#if MYSQL_6_10

// Copyright ?2014, 2018, Oracle and/or its affiliates. All rights reserved.
//
// MySQL Connector/NET is licensed under the terms of the GPLv2
// <http://www.gnu.org/licenses/old-licenses/gpl-2.0.html>, like most 
// MySQL Connectors. There are special exceptions to the terms and 
// conditions of the GPLv2 as it is applied to this software, see the 
// FLOSS License Exception
// <http://www.mysql.com/about/legal/licensing/foss-exception.html>.
//
// This program is free software; you can redistribute it and/or modify 
// it under the terms of the GNU General Public License as published 
// by the Free Software Foundation; version 2 of the License.
//
// This program is distributed in the hope that it will be useful, but 
// WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY 
// or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 
// for more details.
//
// You should have received a copy of the GNU General Public License along 
// with this program; if not, write to the Free Software Foundation, Inc., 
// 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA



using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Text;

namespace Externals.MySql.Data.MySqlClient.Replication
{
    /// <summary>
    /// Base class used to implement load balancing features.
    /// </summary>
    internal abstract class ReplicationServerGroup
    {
        /// <summary>
        /// List of servers available for replication.
        /// </summary>
        protected List<ReplicationServer> servers = new List<ReplicationServer>();

        /// <param name="name">The group name.</param>
        /// <param name="retryTime">The number of seconds to perform a retry.</param>
        public ReplicationServerGroup(string name, int retryTime)
        {
            Servers = servers;
            Name = name;
            RetryTime = retryTime;
        }

        /// <summary>
        /// Gets the group name.
        /// </summary>
        public string Name { get; protected set; }
        /// <summary>
        /// Gets the retry time between connections to failed servers.
        /// </summary>
        public int RetryTime { get; protected set; }
        /// <summary>
        /// Gets the server list in the group.
        /// </summary>
        protected IList<ReplicationServer> Servers { get; private set; }

        /// <summary>
        /// Adds a server into the group.
        /// </summary>
        /// <param name="name">The server name.</param>
        /// <param name="isMaster">A flag indicating if the server to add is master or slave.</param>
        /// <param name="connectionString">The connection string used by this server.</param>
        /// <returns>A <see cref="ReplicationServer"/> object representing the recently added object.</returns>
        internal protected ReplicationServer AddServer(string name, bool isMaster, string connectionString)
        {
            ReplicationServer server = new ReplicationServer(name, isMaster, connectionString);
            servers.Add(server);
            return server;
        }

        /// <summary>
        /// Removes a server from the group.
        /// </summary>
        /// <param name="name">The server name.</param>
        internal protected void RemoveServer(string name)
        {
            ReplicationServer serverToRemove = GetServer(name);
            if (serverToRemove == null)
                throw new MySqlException(String.Format(Resources.ReplicationServerNotFound, name));
            servers.Remove(serverToRemove);
        }

        /// <summary>
        /// Gets a server by name.
        /// </summary>
        /// <param name="name">The server name.</param>
        /// <returns>The replication server.</returns>
        internal protected ReplicationServer GetServer(string name)
        {
            foreach (var server in servers)
                if (String.Compare(name, server.Name, StringComparison.OrdinalIgnoreCase) == 0) return server;
            return null;
        }

        /// <summary>
        /// Must be implemented. Defines the next server for a custom load balancing implementation.
        /// </summary>
        /// <param name="isMaster">Defines if the server to return is a master or any.</param>
        /// <returns>The next server based on the load balancing implementation.
        /// Null if no available server is found.
        /// </returns>
        internal protected abstract ReplicationServer GetServer(bool isMaster);

        /// <summary>
        /// Defines the next server for a custom load balancing implementation.
        /// </summary>
        /// <param name="isMaster">Defines if the server to return is a master or any.</param>
        /// <param name="settings">Currently not being used.</param>
        /// <returns>The next server based on the load balancing implementation.
        /// Null if no available server is found.
        /// </returns>
        internal protected virtual ReplicationServer GetServer(bool isMaster, MySqlConnectionStringBuilder settings)
        {
            return GetServer(isMaster);
        }

        /// <summary>
        /// Handles a failed connection to a server.
        /// </summary>
        /// <param name="server">The failed server.</param>
        /// <remarks>This method can be overrided to implement a custom failover handling.</remarks>
        internal protected virtual void HandleFailover(ReplicationServer server)
        {
            BackgroundWorker worker = new BackgroundWorker();
            worker.DoWork += delegate (object sender, DoWorkEventArgs e)
            {
                bool isRunning = false;
                ReplicationServer server1 = e.Argument as ReplicationServer;
#if !NETSTANDARD1_3
          System.Timers.Timer timer = new System.Timers.Timer(RetryTime * 1000.0);

                System.Timers.ElapsedEventHandler elapsedEvent = delegate (object sender1, System.Timers.ElapsedEventArgs e1)
          {
                  if (isRunning) return;
                  try
                  {
                      isRunning = true;
                      using (MySqlConnection connectionFailed = new MySqlConnection(server.ConnectionString))
                      {
                          connectionFailed.Open();
                          server1.IsAvailable = true;
                          timer.Stop();
                      }
                  }
                  catch
                  {
                      MySqlTrace.LogWarning(0,
                  string.Format(Resources.Replication_ConnectionAttemptFailed, server1.Name));
                  }
                  finally
                  {
                      isRunning = false;
                  }
              };
                timer.Elapsed += elapsedEvent;
                timer.Start();
                elapsedEvent(sender, null);
#else
              Windows.UI.Xaml.DispatcherTimer timer = new Windows.UI.Xaml.DispatcherTimer();
              TimeSpan ts = new TimeSpan(RetryTime * 1000);
              System.EventHandler<object> elapsedEvent = (TickSender, TickEventArgs) =>
              {
                  if (isRunning) return;
                  try
                  {
                      isRunning = true;
                      using (MySqlConnection connectionFailed = new MySqlConnection(server.ConnectionString))
                      {
                          connectionFailed.Open();
                          server1.IsAvailable = true;
                          timer.Stop();
                      }
                  }
                  catch
                  {
                      MySqlTrace.LogWarning(0,
                        string.Format(Properties.Resources.Replication_ConnectionAttemptFailed, server1.Name));
                  }
                  finally
                  {
                      isRunning = false;
                  }
              };
              timer.Tick += elapsedEvent;
              elapsedEvent(sender, null);
              timer.Start();
#endif
      };

            worker.RunWorkerAsync(server);
        }

        /// <summary>
        /// Handles a failed connection to a server.
        /// </summary>
        /// <param name="server">The failed server.</param>
        /// <param name="exception">The exception that caused the failover.</param>
        internal protected virtual void HandleFailover(ReplicationServer server, Exception exception)
        {
            HandleFailover(server);
        }
    }
}

#endif