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.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.CsvSource;
  import org.junit.jupiter.params.provider.ValueSource;
  
  import java.util.Optional;
  import java.util.OptionalInt;
  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.assertTrue;
  
  public class UnattachedStateTest {
  
      private final MockTime time = new MockTime();
      private final LogContext logContext = new LogContext();
      private final int epoch = 5;
      private final int electionTimeoutMs = 10000;
      private final Set<Integer> voters = Set.of(1, 2, 3);
      private final ReplicaKey voter1Key = ReplicaKey.of(1, Uuid.randomUuid());
      private final ReplicaKey votedKey = voter1Key;
  
      private UnattachedState newUnattachedState(
          OptionalInt leaderId,
          Optional<ReplicaKey> votedKey
      ) {
          return new UnattachedState(
              time,
              epoch,
              leaderId,
              votedKey,
              voters,
              Optional.empty(),
              electionTimeoutMs,
              logContext
          );
      }
  
      @ParameterizedTest
      @CsvSource({ "true,false", "false,true", "false,false" })
      public void testElectionStateAndElectionTimeout(boolean hasVotedKey, boolean hasLeaderId) {
          OptionalInt leader = hasLeaderId ? OptionalInt.of(3) : OptionalInt.empty();
          Optional<ReplicaKey> votedKey = hasVotedKey ? Optional.of(this.votedKey) : Optional.empty();
          UnattachedState state = newUnattachedState(leader, votedKey);
  
          assertEquals(
              new ElectionState(epoch, leader, votedKey, voters),
              state.election()
          );
          assertEquals(electionTimeoutMs, state.remainingElectionTimeMs(time.milliseconds()));
          assertFalse(state.hasElectionTimeoutExpired(time.milliseconds()));
  
          time.sleep(electionTimeoutMs / 2);
          assertEquals(electionTimeoutMs / 2, state.remainingElectionTimeMs(time.milliseconds()));
          assertFalse(state.hasElectionTimeoutExpired(time.milliseconds()));
  
          time.sleep(electionTimeoutMs / 2);
          assertEquals(0, state.remainingElectionTimeMs(time.milliseconds()));
          assertTrue(state.hasElectionTimeoutExpired(time.milliseconds()));
      }
  
      @ParameterizedTest
      @ValueSource(booleans = {true, false})
      public void testGrantVoteWithoutVotedKey(boolean isLogUpToDate) {
          UnattachedState state = newUnattachedState(OptionalInt.empty(), Optional.empty());
  
          assertEquals(
              isLogUpToDate,
              state.canGrantVote(voter1Key, isLogUpToDate, true)
          );
          assertEquals(
              isLogUpToDate,
              state.canGrantVote(voter1Key, isLogUpToDate, false)
          );
  
          assertEquals(
              isLogUpToDate,
              state.canGrantVote(ReplicaKey.of(2, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, true)
          );
          assertEquals(
              isLogUpToDate,
              state.canGrantVote(ReplicaKey.of(2, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, false)
          );
  
          assertEquals(
              isLogUpToDate,
              state.canGrantVote(ReplicaKey.of(3, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, true)
          );
          assertEquals(
              isLogUpToDate,
              state.canGrantVote(ReplicaKey.of(3, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, false)
          );
  
          assertEquals(
              isLogUpToDate,
              state.canGrantVote(ReplicaKey.of(10, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, true)
          );
          assertEquals(
              isLogUpToDate,
              state.canGrantVote(ReplicaKey.of(10, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, false)
          );
      }
  
      @ParameterizedTest
      @ValueSource(booleans = {true, false})
      public void testCanGrantVoteWithVotedKey(boolean isLogUpToDate) {
          UnattachedState state = newUnattachedState(OptionalInt.empty(), Optional.of(votedKey));
  
          // Same voterKey
          // Local can reject PreVote for a replica that local has already granted a standard vote to if their log is behind
          assertEquals(
              isLogUpToDate,
              state.canGrantVote(votedKey, isLogUpToDate, true)
          );
          assertTrue(state.canGrantVote(votedKey, isLogUpToDate, false));
  
          // Different directoryId
          // Local can grant PreVote for a replica that local has already granted a standard vote to if their log is up-to-date,
          // even if the directoryId is different
          assertEquals(
              isLogUpToDate,
              state.canGrantVote(ReplicaKey.of(votedKey.id(), Uuid.randomUuid()), isLogUpToDate, true)
          );
          assertFalse(state.canGrantVote(ReplicaKey.of(votedKey.id(), Uuid.randomUuid()), isLogUpToDate, false));
  
          // Missing directoryId
          assertEquals(
              isLogUpToDate,
              state.canGrantVote(ReplicaKey.of(votedKey.id(), ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, true)
          );
          assertFalse(state.canGrantVote(ReplicaKey.of(votedKey.id(), ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, false));
  
          // Different voterId
          assertEquals(
              isLogUpToDate,
              state.canGrantVote(ReplicaKey.of(2, votedKey.directoryId().get()), isLogUpToDate, true)
          );
          assertEquals(
              isLogUpToDate,
              state.canGrantVote(ReplicaKey.of(2, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, true)
          );
          assertFalse(state.canGrantVote(ReplicaKey.of(2, votedKey.directoryId().get()), isLogUpToDate, false));
          assertFalse(state.canGrantVote(ReplicaKey.of(2, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, false));
  
          // Observer
          assertEquals(
              isLogUpToDate,
              state.canGrantVote(ReplicaKey.of(10, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, true)
          );
          assertFalse(state.canGrantVote(ReplicaKey.of(10, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, false));
      }
  
      @ParameterizedTest
      @ValueSource(booleans = {true, false})
      void testGrantVoteWithLeader(boolean isLogUpToDate) {
          int leaderId = 3;
          UnattachedState state = newUnattachedState(OptionalInt.of(leaderId), Optional.empty());
  
          // Check that the leader is persisted if the leader is known
          assertEquals(ElectionState.withElectedLeader(epoch, leaderId, Optional.empty(), voters), state.election());
  
          // Check that the replica can grant PreVotes if the log is up-to-date, even if the last leader is known
          // This is because nodes in Unattached have not successfully fetched from the leader yet
          assertEquals(
              isLogUpToDate,
              state.canGrantVote(voter1Key, isLogUpToDate, true)
          );
          assertEquals(
              isLogUpToDate,
              state.canGrantVote(ReplicaKey.of(2, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, true)
          );
          assertEquals(
              isLogUpToDate,
              state.canGrantVote(ReplicaKey.of(leaderId, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, true)
          );
          assertEquals(
              isLogUpToDate,
              state.canGrantVote(ReplicaKey.of(10, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, true)
          );
  
          // Check that the replica rejects all standard votes request if the leader is known
          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(leaderId, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, false));
          assertFalse(state.canGrantVote(ReplicaKey.of(10, ReplicaKey.NO_DIRECTORY_ID), isLogUpToDate, false));
      }
  
      @Test
      public void testLeaderEndpoints() {
          UnattachedState state = newUnattachedState(OptionalInt.of(3), Optional.of(this.votedKey));
  
          assertEquals(Endpoints.empty(), state.leaderEndpoints());
      }
  }
  