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 * 
 * *   Redistributions of source code must retain the above 
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 *     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 
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 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
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using System;
using System.Collections.Generic;
using XenAdmin.Actions;
using XenAPI;
using XenAdmin.Network;
using XenAdmin.Model;


namespace XenAdmin.Core
{
    public class HealthCheck
    {
        public static event Action<bool> CheckForAnalysisResultsCompleted;

        /// <summary>
        /// Checks the analysis results for all connections.
        /// Will only perform the check for the connection that have sufficient rights; will not show the action progress.
        /// </summary>
        public static void CheckForAnalysisResults()
        {
            List<AsyncAction> actions = new List<AsyncAction>();
            foreach (IXenConnection xenConnection in ConnectionsManager.XenConnectionsCopy)
            {
                var action = GetAction(xenConnection, true);
                if (action != null)
                    actions.Add(action);
            }

            if (actions.Count == 1)
            {
                actions[0].Completed += actionCompleted;
                actions[0].RunAsync();
            }
            else if (actions.Count > 1)
            {
                var parallelAction = new ParallelAction(null, "", "", "", actions);
                parallelAction.Completed += actionCompleted;
                parallelAction.RunAsync();
            }
        }

        /// <summary>
        /// Checks the analysis results for the specified connections. 
        /// Will only perform the check if the connection has sufficient rights; will not show the action progress.
        /// </summary>
        public static void CheckForAnalysisResults(object connection)
        {
            CheckForAnalysisResults(connection, true);
        }
        
        /// <summary>
        /// Checks the analysis results for the specified connections.
        /// Will only perform the check if the connection has sufficient rights; If suppressHistory is false, it will show the action progress.
        /// </summary>
        public static void CheckForAnalysisResults(object connection, bool suppressHistory)
        {
            var action = GetAction((IXenConnection)connection, suppressHistory);
            if (action != null)
            {
                action.Completed += actionCompleted;
                action.RunAsync();
            }
        }

        private static AsyncAction GetAction(IXenConnection connection, bool suppressHistory)
        {
            Pool pool = Helpers.GetPoolOfOne(connection);
            if (pool == null || Helpers.FeatureForbidden(connection, Host.RestrictHealthCheck))
                return null;

            var healthCheckSettings = pool.HealthCheckSettings;

            if (healthCheckSettings.Status == HealthCheckStatus.Enabled && !healthCheckSettings.HasAnalysisResult)
            {
                if (PassedRbacChecks(pool.Connection))
                    return new GetHealthCheckAnalysisResultAction(pool, Registry.HealthCheckDiagnosticDomainName, suppressHistory);
            }
            return null;
        }

        public static bool PassedRbacChecks(IXenConnection connection)
        {
            return Role.CanPerform(new RbacMethodList("pool.set_health_check_config"), connection);
        }

        private static void actionCompleted(ActionBase sender)
        {
            Program.AssertOffEventThread();

            GetHealthCheckAnalysisResultAction action = sender as GetHealthCheckAnalysisResultAction;
            if (action == null)
                return;

            if (CheckForAnalysisResultsCompleted != null)
                CheckForAnalysisResultsCompleted(action.Succeeded);
        }
    }
}