/**
 * 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
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * 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.ambari.server.actionmanager;

import static org.junit.Assert.assertFalse;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.assertTrue;
import static org.mockito.Matchers.anyString;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.when;

import java.util.ArrayList;
import java.util.List;

import junit.framework.Assert;

import org.apache.ambari.server.Role;
import org.apache.ambari.server.actionmanager.ActionScheduler.RoleStats;
import org.apache.ambari.server.agent.ActionQueue;
import org.apache.ambari.server.agent.AgentCommand;
import org.apache.ambari.server.agent.ExecutionCommand;
import org.apache.ambari.server.controller.HostsMap;
import org.apache.ambari.server.state.Cluster;
import org.apache.ambari.server.state.Clusters;
import org.apache.ambari.server.state.Service;
import org.apache.ambari.server.state.ServiceComponent;
import org.apache.ambari.server.state.ServiceComponentHost;
import org.apache.ambari.server.utils.StageUtils;
import org.apache.ambari.server.utils.TestStageUtils;
import org.junit.Test;

public class TestActionScheduler {

  /**
   * This test sends a new action to the action scheduler and verifies that the action
   * shows up in the action queue.
   */
  @Test
  public void testActionSchedule() throws Exception {
    ActionQueue aq = new ActionQueue();
    Clusters fsm = mock(Clusters.class);
    Cluster oneClusterMock = mock(Cluster.class);
    Service serviceObj = mock(Service.class);
    ServiceComponent scomp = mock(ServiceComponent.class);
    ServiceComponentHost sch = mock(ServiceComponentHost.class);
    when(fsm.getCluster(anyString())).thenReturn(oneClusterMock);
    when(oneClusterMock.getService(anyString())).thenReturn(serviceObj);
    when(serviceObj.getServiceComponent(anyString())).thenReturn(scomp);
    when(scomp.getServiceComponentHost(anyString())).thenReturn(sch);
    when(serviceObj.getCluster()).thenReturn(oneClusterMock);

    ActionDBAccessor db = mock(ActionDBAccessorImpl.class);
    List<Stage> stages = new ArrayList<Stage>();
    String hostname = "ahost.ambari.apache.org";
    Stage s = StageUtils.getATestStage(1, 977, hostname);
    stages.add(s);
    when(db.getStagesInProgress()).thenReturn(stages);

    //Keep large number of attempts so that the task is not expired finally
    //Small action timeout to test rescheduling
    ActionScheduler scheduler = new ActionScheduler(100, 100, db, aq, fsm,
        10000, new HostsMap((String) null));
    scheduler.setTaskTimeoutAdjustment(false);
    // Start the thread
    scheduler.start();

    List<AgentCommand> ac = waitForQueueSize(hostname, aq, 1);
    assertTrue(ac.get(0) instanceof ExecutionCommand);
    assertEquals("1-977", ((ExecutionCommand) (ac.get(0))).getCommandId());

    //The action status has not changed, it should be queued again.
    ac = waitForQueueSize(hostname, aq, 1);
    assertTrue(ac.get(0) instanceof ExecutionCommand);
    assertEquals("1-977", ((ExecutionCommand) (ac.get(0))).getCommandId());

    //Now change the action status
    s.setHostRoleStatus(hostname, "NAMENODE", HostRoleStatus.COMPLETED);
    ac = aq.dequeueAll(hostname);

    //Wait for sometime, it shouldn't be scheduled this time.
    ac = waitForQueueSize(hostname, aq, 0);
    scheduler.stop();
  }

  private List<AgentCommand> waitForQueueSize(String hostname, ActionQueue aq,
      int expectedQueueSize) throws InterruptedException {
    while (true) {
      List<AgentCommand> ac = aq.dequeueAll(hostname);
      if (ac != null) {
        if (ac.size() == expectedQueueSize) {
          return ac;
        } else if (ac.size() > expectedQueueSize) {
          Assert.fail("Expected size : " + expectedQueueSize + " Actual size="
              + ac.size());
        }
      }
      Thread.sleep(100);
    }
  }

  /**
   * Test whether scheduler times out an action
   */
  @Test
  public void testActionTimeout() throws Exception {
    ActionQueue aq = new ActionQueue();
    Clusters fsm = mock(Clusters.class);
    Cluster oneClusterMock = mock(Cluster.class);
    Service serviceObj = mock(Service.class);
    ServiceComponent scomp = mock(ServiceComponent.class);
    ServiceComponentHost sch = mock(ServiceComponentHost.class);
    when(fsm.getCluster(anyString())).thenReturn(oneClusterMock);
    when(oneClusterMock.getService(anyString())).thenReturn(serviceObj);
    when(serviceObj.getServiceComponent(anyString())).thenReturn(scomp);
    when(scomp.getServiceComponentHost(anyString())).thenReturn(sch);
    when(serviceObj.getCluster()).thenReturn(oneClusterMock);

    ActionDBAccessor db = new ActionDBInMemoryImpl();
    String hostname = "ahost.ambari.apache.org";
    List<Stage> stages = new ArrayList<Stage>();
    Stage s = StageUtils.getATestStage(1, 977, hostname);
    stages.add(s);
    db.persistActions(stages);

    //Small action timeout to test rescheduling
    ActionScheduler scheduler = new ActionScheduler(100, 50, db, aq, fsm, 3, 
        new HostsMap((String) null));
    scheduler.setTaskTimeoutAdjustment(false);
    // Start the thread
    scheduler.start();

    while (!stages.get(0).getHostRoleStatus(hostname, "NAMENODE")
        .equals(HostRoleStatus.TIMEDOUT)) {
      Thread.sleep(100);
    }
    assertEquals(stages.get(0).getHostRoleStatus(hostname, "NAMENODE"),
        HostRoleStatus.TIMEDOUT);
  }
  
  @Test
  public void testSuccessFactors() {
    Stage s = StageUtils.getATestStage(1, 1);
    assertEquals(new Float(0.5), new Float(s.getSuccessFactor(Role.DATANODE)));
    assertEquals(new Float(0.5), new Float(s.getSuccessFactor(Role.TASKTRACKER)));
    assertEquals(new Float(0.5), new Float(s.getSuccessFactor(Role.GANGLIA_MONITOR)));
    assertEquals(new Float(0.5), new Float(s.getSuccessFactor(Role.HBASE_REGIONSERVER)));
    assertEquals(new Float(1.0), new Float(s.getSuccessFactor(Role.NAMENODE)));
    assertEquals(new Float(1.0), new Float(s.getSuccessFactor(Role.GANGLIA_SERVER)));
  }
  
  @Test
  public void testSuccessCriteria() {
    RoleStats rs1 = new RoleStats(1, (float)0.5);
    rs1.numSucceeded = 1;
    assertTrue(rs1.isSuccessFactorMet());
    rs1.numSucceeded = 0;
    assertFalse(rs1.isSuccessFactorMet());
    
    RoleStats rs2 = new RoleStats(2, (float)0.5);
    rs2.numSucceeded = 1;
    assertTrue(rs2.isSuccessFactorMet());
    
    RoleStats rs3 = new RoleStats(3, (float)0.5);
    rs3.numSucceeded = 2;
    assertTrue(rs2.isSuccessFactorMet());
    rs3.numSucceeded = 1;
    assertFalse(rs3.isSuccessFactorMet());
    
    RoleStats rs4 = new RoleStats(3, (float)1.0);
    rs4.numSucceeded = 2;
    assertFalse(rs3.isSuccessFactorMet());
  }
}