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 *     following disclaimer. 
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using System;
using System.Collections.Generic;
using System.Drawing;
using System.Linq;
using System.Windows.Forms;
using XenAdmin.Core;
using XenAdmin.Dialogs;
using XenAdmin.Network;
using XenAdmin.Properties;
using XenAdmin.Wizards.CrossPoolMigrateWizard;
using XenAdmin.Wizards.CrossPoolMigrateWizard.Filters;
using XenAPI;


namespace XenAdmin.Commands
{
    internal class CrossPoolMigrateCommand : VMOperationCommand
    {
        private bool _resumeAfter;

        public CrossPoolMigrateCommand(IMainWindow mainWindow, IEnumerable<SelectedItem> selection)
            : base(mainWindow, selection)
        { }

        protected Host preSelectedHost = null;
        public CrossPoolMigrateCommand(IMainWindow mainWindow, IEnumerable<SelectedItem> selection, Host preSelectedHost, bool resumeAfter=false)
            : base(mainWindow, selection)
        {
            this.preSelectedHost = preSelectedHost;
            _resumeAfter = resumeAfter;
        }

        public override string MenuText
        {
            get
            {
                if (preSelectedHost == null)
                    return Messages.HOST_MENU_CPM_TEXT;

                var cantExecuteReason = CantExecuteReason;
                return string.IsNullOrEmpty(cantExecuteReason)
                    ? preSelectedHost.Name().EscapeAmpersands()
                    : string.Format(Messages.MAINWINDOW_CONTEXT_REASON, preSelectedHost.Name().EscapeAmpersands(), cantExecuteReason);
            }
        }

        public override string ContextMenuText { get { return Messages.HOST_MENU_CPM_TEXT; } }

        public override Image MenuImage
        {
            get { return preSelectedHost == null ? Images.StaticImages._000_MigrateVM_h32bit_16 : Images.StaticImages._000_TreeConnected_h32bit_16; }
        }

        protected override void ExecuteCore(SelectedItemCollection selection)
        {
            var con = selection.GetConnectionOfFirstItem();

            if (Helpers.FeatureForbidden(con, Host.RestrictCrossPoolMigrate))
            {
                ShowUpsellDialog(Parent);
            }
            else
            {
                var wizard = new CrossPoolMigrateWizard(con, selection, preSelectedHost, WizardMode.Migrate, _resumeAfter);
                MainWindowCommandInterface.ShowPerConnectionWizard(con, wizard); 
            }
        }

        protected override Host GetHost(VM vm)
        {
            return Helpers.GetMaster(vm.Connection);
        }

        public static void ShowUpsellDialog(IWin32Window parent)
        {
            using (var dlg = new UpsellDialog(HiddenFeatures.LinkLabelHidden ? Messages.UPSELL_BLURB_CPM : Messages.UPSELL_BLURB_CPM + Messages.UPSELL_BLURB_TRIAL,
                                                InvisibleMessages.UPSELL_LEARNMOREURL_TRIAL))
                dlg.ShowDialog(parent);
        }

        private readonly Dictionary<VM, string> cantExecuteReasons = new Dictionary<VM, string>();

        protected override bool CanExecute(VM vm)
        {
            if (preSelectedHost == null)
                return CanExecute(vm, preSelectedHost);

            var filter = new CrossPoolMigrateCanMigrateFilter(preSelectedHost, new List<VM> {vm}, WizardMode.Migrate);
            var canExecute = CanExecute(vm, preSelectedHost, filter);
            if (string.IsNullOrEmpty(filter.Reason))
                cantExecuteReasons.Remove(vm);
            else
                cantExecuteReasons[vm] = filter.Reason;
            return canExecute;
        }

        public static bool CanExecute(VM vm, Host preselectedHost, CrossPoolMigrateCanMigrateFilter filter = null)
        {
            bool failureFound = false;

            if (preselectedHost != null)
            {
                failureFound = filter == null 
                    ? new CrossPoolMigrateCanMigrateFilter(preselectedHost, new List<VM> {vm}, WizardMode.Migrate).FailureFound
                    : filter.FailureFound;
            }

            return !failureFound &&
                   vm.allowed_operations != null &&
                   vm.allowed_operations.Contains(vm_operations.migrate_send) &&
                   !Helpers.CrossPoolMigrationRestrictedWithWlb(vm.Connection) &&
                   vm.SRs().ToList().All(sr=> sr != null && !sr.HBALunPerVDI()) &&
                   (preselectedHost == null || vm.Connection.Resolve(vm.resident_on) != preselectedHost); //Not the same as the pre-selected host
        }

        public string CantExecuteReason
        {
            get
            {
                if (cantExecuteReasons.Count == GetSelection().Count) // none can execute
                {
                    var uniqueReasons = cantExecuteReasons.Values.Distinct().ToList();

                    if (uniqueReasons.Count == 1)
                        return uniqueReasons[0];
                }
                return null;
            }
        }
    }
}