MQTTnet/Source/MQTTnet/Server/MqttServerExtensions.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.Text;
using System.Threading.Tasks;
using MQTTnet.Internal;
using MQTTnet.Packets;
using MQTTnet.Protocol;
using MQTTnet.Server.Disconnecting;

namespace MQTTnet.Server
{
    public static class MqttServerExtensions
    {
        public static Task DisconnectClientAsync(this MqttServer server, string id, MqttDisconnectReasonCode reasonCode = MqttDisconnectReasonCode.NormalDisconnection)
        {
            if (server == null)
            {
                throw new ArgumentNullException(nameof(server));
            }

            return server.DisconnectClientAsync(id, new MqttServerClientDisconnectOptions { ReasonCode = reasonCode });
        }

        public static Task InjectApplicationMessage(
            this MqttServer server,
            string topic,
            string payload = null,
            MqttQualityOfServiceLevel qualityOfServiceLevel = MqttQualityOfServiceLevel.AtMostOnce,
            bool retain = false)
        {
            if (server == null)
            {
                throw new ArgumentNullException(nameof(server));
            }

            if (topic == null)
            {
                throw new ArgumentNullException(nameof(topic));
            }

            var payloadBuffer = EmptyBuffer.Array;
            if (payload is string stringPayload)
            {
                payloadBuffer = Encoding.UTF8.GetBytes(stringPayload);
            }

            return server.InjectApplicationMessage(
                new InjectedMqttApplicationMessage(
                    new MqttApplicationMessage
                    {
                        Topic = topic,
                        PayloadSegment = new ArraySegment<byte>(payloadBuffer),
                        QualityOfServiceLevel = qualityOfServiceLevel,
                        Retain = retain
                    }));
        }

        public static Task StopAsync(this MqttServer server)
        {
            if (server == null)
            {
                throw new ArgumentNullException(nameof(server));
            }

            return server.StopAsync(new MqttServerStopOptions());
        }

        public static Task SubscribeAsync(this MqttServer server, string clientId, params MqttTopicFilter[] topicFilters)
        {
            if (server == null)
            {
                throw new ArgumentNullException(nameof(server));
            }

            if (clientId == null)
            {
                throw new ArgumentNullException(nameof(clientId));
            }

            if (topicFilters == null)
            {
                throw new ArgumentNullException(nameof(topicFilters));
            }

            return server.SubscribeAsync(clientId, topicFilters);
        }

        public static Task SubscribeAsync(this MqttServer server, string clientId, string topic)
        {
            if (server == null)
            {
                throw new ArgumentNullException(nameof(server));
            }

            if (clientId == null)
            {
                throw new ArgumentNullException(nameof(clientId));
            }

            if (topic == null)
            {
                throw new ArgumentNullException(nameof(topic));
            }

            var topicFilters = new MqttTopicFilterBuilder().WithTopic(topic).Build();
            return server.SubscribeAsync(clientId, topicFilters);
        }
    }
}