/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with this
 * work for additional information regarding copyright ownership.  The ASF
 * licenses this file to you 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
 * <p>
 * http://www.apache.org/licenses/LICENSE-2.0
 * <p>
 * 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 org.apache.hadoop.hdds.scm.server;

import java.io.IOException;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.UUID;

import org.apache.hadoop.hdds.protocol.DatanodeDetails;
import org.apache.hadoop.hdds.protocol.proto.
    StorageContainerDatanodeProtocolProtos.CommandStatusReportsProto;
import org.apache.hadoop.hdds.scm.server.
    SCMDatanodeHeartbeatDispatcher.CommandStatusReportFromDatanode;
import org.apache.hadoop.hdds.protocol.proto
    .StorageContainerDatanodeProtocolProtos.ContainerReportsProto;
import org.apache.hadoop.hdds.protocol.proto
    .StorageContainerDatanodeProtocolProtos.NodeReportProto;
import org.apache.hadoop.hdds.protocol.proto
    .StorageContainerDatanodeProtocolProtos.SCMHeartbeatRequestProto;
import org.apache.hadoop.hdds.scm.TestUtils;
import org.apache.hadoop.hdds.scm.node.NodeManager;
import org.apache.hadoop.hdds.scm.server.SCMDatanodeHeartbeatDispatcher
    .ContainerReportFromDatanode;
import org.apache.hadoop.hdds.scm.server.SCMDatanodeHeartbeatDispatcher
    .NodeReportFromDatanode;
import org.apache.hadoop.hdds.server.events.Event;
import org.apache.hadoop.hdds.server.events.EventPublisher;
import org.apache.hadoop.ozone.protocol.commands.ReregisterCommand;

import org.junit.Assert;
import org.junit.Test;
import org.mockito.Mockito;

import static org.apache.hadoop.hdds.scm.events.SCMEvents.CONTAINER_REPORT;
import static org.apache.hadoop.hdds.scm.events.SCMEvents.NODE_REPORT;
import static org.apache.hadoop.hdds.scm.events.SCMEvents.CMD_STATUS_REPORT;

/**
 * This class tests the behavior of SCMDatanodeHeartbeatDispatcher.
 */
public class TestSCMDatanodeHeartbeatDispatcher {


  @Test
  public void testNodeReportDispatcher() throws IOException {

    AtomicInteger eventReceived = new AtomicInteger();

    NodeReportProto nodeReport = NodeReportProto.getDefaultInstance();

    NodeManager mockNodeManager = Mockito.mock(NodeManager.class);
    Mockito.when(mockNodeManager.isNodeRegistered(Mockito.any()))
        .thenReturn(true);

    SCMDatanodeHeartbeatDispatcher dispatcher =
        new SCMDatanodeHeartbeatDispatcher(mockNodeManager,
            new EventPublisher() {
          @Override
          public <PAYLOAD, EVENT_TYPE extends Event<PAYLOAD>> void fireEvent(
              EVENT_TYPE event, PAYLOAD payload) {
            Assert.assertEquals(event, NODE_REPORT);
            eventReceived.incrementAndGet();
            Assert.assertEquals(nodeReport,
                ((NodeReportFromDatanode)payload).getReport());

          }
        });

    DatanodeDetails datanodeDetails = TestUtils.randomDatanodeDetails();

    SCMHeartbeatRequestProto heartbeat =
        SCMHeartbeatRequestProto.newBuilder()
        .setDatanodeDetails(datanodeDetails.getProtoBufMessage())
        .setNodeReport(nodeReport)
        .build();
    dispatcher.dispatch(heartbeat);
    Assert.assertEquals(1, eventReceived.get());


  }

  @Test
  public void testContainerReportDispatcher() throws IOException {


    AtomicInteger eventReceived = new AtomicInteger();

    ContainerReportsProto containerReport =
        ContainerReportsProto.getDefaultInstance();
    CommandStatusReportsProto commandStatusReport =
        CommandStatusReportsProto.getDefaultInstance();

    NodeManager mockNodeManager = Mockito.mock(NodeManager.class);
    Mockito.when(mockNodeManager.isNodeRegistered(Mockito.any()))
        .thenReturn(true);

    SCMDatanodeHeartbeatDispatcher dispatcher =
        new SCMDatanodeHeartbeatDispatcher(
            mockNodeManager,
            new EventPublisher() {
          @Override
          public <PAYLOAD, EVENT_TYPE extends Event<PAYLOAD>> void fireEvent(
              EVENT_TYPE event, PAYLOAD payload) {
            Assert.assertTrue(
                event.equals(CONTAINER_REPORT)
                    || event.equals(CMD_STATUS_REPORT));

            if (payload instanceof ContainerReportFromDatanode) {
              Assert.assertEquals(containerReport,
                  ((ContainerReportFromDatanode) payload).getReport());
            }
            if (payload instanceof CommandStatusReportFromDatanode) {
              Assert.assertEquals(commandStatusReport,
                  ((CommandStatusReportFromDatanode) payload).getReport());
            }
            eventReceived.incrementAndGet();
          }
        });

    DatanodeDetails datanodeDetails = TestUtils.randomDatanodeDetails();

    SCMHeartbeatRequestProto heartbeat =
        SCMHeartbeatRequestProto.newBuilder()
            .setDatanodeDetails(datanodeDetails.getProtoBufMessage())
            .setContainerReport(containerReport)
            .addCommandStatusReports(commandStatusReport)
            .build();
    dispatcher.dispatch(heartbeat);
    Assert.assertEquals(2, eventReceived.get());


  }

  /**
   * Asserts scm informs datanodes to re-register on a restart.
   *
   * @throws Exception
   */
  @Test
  public void testScmHeartbeatAfterRestart() throws Exception {

    NodeManager mockNodeManager = Mockito.mock(NodeManager.class);
    SCMDatanodeHeartbeatDispatcher dispatcher =
        new SCMDatanodeHeartbeatDispatcher(
            mockNodeManager, Mockito.mock(EventPublisher.class));

    DatanodeDetails datanodeDetails = TestUtils.randomDatanodeDetails();

    SCMHeartbeatRequestProto heartbeat =
        SCMHeartbeatRequestProto.newBuilder()
            .setDatanodeDetails(datanodeDetails.getProtoBufMessage())
            .build();

    dispatcher.dispatch(heartbeat);
    // If SCM receives heartbeat from a node after it restarts and the node
    // is not registered, it should send a Re-Register command back to the node.
    Mockito.verify(mockNodeManager, Mockito.times(1)).addDatanodeCommand(
        Mockito.any(UUID.class), Mockito.any(ReregisterCommand.class));
  }
}