/*
 * Copyright (c) 2015 Brocade Communications 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.datastore.compat;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertTrue;
import static org.mockito.Mockito.inOrder;
import static org.opendaylight.controller.cluster.datastore.DataStoreVersions.HELIUM_2_VERSION;
import akka.actor.ActorRef;
import akka.actor.PoisonPill;
import akka.dispatch.Dispatchers;
import akka.dispatch.OnComplete;
import akka.pattern.Patterns;
import akka.testkit.TestActorRef;
import akka.util.Timeout;
import com.google.common.base.Optional;
import java.io.IOException;
import java.util.Collections;
import java.util.HashSet;
import java.util.Set;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;
import org.junit.Test;
import org.mockito.InOrder;
import org.opendaylight.controller.cluster.datastore.AbstractShardTest;
import org.opendaylight.controller.cluster.datastore.Shard;
import org.opendaylight.controller.cluster.datastore.ShardDataTree;
import org.opendaylight.controller.cluster.datastore.ShardDataTreeCohort;
import org.opendaylight.controller.cluster.datastore.ShardTestKit;
import org.opendaylight.controller.cluster.datastore.messages.CanCommitTransaction;
import org.opendaylight.controller.cluster.datastore.messages.CanCommitTransactionReply;
import org.opendaylight.controller.cluster.datastore.messages.CommitTransaction;
import org.opendaylight.controller.cluster.datastore.messages.CommitTransactionReply;
import org.opendaylight.controller.cluster.datastore.messages.ForwardedReadyTransaction;
import org.opendaylight.controller.cluster.datastore.messages.ReadyTransactionReply;
import org.opendaylight.controller.cluster.datastore.modification.MergeModification;
import org.opendaylight.controller.cluster.datastore.modification.Modification;
import org.opendaylight.controller.cluster.datastore.modification.ModificationPayload;
import org.opendaylight.controller.cluster.datastore.modification.MutableCompositeModification;
import org.opendaylight.controller.cluster.datastore.modification.WriteModification;
import org.opendaylight.controller.cluster.datastore.node.NormalizedNodeToNodeCodec;
import org.opendaylight.controller.cluster.raft.ReplicatedLogEntry;
import org.opendaylight.controller.cluster.raft.ReplicatedLogImplEntry;
import org.opendaylight.controller.cluster.raft.Snapshot;
import org.opendaylight.controller.cluster.raft.base.messages.ApplyLogEntries;
import org.opendaylight.controller.cluster.raft.base.messages.ApplyState;
import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationByteStringPayload;
import org.opendaylight.controller.cluster.raft.protobuff.client.messages.CompositeModificationPayload;
import org.opendaylight.controller.cluster.raft.utils.InMemoryJournal;
import org.opendaylight.controller.cluster.raft.utils.InMemorySnapshotStore;
import org.opendaylight.controller.md.cluster.datastore.model.TestModel;
import org.opendaylight.controller.protobuff.messages.common.NormalizedNodeMessages;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
import org.opendaylight.yangtools.yang.data.api.schema.DataContainerChild;
import org.opendaylight.yangtools.yang.data.api.schema.MapEntryNode;
import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTree;
import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNodes;
import org.opendaylight.yangtools.yang.data.impl.schema.tree.InMemoryDataTreeFactory;
import scala.concurrent.Future;
import scala.concurrent.duration.FiniteDuration;

/**
 * Unit tests for backwards compatibility with pre-Lithium versions.
 *
 * @author Thomas Pantelis
 */
public class PreLithiumShardTest extends AbstractShardTest {

    private static CompositeModificationPayload newLegacyPayload(final Modification... mods) {
        MutableCompositeModification compMod = new MutableCompositeModification();
        for(Modification mod: mods) {
            compMod.addModification(mod);
        }

        return new CompositeModificationPayload(compMod.toSerializable());
    }

    private static CompositeModificationByteStringPayload newLegacyByteStringPayload(final Modification... mods) {
        MutableCompositeModification compMod = new MutableCompositeModification();
        for(Modification mod: mods) {
            compMod.addModification(mod);
        }

        return new CompositeModificationByteStringPayload(compMod.toSerializable());
    }

    private static ModificationPayload newModificationPayload(final Modification... mods) throws IOException {
        MutableCompositeModification compMod = new MutableCompositeModification();
        for(Modification mod: mods) {
            compMod.addModification(mod);
        }

        return new ModificationPayload(compMod);
    }

    @Test
    public void testApplyHelium2VersionSnapshot() throws Exception {
        TestActorRef<Shard> shard = TestActorRef.create(getSystem(), newShardProps(),
                "testApplyHelium2VersionSnapshot");

        NormalizedNodeToNodeCodec codec = new NormalizedNodeToNodeCodec(SCHEMA_CONTEXT);

        DataTree store = InMemoryDataTreeFactory.getInstance().create();
        store.setSchemaContext(SCHEMA_CONTEXT);

        writeToStore(store, TestModel.TEST_PATH, ImmutableNodes.containerNode(TestModel.TEST_QNAME));

        YangInstanceIdentifier root = YangInstanceIdentifier.builder().build();
        NormalizedNode<?,?> expected = readStore(store, root);

        NormalizedNodeMessages.Container encode = codec.encode(expected);

        Snapshot snapshot = Snapshot.create(encode.getNormalizedNode().toByteString().toByteArray(),
                Collections.<ReplicatedLogEntry>emptyList(), 1, 2, 3, 4);

        shard.underlyingActor().getRaftActorSnapshotCohort().applySnapshot(snapshot.getState());

        NormalizedNode<?,?> actual = readStore(shard, root);

        assertEquals("Root node", expected, actual);

        shard.tell(PoisonPill.getInstance(), ActorRef.noSender());
    }

    @Test
    public void testHelium2VersionApplyStateLegacy() throws Exception {
        new ShardTestKit(getSystem()) {{
            TestActorRef<Shard> shard = TestActorRef.create(getSystem(), newShardProps(),
                    "testHelium2VersionApplyStateLegacy");

            waitUntilLeader(shard);

            NormalizedNode<?, ?> node = ImmutableNodes.containerNode(TestModel.TEST_QNAME);

            ApplyState applyState = new ApplyState(null, "test", new ReplicatedLogImplEntry(1, 2,
                    newLegacyByteStringPayload(new WriteModification(TestModel.TEST_PATH, node))));

            shard.underlyingActor().onReceiveCommand(applyState);

            NormalizedNode<?,?> actual = readStore(shard, TestModel.TEST_PATH);
            assertEquals("Applied state", node, actual);

            shard.tell(PoisonPill.getInstance(), ActorRef.noSender());
        }};
    }

    @Test
    public void testHelium2VersionRecovery() throws Exception {

        DataTree testStore = InMemoryDataTreeFactory.getInstance().create();
        testStore.setSchemaContext(SCHEMA_CONTEXT);

        writeToStore(testStore, TestModel.TEST_PATH, ImmutableNodes.containerNode(TestModel.TEST_QNAME));

        NormalizedNode<?, ?> root = readStore(testStore, YangInstanceIdentifier.builder().build());

        InMemorySnapshotStore.addSnapshot(shardID.toString(), Snapshot.create(
                new NormalizedNodeToNodeCodec(SCHEMA_CONTEXT).encode(root).
                                getNormalizedNode().toByteString().toByteArray(),
                                Collections.<ReplicatedLogEntry>emptyList(), 0, 1, -1, -1));

        InMemoryJournal.addEntry(shardID.toString(), 0, new String("Dummy data as snapshot sequence number is " +
                "set to 0 in InMemorySnapshotStore and journal recovery seq number will start from 1"));

        // Set up the InMemoryJournal.

        InMemoryJournal.addEntry(shardID.toString(), 1, new ReplicatedLogImplEntry(0, 1, newLegacyPayload(
                  new WriteModification(TestModel.OUTER_LIST_PATH,
                          ImmutableNodes.mapNodeBuilder(TestModel.OUTER_LIST_QNAME).build()))));

        int nListEntries = 16;
        Set<Integer> listEntryKeys = new HashSet<>();
        int i = 1;

        // Add some CompositeModificationPayload entries
        for(; i <= 8; i++) {
            listEntryKeys.add(Integer.valueOf(i));
            YangInstanceIdentifier path = YangInstanceIdentifier.builder(TestModel.OUTER_LIST_PATH)
                    .nodeWithKey(TestModel.OUTER_LIST_QNAME, TestModel.ID_QNAME, i).build();
            Modification mod = new MergeModification(path,
                    ImmutableNodes.mapEntry(TestModel.OUTER_LIST_QNAME, TestModel.ID_QNAME, i));
            InMemoryJournal.addEntry(shardID.toString(), i+1, new ReplicatedLogImplEntry(i, 1,
                    newLegacyPayload(mod)));
        }

        // Add some CompositeModificationByteStringPayload entries
        for(; i <= nListEntries; i++) {
            listEntryKeys.add(Integer.valueOf(i));
            YangInstanceIdentifier path = YangInstanceIdentifier.builder(TestModel.OUTER_LIST_PATH)
                    .nodeWithKey(TestModel.OUTER_LIST_QNAME, TestModel.ID_QNAME, i).build();
            Modification mod = new MergeModification(path,
                    ImmutableNodes.mapEntry(TestModel.OUTER_LIST_QNAME, TestModel.ID_QNAME, i));
            InMemoryJournal.addEntry(shardID.toString(), i+1, new ReplicatedLogImplEntry(i, 1,
                    newLegacyByteStringPayload(mod)));
        }

        InMemoryJournal.addEntry(shardID.toString(), nListEntries + 2, new ApplyLogEntries(nListEntries));

        testRecovery(listEntryKeys);
    }

    @SuppressWarnings({ "unchecked" })
    @Test
    public void testPreLithiumConcurrentThreePhaseCommits() throws Throwable {
        new ShardTestKit(getSystem()) {{
            final TestActorRef<Shard> shard = TestActorRef.create(getSystem(),
                    newShardProps().withDispatcher(Dispatchers.DefaultDispatcherId()),
                    "testPreLithiumConcurrentThreePhaseCommits");

            waitUntilLeader(shard);

            // Setup 3 simulated transactions with mock cohorts backed by real cohorts.

            ShardDataTree dataStore = shard.underlyingActor().getDataStore();

            String transactionID1 = "tx1";
            MutableCompositeModification modification1 = new MutableCompositeModification();
            ShardDataTreeCohort cohort1 = setupMockWriteTransaction("cohort1", dataStore,
                    TestModel.TEST_PATH, ImmutableNodes.containerNode(TestModel.TEST_QNAME), modification1);

            String transactionID2 = "tx2";
            MutableCompositeModification modification2 = new MutableCompositeModification();
            ShardDataTreeCohort cohort2 = setupMockWriteTransaction("cohort2", dataStore,
                    TestModel.OUTER_LIST_PATH,
                    ImmutableNodes.mapNodeBuilder(TestModel.OUTER_LIST_QNAME).build(),
                    modification2);

            String transactionID3 = "tx3";
            MutableCompositeModification modification3 = new MutableCompositeModification();
            ShardDataTreeCohort cohort3 = setupMockWriteTransaction("cohort3", dataStore,
                    YangInstanceIdentifier.builder(TestModel.OUTER_LIST_PATH)
                        .nodeWithKey(TestModel.OUTER_LIST_QNAME, TestModel.ID_QNAME, 1).build(),
                    ImmutableNodes.mapEntry(TestModel.OUTER_LIST_QNAME, TestModel.ID_QNAME, 1),
                    modification3);

            long timeoutSec = 5;
            final FiniteDuration duration = FiniteDuration.create(timeoutSec, TimeUnit.SECONDS);
            final Timeout timeout = new Timeout(duration);

            // Simulate the ForwardedReadyTransaction message for the first Tx that would be sent
            // by the ShardTransaction.

            shard.tell(new ForwardedReadyTransaction(transactionID1, HELIUM_2_VERSION,
                    cohort1, modification1, true, false), getRef());
            ReadyTransactionReply readyReply = ReadyTransactionReply.fromSerializable(
                    expectMsgClass(duration, ReadyTransactionReply.SERIALIZABLE_CLASS));
            assertEquals("Cohort path", shard.path().toString(), readyReply.getCohortPath());

            // Send the CanCommitTransaction message for the first Tx.

            shard.tell(new CanCommitTransaction(transactionID1).toSerializable(), getRef());
            CanCommitTransactionReply canCommitReply = CanCommitTransactionReply.fromSerializable(
                    expectMsgClass(duration, CanCommitTransactionReply.SERIALIZABLE_CLASS));
            assertEquals("Can commit", true, canCommitReply.getCanCommit());

            // Send the ForwardedReadyTransaction for the next 2 Tx's.

            shard.tell(new ForwardedReadyTransaction(transactionID2, HELIUM_2_VERSION,
                    cohort2, modification2, true, false), getRef());
            expectMsgClass(duration, ReadyTransactionReply.SERIALIZABLE_CLASS);

            shard.tell(new ForwardedReadyTransaction(transactionID3, HELIUM_2_VERSION,
                    cohort3, modification3, true, false), getRef());
            expectMsgClass(duration, ReadyTransactionReply.SERIALIZABLE_CLASS);

            // Send the CanCommitTransaction message for the next 2 Tx's. These should get queued and
            // processed after the first Tx completes.

            Future<Object> canCommitFuture1 = Patterns.ask(shard,
                    new CanCommitTransaction(transactionID2).toSerializable(), timeout);

            Future<Object> canCommitFuture2 = Patterns.ask(shard,
                    new CanCommitTransaction(transactionID3).toSerializable(), timeout);

            // Send the CommitTransaction message for the first Tx. After it completes, it should
            // trigger the 2nd Tx to proceed which should in turn then trigger the 3rd.

            shard.tell(new CommitTransaction(transactionID1).toSerializable(), getRef());
            expectMsgClass(duration, CommitTransactionReply.SERIALIZABLE_CLASS);

            // Wait for the next 2 Tx's to complete.

            final AtomicReference<Throwable> caughtEx = new AtomicReference<>();
            final CountDownLatch commitLatch = new CountDownLatch(2);

            class OnFutureComplete extends OnComplete<Object> {
                private final Class<?> expRespType;

                OnFutureComplete(final Class<?> expRespType) {
                    this.expRespType = expRespType;
                }

                @Override
                public void onComplete(final Throwable error, final Object resp) {
                    if(error != null) {
                        caughtEx.set(new AssertionError(getClass().getSimpleName() + " failure", error));
                    } else {
                        try {
                            assertEquals("Commit response type", expRespType, resp.getClass());
                            onSuccess(resp);
                        } catch (Exception e) {
                            caughtEx.set(e);
                        }
                    }
                }

                void onSuccess(final Object resp) throws Exception {
                }
            }

            class OnCommitFutureComplete extends OnFutureComplete {
                OnCommitFutureComplete() {
                    super(CommitTransactionReply.SERIALIZABLE_CLASS);
                }

                @Override
                public void onComplete(final Throwable error, final Object resp) {
                    super.onComplete(error, resp);
                    commitLatch.countDown();
                }
            }

            class OnCanCommitFutureComplete extends OnFutureComplete {
                private final String transactionID;

                OnCanCommitFutureComplete(final String transactionID) {
                    super(CanCommitTransactionReply.SERIALIZABLE_CLASS);
                    this.transactionID = transactionID;
                }

                @Override
                void onSuccess(final Object resp) throws Exception {
                    CanCommitTransactionReply canCommitReply =
                            CanCommitTransactionReply.fromSerializable(resp);
                    assertEquals("Can commit", true, canCommitReply.getCanCommit());

                    Future<Object> commitFuture = Patterns.ask(shard,
                            new CommitTransaction(transactionID).toSerializable(), timeout);
                    commitFuture.onComplete(new OnCommitFutureComplete(), getSystem().dispatcher());
                }
            }

            canCommitFuture1.onComplete(new OnCanCommitFutureComplete(transactionID2),
                    getSystem().dispatcher());

            canCommitFuture2.onComplete(new OnCanCommitFutureComplete(transactionID3),
                    getSystem().dispatcher());

            boolean done = commitLatch.await(timeoutSec, TimeUnit.SECONDS);

            if(caughtEx.get() != null) {
                throw caughtEx.get();
            }

            assertEquals("Commits complete", true, done);

            InOrder inOrder = inOrder(cohort1, cohort2, cohort3);
            inOrder.verify(cohort1).canCommit();
            inOrder.verify(cohort1).preCommit();
            inOrder.verify(cohort1).commit();
            inOrder.verify(cohort2).canCommit();
            inOrder.verify(cohort2).preCommit();
            inOrder.verify(cohort2).commit();
            inOrder.verify(cohort3).canCommit();
            inOrder.verify(cohort3).preCommit();
            inOrder.verify(cohort3).commit();

            // Verify data in the data store.

            NormalizedNode<?, ?> outerList = readStore(shard, TestModel.OUTER_LIST_PATH);
            assertNotNull(TestModel.OUTER_LIST_QNAME.getLocalName() + " not found", outerList);
            assertTrue(TestModel.OUTER_LIST_QNAME.getLocalName() + " value is not Iterable",
                    outerList.getValue() instanceof Iterable);
            Object entry = ((Iterable<Object>)outerList.getValue()).iterator().next();
            assertTrue(TestModel.OUTER_LIST_QNAME.getLocalName() + " entry is not MapEntryNode",
                       entry instanceof MapEntryNode);
            MapEntryNode mapEntry = (MapEntryNode)entry;
            Optional<DataContainerChild<? extends PathArgument, ?>> idLeaf =
                    mapEntry.getChild(new YangInstanceIdentifier.NodeIdentifier(TestModel.ID_QNAME));
            assertTrue("Missing leaf " + TestModel.ID_QNAME.getLocalName(), idLeaf.isPresent());
            assertEquals(TestModel.ID_QNAME.getLocalName() + " value", 1, idLeaf.get().getValue());

            verifyLastApplied(shard, 2);

            shard.tell(PoisonPill.getInstance(), ActorRef.noSender());
        }};
    }
}