/* Copyright (c) Citrix Systems, Inc. 
 * All rights reserved. 
 * 
 * Redistribution and use in source and binary forms, 
 * with or without modification, are permitted provided 
 * that the following conditions are met: 
 * 
 * *   Redistributions of source code must retain the above 
 *     copyright notice, this list of conditions and the 
 *     following disclaimer. 
 * *   Redistributions in binary form must reproduce the above 
 *     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 
 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, 
 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR 
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR 
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, 
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING 
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
 * SUCH DAMAGE.
 */

using System.Collections.Generic;

namespace XenAdmin.Alerts
{
    public class NewVersionPriorityAlertComparer : IComparer<Alert>
    {
        public int Compare(Alert alert1, Alert alert2)
        {
            if (alert1 == null || alert2 == null)
                return 0;

            int sortResult = 0;

            if (IsVersionOrVersionUpdateAlert(alert1) && !IsVersionOrVersionUpdateAlert(alert2))
                sortResult = 1;

            if (!IsVersionOrVersionUpdateAlert(alert1) && IsVersionOrVersionUpdateAlert(alert2))
                sortResult = -1;

            if (sortResult == 0)
                sortResult = Alert.CompareOnDate(alert1, alert2);

            return -sortResult;
        }

        private bool IsVersionOrVersionUpdateAlert(Alert alert)
        {
            return alert is XenServerPatchAlert xspAlert && xspAlert.ShowAsNewVersion
                || alert is XenServerVersionAlert
                || alert is ClientUpdateAlert;
        }
    }
}