MQTTnet/Source/MQTTnet.Extensions.Rpc/DefaultMqttRpcClientTopicGenerationStrategy.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;

namespace MQTTnet.Extensions.Rpc;

public sealed class DefaultMqttRpcClientTopicGenerationStrategy : IMqttRpcClientTopicGenerationStrategy
{
    public MqttRpcTopicPair CreateRpcTopics(TopicGenerationContext context)
    {
        ArgumentNullException.ThrowIfNull(context);

        if (context.MethodName.Contains("/") || context.MethodName.Contains("+") || context.MethodName.Contains("#"))
        {
            throw new ArgumentException("The method name cannot contain /, + or #.");
        }

        var requestTopic = $"MQTTnet.RPC/{Guid.NewGuid():N}/{context.MethodName}";
        var responseTopic = requestTopic + "/response";

        return new MqttRpcTopicPair
        {
            RequestTopic = requestTopic,
            ResponseTopic = responseTopic
        };
    }
}