/*
 * Copyright (c) 2008-2017, Hazelcast, Inc. All Rights Reserved.
 *
 * Licensed 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 com.hazelcast.internal.cluster.impl;

import com.hazelcast.cluster.ClusterState;
import com.hazelcast.config.Config;
import com.hazelcast.config.ServiceConfig;
import com.hazelcast.core.HazelcastInstance;
import com.hazelcast.instance.Node;
import com.hazelcast.internal.partition.InternalPartition;
import com.hazelcast.internal.partition.InternalPartitionService;
import com.hazelcast.nio.Address;
import com.hazelcast.spi.MigrationAwareService;
import com.hazelcast.spi.Operation;
import com.hazelcast.spi.PartitionMigrationEvent;
import com.hazelcast.spi.PartitionReplicationEvent;
import com.hazelcast.test.AssertTask;
import com.hazelcast.test.HazelcastParallelClassRunner;
import com.hazelcast.test.HazelcastTestSupport;
import com.hazelcast.test.TestHazelcastInstanceFactory;
import com.hazelcast.test.annotation.ParallelTest;
import com.hazelcast.test.annotation.QuickTest;
import org.junit.Test;
import org.junit.experimental.categories.Category;
import org.junit.runner.RunWith;

import java.util.List;
import java.util.concurrent.atomic.AtomicReference;

import static com.hazelcast.instance.TestUtil.terminateInstance;
import static com.hazelcast.internal.cluster.impl.AdvancedClusterStateTest.changeClusterStateEventually;
import static org.hamcrest.Matchers.empty;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertThat;

@RunWith(HazelcastParallelClassRunner.class)
@Category({QuickTest.class, ParallelTest.class})
public class NoMigrationClusterStateTest extends HazelcastTestSupport {

    private final NoReplicationService service = new NoReplicationService();

    @Test
    public void rebalancing_shouldNotHappen_whenMemberLeaves() {
        Config config = newConfigWithMigrationAwareService();
        TestHazelcastInstanceFactory factory = createHazelcastInstanceFactory();
        HazelcastInstance[] instances = factory.newInstances(config, 3);
        warmUpPartitions(instances);
        waitAllForSafeState(instances);

        changeClusterStateEventually(instances[1], ClusterState.NO_MIGRATION);
        terminateInstance(instances[0]);

        final HazelcastInstance hz = factory.newHazelcastInstance(config);

        assertTrueAllTheTime(new AssertTask() {
            final Node node = getNode(hz);
            final InternalPartitionService partitionService = node.getPartitionService();

            @Override
            public void run() throws Exception {
                List<Integer> memberPartitions = partitionService.getMemberPartitions(node.getThisAddress());
                assertThat(memberPartitions, empty());
                service.assertNoReplication();
            }
        }, 10);
    }

    @Test
    public void promotions_shouldHappen_whenMemberLeaves() {
        TestHazelcastInstanceFactory factory = createHazelcastInstanceFactory();
        HazelcastInstance[] instances = factory.newInstances(new Config(), 3);
        warmUpPartitions(instances);
        waitAllForSafeState(instances);

        changeClusterStateEventually(instances[1], ClusterState.NO_MIGRATION);
        terminateInstance(instances[0]);

        assertClusterSizeEventually(2, instances[1]);
        assertAllPartitionsAreAssigned(instances[1], 1);

        assertClusterSizeEventually(2, instances[2]);
        assertAllPartitionsAreAssigned(instances[2], 1);
    }

    private static void assertAllPartitionsAreAssigned(HazelcastInstance instance, final int replicaCount) {
        final ClusterServiceImpl clusterService = getNode(instance).getClusterService();
        final InternalPartitionService partitionService = getNode(instance).getPartitionService();

        assertTrueEventually(new AssertTask() {
            @Override
            public void run() throws Exception {
                InternalPartition[] partitions = partitionService.getInternalPartitions();
                for (InternalPartition partition : partitions) {
                    for (int i = 0; i < replicaCount; i++) {
                        Address owner = partition.getReplicaAddress(i);
                        assertNotNull(i + "th replica owner is null: " + partition, owner);
                        assertNotNull("No member for: " + owner, clusterService.getMember(owner));
                    }
                }
            }
        });
    }

    @Test
    public void backupReplication_shouldNotHappen_whenMemberLeaves() {
        Config config = newConfigWithMigrationAwareService();
        TestHazelcastInstanceFactory factory = createHazelcastInstanceFactory();
        HazelcastInstance[] instances = factory.newInstances(config, 3);
        warmUpPartitions(instances);
        waitAllForSafeState(instances);

        changeClusterStateEventually(instances[1], ClusterState.NO_MIGRATION);
        terminateInstance(instances[0]);

        assertClusterSizeEventually(2, instances[1], instances[2]);

        assertTrueAllTheTime(new AssertTask() {
            @Override
            public void run() throws Exception {
                service.assertNoReplication();
            }
        }, 10);
    }

    @Test
    public void rebalancing_shouldHappen_whenStateBecomesActive() {
        TestHazelcastInstanceFactory factory = createHazelcastInstanceFactory();
        HazelcastInstance[] instances = factory.newInstances(new Config(), 3);
        warmUpPartitions(instances);
        waitAllForSafeState(instances);

        changeClusterStateEventually(instances[1], ClusterState.NO_MIGRATION);
        terminateInstance(instances[0]);

        assertClusterSizeEventually(2, instances[1], instances[2]);

        changeClusterStateEventually(instances[1], ClusterState.ACTIVE);
        assertAllPartitionsAreAssigned(instances[1], 2);
        assertAllPartitionsAreAssigned(instances[2], 2);
    }

    @Test
    public void rebalancing_shouldNotHappen_whenStateBecomesFrozen() {
        TestHazelcastInstanceFactory factory = createHazelcastInstanceFactory();
        HazelcastInstance[] instances = factory.newInstances(newConfigWithMigrationAwareService(), 3);
        warmUpPartitions(instances);
        waitAllForSafeState(instances);

        changeClusterStateEventually(instances[1], ClusterState.NO_MIGRATION);
        terminateInstance(instances[0]);

        assertClusterSizeEventually(2, instances[1], instances[2]);

        changeClusterStateEventually(instances[1], ClusterState.FROZEN);

        assertTrueAllTheTime(new AssertTask() {
            @Override
            public void run() throws Exception {
                service.assertNoReplication();
            }
        }, 10);
    }

    private Config newConfigWithMigrationAwareService() {
        Config config = new Config();
        config.getServicesConfig().addServiceConfig(new ServiceConfig()
                .setEnabled(true)
                .setName("no-replication-service")
                .setImplementation(service));
        return config;
    }

    private static class NoReplicationService implements MigrationAwareService {

        private final AtomicReference<AssertionError> replicationRequested = new AtomicReference<AssertionError>();

        @Override
        public Operation prepareReplicationOperation(PartitionReplicationEvent event) {
            AssertionError error = new AssertionError("Replication requested: " + event);
            replicationRequested.compareAndSet(null, error);
            throw error;
        }

        @Override
        public void beforeMigration(PartitionMigrationEvent event) {
        }

        @Override
        public void commitMigration(PartitionMigrationEvent event) {
        }

        @Override
        public void rollbackMigration(PartitionMigrationEvent event) {
        }

        void assertNoReplication() {
            AssertionError error = replicationRequested.get();
            if (error != null) {
                throw error;
            }
        }
    }
}