package org.opendaylight.controller.cluster.datastore;

import akka.actor.ActorRef;
import akka.actor.ActorSelection;
import akka.actor.ActorSystem;
import akka.actor.Props;
import akka.dispatch.Futures;
import akka.testkit.JavaTestKit;
import com.google.common.base.Optional;
import com.google.common.collect.ImmutableMap;
import com.google.common.util.concurrent.CheckedFuture;
import com.typesafe.config.Config;
import com.typesafe.config.ConfigFactory;
import org.junit.AfterClass;
import org.junit.Before;
import org.junit.BeforeClass;
import org.junit.Test;
import org.mockito.ArgumentMatcher;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;
import org.opendaylight.controller.cluster.datastore.TransactionProxy.TransactionType;
import org.opendaylight.controller.cluster.datastore.exceptions.PrimaryNotFoundException;
import org.opendaylight.controller.cluster.datastore.exceptions.TimeoutException;
import org.opendaylight.controller.cluster.datastore.messages.CloseTransaction;
import org.opendaylight.controller.cluster.datastore.messages.CreateTransaction;
import org.opendaylight.controller.cluster.datastore.messages.DataExists;
import org.opendaylight.controller.cluster.datastore.messages.DataExistsReply;
import org.opendaylight.controller.cluster.datastore.messages.DeleteData;
import org.opendaylight.controller.cluster.datastore.messages.DeleteDataReply;
import org.opendaylight.controller.cluster.datastore.messages.MergeData;
import org.opendaylight.controller.cluster.datastore.messages.MergeDataReply;
import org.opendaylight.controller.cluster.datastore.messages.ReadData;
import org.opendaylight.controller.cluster.datastore.messages.ReadDataReply;
import org.opendaylight.controller.cluster.datastore.messages.ReadyTransaction;
import org.opendaylight.controller.cluster.datastore.messages.ReadyTransactionReply;
import org.opendaylight.controller.cluster.datastore.messages.WriteData;
import org.opendaylight.controller.cluster.datastore.messages.WriteDataReply;
import org.opendaylight.controller.cluster.datastore.shardstrategy.DefaultShardStrategy;
import org.opendaylight.controller.cluster.datastore.shardstrategy.ShardStrategyFactory;
import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
import org.opendaylight.controller.cluster.datastore.utils.DoNothingActor;
import org.opendaylight.controller.cluster.datastore.utils.MockConfiguration;
import org.opendaylight.controller.md.cluster.datastore.model.TestModel;
import org.opendaylight.controller.md.sal.common.api.data.ReadFailedException;
import org.opendaylight.controller.protobuff.messages.transaction.ShardTransactionMessages.CreateTransactionReply;
import org.opendaylight.controller.sal.core.spi.data.DOMStoreThreePhaseCommitCohort;
import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNodes;
import org.opendaylight.yangtools.yang.model.api.SchemaContext;
import scala.concurrent.Await;
import scala.concurrent.Future;
import scala.concurrent.duration.Duration;
import java.io.IOException;
import java.util.List;
import java.util.concurrent.TimeUnit;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertNotNull;
import static org.junit.Assert.assertTrue;
import static org.junit.Assert.fail;
import static org.mockito.Matchers.any;
import static org.mockito.Matchers.anyString;
import static org.mockito.Mockito.argThat;
import static org.mockito.Mockito.doReturn;
import static org.mockito.Mockito.eq;
import static org.mockito.Mockito.isA;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.opendaylight.controller.cluster.datastore.TransactionProxy.TransactionType.READ_ONLY;
import static org.opendaylight.controller.cluster.datastore.TransactionProxy.TransactionType.READ_WRITE;
import static org.opendaylight.controller.cluster.datastore.TransactionProxy.TransactionType.WRITE_ONLY;

@SuppressWarnings("resource")
public class TransactionProxyTest {

    @SuppressWarnings("serial")
    static class TestException extends RuntimeException {
    }

    static interface Invoker {
        CheckedFuture<?, ReadFailedException> invoke(TransactionProxy proxy) throws Exception;
    }

    private static ActorSystem system;

    private final Configuration configuration = new MockConfiguration();

    @Mock
    private ActorContext mockActorContext;

    private SchemaContext schemaContext;

    @Mock
    private ClusterWrapper mockClusterWrapper;

    String memberName = "mock-member";

    @BeforeClass
    public static void setUpClass() throws IOException {

        Config config = ConfigFactory.parseMap(ImmutableMap.<String, Object>builder().
                put("akka.actor.default-dispatcher.type",
                        "akka.testkit.CallingThreadDispatcherConfigurator").build()).
                withFallback(ConfigFactory.load());
        system = ActorSystem.create("test", config);
    }

    @AfterClass
    public static void tearDownClass() throws IOException {
        JavaTestKit.shutdownActorSystem(system);
        system = null;
    }

    @Before
    public void setUp(){
        MockitoAnnotations.initMocks(this);

        schemaContext = TestModel.createTestContext();

        DatastoreContext dataStoreContext = DatastoreContext.newBuilder().build();

        doReturn(getSystem()).when(mockActorContext).getActorSystem();
        doReturn(memberName).when(mockActorContext).getCurrentMemberName();
        doReturn(schemaContext).when(mockActorContext).getSchemaContext();
        doReturn(mockClusterWrapper).when(mockActorContext).getClusterWrapper();
        doReturn(mockClusterWrapper).when(mockActorContext).getClusterWrapper();
        doReturn(dataStoreContext).when(mockActorContext).getDatastoreContext();

        ShardStrategyFactory.setConfiguration(configuration);
    }

    private ActorSystem getSystem() {
        return system;
    }

    private CreateTransaction eqCreateTransaction(final String memberName,
            final TransactionType type) {
        ArgumentMatcher<CreateTransaction> matcher = new ArgumentMatcher<CreateTransaction>() {
            @Override
            public boolean matches(Object argument) {
                CreateTransaction obj = CreateTransaction.fromSerializable(argument);
                return obj.getTransactionId().startsWith(memberName) &&
                       obj.getTransactionType() == type.ordinal();
            }
        };

        return argThat(matcher);
    }

    private DataExists eqSerializedDataExists() {
        ArgumentMatcher<DataExists> matcher = new ArgumentMatcher<DataExists>() {
            @Override
            public boolean matches(Object argument) {
                return DataExists.SERIALIZABLE_CLASS.equals(argument.getClass()) &&
                       DataExists.fromSerializable(argument).getPath().equals(TestModel.TEST_PATH);
            }
        };

        return argThat(matcher);
    }

    private DataExists eqDataExists() {
        ArgumentMatcher<DataExists> matcher = new ArgumentMatcher<DataExists>() {
            @Override
            public boolean matches(Object argument) {
                return (argument instanceof DataExists) &&
                    ((DataExists)argument).getPath().equals(TestModel.TEST_PATH);
            }
        };

        return argThat(matcher);
    }

    private ReadData eqSerializedReadData() {
        ArgumentMatcher<ReadData> matcher = new ArgumentMatcher<ReadData>() {
            @Override
            public boolean matches(Object argument) {
                return ReadData.SERIALIZABLE_CLASS.equals(argument.getClass()) &&
                       ReadData.fromSerializable(argument).getPath().equals(TestModel.TEST_PATH);
            }
        };

        return argThat(matcher);
    }

    private ReadData eqReadData() {
        ArgumentMatcher<ReadData> matcher = new ArgumentMatcher<ReadData>() {
            @Override
            public boolean matches(Object argument) {
                return (argument instanceof ReadData) &&
                    ((ReadData)argument).getPath().equals(TestModel.TEST_PATH);
            }
        };

        return argThat(matcher);
    }

    private WriteData eqSerializedWriteData(final NormalizedNode<?, ?> nodeToWrite) {
        ArgumentMatcher<WriteData> matcher = new ArgumentMatcher<WriteData>() {
            @Override
            public boolean matches(Object argument) {
                if(!WriteData.SERIALIZABLE_CLASS.equals(argument.getClass())) {
                    return false;
                }

                WriteData obj = WriteData.fromSerializable(argument, schemaContext);
                return obj.getPath().equals(TestModel.TEST_PATH) &&
                       obj.getData().equals(nodeToWrite);
            }
        };

        return argThat(matcher);
    }

    private WriteData eqWriteData(final NormalizedNode<?, ?> nodeToWrite) {
        ArgumentMatcher<WriteData> matcher = new ArgumentMatcher<WriteData>() {
            @Override
            public boolean matches(Object argument) {
                if(argument instanceof WriteData) {
                    WriteData obj = (WriteData) argument;
                    return obj.getPath().equals(TestModel.TEST_PATH) &&
                        obj.getData().equals(nodeToWrite);
                }
                return false;
            }
        };

        return argThat(matcher);
    }

    private MergeData eqSerializedMergeData(final NormalizedNode<?, ?> nodeToWrite) {
        ArgumentMatcher<MergeData> matcher = new ArgumentMatcher<MergeData>() {
            @Override
            public boolean matches(Object argument) {
                if(!MergeData.SERIALIZABLE_CLASS.equals(argument.getClass())) {
                    return false;
                }

                MergeData obj = MergeData.fromSerializable(argument, schemaContext);
                return obj.getPath().equals(TestModel.TEST_PATH) &&
                       obj.getData().equals(nodeToWrite);
            }
        };

        return argThat(matcher);
    }

    private MergeData eqMergeData(final NormalizedNode<?, ?> nodeToWrite) {
        ArgumentMatcher<MergeData> matcher = new ArgumentMatcher<MergeData>() {
            @Override
            public boolean matches(Object argument) {
                if(argument instanceof MergeData) {
                    MergeData obj = ((MergeData) argument);
                    return obj.getPath().equals(TestModel.TEST_PATH) &&
                        obj.getData().equals(nodeToWrite);
                }

               return false;
            }
        };

        return argThat(matcher);
    }

    private DeleteData eqSerializedDeleteData() {
        ArgumentMatcher<DeleteData> matcher = new ArgumentMatcher<DeleteData>() {
            @Override
            public boolean matches(Object argument) {
                return DeleteData.SERIALIZABLE_CLASS.equals(argument.getClass()) &&
                       DeleteData.fromSerializable(argument).getPath().equals(TestModel.TEST_PATH);
            }
        };

        return argThat(matcher);
    }

        private DeleteData eqDeleteData() {
        ArgumentMatcher<DeleteData> matcher = new ArgumentMatcher<DeleteData>() {
            @Override
            public boolean matches(Object argument) {
                return argument instanceof DeleteData &&
                    ((DeleteData)argument).getPath().equals(TestModel.TEST_PATH);
            }
        };

        return argThat(matcher);
    }

    private Future<Object> readySerializedTxReply(String path) {
        return Futures.successful((Object)new ReadyTransactionReply(path).toSerializable());
    }

    private Future<Object> readyTxReply(String path) {
        return Futures.successful((Object)new ReadyTransactionReply(path));
    }


    private Future<Object> readSerializedDataReply(NormalizedNode<?, ?> data) {
        return Futures.successful(new ReadDataReply(schemaContext, data).toSerializable());
    }

    private Future<ReadDataReply> readDataReply(NormalizedNode<?, ?> data) {
        return Futures.successful(new ReadDataReply(schemaContext, data));
    }

    private Future<Object> dataExistsSerializedReply(boolean exists) {
        return Futures.successful(new DataExistsReply(exists).toSerializable());
    }

    private Future<DataExistsReply> dataExistsReply(boolean exists) {
        return Futures.successful(new DataExistsReply(exists));
    }

    private Future<Object> writeSerializedDataReply() {
        return Futures.successful(new WriteDataReply().toSerializable());
    }

    private Future<WriteDataReply> writeDataReply() {
        return Futures.successful(new WriteDataReply());
    }

    private Future<Object> mergeSerializedDataReply() {
        return Futures.successful(new MergeDataReply().toSerializable());
    }

    private Future<MergeDataReply> mergeDataReply() {
        return Futures.successful(new MergeDataReply());
    }

    private Future<Object> deleteSerializedDataReply() {
        return Futures.successful(new DeleteDataReply().toSerializable());
    }

    private Future<DeleteDataReply> deleteDataReply() {
        return Futures.successful(new DeleteDataReply());
    }

    private ActorSelection actorSelection(ActorRef actorRef) {
        return getSystem().actorSelection(actorRef.path());
    }

    private CreateTransactionReply createTransactionReply(ActorRef actorRef){
        return CreateTransactionReply.newBuilder()
            .setTransactionActorPath(actorRef.path().toString())
            .setTransactionId("txn-1").build();
    }

    private ActorRef setupActorContextWithInitialCreateTransaction(ActorSystem actorSystem, TransactionType type) {
        ActorRef actorRef = actorSystem.actorOf(Props.create(DoNothingActor.class));
        doReturn(actorSystem.actorSelection(actorRef.path())).
                when(mockActorContext).actorSelection(actorRef.path().toString());

        doReturn(Futures.successful(actorSystem.actorSelection(actorRef.path()))).
                when(mockActorContext).findPrimaryShardAsync(eq(DefaultShardStrategy.DEFAULT_SHARD));

        doReturn(Futures.successful(createTransactionReply(actorRef))).when(mockActorContext).
                executeOperationAsync(eq(actorSystem.actorSelection(actorRef.path())),
                        eqCreateTransaction(memberName, type));

        doReturn(false).when(mockActorContext).isLocalPath(actorRef.path().toString());

        return actorRef;
    }

    private void propagateReadFailedExceptionCause(CheckedFuture<?, ReadFailedException> future)
            throws Throwable {

        try {
            future.checkedGet(5, TimeUnit.SECONDS);
            fail("Expected ReadFailedException");
        } catch(ReadFailedException e) {
            throw e.getCause();
        }
    }

    @Test
    public void testRead() throws Exception {
        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                READ_ONLY);

        doReturn(readSerializedDataReply(null)).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedReadData());

        Optional<NormalizedNode<?, ?>> readOptional = transactionProxy.read(
                TestModel.TEST_PATH).get(5, TimeUnit.SECONDS);

        assertEquals("NormalizedNode isPresent", false, readOptional.isPresent());

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

        doReturn(readSerializedDataReply(expectedNode)).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedReadData());

        readOptional = transactionProxy.read(TestModel.TEST_PATH).get(5, TimeUnit.SECONDS);

        assertEquals("NormalizedNode isPresent", true, readOptional.isPresent());

        assertEquals("Response NormalizedNode", expectedNode, readOptional.get());
    }

    @Test(expected = ReadFailedException.class)
    public void testReadWithInvalidReplyMessageType() throws Exception {
        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);

        doReturn(Futures.successful(new Object())).when(mockActorContext).
                executeOperationAsync(eq(actorSelection(actorRef)), eqSerializedReadData());

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                READ_ONLY);

        transactionProxy.read(TestModel.TEST_PATH).checkedGet(5, TimeUnit.SECONDS);
    }

    @Test(expected = TestException.class)
    public void testReadWithAsyncRemoteOperatonFailure() throws Throwable {
        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);

        doReturn(Futures.failed(new TestException())).when(mockActorContext).
                executeOperationAsync(eq(actorSelection(actorRef)), eqSerializedReadData());

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                READ_ONLY);

        propagateReadFailedExceptionCause(transactionProxy.read(TestModel.TEST_PATH));
    }

    private void testExceptionOnInitialCreateTransaction(Exception exToThrow, Invoker invoker)
            throws Throwable {
        ActorRef actorRef = getSystem().actorOf(Props.create(DoNothingActor.class));

        if (exToThrow instanceof PrimaryNotFoundException) {
            doReturn(Futures.failed(exToThrow)).when(mockActorContext).findPrimaryShardAsync(anyString());
        } else {
            doReturn(Futures.successful(getSystem().actorSelection(actorRef.path()))).
                    when(mockActorContext).findPrimaryShardAsync(anyString());
        }

        doReturn(Futures.failed(exToThrow)).when(mockActorContext).executeOperationAsync(
                any(ActorSelection.class), any());

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, READ_ONLY);

        propagateReadFailedExceptionCause(invoker.invoke(transactionProxy));
    }

    private void testReadWithExceptionOnInitialCreateTransaction(Exception exToThrow) throws Throwable {
        testExceptionOnInitialCreateTransaction(exToThrow, new Invoker() {
            @Override
            public CheckedFuture<?, ReadFailedException> invoke(TransactionProxy proxy) throws Exception {
                return proxy.read(TestModel.TEST_PATH);
            }
        });
    }

    @Test(expected = PrimaryNotFoundException.class)
    public void testReadWhenAPrimaryNotFoundExceptionIsThrown() throws Throwable {
        testReadWithExceptionOnInitialCreateTransaction(new PrimaryNotFoundException("test"));
    }

    @Test(expected = TimeoutException.class)
    public void testReadWhenATimeoutExceptionIsThrown() throws Throwable {
        testReadWithExceptionOnInitialCreateTransaction(new TimeoutException("test",
                new Exception("reason")));
    }

    @Test(expected = TestException.class)
    public void testReadWhenAnyOtherExceptionIsThrown() throws Throwable {
        testReadWithExceptionOnInitialCreateTransaction(new TestException());
    }

    @Test(expected = TestException.class)
    public void testReadWithPriorRecordingOperationFailure() throws Throwable {
        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);

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

        doReturn(writeSerializedDataReply()).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedWriteData(nodeToWrite));

        doReturn(Futures.failed(new TestException())).when(mockActorContext).
                executeOperationAsync(eq(actorSelection(actorRef)), eqSerializedDeleteData());

        doReturn(readSerializedDataReply(null)).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedReadData());

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                READ_WRITE);

        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);

        transactionProxy.delete(TestModel.TEST_PATH);

        try {
            propagateReadFailedExceptionCause(transactionProxy.read(TestModel.TEST_PATH));
        } finally {
            verify(mockActorContext, times(0)).executeOperationAsync(
                    eq(actorSelection(actorRef)), eqSerializedReadData());
        }
    }

    @Test
    public void testReadWithPriorRecordingOperationSuccessful() throws Throwable {
        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);

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

        doReturn(writeSerializedDataReply()).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedWriteData(expectedNode));

        doReturn(readSerializedDataReply(expectedNode)).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedReadData());

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                READ_WRITE);

        transactionProxy.write(TestModel.TEST_PATH, expectedNode);

        Optional<NormalizedNode<?, ?>> readOptional = transactionProxy.read(
                TestModel.TEST_PATH).get(5, TimeUnit.SECONDS);

        assertEquals("NormalizedNode isPresent", true, readOptional.isPresent());

        assertEquals("Response NormalizedNode", expectedNode, readOptional.get());
    }

    @Test(expected=IllegalStateException.class)
    public void testReadPreConditionCheck() {

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                WRITE_ONLY);

        transactionProxy.read(TestModel.TEST_PATH);
    }

    @Test(expected=IllegalArgumentException.class)
    public void testInvalidCreateTransactionReply() throws Throwable {
        ActorRef actorRef = getSystem().actorOf(Props.create(DoNothingActor.class));

        doReturn(getSystem().actorSelection(actorRef.path())).when(mockActorContext).
            actorSelection(actorRef.path().toString());

        doReturn(Futures.successful(getSystem().actorSelection(actorRef.path()))).
            when(mockActorContext).findPrimaryShardAsync(eq(DefaultShardStrategy.DEFAULT_SHARD));

        doReturn(Futures.successful(new Object())).when(mockActorContext).executeOperationAsync(
            eq(getSystem().actorSelection(actorRef.path())), eqCreateTransaction(memberName, READ_ONLY));

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, READ_ONLY);

        propagateReadFailedExceptionCause(transactionProxy.read(TestModel.TEST_PATH));
    }

    @Test
    public void testExists() throws Exception {
        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                READ_ONLY);

        doReturn(dataExistsSerializedReply(false)).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedDataExists());

        Boolean exists = transactionProxy.exists(TestModel.TEST_PATH).checkedGet();

        assertEquals("Exists response", false, exists);

        doReturn(dataExistsSerializedReply(true)).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedDataExists());

        exists = transactionProxy.exists(TestModel.TEST_PATH).checkedGet();

        assertEquals("Exists response", true, exists);
    }

    @Test(expected = PrimaryNotFoundException.class)
    public void testExistsWhenAPrimaryNotFoundExceptionIsThrown() throws Throwable {
        testExceptionOnInitialCreateTransaction(new PrimaryNotFoundException("test"), new Invoker() {
            @Override
            public CheckedFuture<?, ReadFailedException> invoke(TransactionProxy proxy) throws Exception {
                return proxy.exists(TestModel.TEST_PATH);
            }
        });
    }

    @Test(expected = ReadFailedException.class)
    public void testExistsWithInvalidReplyMessageType() throws Exception {
        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);

        doReturn(Futures.successful(new Object())).when(mockActorContext).
                executeOperationAsync(eq(actorSelection(actorRef)), eqSerializedDataExists());

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                READ_ONLY);

        transactionProxy.exists(TestModel.TEST_PATH).checkedGet(5, TimeUnit.SECONDS);
    }

    @Test(expected = TestException.class)
    public void testExistsWithAsyncRemoteOperatonFailure() throws Throwable {
        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);

        doReturn(Futures.failed(new TestException())).when(mockActorContext).
                executeOperationAsync(eq(actorSelection(actorRef)), eqSerializedDataExists());

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                READ_ONLY);

        propagateReadFailedExceptionCause(transactionProxy.exists(TestModel.TEST_PATH));
    }

    @Test(expected = TestException.class)
    public void testExistsWithPriorRecordingOperationFailure() throws Throwable {
        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);

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

        doReturn(writeSerializedDataReply()).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedWriteData(nodeToWrite));

        doReturn(Futures.failed(new TestException())).when(mockActorContext).
                executeOperationAsync(eq(actorSelection(actorRef)), eqSerializedDeleteData());

        doReturn(dataExistsSerializedReply(false)).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedDataExists());

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                READ_WRITE);

        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);

        transactionProxy.delete(TestModel.TEST_PATH);

        try {
            propagateReadFailedExceptionCause(transactionProxy.exists(TestModel.TEST_PATH));
        } finally {
            verify(mockActorContext, times(0)).executeOperationAsync(
                    eq(actorSelection(actorRef)), eqSerializedDataExists());
        }
    }

    @Test
    public void testExistsWithPriorRecordingOperationSuccessful() throws Throwable {
        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);

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

        doReturn(writeSerializedDataReply()).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedWriteData(nodeToWrite));

        doReturn(dataExistsSerializedReply(true)).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedDataExists());

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                READ_WRITE);

        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);

        Boolean exists = transactionProxy.exists(TestModel.TEST_PATH).checkedGet();

        assertEquals("Exists response", true, exists);
    }

    @Test(expected=IllegalStateException.class)
    public void testxistsPreConditionCheck() {

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                WRITE_ONLY);

        transactionProxy.exists(TestModel.TEST_PATH);
    }

    private void verifyRecordingOperationFutures(List<Future<Object>> futures,
            Class<?>... expResultTypes) throws Exception {
        assertEquals("getRecordingOperationFutures size", expResultTypes.length, futures.size());

        int i = 0;
        for( Future<Object> future: futures) {
            assertNotNull("Recording operation Future is null", future);

            Class<?> expResultType = expResultTypes[i++];
            if(Throwable.class.isAssignableFrom(expResultType)) {
                try {
                    Await.result(future, Duration.create(5, TimeUnit.SECONDS));
                    fail("Expected exception from recording operation Future");
                } catch(Exception e) {
                    // Expected
                }
            } else {
                assertEquals("Recording operation Future result type", expResultType,
                             Await.result(future, Duration.create(5, TimeUnit.SECONDS)).getClass());
            }
        }
    }

    @Test
    public void testWrite() throws Exception {
        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);

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

        doReturn(writeSerializedDataReply()).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedWriteData(nodeToWrite));

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                WRITE_ONLY);

        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);

        verify(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedWriteData(nodeToWrite));

        verifyRecordingOperationFutures(transactionProxy.getRecordedOperationFutures(),
                WriteDataReply.SERIALIZABLE_CLASS);
    }

    @Test(expected=IllegalStateException.class)
    public void testWritePreConditionCheck() {

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                READ_ONLY);

        transactionProxy.write(TestModel.TEST_PATH,
                ImmutableNodes.containerNode(TestModel.TEST_QNAME));
    }

    @Test(expected=IllegalStateException.class)
    public void testWriteAfterReadyPreConditionCheck() {

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                WRITE_ONLY);

        transactionProxy.ready();

        transactionProxy.write(TestModel.TEST_PATH,
                ImmutableNodes.containerNode(TestModel.TEST_QNAME));
    }

    @Test
    public void testMerge() throws Exception {
        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);

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

        doReturn(mergeSerializedDataReply()).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedMergeData(nodeToWrite));

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, WRITE_ONLY);

        transactionProxy.merge(TestModel.TEST_PATH, nodeToWrite);

        verify(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedMergeData(nodeToWrite));

        verifyRecordingOperationFutures(transactionProxy.getRecordedOperationFutures(),
                MergeDataReply.SERIALIZABLE_CLASS);
    }

    @Test
    public void testDelete() throws Exception {
        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);

        doReturn(deleteSerializedDataReply()).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedDeleteData());

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                WRITE_ONLY);

        transactionProxy.delete(TestModel.TEST_PATH);

        verify(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedDeleteData());

        verifyRecordingOperationFutures(transactionProxy.getRecordedOperationFutures(),
                DeleteDataReply.SERIALIZABLE_CLASS);
    }

    private void verifyCohortFutures(ThreePhaseCommitCohortProxy proxy,
        Object... expReplies) throws Exception {
        assertEquals("getReadyOperationFutures size", expReplies.length,
                proxy.getCohortFutures().size());

        int i = 0;
        for( Future<ActorSelection> future: proxy.getCohortFutures()) {
            assertNotNull("Ready operation Future is null", future);

            Object expReply = expReplies[i++];
            if(expReply instanceof ActorSelection) {
                ActorSelection actual = Await.result(future, Duration.create(5, TimeUnit.SECONDS));
                assertEquals("Cohort actor path", expReply, actual);
            } else {
                // Expecting exception.
                try {
                    Await.result(future, Duration.create(5, TimeUnit.SECONDS));
                    fail("Expected exception from ready operation Future");
                } catch(Exception e) {
                    // Expected
                }
            }
        }
    }

    @SuppressWarnings("unchecked")
    @Test
    public void testReady() throws Exception {
        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);

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

        doReturn(readSerializedDataReply(null)).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedReadData());

        doReturn(writeSerializedDataReply()).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedWriteData(nodeToWrite));

        doReturn(readySerializedTxReply(actorRef.path().toString())).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), isA(ReadyTransaction.SERIALIZABLE_CLASS));

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                READ_WRITE);

        transactionProxy.read(TestModel.TEST_PATH);

        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);

        DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();

        assertTrue(ready instanceof ThreePhaseCommitCohortProxy);

        ThreePhaseCommitCohortProxy proxy = (ThreePhaseCommitCohortProxy) ready;

        verifyRecordingOperationFutures(transactionProxy.getRecordedOperationFutures(),
                WriteDataReply.SERIALIZABLE_CLASS);

        verifyCohortFutures(proxy, getSystem().actorSelection(actorRef.path()));
    }

    @SuppressWarnings("unchecked")
    @Test
    public void testReadyWithRecordingOperationFailure() throws Exception {
        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);

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

        doReturn(mergeSerializedDataReply()).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedMergeData(nodeToWrite));

        doReturn(Futures.failed(new TestException())).when(mockActorContext).
                executeOperationAsync(eq(actorSelection(actorRef)), eqSerializedWriteData(nodeToWrite));

        doReturn(readySerializedTxReply(actorRef.path().toString())).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), isA(ReadyTransaction.SERIALIZABLE_CLASS));

        doReturn(false).when(mockActorContext).isLocalPath(actorRef.path().toString());

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                WRITE_ONLY);

        transactionProxy.merge(TestModel.TEST_PATH, nodeToWrite);

        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);

        DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();

        assertTrue(ready instanceof ThreePhaseCommitCohortProxy);

        ThreePhaseCommitCohortProxy proxy = (ThreePhaseCommitCohortProxy) ready;

        verifyCohortFutures(proxy, TestException.class);

        verifyRecordingOperationFutures(transactionProxy.getRecordedOperationFutures(),
                MergeDataReply.SERIALIZABLE_CLASS, TestException.class);
    }

    @SuppressWarnings("unchecked")
    @Test
    public void testReadyWithReplyFailure() throws Exception {
        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);

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

        doReturn(mergeSerializedDataReply()).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedMergeData(nodeToWrite));

        doReturn(Futures.failed(new TestException())).when(mockActorContext).
                executeOperationAsync(eq(actorSelection(actorRef)),
                        isA(ReadyTransaction.SERIALIZABLE_CLASS));

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                WRITE_ONLY);

        transactionProxy.merge(TestModel.TEST_PATH, nodeToWrite);

        DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();

        assertTrue(ready instanceof ThreePhaseCommitCohortProxy);

        ThreePhaseCommitCohortProxy proxy = (ThreePhaseCommitCohortProxy) ready;

        verifyRecordingOperationFutures(transactionProxy.getRecordedOperationFutures(),
                MergeDataReply.SERIALIZABLE_CLASS);

        verifyCohortFutures(proxy, TestException.class);
    }

    @Test
    public void testReadyWithInitialCreateTransactionFailure() throws Exception {

        doReturn(Futures.failed(new PrimaryNotFoundException("mock"))).when(
                mockActorContext).findPrimaryShardAsync(anyString());

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                WRITE_ONLY);

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

        transactionProxy.merge(TestModel.TEST_PATH, nodeToWrite);

        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);

        transactionProxy.delete(TestModel.TEST_PATH);

        DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();

        assertTrue(ready instanceof ThreePhaseCommitCohortProxy);

        ThreePhaseCommitCohortProxy proxy = (ThreePhaseCommitCohortProxy) ready;

        verifyCohortFutures(proxy, PrimaryNotFoundException.class);
    }

    @SuppressWarnings("unchecked")
    @Test
    public void testReadyWithInvalidReplyMessageType() throws Exception {
        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);

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

        doReturn(writeSerializedDataReply()).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedWriteData(nodeToWrite));

        doReturn(Futures.successful(new Object())).when(mockActorContext).
                executeOperationAsync(eq(actorSelection(actorRef)),
                        isA(ReadyTransaction.SERIALIZABLE_CLASS));

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                WRITE_ONLY);

        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);

        DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();

        assertTrue(ready instanceof ThreePhaseCommitCohortProxy);

        ThreePhaseCommitCohortProxy proxy = (ThreePhaseCommitCohortProxy) ready;

        verifyCohortFutures(proxy, IllegalArgumentException.class);
    }

    @Test
    public void testGetIdentifier() {
        setupActorContextWithInitialCreateTransaction(getSystem(), READ_ONLY);
        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                TransactionProxy.TransactionType.READ_ONLY);

        Object id = transactionProxy.getIdentifier();
        assertNotNull("getIdentifier returned null", id);
        assertTrue("Invalid identifier: " + id, id.toString().startsWith(memberName));
    }

    @SuppressWarnings("unchecked")
    @Test
    public void testClose() throws Exception{
        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);

        doReturn(readSerializedDataReply(null)).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(actorRef)), eqSerializedReadData());

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,
                READ_WRITE);

        transactionProxy.read(TestModel.TEST_PATH);

        transactionProxy.close();

        verify(mockActorContext).sendOperationAsync(
                eq(actorSelection(actorRef)), isA(CloseTransaction.SERIALIZABLE_CLASS));
    }


    /**
     * Method to test a local Tx actor. The Tx paths are matched to decide if the
     * Tx actor is local or not. This is done by mocking the Tx actor path
     * and the caller paths and ensuring that the paths have the remote-address format
     *
     * Note: Since the default akka provider for test is not a RemoteActorRefProvider,
     * the paths returned for the actors for all the tests are not qualified remote paths.
     * Hence are treated as non-local/remote actors. In short, all tests except
     * few below run for remote actors
     *
     * @throws Exception
     */
    @Test
    public void testLocalTxActorRead() throws Exception {
        ActorSystem actorSystem = getSystem();
        ActorRef shardActorRef = actorSystem.actorOf(Props.create(DoNothingActor.class));

        doReturn(actorSystem.actorSelection(shardActorRef.path())).
            when(mockActorContext).actorSelection(shardActorRef.path().toString());

        doReturn(Futures.successful(actorSystem.actorSelection(shardActorRef.path()))).
            when(mockActorContext).findPrimaryShardAsync(eq(DefaultShardStrategy.DEFAULT_SHARD));

        String actorPath = "akka.tcp://system@127.0.0.1:2550/user/tx-actor";
        CreateTransactionReply createTransactionReply = CreateTransactionReply.newBuilder()
            .setTransactionId("txn-1")
            .setTransactionActorPath(actorPath)
            .build();

        doReturn(Futures.successful(createTransactionReply)).when(mockActorContext).
            executeOperationAsync(eq(actorSystem.actorSelection(shardActorRef.path())),
                eqCreateTransaction(memberName, READ_ONLY));

        doReturn(true).when(mockActorContext).isLocalPath(actorPath);

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext,READ_ONLY);

        // negative test case with null as the reply
        doReturn(readDataReply(null)).when(mockActorContext).executeOperationAsync(
            any(ActorSelection.class), eqReadData());

        Optional<NormalizedNode<?, ?>> readOptional = transactionProxy.read(
            TestModel.TEST_PATH).get(5, TimeUnit.SECONDS);

        assertEquals("NormalizedNode isPresent", false, readOptional.isPresent());

        // test case with node as read data reply
        NormalizedNode<?, ?> expectedNode = ImmutableNodes.containerNode(TestModel.TEST_QNAME);

        doReturn(readDataReply(expectedNode)).when(mockActorContext).executeOperationAsync(
            any(ActorSelection.class), eqReadData());

        readOptional = transactionProxy.read(TestModel.TEST_PATH).get(5, TimeUnit.SECONDS);

        assertEquals("NormalizedNode isPresent", true, readOptional.isPresent());

        assertEquals("Response NormalizedNode", expectedNode, readOptional.get());

        // test for local data exists
        doReturn(dataExistsReply(true)).when(mockActorContext).executeOperationAsync(
            any(ActorSelection.class), eqDataExists());

        boolean exists = transactionProxy.exists(TestModel.TEST_PATH).checkedGet();

        assertEquals("Exists response", true, exists);
    }

    @Test
    public void testLocalTxActorWrite() throws Exception {
        ActorSystem actorSystem = getSystem();
        ActorRef shardActorRef = actorSystem.actorOf(Props.create(DoNothingActor.class));

        doReturn(actorSystem.actorSelection(shardActorRef.path())).
            when(mockActorContext).actorSelection(shardActorRef.path().toString());

        doReturn(Futures.successful(actorSystem.actorSelection(shardActorRef.path()))).
            when(mockActorContext).findPrimaryShardAsync(eq(DefaultShardStrategy.DEFAULT_SHARD));

        String actorPath = "akka.tcp://system@127.0.0.1:2550/user/tx-actor";
        CreateTransactionReply createTransactionReply = CreateTransactionReply.newBuilder()
            .setTransactionId("txn-1")
            .setTransactionActorPath(actorPath)
            .build();

        doReturn(Futures.successful(createTransactionReply)).when(mockActorContext).
        executeOperationAsync(eq(actorSystem.actorSelection(shardActorRef.path())),
                eqCreateTransaction(memberName, WRITE_ONLY));

        doReturn(true).when(mockActorContext).isLocalPath(actorPath);

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

        doReturn(writeDataReply()).when(mockActorContext).executeOperationAsync(
            any(ActorSelection.class), eqWriteData(nodeToWrite));

        TransactionProxy transactionProxy = new TransactionProxy(mockActorContext, WRITE_ONLY);
        transactionProxy.write(TestModel.TEST_PATH, nodeToWrite);

        verify(mockActorContext).executeOperationAsync(
            any(ActorSelection.class), eqWriteData(nodeToWrite));

        //testing local merge
        doReturn(mergeDataReply()).when(mockActorContext).executeOperationAsync(
            any(ActorSelection.class), eqMergeData(nodeToWrite));

        transactionProxy.merge(TestModel.TEST_PATH, nodeToWrite);

        verify(mockActorContext).executeOperationAsync(
            any(ActorSelection.class), eqMergeData(nodeToWrite));


        //testing local delete
        doReturn(deleteDataReply()).when(mockActorContext).executeOperationAsync(
            any(ActorSelection.class), eqDeleteData());

        transactionProxy.delete(TestModel.TEST_PATH);

        verify(mockActorContext).executeOperationAsync(any(ActorSelection.class), eqDeleteData());

        verifyRecordingOperationFutures(transactionProxy.getRecordedOperationFutures(),
            WriteDataReply.class, MergeDataReply.class, DeleteDataReply.class);

        // testing ready
        doReturn(readyTxReply(shardActorRef.path().toString())).when(mockActorContext).executeOperationAsync(
            any(ActorSelection.class), isA(ReadyTransaction.class));

        DOMStoreThreePhaseCommitCohort ready = transactionProxy.ready();

        assertTrue(ready instanceof ThreePhaseCommitCohortProxy);

        ThreePhaseCommitCohortProxy proxy = (ThreePhaseCommitCohortProxy) ready;

        verifyCohortFutures(proxy, getSystem().actorSelection(shardActorRef.path()));
    }
}