLeader)) {
                  return true;
              }
              cluster.transferLeader(oldLeader, setting.ver, rangeId, newLeader).toCompletableFuture().join();
              setting = cluster.kvRangeSetting(rangeId);
              return setting.leader.equals(newLeader);
          });
          // transfer back
          await().ignoreExceptions().until(() -> {
              KVRangeConfig setting = cluster.kvRangeSetting(rangeId);
              if (setting.leader.equals(oldLeader)) {
                  return true;
              }
              cluster.transferLeader(newLeader, setting.ver, rangeId, oldLeader).toCompletableFuture().join();
              setting = cluster.kvRangeSetting(rangeId);
              return setting.leader.equals(oldLeader);
          });
      }
  }
  