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 *     following disclaimer. 
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 *     following disclaimer in the documentation and/or other 
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using System.Collections.Generic;
using System.Diagnostics;
using XenAdmin.Core;
using XenAdmin.Diagnostics.Problems;
using XenAPI;

namespace XenAdmin.Diagnostics.Checks
{
    public abstract class Check
    {
        protected abstract Problem RunCheck();

        /// <summary>
        /// By default, most Checks return zero or one Problems, but a 
        /// Check can override this to return multiple Problems
        /// </summary>
        public virtual List<Problem> RunAllChecks()
        {
            var list = new List<Problem>(1);
            var problem = RunCheck();
            if (problem != null)
                list.Add(problem);
            return list;
        }

        public abstract string Description { get; }
        public abstract IXenObject XenObject { get; }

        public virtual string SuccessfulCheckDescription =>
            string.IsNullOrEmpty(Description)
                ? string.Empty
                : string.Format(Messages.PATCHING_WIZARD_CHECK_OK, Description);
    }


    public abstract class PoolCheck : Check
    {
        protected PoolCheck(Pool pool)
        {
            Pool = pool;
        }

        protected Pool Pool { get; }

        public sealed override IXenObject XenObject => Pool;

        public override string SuccessfulCheckDescription =>
            string.IsNullOrEmpty(Description)
                ? string.Empty
                : string.Format(Messages.PATCHING_WIZARD_CHECK_ON_XENOBJECT_OK, Helpers.GetPoolOfOne(Pool.Connection), Description);
    }


    public abstract class HostCheck : Check
    {
        protected HostCheck(Host host)
        {
            Debug.Assert(host != null);
            Host = host;
        }

        protected Host Host { get; }

        public sealed override IXenObject XenObject => Host;

        public override string SuccessfulCheckDescription =>
            string.IsNullOrEmpty(Description)
                ? string.Empty
                : string.Format(Messages.PATCHING_WIZARD_CHECK_ON_XENOBJECT_OK, Host.Name(), Description);
    }
}