// The MIT License (MIT)

//

// Copyright (c) 2015-2020 Rasmus Mikkelsen

// Copyright (c) 2015-2020 eBay Software Foundation

// https://github.com/eventflow/EventFlow

//

// Permission is hereby granted, free of charge, to any person obtaining a copy of

// this software and associated documentation files (the "Software"), to deal in

// the Software without restriction, including without limitation the rights to

// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of

// the Software, and to permit persons to whom the Software is furnished to do so,

// subject to the following conditions:

//

// The above copyright notice and this permission notice shall be included in all

// copies or substantial portions of the Software.

//

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS

// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR

// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER

// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN

// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

using System;

using System.Collections.Generic;

using System.Linq;

using System.Net.NetworkInformation;

namespace EventFlow.TestHelpers

{

public class TcpHelper

{

private static readonly Random Random = new Random();

public static int GetFreePort()

{

var ipGlobalProperties = IPGlobalProperties.GetIPGlobalProperties();

var usedPorts = Enumerable.Empty<int>()

.Concat(ipGlobalProperties.GetActiveTcpListeners().Select(l => l.Port))

.Concat(ipGlobalProperties.GetActiveUdpListeners().Select(l => l.Port))

.Concat(ipGlobalProperties.GetActiveTcpConnections().Select(c => c.LocalEndPoint.Port))

.Distinct();

var portLookup = new HashSet<int>(usedPorts);

while (true)

{

var port = Random.Next(10000, 60000);

if (!portLookup.Contains(port))

{

return port;

}

}

}

}

}