/*
 *
 *  Copyright (c) 2014 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.datastore;

import static org.junit.Assert.assertEquals;
import static org.junit.Assert.fail;
import static org.mockito.Matchers.anyObject;
import static org.mockito.Matchers.eq;
import static org.mockito.Matchers.isA;
import static org.mockito.Mockito.doReturn;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.never;
import static org.mockito.Mockito.timeout;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.opendaylight.controller.cluster.datastore.TransactionProxy.TransactionType.READ_WRITE;
import static org.opendaylight.controller.cluster.datastore.TransactionProxy.TransactionType.WRITE_ONLY;
import akka.actor.ActorRef;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;
import org.junit.Assert;
import org.junit.Test;
import org.opendaylight.controller.cluster.datastore.messages.BatchedModifications;
import org.opendaylight.controller.cluster.datastore.messages.BatchedModificationsReply;
import org.opendaylight.controller.cluster.datastore.messages.ReadyTransaction;
import org.opendaylight.controller.cluster.datastore.modification.WriteModification;
import org.opendaylight.controller.cluster.datastore.shardstrategy.DefaultShardStrategy;
import org.opendaylight.controller.cluster.datastore.utils.ActorContext;
import org.opendaylight.controller.md.cluster.datastore.model.TestModel;
import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadTransaction;
import org.opendaylight.controller.sal.core.spi.data.DOMStoreReadWriteTransaction;
import org.opendaylight.controller.sal.core.spi.data.DOMStoreTransaction;
import org.opendaylight.controller.sal.core.spi.data.DOMStoreWriteTransaction;
import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
import org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNodes;
import scala.concurrent.Promise;

public class TransactionChainProxyTest extends AbstractTransactionProxyTest {

    @SuppressWarnings("resource")
    @Test
    public void testNewReadOnlyTransaction() throws Exception {

     DOMStoreTransaction dst = new TransactionChainProxy(mockActorContext).newReadOnlyTransaction();
         Assert.assertTrue(dst instanceof DOMStoreReadTransaction);

    }

    @SuppressWarnings("resource")
    @Test
    public void testNewReadWriteTransaction() throws Exception {
        DOMStoreTransaction dst = new TransactionChainProxy(mockActorContext).newReadWriteTransaction();
        Assert.assertTrue(dst instanceof DOMStoreReadWriteTransaction);

    }

    @SuppressWarnings("resource")
    @Test
    public void testNewWriteOnlyTransaction() throws Exception {
        DOMStoreTransaction dst = new TransactionChainProxy(mockActorContext).newWriteOnlyTransaction();
        Assert.assertTrue(dst instanceof DOMStoreWriteTransaction);

    }

    @Test
    public void testClose() throws Exception {
        new TransactionChainProxy(mockActorContext).close();

        verify(mockActorContext, times(1)).broadcast(anyObject());
    }

    @Test
    public void testTransactionChainsHaveUniqueId(){
        TransactionChainProxy one = new TransactionChainProxy(mock(ActorContext.class));
        TransactionChainProxy two = new TransactionChainProxy(mock(ActorContext.class));

        Assert.assertNotEquals(one.getTransactionChainId(), two.getTransactionChainId());
    }

    @Test
    public void testRateLimitingUsedInReadWriteTxCreation(){
        TransactionChainProxy txChainProxy = new TransactionChainProxy(mockActorContext);

        txChainProxy.newReadWriteTransaction();

        verify(mockActorContext, times(1)).acquireTxCreationPermit();
    }

    @Test
    public void testRateLimitingUsedInWriteOnlyTxCreation(){
        TransactionChainProxy txChainProxy = new TransactionChainProxy(mockActorContext);

        txChainProxy.newWriteOnlyTransaction();

        verify(mockActorContext, times(1)).acquireTxCreationPermit();
    }


    @Test
    public void testRateLimitingNotUsedInReadOnlyTxCreation(){
        TransactionChainProxy txChainProxy = new TransactionChainProxy(mockActorContext);

        txChainProxy.newReadOnlyTransaction();

        verify(mockActorContext, times(0)).acquireTxCreationPermit();
    }

    /**
     * Tests 2 successive chained write-only transactions and verifies the second transaction isn't
     * initiated until the first one completes its read future.
     */
    @Test
    public void testChainedWriteOnlyTransactions() throws Exception {
        dataStoreContextBuilder.writeOnlyTransactionOptimizationsEnabled(true);

        TransactionChainProxy txChainProxy = new TransactionChainProxy(mockActorContext);

        ActorRef txActorRef1 = setupActorContextWithoutInitialCreateTransaction(getSystem());

        Promise<Object> batchedReplyPromise1 = akka.dispatch.Futures.promise();
        doReturn(batchedReplyPromise1.future()).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(txActorRef1)), isA(BatchedModifications.class));

        DOMStoreWriteTransaction writeTx1 = txChainProxy.newWriteOnlyTransaction();

        NormalizedNode<?, ?> writeNode1 = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
        writeTx1.write(TestModel.TEST_PATH, writeNode1);

        writeTx1.ready();

        verify(mockActorContext, times(1)).findPrimaryShardAsync(eq(DefaultShardStrategy.DEFAULT_SHARD));

        verifyOneBatchedModification(txActorRef1, new WriteModification(TestModel.TEST_PATH, writeNode1), true);

        ActorRef txActorRef2 = setupActorContextWithoutInitialCreateTransaction(getSystem());

        expectBatchedModifications(txActorRef2, 1);

        final NormalizedNode<?, ?> writeNode2 = ImmutableNodes.containerNode(TestModel.OUTER_LIST_QNAME);

        final DOMStoreWriteTransaction writeTx2 = txChainProxy.newWriteOnlyTransaction();

        final AtomicReference<Exception> caughtEx = new AtomicReference<>();
        final CountDownLatch write2Complete = new CountDownLatch(1);
        new Thread() {
            @Override
            public void run() {
                try {
                    writeTx2.write(TestModel.OUTER_LIST_PATH, writeNode2);
                } catch (Exception e) {
                    caughtEx.set(e);
                } finally {
                    write2Complete.countDown();
                }
            }
        }.start();

        assertEquals("Tx 2 write should've completed", true, write2Complete.await(5, TimeUnit.SECONDS));

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

        try {
            verify(mockActorContext, times(1)).findPrimaryShardAsync(eq(DefaultShardStrategy.DEFAULT_SHARD));
        } catch (AssertionError e) {
            fail("Tx 2 should not have initiated until the Tx 1's ready future completed");
        }

        batchedReplyPromise1.success(new BatchedModificationsReply(1, txActorRef1.path().toString()));

        // Tx 2 should've proceeded to find the primary shard.
        verify(mockActorContext, timeout(5000).times(2)).findPrimaryShardAsync(eq(DefaultShardStrategy.DEFAULT_SHARD));
    }

    /**
     * Tests 2 successive chained read-write transactions and verifies the second transaction isn't
     * initiated until the first one completes its read future.
     */
    @Test
    public void testChainedReadWriteTransactions() throws Exception {
        TransactionChainProxy txChainProxy = new TransactionChainProxy(mockActorContext);

        ActorRef txActorRef1 = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE);

        expectBatchedModifications(txActorRef1, 1);

        Promise<Object> readyReplyPromise1 = akka.dispatch.Futures.promise();
        doReturn(readyReplyPromise1.future()).when(mockActorContext).executeOperationAsync(
                eq(actorSelection(txActorRef1)), isA(ReadyTransaction.SERIALIZABLE_CLASS));

        DOMStoreWriteTransaction writeTx1 = txChainProxy.newReadWriteTransaction();

        NormalizedNode<?, ?> writeNode1 = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
        writeTx1.write(TestModel.TEST_PATH, writeNode1);

        writeTx1.ready();

        verifyOneBatchedModification(txActorRef1, new WriteModification(TestModel.TEST_PATH, writeNode1), false);

        String tx2MemberName = "tx2MemberName";
        doReturn(tx2MemberName).when(mockActorContext).getCurrentMemberName();
        ActorRef shardActorRef2 = setupActorContextWithoutInitialCreateTransaction(getSystem());
        ActorRef txActorRef2 = setupActorContextWithInitialCreateTransaction(getSystem(), READ_WRITE,
                DataStoreVersions.CURRENT_VERSION, tx2MemberName, shardActorRef2);

        expectBatchedModifications(txActorRef2, 1);

        final NormalizedNode<?, ?> writeNode2 = ImmutableNodes.containerNode(TestModel.OUTER_LIST_QNAME);

        final DOMStoreWriteTransaction writeTx2 = txChainProxy.newReadWriteTransaction();

        final AtomicReference<Exception> caughtEx = new AtomicReference<>();
        final CountDownLatch write2Complete = new CountDownLatch(1);
        new Thread() {
            @Override
            public void run() {
                try {
                    writeTx2.write(TestModel.OUTER_LIST_PATH, writeNode2);
                } catch (Exception e) {
                    caughtEx.set(e);
                } finally {
                    write2Complete.countDown();
                }
            }
        }.start();

        assertEquals("Tx 2 write should've completed", true, write2Complete.await(5, TimeUnit.SECONDS));

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

        try {
            verify(mockActorContext, never()).executeOperationAsync(eq(getSystem().actorSelection(shardActorRef2.path())),
                    eqCreateTransaction(tx2MemberName, READ_WRITE));
        } catch (AssertionError e) {
            fail("Tx 2 should not have initiated until the Tx 1's ready future completed");
        }

        readyReplyPromise1.success(readySerializedTxReply(txActorRef1.path().toString()).value().get().get());

        verify(mockActorContext, timeout(5000)).executeOperationAsync(eq(getSystem().actorSelection(shardActorRef2.path())),
                eqCreateTransaction(tx2MemberName, READ_WRITE));
    }

    @Test(expected=IllegalStateException.class)
    public void testChainedWriteTransactionsWithPreviousTxNotReady() throws Exception {
        ActorRef actorRef = setupActorContextWithInitialCreateTransaction(getSystem(), WRITE_ONLY);

        expectBatchedModifications(actorRef, 1);

        TransactionChainProxy txChainProxy = new TransactionChainProxy(mockActorContext);

        DOMStoreWriteTransaction writeTx1 = txChainProxy.newWriteOnlyTransaction();

        NormalizedNode<?, ?> writeNode1 = ImmutableNodes.containerNode(TestModel.TEST_QNAME);
        writeTx1.write(TestModel.TEST_PATH, writeNode1);

        NormalizedNode<?, ?> writeNode2 = ImmutableNodes.containerNode(TestModel.OUTER_LIST_QNAME);

        txChainProxy.newWriteOnlyTransaction();
    }
}