MQTTnet/Source/MQTTnet.Server/Events/InterceptingSubscriptionEventArgs.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.Collections;
using MQTTnet.Packets;

namespace MQTTnet.Server;

public sealed class InterceptingSubscriptionEventArgs : EventArgs
{
    public InterceptingSubscriptionEventArgs(
        CancellationToken cancellationToken,
        string clientId,
        string userName,
        MqttSessionStatus session,
        MqttTopicFilter topicFilter,
        List<MqttUserProperty> userProperties)
    {
        CancellationToken = cancellationToken;
        ClientId = clientId;
        UserName = userName;
        Session = session;
        TopicFilter = topicFilter;
        UserProperties = userProperties;
    }

    /// <summary>
    ///     Gets the cancellation token which can indicate that the client connection gets down.
    /// </summary>
    public CancellationToken CancellationToken { get; }

    /// <summary>
    ///     Gets the client identifier.
    ///     Hint: This identifier needs to be unique over all used clients / devices on the broker to avoid connection issues.
    /// </summary>
    public string ClientId { get; }

    /// <summary>
    /// Gets the user name of the client.
    /// </summary>
    public string UserName { get; }

    /// <summary>
    ///     Gets or sets whether the broker should close the client connection.
    /// </summary>
    public bool CloseConnection { get; set; }

    /// <summary>
    ///     Gets or sets whether the broker should create an internal subscription for the client.
    ///     The broker can also avoid this and return "success" to the client.
    ///     This feature allows using the MQTT Broker as the Frontend and another system as the backend.
    /// </summary>
    public bool ProcessSubscription { get; set; } = true;

    /// <summary>
    ///     Gets or sets the reason string which will be sent to the client in the SUBACK packet.
    /// </summary>
    public string ReasonString { get; set; }

    /// <summary>
    ///     Gets the response which will be sent to the client via the SUBACK packet.
    /// </summary>
    public SubscribeResponse Response { get; } = new SubscribeResponse();

    /// <summary>
    ///     Gets the current client session.
    /// </summary>
    public MqttSessionStatus Session { get; }

    /// <summary>
    ///     Gets or sets a key/value collection that can be used to share data within the scope of this session.
    /// </summary>
    public IDictionary SessionItems => Session.Items;

    /// <summary>
    ///     Gets or sets the topic filter.
    ///     The topic filter can contain topics and wildcards.
    /// </summary>
    public MqttTopicFilter TopicFilter { get; set; }

    /// <summary>
    ///     Gets or sets the user properties.
    ///     <remarks>MQTT 5.0.0+ feature.</remarks>
    /// </summary>
    public List<MqttUserProperty> UserProperties { get; set; }
}