content: //
  // 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.xenserver.resource.wrapper.xenbase;
  
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  import java.util.Set;
  
  import org.apache.cloudstack.storage.to.VolumeObjectTO;
  
  import com.cloud.agent.api.Answer;
  import com.cloud.agent.api.RevertToVMSnapshotAnswer;
  import com.cloud.agent.api.RevertToVMSnapshotCommand;
  import com.cloud.hypervisor.xenserver.resource.CitrixResourceBase;
  import com.cloud.resource.CommandWrapper;
  import com.cloud.resource.ResourceWrapper;
  import com.cloud.vm.VirtualMachine.PowerState;
  import com.cloud.vm.snapshot.VMSnapshot;
  import com.xensource.xenapi.Connection;
  import com.xensource.xenapi.Types;
  import com.xensource.xenapi.VBD;
  import com.xensource.xenapi.VDI;
  import com.xensource.xenapi.VM;
  
  @ResourceWrapper(handles =  RevertToVMSnapshotCommand.class)
  public final class CitrixRevertToVMSnapshotCommandWrapper extends CommandWrapper<RevertToVMSnapshotCommand, Answer, CitrixResourceBase> {
  
  
      @Override
      public Answer execute(final RevertToVMSnapshotCommand command, final CitrixResourceBase citrixResourceBase) {
          final String vmName = command.getVmName();
          final List<VolumeObjectTO> listVolumeTo = command.getVolumeTOs();
          final VMSnapshot.Type vmSnapshotType = command.getTarget().getType();
          final Boolean snapshotMemory = vmSnapshotType == VMSnapshot.Type.DiskAndMemory;
          final Connection conn = citrixResourceBase.getConnection();
          PowerState vmState;
          VM vm;
          try {
  
              final Set<VM> vmSnapshots = VM.getByNameLabel(conn, command.getTarget().getSnapshotName());
              if (vmSnapshots == null || vmSnapshots.isEmpty()) {
                  return new RevertToVMSnapshotAnswer(command, false, "Cannot find vmSnapshot with name: " + command.getTarget().getSnapshotName());
              }
  
              final VM vmSnapshot = vmSnapshots.iterator().next();
  
              // find target VM or creating a work VM
              try {
                  vm = citrixResourceBase.getVM(conn, vmName);
              } catch (final Exception e) {
                  logger.debug("Failed to find VM with name: {} due to:", vmName, e);
                  vm = citrixResourceBase.createWorkingVM(conn, vmName, command.getGuestOSType(), command.getPlatformEmulator(), listVolumeTo);
              }
  
              if (vm == null) {
                  return new RevertToVMSnapshotAnswer(command, false, "Revert to VM Snapshot Failed due to can not find vm: " + vmName);
              }
  
              // call plugin to execute revert
              citrixResourceBase.revertToSnapshot(conn, vmSnapshot, vmName, vm.getUuid(conn), snapshotMemory, citrixResourceBase.getHost().getUuid());
              vm = citrixResourceBase.getVM(conn, vmName);
              final Set<VBD> vbds = vm.getVBDs(conn);
              final Map<String, VDI> vdiMap = new HashMap<>();
              // get vdi:vbdr to a map
              for (final VBD vbd : vbds) {
                  final VBD.Record vbdr = vbd.getRecord(conn);
                  if (vbdr.type == Types.VbdType.DISK) {
                      final VDI vdi = vbdr.VDI;
                      vdiMap.put(vbdr.userdevice, vdi);
                  }
              }
  
              if (!snapshotMemory) {
                  citrixResourceBase.destroyVm(vm, conn);
                  vmState = PowerState.PowerOff;
              } else {
                  vmState = PowerState.PowerOn;
              }
  
              // after revert, VM's volumes path have been changed, need to report to manager
              for (final VolumeObjectTO volumeTo : listVolumeTo) {
                  final Long deviceId = volumeTo.getDeviceId();
                  final VDI vdi = vdiMap.get(deviceId.toString());
                  volumeTo.setPath(vdi.getUuid(conn));
              }
  
              return new RevertToVMSnapshotAnswer(command, listVolumeTo, vmState);
          } catch (final Exception e) {
              logger.error("revert vm {} to snapshot {} failed due to {}", vmName, command.getTarget().getSnapshotName(), e.getMessage());
              return new RevertToVMSnapshotAnswer(command, false, e.getMessage());
          }
      }
  }
  