/*
 * Copyright (c) 2016 Cisco Systems, Inc. and others.  All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
 * and is available at http://www.eclipse.org/legal/epl-v10.html
 */

package org.opendaylight.controller.cluster.sharding;

import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;

import akka.actor.ActorRef;
import akka.actor.ActorSystem;
import akka.actor.Address;
import akka.actor.AddressFromURIString;
import akka.cluster.Cluster;
import akka.testkit.JavaTestKit;
import com.google.common.collect.Lists;
import com.typesafe.config.ConfigFactory;
import java.util.Collections;
import org.junit.After;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Ignore;
import org.junit.Test;
import org.mockito.Mockito;
import org.opendaylight.controller.cluster.datastore.AbstractTest;
import org.opendaylight.controller.cluster.datastore.DatastoreContext;
import org.opendaylight.controller.cluster.datastore.DatastoreContext.Builder;
import org.opendaylight.controller.cluster.datastore.DistributedDataStore;
import org.opendaylight.controller.cluster.datastore.IntegrationTestKit;
import org.opendaylight.controller.cluster.datastore.messages.FindLocalShard;
import org.opendaylight.controller.cluster.datastore.messages.FindPrimary;
import org.opendaylight.controller.cluster.datastore.messages.LocalPrimaryShardFound;
import org.opendaylight.controller.cluster.datastore.messages.LocalShardFound;
import org.opendaylight.controller.cluster.datastore.messages.RemotePrimaryShardFound;
import org.opendaylight.controller.cluster.datastore.utils.ClusterUtils;
import org.opendaylight.controller.cluster.raft.policy.DisableElectionsRaftPolicy;
import org.opendaylight.controller.md.cluster.datastore.model.SchemaContextHelper;
import org.opendaylight.controller.md.cluster.datastore.model.TestModel;
import org.opendaylight.mdsal.common.api.LogicalDatastoreType;
import org.opendaylight.mdsal.dom.api.DOMDataTreeCursorAwareTransaction;
import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
import org.opendaylight.mdsal.dom.api.DOMDataTreeProducer;
import org.opendaylight.mdsal.dom.api.DOMDataTreeShardingConflictException;
import org.opendaylight.mdsal.dom.api.DOMDataTreeWriteCursor;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.NodeIdentifier;
import org.opendaylight.yangtools.yang.data.impl.schema.builder.impl.ImmutableLeafNodeBuilder;

public class DistributedShardedDOMDataTreeTest extends AbstractTest {

    private static final Address MEMBER_1_ADDRESS =
            AddressFromURIString.parse("akka://cluster-test@127.0.0.1:2558");

    private static final DOMDataTreeIdentifier TEST_ID =
            new DOMDataTreeIdentifier(LogicalDatastoreType.CONFIGURATION, TestModel.TEST_PATH);

    private ActorSystem leaderSystem;
    private ActorSystem followerSystem;


    private final Builder leaderDatastoreContextBuilder =
            DatastoreContext.newBuilder().shardHeartbeatIntervalInMillis(100).shardElectionTimeoutFactor(2);

    private final DatastoreContext.Builder followerDatastoreContextBuilder =
            DatastoreContext.newBuilder().shardHeartbeatIntervalInMillis(100).shardElectionTimeoutFactor(5)
                    .customRaftPolicyImplementation(DisableElectionsRaftPolicy.class.getName());

    private DistributedDataStore followerDistributedDataStore;
    private DistributedDataStore leaderDistributedDataStore;
    private IntegrationTestKit followerTestKit;
    private IntegrationTestKit leaderTestKit;

    private DistributedShardedDOMDataTree leaderShardFactory;
    private DistributedShardedDOMDataTree followerShardFactory;

    @Before
    public void setUp() {
        leaderSystem = ActorSystem.create("cluster-test", ConfigFactory.load().getConfig("Member1"));
        Cluster.get(leaderSystem).join(MEMBER_1_ADDRESS);

        followerSystem = ActorSystem.create("cluster-test", ConfigFactory.load().getConfig("Member2"));
        Cluster.get(followerSystem).join(MEMBER_1_ADDRESS);
    }

    @After
    public void tearDown() {
        if (followerDistributedDataStore != null) {
            leaderDistributedDataStore.close();
        }
        if (leaderDistributedDataStore != null) {
            leaderDistributedDataStore.close();
        }

        JavaTestKit.shutdownActorSystem(leaderSystem);
        JavaTestKit.shutdownActorSystem(followerSystem);
    }

    private void initEmptyDatastore(final String type) {
        leaderTestKit = new IntegrationTestKit(leaderSystem, leaderDatastoreContextBuilder);

        leaderDistributedDataStore =
                leaderTestKit.setupDistributedDataStoreWithoutConfig(type, SchemaContextHelper.full());

        followerTestKit = new IntegrationTestKit(followerSystem, followerDatastoreContextBuilder);
        followerDistributedDataStore =
                followerTestKit.setupDistributedDataStoreWithoutConfig(type, SchemaContextHelper.full());

        leaderShardFactory = new DistributedShardedDOMDataTree(leaderSystem,
                Mockito.mock(DistributedDataStore.class),
                leaderDistributedDataStore);

        followerShardFactory = new DistributedShardedDOMDataTree(followerSystem,
                Mockito.mock(DistributedDataStore.class),
                followerDistributedDataStore);
    }

    @Test
    public void testProducerRegistrations() throws Exception {
        initEmptyDatastore("config");

        leaderShardFactory.createDistributedShard(TEST_ID,
                Lists.newArrayList(AbstractTest.MEMBER_NAME, AbstractTest.MEMBER_2_NAME));

        leaderTestKit.waitUntilLeader(leaderDistributedDataStore.getActorContext(),
                ClusterUtils.getCleanShardName(TEST_ID.getRootIdentifier()));

        final ActorRef leaderShardManager = leaderDistributedDataStore.getActorContext().getShardManager();

        leaderShardManager.tell(
                new FindLocalShard(ClusterUtils.getCleanShardName(TestModel.TEST_PATH), true), leaderTestKit.getRef());
        leaderTestKit.expectMsgClass(JavaTestKit.duration("10 seconds"), LocalShardFound.class);

        IntegrationTestKit.findLocalShard(followerDistributedDataStore.getActorContext(),
                ClusterUtils.getCleanShardName(TEST_ID.getRootIdentifier()));

        leaderShardManager.tell(
                new FindPrimary(ClusterUtils.getCleanShardName(TestModel.TEST_PATH), true), leaderTestKit.getRef());
        leaderTestKit.expectMsgClass(JavaTestKit.duration("10 seconds"), LocalPrimaryShardFound.class);

        final ActorRef followerShardManager = followerDistributedDataStore.getActorContext().getShardManager();
        followerShardManager.tell(
                new FindPrimary(ClusterUtils.getCleanShardName(TestModel.TEST_PATH), true), followerTestKit.getRef());
        followerTestKit.expectMsgClass(JavaTestKit.duration("10 seconds"), RemotePrimaryShardFound.class);

        final DOMDataTreeProducer producer = leaderShardFactory.createProducer(Collections.singleton(TEST_ID));
        try {
            followerShardFactory.createProducer(Collections.singleton(TEST_ID));
            fail("Producer should be already registered on the other node");
        } catch (final IllegalArgumentException e) {
            assertTrue(e.getMessage().contains("is attached to producer"));
        }

        producer.close();

        final DOMDataTreeProducer followerProducer =
                followerShardFactory.createProducer(Collections.singleton(TEST_ID));
        try {
            leaderShardFactory.createProducer(Collections.singleton(TEST_ID));
            fail("Producer should be already registered on the other node");
        } catch (final IllegalArgumentException e) {
            assertTrue(e.getMessage().contains("is attached to producer"));
        }

        followerProducer.close();
        // try to create a shard on an already registered prefix on follower
        try {
            followerShardFactory.createDistributedShard(TEST_ID,
                    Lists.newArrayList(AbstractTest.MEMBER_NAME, AbstractTest.MEMBER_2_NAME));
            fail("This prefix already should have a shard registration that was forwarded from the other node");
        } catch (final DOMDataTreeShardingConflictException e) {
            assertTrue(e.getMessage().contains("is already occupied by shard"));
        }
    }

    @Test
    @Ignore("Needs some other stuff related to 5280")
    public void testWriteIntoMultipleShards() throws Exception {
        initEmptyDatastore("config");

        leaderShardFactory.createDistributedShard(TEST_ID,
                Lists.newArrayList(AbstractTest.MEMBER_NAME, AbstractTest.MEMBER_2_NAME));

        leaderTestKit.waitUntilLeader(leaderDistributedDataStore.getActorContext(),
                ClusterUtils.getCleanShardName(TEST_ID.getRootIdentifier()));

        final ActorRef leaderShardManager = leaderDistributedDataStore.getActorContext().getShardManager();

        new JavaTestKit(leaderSystem) {
            {
                leaderShardManager.tell(
                        new FindLocalShard(ClusterUtils.getCleanShardName(TestModel.TEST_PATH), true), getRef());
                expectMsgClass(duration("5 seconds"), LocalShardFound.class);

                final ActorRef followerShardManager = followerDistributedDataStore.getActorContext().getShardManager();

                followerShardManager.tell(
                        new FindLocalShard(ClusterUtils.getCleanShardName(TestModel.TEST_PATH), true), getRef());
                expectMsgClass(duration("5 seconds"), LocalShardFound.class);

                leaderDistributedDataStore.getActorContext().getShardManager().tell(
                        new FindPrimary(ClusterUtils.getCleanShardName(TestModel.TEST_PATH), true), getRef());
                expectMsgClass(duration("5 seconds"), LocalPrimaryShardFound.class);
            }
        };

        final DOMDataTreeProducer producer = leaderShardFactory.createProducer(Collections.singleton(TEST_ID));

        final DOMDataTreeCursorAwareTransaction tx = producer.createTransaction(true);
        final DOMDataTreeWriteCursor cursor = tx.createCursor(TEST_ID);
        Assert.assertNotNull(cursor);
        final YangInstanceIdentifier nameId =
                YangInstanceIdentifier.builder(TestModel.TEST_PATH).node(TestModel.NAME_QNAME).build();
        cursor.write(nameId.getLastPathArgument(),
                ImmutableLeafNodeBuilder.<String>create()
                        .withNodeIdentifier(new NodeIdentifier(TestModel.NAME_QNAME)).withValue("Test Value").build());

        cursor.close();
        tx.submit();


    }
}