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 * with or without modification, are permitted provided 
 * that the following conditions are met: 
 * 
 * *   Redistributions of source code must retain the above 
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 *     following disclaimer. 
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 *     copyright notice, this list of conditions and the 
 *     following disclaimer in the documentation and/or other 
 *     materials provided with the distribution. 
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 
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 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
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using System;
using System.Collections.Generic;
using System.Linq;
using XenAPI;
using XenAdmin.Dialogs;


namespace XenAdmin.Commands
{
    /// <summary>
    /// Shows the move virtual disk dialog
    /// </summary>
    internal class MoveVirtualDiskCommand : Command
    {
        /// <summary>
        /// Initializes a new instance of this Command. The parameter-less constructor is required in the derived
        /// class if it is to be attached to a ToolStrip menu item or button. It should not be used in any other scenario.
        /// </summary>
        public MoveVirtualDiskCommand()
        {
        }

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

        public override string ContextMenuText
        {
            get { return GetSelection().Count > 1 ? Messages.MAINWINDOW_MOVE_OBJECTS : Messages.MOVE_VDI_CONTEXT_MENU; }
        }

        protected override void ExecuteCore(SelectedItemCollection selection)
        {
            var vdis = selection.AsXenObjects<VDI>();
            new MoveVirtualDiskDialog(selection.GetConnectionOfFirstItem(), vdis).Show(Program.MainWindow);
        }

        protected override bool CanExecuteCore(SelectedItemCollection selection)
        {
            return selection.Count > 0 && selection.All(v => CanBeMoved(v.XenObject as VDI));
        }

        private bool CanBeMoved(VDI vdi)
        {
            if (vdi == null || vdi.is_a_snapshot || vdi.Locked || vdi.IsHaType() || vdi.cbt_enabled)
                return false;

            SR sr = vdi.Connection.Resolve(vdi.SR);
            if (sr == null || sr.HBALunPerVDI())
                return false;

            if (vdi.GetVMs().Any(vm => vm.power_state != vm_power_state.Halted))
                return false;

            return true;
        }

        protected override string GetCantExecuteReasonCore(SelectedItem item)
        {
            VDI vdi = item.XenObject as VDI;
            if (vdi == null)
                return base.GetCantExecuteReasonCore(item);

            if (vdi.is_a_snapshot)
                return Messages.CANNOT_MOVE_VDI_IS_SNAPSHOT;
            if (vdi.Locked)
                return Messages.CANNOT_MOVE_VDI_IN_USE;
            if (vdi.IsHaType())
                return Messages.CANNOT_MOVE_HA_VD;
            if (vdi.cbt_enabled)
                return Messages.CANNOT_MOVE_CBT_ENABLED_VDI;
            if (vdi.IsMetadataForDR())
                return Messages.CANNOT_MOVE_DR_VD;

            SR sr = vdi.Connection.Resolve(vdi.SR);
            if (sr == null)
                return base.GetCantExecuteReasonCore(item);
            
            if (sr.HBALunPerVDI())
                return Messages.UNSUPPORTED_SR_TYPE;

            return base.GetCantExecuteReasonCore(item);
        }
    }
}