// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.

using Microsoft.Extensions.Primitives;

namespace Microsoft.Extensions.Options
{
    /// <summary>
    /// Fetches a <see cref="IChangeToken"/> that's used for tracking options changes.
    /// </summary>
    /// <typeparam name="TOptions">The options type being changed.</typeparam>
    public interface IOptionsChangeTokenSource<out TOptions>
    {
        /// <summary>
        /// Returns a <see cref="IChangeToken"/> that can be used to register a change notification callback.
        /// </summary>
        /// <returns>A change token.</returns>
        IChangeToken GetChangeToken();

        /// <summary>
        /// Gets the name of the option instance being changed.
        /// </summary>
        string? Name { get; }
    }
}