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.kafka.raft;
  
  import org.apache.kafka.common.Uuid;
  import org.apache.kafka.common.network.ListenerName;
  import org.apache.kafka.common.utils.LogContext;
  import org.apache.kafka.common.utils.MockTime;
  
  import org.junit.jupiter.api.Test;
  import org.junit.jupiter.params.ParameterizedTest;
  import org.junit.jupiter.params.provider.ValueSource;
  
  import java.net.InetSocketAddress;
  import java.util.Map;
  import java.util.Optional;
  import java.util.OptionalLong;
  import java.util.Set;
  
  import static org.junit.jupiter.api.Assertions.assertEquals;
  import static org.junit.jupiter.api.Assertions.assertFalse;
  import static org.junit.jupiter.api.Assertions.assertThrows;
  import static org.junit.jupiter.api.Assertions.assertTrue;
  
  public class FollowerStateTest {
      private final MockTime time = new MockTime();
      private final LogContext logContext = new LogContext();
      private final int epoch = 5;
      private final int fetchTimeoutMs = 15000;
      private final int leaderId = 3;
      private final Endpoints leaderEndpoints = Endpoints.fromInetSocketAddresses(
          Map.of(
              ListenerName.normalised("CONTROLLER"),
              InetSocketAddress.createUnresolved("mock-host-3", 1234)
          )
      );
      private final ReplicaKey votedKey = ReplicaKey.of(2, Uuid.randomUuid());
  
      private FollowerState newFollowerState(
          Set<Integer> voters
      ) {
          return new FollowerState(
              time,
              epoch,
              leaderId,
              leaderEndpoints,
              Optional.of(votedKey),
              voters,
              Optional.empty(),
              fetchTimeoutMs,
              logContext
          );
      }
  
      @Test
      public void testFetchTimeoutExpiration() {
          FollowerState state = newFollowerState(Set.of(1, 2, 3));
  
          assertFalse(state.hasFetchTimeoutExpired(time.milliseconds()));
          assertEquals(fetchTimeoutMs, state.remainingFetchTimeMs(time.milliseconds()));
  
          time.sleep(5000);
          assertFalse(state.hasFetchTimeoutExpired(time.milliseconds()));
          assertEquals(fetchTimeoutMs - 5000, state.remainingFetchTimeMs(time.milliseconds()));
  
          time.sleep(10000);
          assertTrue(state.hasFetchTimeoutExpired(time.milliseconds()));
          assertEquals(0, state.remainingFetchTimeMs(time.milliseconds()));
      }
  
      @Test
      public void testMonotonicHighWatermark() {
          FollowerState state = newFollowerState(Set.of(1, 2, 3));
  
          OptionalLong highWatermark = OptionalLong.of(15L);
          state.updateHighWatermark(highWatermark);
          assertThrows(IllegalArgumentException.class, () -> state.updateHighWatermark(OptionalLong.empty()));
          assertThrows(IllegalArgumentException.class, () -> state.updateHighWatermark(OptionalLong.of(14L)));
          state.updateHighWatermark(highWatermark);
          assertEquals(Optional.of(new LogOffsetMetadata(15L)), state.highWatermark());
      }
  
      @ParameterizedTest
      @ValueSource(booleans = {true, false})
      public void testPreVoteIfHasNotFetchedFromLeaderYet(boolean isLogUpToDate) {
          FollowerState state = newFollowerState(Set.of(1, 2, 3));
  
          assertEquals(isLogUpToDate, state.canGrantVote(ReplicaKey.of(1, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, true));
          assertEquals(isLogUpToDate, state.canGrantVote(ReplicaKey.of(2, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, true));
          assertEquals(isLogUpToDate, state.canGrantVote(ReplicaKey.of(3, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, true));
          assertEquals(isLogUpToDate, state.canGrantVote(ReplicaKey.of(10, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, true));
      }
  
      @ParameterizedTest
      @ValueSource(booleans = {true, false})
      public void testPreVoteAfterSuccessfulFetchFromLeader(boolean isLogUpToDate) {
          FollowerState state = newFollowerState(Set.of(1, 2, 3));
          state.resetFetchTimeoutForSuccessfulFetch(time.milliseconds());
  
          assertFalse(state.canGrantVote(ReplicaKey.of(1, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, true));
          assertFalse(state.canGrantVote(ReplicaKey.of(2, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, true));
          assertFalse(state.canGrantVote(ReplicaKey.of(3, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, true));
          assertFalse(state.canGrantVote(ReplicaKey.of(10, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, true));
  
          assertFalse(state.canGrantVote(ReplicaKey.of(1, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, false));
          assertFalse(state.canGrantVote(ReplicaKey.of(2, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, false));
          assertFalse(state.canGrantVote(ReplicaKey.of(3, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, false));
          assertFalse(state.canGrantVote(ReplicaKey.of(10, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, false));
      }
  
      @ParameterizedTest
      @ValueSource(booleans = {true, false})
      public void testGrantStandardVote(boolean isLogUpToDate) {
          FollowerState state = newFollowerState(Set.of(1, 2, 3));
  
          assertFalse(state.canGrantVote(ReplicaKey.of(1, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, false));
          assertFalse(state.canGrantVote(ReplicaKey.of(2, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, false));
          assertFalse(state.canGrantVote(ReplicaKey.of(3, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, false));
          assertFalse(state.canGrantVote(ReplicaKey.of(10, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, false));
      }
  
      @Test
      public void testLeaderIdAndEndpoint() {
          FollowerState state = newFollowerState(Set.of(0, 1, 2));
  
          assertEquals(leaderId, state.leaderId());
          assertEquals(leaderEndpoints, state.leaderEndpoints());
      }
  
      @Test
      public void testHasUpdatedLeader() {
          FollowerState state = newFollowerState(Set.of(0, 1, 2));
  
          assertFalse(state.hasUpdatedLeader());
          state.setHasUpdatedLeader();
          assertTrue(state.hasUpdatedLeader());
      }
  }
  