// 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 com.cloud.hypervisor.vmware.mo;

import java.util.ArrayList;
import java.util.GregorianCalendar;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.regex.Pattern;

import org.apache.log4j.Logger;
import org.apache.xerces.impl.xs.identity.Selector.Matcher;

import com.cloud.hypervisor.vmware.util.VmwareContext;
import com.cloud.hypervisor.vmware.util.VmwareHelper;
import com.cloud.utils.Pair;
import com.cloud.utils.exception.CloudRuntimeException;
import com.google.gson.Gson;
import com.vmware.vim25.AboutInfo;
import com.vmware.vim25.AlreadyExistsFaultMsg;
import com.vmware.vim25.ClusterDasConfigInfo;
import com.vmware.vim25.ComputeResourceSummary;
import com.vmware.vim25.DatastoreSummary;
import com.vmware.vim25.DynamicProperty;
import com.vmware.vim25.HostConfigManager;
import com.vmware.vim25.HostConnectInfo;
import com.vmware.vim25.HostFirewallInfo;
import com.vmware.vim25.HostFirewallRuleset;
import com.vmware.vim25.HostHardwareSummary;
import com.vmware.vim25.HostHyperThreadScheduleInfo;
import com.vmware.vim25.HostIpRouteEntry;
import com.vmware.vim25.HostListSummaryQuickStats;
import com.vmware.vim25.HostNetworkInfo;
import com.vmware.vim25.HostNetworkPolicy;
import com.vmware.vim25.HostNetworkSecurityPolicy;
import com.vmware.vim25.HostNetworkTrafficShapingPolicy;
import com.vmware.vim25.HostPortGroup;
import com.vmware.vim25.HostPortGroupSpec;
import com.vmware.vim25.HostRuntimeInfo;
import com.vmware.vim25.HostSystemConnectionState;
import com.vmware.vim25.HostVirtualNic;
import com.vmware.vim25.HostVirtualSwitch;
import com.vmware.vim25.ManagedObjectReference;
import com.vmware.vim25.ObjectContent;
import com.vmware.vim25.ObjectSpec;
import com.vmware.vim25.OptionValue;
import com.vmware.vim25.PropertyFilterSpec;
import com.vmware.vim25.PropertySpec;
import com.vmware.vim25.TraversalSpec;
import com.vmware.vim25.VirtualMachineConfigSpec;
import com.vmware.vim25.VirtualMachinePowerState;
import com.vmware.vim25.VirtualNicManagerNetConfig;
import com.vmware.vim25.NasDatastoreInfo;

import java.util.Arrays;

public class HostMO extends BaseMO implements VmwareHypervisorHost {
    private static final Logger s_logger = Logger.getLogger(HostMO.class);
    Map<String, VirtualMachineMO> _vmCache = new HashMap<String, VirtualMachineMO>();
    //Map<String, String> _vmInternalNameMapCache = new HashMap<String, String>();

	public HostMO (VmwareContext context, ManagedObjectReference morHost) {
		super(context, morHost);
	}

	public HostMO (VmwareContext context, String morType, String morValue) {
		super(context, morType, morValue);
	}

	public HostHardwareSummary getHostHardwareSummary() throws Exception {
		HostConnectInfo hostInfo = _context.getService().queryHostConnectionInfo(_mor);
		HostHardwareSummary hardwareSummary = hostInfo.getHost().getHardware();
		return hardwareSummary;
	}

	public HostConfigManager getHostConfigManager() throws Exception {
		return (HostConfigManager)_context.getVimClient().getDynamicProperty(_mor, "configManager");
	}

	public List<VirtualNicManagerNetConfig> getHostVirtualNicManagerNetConfig() throws Exception {
		return (List<VirtualNicManagerNetConfig>)_context.getVimClient().getDynamicProperty(_mor,
			"config.virtualNicManagerInfo.netConfig");
	}

	public List<HostIpRouteEntry> getHostIpRouteEntries() throws Exception {
		return (List<HostIpRouteEntry>)_context.getVimClient().getDynamicProperty(_mor,
			"config.network.routeTableInfo.ipRoute");
	}

	public HostListSummaryQuickStats getHostQuickStats() throws Exception {
		return (HostListSummaryQuickStats)_context.getVimClient().getDynamicProperty(_mor, "summary.quickStats");
	}

	public HostHyperThreadScheduleInfo getHostHyperThreadInfo() throws Exception {
		return (HostHyperThreadScheduleInfo)_context.getVimClient().getDynamicProperty(_mor, "config.hyperThread");
	}

	public HostNetworkInfo getHostNetworkInfo() throws Exception {
		return (HostNetworkInfo)_context.getVimClient().getDynamicProperty(_mor, "config.network");
	}

	public HostPortGroupSpec getHostPortGroupSpec(String portGroupName) throws Exception {

		HostNetworkInfo hostNetInfo = getHostNetworkInfo();

		List<HostPortGroup> portGroups = hostNetInfo.getPortgroup();
		if(portGroups != null) {
			for(HostPortGroup portGroup : portGroups) {
				HostPortGroupSpec spec = portGroup.getSpec();
				if(spec.getName().equals(portGroupName))
					return spec;
			}
		}

		return null;
	}

	@Override
	public String getHyperHostName() throws Exception {
		return getName();
	}

	@Override
	public ClusterDasConfigInfo getDasConfig() throws Exception {
		ManagedObjectReference morParent = getParentMor();
		if(morParent.getType().equals("ClusterComputeResource")) {
			ClusterMO clusterMo = new ClusterMO(_context, morParent);
			return clusterMo.getDasConfig();
		}

		return null;
	}

	@Override
	public String getHyperHostDefaultGateway() throws Exception {
		List<HostIpRouteEntry> entries = getHostIpRouteEntries();
		for(HostIpRouteEntry entry : entries) {
			if(entry.getNetwork().equalsIgnoreCase("0.0.0.0"))
				return entry.getGateway();
		}

		throw new Exception("Could not find host default gateway, host is not properly configured?");
	}

	public HostStorageSystemMO getHostStorageSystemMO() throws Exception {
		return new HostStorageSystemMO(_context,
			(ManagedObjectReference)_context.getVimClient().getDynamicProperty(
				_mor, "configManager.storageSystem")
		);
	}

	public HostDatastoreSystemMO getHostDatastoreSystemMO() throws Exception {
		return new HostDatastoreSystemMO(_context,
			(ManagedObjectReference)_context.getVimClient().getDynamicProperty(
				_mor, "configManager.datastoreSystem")
		);
	}

	public HostDatastoreBrowserMO getHostDatastoreBrowserMO() throws Exception {
		return new HostDatastoreBrowserMO(_context,
				(ManagedObjectReference)_context.getVimClient().getDynamicProperty(
					_mor, "datastoreBrowser")
			);
	}

	private DatastoreMO getHostDatastoreMO(String datastoreName) throws Exception {
		ObjectContent[] ocs = getDatastorePropertiesOnHyperHost(new String[] { "name"} );
		if(ocs != null && ocs.length > 0) {
    		for(ObjectContent oc : ocs) {
		        List<DynamicProperty> objProps = oc.getPropSet();
		        if(objProps != null) {
		        	for(DynamicProperty objProp : objProps) {
		        		if(objProp.getVal().toString().equals(datastoreName))
		        			return new DatastoreMO(_context, oc.getObj());
		        	}
		        }
    		}
		}
		return null;
	}

	public HostNetworkSystemMO getHostNetworkSystemMO() throws Exception {
		HostConfigManager configMgr = getHostConfigManager();
		return new HostNetworkSystemMO(_context, configMgr.getNetworkSystem());
	}

	public HostFirewallSystemMO getHostFirewallSystemMO() throws Exception {
		HostConfigManager configMgr = getHostConfigManager();
		ManagedObjectReference morFirewall = configMgr.getFirewallSystem();

		// only ESX hosts have firewall manager
		if(morFirewall != null)
			return new HostFirewallSystemMO(_context, morFirewall);
		return null;
	}

	@Override
	public ManagedObjectReference getHyperHostDatacenter() throws Exception {
		Pair<DatacenterMO, String> dcPair = DatacenterMO.getOwnerDatacenter(getContext(), getMor());
		assert(dcPair != null);
		return dcPair.first().getMor();
	}

	@Override
	public ManagedObjectReference getHyperHostOwnerResourcePool() throws Exception {
		ManagedObjectReference morComputerResource = (ManagedObjectReference)_context.getVimClient().getDynamicProperty(_mor, "parent");
		return (ManagedObjectReference)_context.getVimClient().getDynamicProperty(morComputerResource, "resourcePool");
	}

	@Override
	public ManagedObjectReference getHyperHostCluster() throws Exception {
		ManagedObjectReference morParent = (ManagedObjectReference)_context.getVimClient().getDynamicProperty(_mor, "parent");

		if(morParent.getType().equalsIgnoreCase("ClusterComputeResource")) {
			return morParent;
		}

		assert(false);
		throw new Exception("Standalone host is not supported");
	}

	public ManagedObjectReference[] getHostLocalDatastore() throws Exception {
		List<ManagedObjectReference> datastores = (List<ManagedObjectReference>)_context.getVimClient().getDynamicProperty(
			_mor, "datastore");
		List<ManagedObjectReference> l = new ArrayList<ManagedObjectReference>();
		if(datastores != null) {
			for(ManagedObjectReference mor : datastores) {
				DatastoreSummary summary = (DatastoreSummary)_context.getVimClient().getDynamicProperty(mor, "summary");
				if(summary.getType().equalsIgnoreCase("VMFS") && !summary.isMultipleHostAccess())
					l.add(mor);
			}
		}
		return l.toArray(new ManagedObjectReference[1]);
	}

	public HostVirtualSwitch getHostVirtualSwitchByName(String name) throws Exception {
		List<HostVirtualSwitch> switches = (List<HostVirtualSwitch>)_context.getVimClient().getDynamicProperty(
			_mor, "config.network.vswitch");

		if(switches != null) {
			for(HostVirtualSwitch vswitch : switches) {
				if(vswitch.getName().equals(name))
					return vswitch;
			}
		}
		return null;
	}

	public List<HostVirtualSwitch> getHostVirtualSwitch() throws Exception {
		return (List<HostVirtualSwitch>)_context.getVimClient().getDynamicProperty(_mor, "config.network.vswitch");
	}

	public AboutInfo getHostAboutInfo() throws Exception {
		return (AboutInfo)_context.getVimClient().getDynamicProperty(_mor, "config.product");
	}

	public VmwareHostType getHostType() throws Exception {
		AboutInfo aboutInfo = getHostAboutInfo();
		if("VMware ESXi".equals(aboutInfo.getName()))
			return VmwareHostType.ESXi;
		else if("VMware ESX".equals(aboutInfo.getName()))
			return VmwareHostType.ESX;

		throw new Exception("Unrecognized VMware host type " + aboutInfo.getName());
	}

	// default virtual switch is which management network residents on
	public HostVirtualSwitch getHostDefaultVirtualSwitch() throws Exception {
		String managementPortGroup = getPortGroupNameByNicType(HostVirtualNicType.management);
		if(managementPortGroup != null)
			return getPortGroupVirtualSwitch(managementPortGroup);

		return null;
	}

	public HostVirtualSwitch getPortGroupVirtualSwitch(String portGroupName) throws Exception {
		String vSwitchName = getPortGroupVirtualSwitchName(portGroupName);
		if(vSwitchName != null)
			return getVirtualSwitchByName(vSwitchName);

		return null;
	}

	public HostVirtualSwitch getVirtualSwitchByName(String vSwitchName) throws Exception {

		List<HostVirtualSwitch> vSwitchs = getHostVirtualSwitch();
		if(vSwitchs != null) {
			for(HostVirtualSwitch vSwitch: vSwitchs) {
				if(vSwitch.getName().equals(vSwitchName))
					return vSwitch;
			}
		}

		return null;
	}

	public String getPortGroupVirtualSwitchName(String portGroupName) throws Exception {
		HostNetworkInfo hostNetInfo = getHostNetworkInfo();
		List<HostPortGroup> portGroups = hostNetInfo.getPortgroup();
		if(portGroups != null) {
			for(HostPortGroup portGroup : portGroups) {
				HostPortGroupSpec spec = portGroup.getSpec();
				if(spec.getName().equals(portGroupName))
					return spec.getVswitchName();
			}
		}

		return null;
	}

	public HostPortGroupSpec getPortGroupSpec(String portGroupName) throws Exception {
		HostNetworkInfo hostNetInfo = getHostNetworkInfo();
		List<HostPortGroup> portGroups = hostNetInfo.getPortgroup();
		if(portGroups != null) {
			for(HostPortGroup portGroup : portGroups) {
				HostPortGroupSpec spec = portGroup.getSpec();
				if(spec.getName().equals(portGroupName))
					return spec;
			}
		}

		return null;
	}

	public String getPortGroupNameByNicType(HostVirtualNicType nicType) throws Exception {
		assert(nicType != null);

		List<VirtualNicManagerNetConfig> netConfigs = (List<VirtualNicManagerNetConfig>)_context.getVimClient().getDynamicProperty(_mor,
			"config.virtualNicManagerInfo.netConfig");

		if(netConfigs != null) {
			for(VirtualNicManagerNetConfig netConfig : netConfigs) {
				if(netConfig.getNicType().equals(nicType.toString())) {
					List<HostVirtualNic> nics = netConfig.getCandidateVnic();
					if(nics != null) {
						for(HostVirtualNic nic : nics) {
							return nic.getPortgroup();
						}
					}
				}
			}
		}

		if(nicType == HostVirtualNicType.management) {
			// ESX management network is configured in service console
			HostNetworkInfo netInfo = getHostNetworkInfo();
			assert(netInfo != null);
			List<HostVirtualNic> nics = netInfo.getConsoleVnic();
			if(nics != null) {
				for(HostVirtualNic nic : nics) {
					return nic.getPortgroup();
				}
			}
		}

		return null;
	}

	public boolean hasPortGroup(HostVirtualSwitch vSwitch, String portGroupName) throws Exception {
		ManagedObjectReference morNetwork = getNetworkMor(portGroupName);
		if(morNetwork != null)
			return true;
		return false;
	}

	public void createPortGroup(HostVirtualSwitch vSwitch, String portGroupName, Integer vlanId, HostNetworkSecurityPolicy secPolicy, HostNetworkTrafficShapingPolicy shapingPolicy) throws Exception {
		assert(portGroupName != null);
		HostNetworkSystemMO hostNetMo = getHostNetworkSystemMO();
		assert(hostNetMo != null);

		HostPortGroupSpec spec = new HostPortGroupSpec();

		spec.setName(portGroupName);
		if(vlanId != null)
			spec.setVlanId(vlanId.intValue());
		HostNetworkPolicy policy = new HostNetworkPolicy();
		if (secPolicy != null)
			policy.setSecurity(secPolicy);
		policy.setShapingPolicy(shapingPolicy);
		spec.setPolicy(policy);
		spec.setVswitchName(vSwitch.getName());
		hostNetMo.addPortGroup(spec);
	}

	public void updatePortGroup(HostVirtualSwitch vSwitch, String portGroupName, Integer vlanId, HostNetworkSecurityPolicy secPolicy, HostNetworkTrafficShapingPolicy shapingPolicy) throws Exception {
		assert(portGroupName != null);
		HostNetworkSystemMO hostNetMo = getHostNetworkSystemMO();
		assert(hostNetMo != null);

		HostPortGroupSpec spec = new HostPortGroupSpec();

		spec.setName(portGroupName);
		if(vlanId != null)
			spec.setVlanId(vlanId.intValue());
		HostNetworkPolicy policy = new HostNetworkPolicy();
		if (secPolicy != null)
			policy.setSecurity(secPolicy);
		policy.setShapingPolicy(shapingPolicy);
		spec.setPolicy(policy);
		spec.setVswitchName(vSwitch.getName());
		hostNetMo.updatePortGroup(portGroupName, spec);
	}

	public void deletePortGroup(String portGroupName) throws Exception {
		assert(portGroupName != null);
		HostNetworkSystemMO hostNetMo = getHostNetworkSystemMO();
		assert(hostNetMo != null);
		hostNetMo.removePortGroup(portGroupName);
	}

	public ManagedObjectReference getNetworkMor(String portGroupName) throws Exception {
		PropertySpec pSpec = new PropertySpec();
		pSpec.setType("Network");
		pSpec.getPathSet().add("summary.name");

	    TraversalSpec host2NetworkTraversal = new TraversalSpec();
	    host2NetworkTraversal.setType("HostSystem");
	    host2NetworkTraversal.setPath("network");
	    host2NetworkTraversal.setName("host2NetworkTraversal");

	    ObjectSpec oSpec = new ObjectSpec();
	    oSpec.setObj(_mor);
	    oSpec.setSkip(Boolean.TRUE);
	    oSpec.getSelectSet().add(host2NetworkTraversal);

	    PropertyFilterSpec pfSpec = new PropertyFilterSpec();
	    pfSpec.getPropSet().add(pSpec);
	    pfSpec.getObjectSet().add(oSpec);
        List<PropertyFilterSpec> pfSpecArr = new ArrayList<PropertyFilterSpec>();
        pfSpecArr.add(pfSpec);

	    List<ObjectContent> ocs = _context.getService().retrieveProperties(
	    	_context.getPropertyCollector(), pfSpecArr);

	    if(ocs != null) {
	    	for(ObjectContent oc : ocs) {
	    		List<DynamicProperty> props = oc.getPropSet();
	    		if(props != null) {
	    			for(DynamicProperty prop : props) {
	    				if(prop.getVal().equals(portGroupName))
	    					return oc.getObj();
	    			}
	    		}
	    	}
	    }
	    return null;
	}

	public List<ManagedObjectReference> getVmMorsOnNetwork(String portGroupName) throws Exception {
		ManagedObjectReference morNetwork = getNetworkMor(portGroupName);
		if(morNetwork != null)
			return (List<ManagedObjectReference>)_context.getVimClient().getDynamicProperty(morNetwork, "vm");
		return null;
	}

	public String getHostName() throws Exception {
		return (String)_context.getVimClient().getDynamicProperty(_mor, "name");
	}

    @Override
    public synchronized VirtualMachineMO findVmOnHyperHost(String vmName) throws Exception {
    	if(s_logger.isDebugEnabled())
            s_logger.debug("find VM " + vmName + " on host");

        VirtualMachineMO vmMo = _vmCache.get(vmName);
        if(vmMo != null) {
        	if(s_logger.isDebugEnabled())
                s_logger.debug("VM " + vmName + " found in host cache");
            return vmMo;
        }

        s_logger.info("VM " + vmName + " not found in host cache");
        loadVmCache();

        return _vmCache.get(vmName);
    }

    private boolean isUserVMInternalCSName(String vmInternalCSName) {
        // CS generated internal names for user VMs are always of the format i-x-y.

        String internalCSUserVMNamingPattern = "^[i][-][0-9]+[-][0-9]+[-]";
        Pattern p = Pattern.compile(internalCSUserVMNamingPattern);
        java.util.regex.Matcher m = p.matcher(vmInternalCSName);
        if (m.find()) {
            return true;
        } else {
            return false;
        }
    }

    private void loadVmCache() throws Exception {
    	if(s_logger.isDebugEnabled())
    		s_logger.debug("load VM cache on host");

        _vmCache.clear();

        // name is the name of the VM as it appears in vCenter. The CLOUD_VM_INTERNAL_NAME custom
        // field value contains the name of the VM as it is maintained internally by cloudstack (i-x-y).
        ObjectContent[] ocs = getVmPropertiesOnHyperHost(new String[] { "name" });
        if(ocs != null && ocs.length > 0) {
            for(ObjectContent oc : ocs) {
                List<DynamicProperty> props = oc.getPropSet();
                if (props != null) {
                    String vmVcenterName = null;
                    String vmInternalCSName = null;
                    for (DynamicProperty prop : props) {
                        if (prop.getName().equals("name")) {
                            vmVcenterName = prop.getVal().toString();
                        }
                    }
                    VirtualMachineMO vmMo = new VirtualMachineMO(_context, oc.getObj());
                    // Check if vmMo has the custom property CLOUD_VM_INTERNAL_NAME set.
                    vmInternalCSName =  vmMo.getCustomFieldValue(CustomFieldConstants.CLOUD_VM_INTERNAL_NAME);
                    String vmName = null;
                    if (vmInternalCSName != null && isUserVMInternalCSName(vmInternalCSName)) {
                        vmName = vmInternalCSName;
                    } else {
                        vmName = vmVcenterName;
                    }

                    if(s_logger.isTraceEnabled())
                        s_logger.trace("put " + vmName + " into host cache");

                    _vmCache.put(vmName, new VirtualMachineMO(_context, oc.getObj()));
                }
            }
        }
    }

	@Override
	public VirtualMachineMO findVmOnPeerHyperHost(String name) throws Exception {
		ManagedObjectReference morParent = getParentMor();

		if(morParent.getType().equals("ClusterComputeResource")) {
			ClusterMO clusterMo = new ClusterMO(_context, morParent);
			return clusterMo.findVmOnHyperHost(name);
		} else {
			// we don't support standalone host, all hosts have to be managed by
			// a cluster within vCenter
			assert(false);
			return null;
		}
	}

	@Override
	public boolean createVm(VirtualMachineConfigSpec vmSpec) throws Exception {
		assert(vmSpec != null);
		DatacenterMO dcMo = new DatacenterMO(_context, getHyperHostDatacenter());
        ManagedObjectReference morPool = getHyperHostOwnerResourcePool();

	    ManagedObjectReference morTask = _context.getService().createVMTask(
	    	dcMo.getVmFolder(), vmSpec, morPool, _mor);
		boolean result = _context.getVimClient().waitForTask(morTask);

		if(result) {
			_context.waitForTaskProgressDone(morTask);
			return true;
		} else {
        	s_logger.error("VMware createVM_Task failed due to " + TaskMO.getTaskFailureInfo(_context, morTask));
		}
		return false;
	}

	public HashMap<String, Integer> getVmVncPortsOnHost() throws Exception {
    	ObjectContent[] ocs = getVmPropertiesOnHyperHost(
            new String[] { "name", "config.extraConfig[\"RemoteDisplay.vnc.port\"]" }
            );

        HashMap<String, Integer> portInfo = new HashMap<String, Integer>();
    	if(ocs != null && ocs.length > 0) {
    		for(ObjectContent oc : ocs) {
		        List<DynamicProperty> objProps = oc.getPropSet();
		        if(objProps != null) {
		            String vmName = null;
		        	String value = null;
		            String vmInternalCSName = null;
		        	for(DynamicProperty objProp : objProps) {
		        		if(objProp.getName().equals("name")) {
		                    vmName = (String)objProp.getVal();
		                } else {
		                    OptionValue optValue = (OptionValue)objProp.getVal();
		                    value = (String)optValue.getValue();
		                }
		            }
		            VirtualMachineMO vmMo = new VirtualMachineMO(_context, oc.getObj());
                    // Check if vmMo has the custom property CLOUD_VM_INTERNAL_NAME set.
                    vmInternalCSName =  vmMo.getCustomFieldValue(CustomFieldConstants.CLOUD_VM_INTERNAL_NAME);
	                if (vmInternalCSName != null && isUserVMInternalCSName(vmInternalCSName))
	                    vmName = vmInternalCSName;

                    if(vmName != null && value != null) {
		                portInfo.put(vmName, Integer.parseInt(value));
		        	}
		        }
    		}
    	}

    	return portInfo;
	}

	@Override
    public ObjectContent[] getVmPropertiesOnHyperHost(String[] propertyPaths) throws Exception {
		if(s_logger.isTraceEnabled())
			s_logger.trace("vCenter API trace - retrieveProperties() for VM properties. target MOR: " + _mor.getValue() + ", properties: " + new Gson().toJson(propertyPaths));

		PropertySpec pSpec = new PropertySpec();
		pSpec.setType("VirtualMachine");
		pSpec.getPathSet().addAll(Arrays.asList(propertyPaths));

	    TraversalSpec host2VmTraversal = new TraversalSpec();
	    host2VmTraversal.setType("HostSystem");
	    host2VmTraversal.setPath("vm");
	    host2VmTraversal.setName("host2VmTraversal");

	    ObjectSpec oSpec = new ObjectSpec();
	    oSpec.setObj(_mor);
	    oSpec.setSkip(Boolean.TRUE);
	    oSpec.getSelectSet().add(host2VmTraversal);

	    PropertyFilterSpec pfSpec = new PropertyFilterSpec();
	    pfSpec.getPropSet().add(pSpec);
	    pfSpec.getObjectSet().add(oSpec);
        List<PropertyFilterSpec> pfSpecArr = new ArrayList<PropertyFilterSpec>();
        pfSpecArr.add(pfSpec);

	    List<ObjectContent> properties = _context.getService().retrieveProperties(
	    	_context.getPropertyCollector(), pfSpecArr);

		if(s_logger.isTraceEnabled())
			s_logger.trace("vCenter API trace - retrieveProperties() done");
	    return properties.toArray(new ObjectContent[properties.size()]);
	}

	@Override
	public ObjectContent[] getDatastorePropertiesOnHyperHost(String[] propertyPaths) throws Exception {
		if(s_logger.isTraceEnabled())
			s_logger.trace("vCenter API trace - retrieveProperties() on Datastore properties. target MOR: " + _mor.getValue() + ", properties: " + new Gson().toJson(propertyPaths));

		PropertySpec pSpec = new PropertySpec();
		pSpec.setType("Datastore");
		pSpec.getPathSet().addAll(Arrays.asList(propertyPaths));

	    TraversalSpec host2DatastoreTraversal = new TraversalSpec();
	    host2DatastoreTraversal.setType("HostSystem");
	    host2DatastoreTraversal.setPath("datastore");
	    host2DatastoreTraversal.setName("host2DatastoreTraversal");

	    ObjectSpec oSpec = new ObjectSpec();
	    oSpec.setObj(_mor);
	    oSpec.setSkip(Boolean.TRUE);
	    oSpec.getSelectSet().add(host2DatastoreTraversal);

	    PropertyFilterSpec pfSpec = new PropertyFilterSpec();
	    pfSpec.getPropSet().add(pSpec);
	    pfSpec.getObjectSet().add(oSpec);
        List<PropertyFilterSpec> pfSpecArr = new ArrayList<PropertyFilterSpec>();
        pfSpecArr.add(pfSpec);

	    List<ObjectContent> properties = _context.getService().retrieveProperties(
	    	_context.getPropertyCollector(), pfSpecArr);

	    if(s_logger.isTraceEnabled())
			s_logger.trace("vCenter API trace - retrieveProperties() done");
	    return properties.toArray(new ObjectContent[properties.size()]);
	}

	public List<Pair<ManagedObjectReference, String>> getDatastoreMountsOnHost() throws Exception {
		List<Pair<ManagedObjectReference, String>> mounts = new ArrayList<Pair<ManagedObjectReference, String>>();

		ObjectContent[] ocs = getDatastorePropertiesOnHyperHost(new String[] {
			String.format("host[\"%s\"].mountInfo.path", _mor.getValue()) });
		if(ocs != null) {
			for(ObjectContent oc : ocs) {
				Pair<ManagedObjectReference, String> mount = new Pair<ManagedObjectReference, String>(
					oc.getObj(), oc.getPropSet().get(0).getVal().toString());
				mounts.add(mount);
			}
		}
		return mounts;
	}

	public List<Pair<ManagedObjectReference, String>> getLocalDatastoreOnHost() throws Exception {
		List<Pair<ManagedObjectReference, String>> dsList = new ArrayList<Pair<ManagedObjectReference, String>>();

		ObjectContent[] ocs = getDatastorePropertiesOnHyperHost(new String[] { "name", "summary" });
		if(ocs != null) {
			for(ObjectContent oc : ocs) {
				DatastoreSummary dsSummary = (DatastoreSummary)VmwareHelper.getPropValue(oc, "summary");
				if(dsSummary.isMultipleHostAccess() == false && dsSummary.isAccessible() && dsSummary.getType().equalsIgnoreCase("vmfs")) {
					ManagedObjectReference morDs = oc.getObj();
					String name = (String)VmwareHelper.getPropValue(oc, "name");

					dsList.add(new Pair<ManagedObjectReference, String>(morDs, name));
				}
			}
		}
		return dsList;
	}

	public void importVmFromOVF(String ovfFilePath, String vmName, String datastoreName, String diskOption) throws Exception {
	    if(s_logger.isTraceEnabled())
			s_logger.trace("vCenter API trace - importVmFromOVF(). target MOR: " + _mor.getValue() + ", ovfFilePath: " + ovfFilePath + ", vmName: " + vmName
				+ ",datastoreName: " + datastoreName + ", diskOption: " + diskOption);

		DatastoreMO dsMo = getHostDatastoreMO(datastoreName);
		if(dsMo == null)
			throw new Exception("Invalid datastore name: " + datastoreName);

		importVmFromOVF(ovfFilePath, vmName, dsMo, diskOption);

	    if(s_logger.isTraceEnabled())
			s_logger.trace("vCenter API trace - importVmFromOVF() done");
	}

	@Override
	public void importVmFromOVF(String ovfFilePath, String vmName, DatastoreMO dsMo, String diskOption) throws Exception {

		ManagedObjectReference morRp = getHyperHostOwnerResourcePool();
		assert(morRp != null);

		HypervisorHostHelper.importVmFromOVF(this, ovfFilePath, vmName, dsMo, diskOption, morRp, _mor);
	}

	@Override
	public boolean createBlankVm(String vmName, String vmInternalCSName, int cpuCount, int cpuSpeedMHz, int cpuReservedMHz, boolean limitCpuUse, int memoryMB, int memoryReserveMB,
		String guestOsIdentifier, ManagedObjectReference morDs, boolean snapshotDirToParent) throws Exception {

		if(s_logger.isTraceEnabled())
			s_logger.trace("vCenter API trace - createBlankVm(). target MOR: " + _mor.getValue() + ", vmName: " + vmName + ", cpuCount: " + cpuCount
				+ ", cpuSpeedMhz: " + cpuSpeedMHz + ", cpuReservedMHz: " + cpuReservedMHz + ", limitCpu: " + limitCpuUse + ", memoryMB: " + memoryMB
				+ ", guestOS: " + guestOsIdentifier + ", datastore: " + morDs.getValue() + ", snapshotDirToParent: " + snapshotDirToParent);

		boolean result = HypervisorHostHelper.createBlankVm(this, vmName, vmInternalCSName, cpuCount, cpuSpeedMHz, cpuReservedMHz, limitCpuUse,
			memoryMB, memoryReserveMB, guestOsIdentifier, morDs, snapshotDirToParent);

		if(s_logger.isTraceEnabled())
			s_logger.trace("vCenter API trace - createBlankVm() done");
		return result;
	}

	public ManagedObjectReference getExistingDataStoreOnHost(boolean vmfsDatastore, String hostAddress,
			int hostPort, String path, String uuid, HostDatastoreSystemMO hostDatastoreSystemMo) {
		// First retrieve the list of Datastores on the host.
		List<ManagedObjectReference> morArray;
		try {
			morArray = hostDatastoreSystemMo.getDatastores();
		} catch (Exception e) {
			s_logger.info("Failed to retrieve list of Managed Object References");
			return null;
		}
		// Next, get all the NAS datastores from this array of datastores.
		if (morArray.size() > 0) {
			int i;
			for (i = 0; i < morArray.size(); i++) {
				NasDatastoreInfo nasDS;
				try {
					nasDS = hostDatastoreSystemMo.getNasDatastoreInfo(morArray.get(i));
					if (nasDS != null) {
						//DatastoreInfo info = (DatastoreInfo)_context.getServiceUtil().getDynamicProperty(morDatastore, "info");
						if (nasDS.getNas().getRemoteHost().equalsIgnoreCase(hostAddress) &&
								nasDS.getNas().getRemotePath().equalsIgnoreCase(path)) {
							return morArray.get(i);
						}
					}
				}  catch (Exception e) {
					s_logger.info("Encountered exception when retrieving nas datastore info");
					return null;
				}
			}
		}
		return null;
	}

	@Override
	public ManagedObjectReference mountDatastore(boolean vmfsDatastore, String poolHostAddress,
		int poolHostPort, String poolPath, String poolUuid) throws Exception {

	    if(s_logger.isTraceEnabled())
			s_logger.trace("vCenter API trace - mountDatastore(). target MOR: " + _mor.getValue() + ", vmfs: " + vmfsDatastore + ", poolHost: " + poolHostAddress
				+ ", poolHostPort: " + poolHostPort + ", poolPath: " + poolPath + ", poolUuid: " + poolUuid);

    	HostDatastoreSystemMO hostDatastoreSystemMo = getHostDatastoreSystemMO();
        ManagedObjectReference morDatastore = hostDatastoreSystemMo.findDatastore(poolUuid);
        if(morDatastore == null) {
        	if(!vmfsDatastore) {
                try {
                    morDatastore = hostDatastoreSystemMo.createNfsDatastore(
                            poolHostAddress,
                            poolHostPort,
                            poolPath,
                            poolUuid);
                } catch (AlreadyExistsFaultMsg e) {
                    s_logger.info("Creation of NFS datastore on vCenter failed since datastore already exists." +
                            " Details: vCenter API trace - mountDatastore(). target MOR: " + _mor.getValue() + ", vmfs: " +
                            vmfsDatastore + ", poolHost: " + poolHostAddress + ", poolHostPort: " + poolHostPort +
                            ", poolPath: " + poolPath + ", poolUuid: " + poolUuid);
                    // Retrieve the morDatastore and return it.
                    return (getExistingDataStoreOnHost(vmfsDatastore, poolHostAddress,
                            poolHostPort, poolPath, poolUuid, hostDatastoreSystemMo));
                } catch (Exception e) {
                    s_logger.info("Creation of NFS datastore on vCenter failed. " +
                            " Details: vCenter API trace - mountDatastore(). target MOR: " + _mor.getValue() + ", vmfs: " +
                            vmfsDatastore + ", poolHost: " + poolHostAddress + ", poolHostPort: " + poolHostPort +
                            ", poolPath: " + poolPath + ", poolUuid: " + poolUuid + ". Exception mesg: " + e.getMessage());
                    throw new Exception("Creation of NFS datastore on vCenter failed.");
                }
	        	if(morDatastore == null) {
	        		String msg = "Unable to create NFS datastore. host: " + poolHostAddress + ", port: "
	    			+ poolHostPort + ", path: " + poolPath + ", uuid: " + poolUuid;
		    		s_logger.error(msg);

					if(s_logger.isTraceEnabled())
						s_logger.trace("vCenter API trace - mountDatastore() done(failed)");
		    		throw new Exception(msg);
	        	}
        	} else {
        		morDatastore = _context.getDatastoreMorByPath(poolPath);
	        	if(morDatastore == null) {
	        		String msg = "Unable to create VMFS datastore. host: " + poolHostAddress + ", port: "
	    			+ poolHostPort + ", path: " + poolPath + ", uuid: " + poolUuid;
		    		s_logger.error(msg);

					if(s_logger.isTraceEnabled())
						s_logger.trace("vCenter API trace - mountDatastore() done(failed)");
		    		throw new Exception(msg);
	        	}

        		DatastoreMO dsMo = new DatastoreMO(_context, morDatastore);
        		dsMo.setCustomFieldValue(CustomFieldConstants.CLOUD_UUID, poolUuid);
        	}
        }

		if(s_logger.isTraceEnabled())
			s_logger.trace("vCenter API trace - mountDatastore() done(successfully)");

    	return morDatastore;
	}

	@Override
	public void unmountDatastore(String uuid) throws Exception {

	    if(s_logger.isTraceEnabled())
			s_logger.trace("vCenter API trace - unmountDatastore(). target MOR: " + _mor.getValue() + ", uuid: " + uuid);

    	HostDatastoreSystemMO hostDatastoreSystemMo = getHostDatastoreSystemMO();
    	if(!hostDatastoreSystemMo.deleteDatastore(uuid)) {
    		String msg = "Unable to unmount datastore. uuid: " + uuid;
    		s_logger.error(msg);

    		if(s_logger.isTraceEnabled())
    			s_logger.trace("vCenter API trace - unmountDatastore() done(failed)");
    		throw new Exception(msg);
    	}

		if(s_logger.isTraceEnabled())
			s_logger.trace("vCenter API trace - unmountDatastore() done");
	}

	@Override
	public ManagedObjectReference findDatastore(String poolUuid) throws Exception {
    	HostDatastoreSystemMO hostDsMo = getHostDatastoreSystemMO();
		return hostDsMo.findDatastore(poolUuid);
	}

	@Override
	public ManagedObjectReference findDatastoreByExportPath(String exportPath) throws Exception {
		HostDatastoreSystemMO datastoreSystemMo = getHostDatastoreSystemMO();
		return datastoreSystemMo.findDatastoreByExportPath(exportPath);
	}

	@Override
	public ManagedObjectReference findMigrationTarget(VirtualMachineMO vmMo) throws Exception {
		return _mor;
	}

	@Override
	public VmwareHypervisorHostResourceSummary getHyperHostResourceSummary() throws Exception {
	    if(s_logger.isTraceEnabled())
			s_logger.trace("vCenter API trace - getHyperHostResourceSummary(). target MOR: " + _mor.getValue());

		VmwareHypervisorHostResourceSummary summary = new VmwareHypervisorHostResourceSummary();

        HostHardwareSummary hardwareSummary = getHostHardwareSummary();
		// TODO: not sure how hyper-thread is counted in VMware resource pool
        summary.setCpuCount(hardwareSummary.getNumCpuCores());
		summary.setMemoryBytes(hardwareSummary.getMemorySize());
		summary.setCpuSpeed(hardwareSummary.getCpuMhz());

	    if(s_logger.isTraceEnabled())
			s_logger.trace("vCenter API trace - getHyperHostResourceSummary() done");
		return summary;
	}

	@Override
	public VmwareHypervisorHostNetworkSummary getHyperHostNetworkSummary(String managementPortGroup) throws Exception {
	    if(s_logger.isTraceEnabled())
			s_logger.trace("vCenter API trace - getHyperHostNetworkSummary(). target MOR: " + _mor.getValue() + ", mgmtPortgroup: " + managementPortGroup);

		VmwareHypervisorHostNetworkSummary summary = new VmwareHypervisorHostNetworkSummary();

		if(this.getHostType() == VmwareHostType.ESXi) {
			List<VirtualNicManagerNetConfig> netConfigs = (List<VirtualNicManagerNetConfig>)_context.getVimClient().getDynamicProperty(_mor,
				"config.virtualNicManagerInfo.netConfig");
			assert(netConfigs != null);

			for(VirtualNicManagerNetConfig netConfig : netConfigs) {
				if(netConfig.getNicType().equals("management")) {
					for(HostVirtualNic nic : netConfig.getCandidateVnic()) {
						if(nic.getPortgroup().equals(managementPortGroup)) {
							summary.setHostIp(nic.getSpec().getIp().getIpAddress());
							summary.setHostNetmask(nic.getSpec().getIp().getSubnetMask());
							summary.setHostMacAddress(nic.getSpec().getMac());

						    if(s_logger.isTraceEnabled())
								s_logger.trace("vCenter API trace - getHyperHostNetworkSummary() done(successfully)");
							return summary;
						}
					}
				}
			}
		} else {
			// try with ESX path
			List<HostVirtualNic> hostVNics = (List<HostVirtualNic>)_context.getVimClient().getDynamicProperty(_mor,
				"config.network.consoleVnic");

			if(hostVNics != null) {
				for(HostVirtualNic vnic : hostVNics) {
					if(vnic.getPortgroup().equals(managementPortGroup)) {
						summary.setHostIp(vnic.getSpec().getIp().getIpAddress());
						summary.setHostNetmask(vnic.getSpec().getIp().getSubnetMask());
						summary.setHostMacAddress(vnic.getSpec().getMac());

					    if(s_logger.isTraceEnabled())
							s_logger.trace("vCenter API trace - getHyperHostNetworkSummary() done(successfully)");
						return summary;
					}
				}
			}
		}

	    if(s_logger.isTraceEnabled())
			s_logger.trace("vCenter API trace - getHyperHostNetworkSummary() done(failed)");
		throw new Exception("Uanble to find management port group " + managementPortGroup);
	}

	@Override
	public ComputeResourceSummary getHyperHostHardwareSummary() throws Exception {
	    if(s_logger.isTraceEnabled())
			s_logger.trace("vCenter API trace - getHyperHostHardwareSummary(). target MOR: " + _mor.getValue());

		//
		// This is to adopt the model when using Cluster as a big host while ComputeResourceSummary is used
		// directly from VMware resource pool
		//
		// When we break cluster hosts into individual hosts used in our resource allocator,
		// we will have to populate ComputeResourceSummary by ourselves here
		//
		HostHardwareSummary hardwareSummary = getHostHardwareSummary();

		ComputeResourceSummary resourceSummary = new ComputeResourceSummary();

		// TODO: not sure how hyper-threading is counted in VMware
        resourceSummary.setNumCpuCores(hardwareSummary.getNumCpuCores());

		// Note: memory here is in Byte unit
		resourceSummary.setTotalMemory(hardwareSummary.getMemorySize());

        // Total CPU is based on (# of cores) x Mhz
        int totalCpu = hardwareSummary.getCpuMhz() * hardwareSummary.getNumCpuCores();
		resourceSummary.setTotalCpu(totalCpu);

		HostListSummaryQuickStats stats = getHostQuickStats();
		if(stats.getOverallCpuUsage() == null || stats.getOverallMemoryUsage() == null)
			throw new Exception("Unable to get valid overal CPU/Memory usage data, host may be disconnected");

		resourceSummary.setEffectiveCpu(totalCpu - stats.getOverallCpuUsage());

		// Note effective memory is in MB unit
		resourceSummary.setEffectiveMemory(hardwareSummary.getMemorySize()/(1024*1024) - stats.getOverallMemoryUsage());

	    if(s_logger.isTraceEnabled())
			s_logger.trace("vCenter API trace - getHyperHostHardwareSummary() done");

		return resourceSummary;
	}

	@Override
	public boolean isHyperHostConnected() throws Exception {
    	HostRuntimeInfo runtimeInfo = (HostRuntimeInfo)_context.getVimClient().getDynamicProperty(_mor, "runtime");
    	return runtimeInfo.getConnectionState() == HostSystemConnectionState.CONNECTED;
	}

    public boolean revertToSnapshot(ManagedObjectReference morSnapshot)
            throws Exception {
        ManagedObjectReference morTask = _context.getService()
                .revertToSnapshotTask(morSnapshot, _mor, false);
        boolean result = _context.getVimClient().waitForTask(morTask);
        if (result) {
            _context.waitForTaskProgressDone(morTask);
            return true;
        } else {
            s_logger.error("VMware revert to snapshot failed due to "
                    + TaskMO.getTaskFailureInfo(_context, morTask));
        }

        return false;
    }

    public LicenseAssignmentManagerMO getLicenseAssignmentManager() throws Exception {
        ManagedObjectReference licenseMgr;
        ManagedObjectReference licenseAssignmentManager;
        LicenseManagerMO licenseMgrMo;

        licenseMgr = _context.getServiceContent().getLicenseManager();
        licenseMgrMo = new LicenseManagerMO(_context, licenseMgr);
        licenseAssignmentManager = licenseMgrMo.getLicenseAssignmentManager();

        return new LicenseAssignmentManagerMO(_context, licenseAssignmentManager);
    }
    
    public void enableVncOnHostFirewall() throws Exception {
        HostFirewallSystemMO firewallMo = getHostFirewallSystemMO();
        boolean bRefresh = false;
        if(firewallMo != null) {
            HostFirewallInfo firewallInfo = firewallMo.getFirewallInfo();
            if(firewallInfo != null && firewallInfo.getRuleset() != null) {
                for(HostFirewallRuleset rule : firewallInfo.getRuleset()) {
                    if("vncServer".equalsIgnoreCase(rule.getKey())) {
                        bRefresh = true;
                        firewallMo.enableRuleset("vncServer");
                    } else if("gdbserver".equalsIgnoreCase(rule.getKey())) {
                        bRefresh = true;
                        firewallMo.enableRuleset("gdbserver");
                    }
                }
            }

            if(bRefresh)
                firewallMo.refreshFirewall();
        }
    }
}