MQTTnet/Source/MQTTnet/Client/Disconnecting/MqttClientDisconnectOptionsValidator.cs

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.

using System;
using System.Linq;
using MQTTnet.Formatter;

namespace MQTTnet.Client
{
    public static class MqttClientDisconnectOptionsValidator
    {
        public static void ThrowIfNotSupported(MqttClientDisconnectOptions options, MqttProtocolVersion protocolVersion)
        {
            if (options == null)
            {
                throw new ArgumentNullException(nameof(options));
            }

            if (protocolVersion == MqttProtocolVersion.V500)
            {
                // Everything is supported.
                return;
            }

            if (options.ReasonString?.Any() == true)
            {
                Throw(nameof(options.ReasonString));
            }

            if (options.Reason != MqttClientDisconnectOptionsReason.NormalDisconnection)
            {
                Throw(nameof(options.Reason));
            }
        }

        static void Throw(string featureName)
        {
            throw new NotSupportedException($"Feature {featureName} requires MQTT version 5.0.0.");
        }
    }
}