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using System.Diagnostics;
using XenAdmin.Actions;
using XenAdmin.Commands;
using XenAdmin.Diagnostics.Checks;
using XenAPI;
using XenAdmin.Actions.VMActions;
using XenAdmin.Core;


namespace XenAdmin.Diagnostics.Problems.VMProblem
{
    public abstract class VMProblem : Problem
    {
        protected VM VM { get; private set; }
        private Host residentOn;

        protected VMProblem(Check check, VM vm)
            : base(check)
        {
            VM = vm;
            residentOn = VM.Connection.Resolve(VM.resident_on);
        }


        protected string ServerName
        {
            get
            {
                return residentOn != null ? Helpers.GetName(residentOn).Ellipsise(30) : Helpers.GetName(Helpers.GetPoolOfOne(VM.Connection)).Ellipsise(30);
            }
        }

        public override string HelpMessage
        {
            get
            {
                if (CanSuspendVM)
                    return Messages.SUSPEND_VM;
                else
                {
                    return Messages.SHUTDOWN_VM;
                }
            }
        }

        public sealed override string Title
        {
            get { return string.Format(Messages.PROBLEM_VMPROBLEM_TITLE, VM.uuid); }
        }

        protected AsyncAction SuspendVM()
        {
            return new VMSuspendAction(VM);
        }

        protected AsyncAction ShutdownVM()
        {
            return new VMHardShutdown(VM);
        }

        protected virtual bool CanSuspendVM
        {
            get
            {
                return VM.allowed_operations.Contains(vm_operations.suspend);
            }
        }

        protected override AsyncAction CreateAction(out bool cancelled)
        {
            cancelled = false;
            if (VM.Connection.Resolve(new XenRef<VM>(VM.opaque_ref)) == null) // check if the vm is still in the cache
                return null;

            if (CanSuspendVM)
                return SuspendVM();
            return ShutdownVM();
        }

        public override AsyncAction CreateUnwindChangesAction()
        {
            if (VM.Connection.Resolve(new XenRef<VM>(VM.opaque_ref)) == null) // check if the vm is still in the cache
                return null;

            Debug.Assert(VM.power_state == vm_power_state.Halted ||
                         VM.power_state == vm_power_state.Suspended, "Expected VM to be suspended or shut down!");
            if(VM.power_state==vm_power_state.Halted)
                return new VMStartOnAction(VM, residentOn, VMOperationCommand.WarningDialogHAInvalidConfig, VMOperationCommand.StartDiagnosisForm);
            else
            {
                return new VMResumeAction(VM, VMOperationCommand.WarningDialogHAInvalidConfig,
                                          VMOperationCommand.StartDiagnosisForm);
            }
        }
    }
}
